# Bernay build - MZT



## mzetati (Aug 2, 2011)

Hi HMEM,

at the moment, I've already made a good amount of work on the cylinders and 'published' it in four different (long, in time and number of pictures, if not in words) posts on the classicsteamengineering forum.
Now, it occurred to me that this build would 'belong' to this place, too. 
'Old' posts will follow, then I will keep both sites updated on my progresses (and regresses). 

Marcello


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## mzetati (Aug 2, 2011)

*The Cylinder Block*

Wish I could find a suitable piece of cast-iron for it: cast-iron, here, being harder to find than pure unobtanium.. ..unless Youre willing to buy complete bars, 6 meters long. 
Started it from that huge block of aluminium: the first hacksaw cutting already made, two more awaiting.









When I got the block to size, painted with the blue and scribed.. I realized I did not want to make it in al. exactly the way its described in the drawings: the block is now I/4 oversize. 








Long time (and a slitting saw, which literally exploded: USE PROTECTIONS!) later, the block is again to size, painted with the blue and scribed.









Drilling the hole for the crankshaft: that 18mm bit does not see much use.








And boring to size (didn t like the look of the carbide tipped boring bars I had, especially on al. It was just a matter of a few minutes at the bench grinder to gain that HSS one).









Now it occurred to me that I could probably have gained better results in less time if I had taken a different path:
1) Drilled that hole, say 19mm.
2) Inserted a press fitted bronze rod
3) Milled the slot in the top face till I reached the horz. diameter of the rod.
4) Inserted a rectangular bronze substitute
5) Bored the two parts rod crank size on the parting line (a V groove in each of them, to duide the drill would have helped).
6) Set on the faceplate to face one side & make the boss.
7) Reversed on the faceplate to face the back

A picture might help:







Too late.




*The Bronze Bearing*
Heres the blank, and an aluminium plug, turned to size, to be used to compare the final diameter of the bearing, fitted into the block.








Reducing one end to less than 20mm (maximum collet size)






Turned oversize, and drilled undersized.







Now, on a V-block for scribing the parting line on the maximum diameter.






Hacksawed, after spending a fair amount of time into smoothing the surfaces (sandpaper)







The 2 parts were loctited , clamped and left curing: heres the egg-shaped item I got after removing the clamps.






Centered (as much as I could center an egg) in the 4jaws, to turn the collet portion round, again.
I did not want to take the risk of seeing the two parts splitting during the cuts, hence the iron wires on the bearing body.







Into a collet, again. Had to use a mill (for rigidity) to straighten the crankshaft hole end make both ends round, once more.







Now machining a couple of aluminium rings, to be press fitted on both ends.








Under the press. 







Its now time to bore to crankshaft size, and the outside to fit the cyl. block.







Some more pictures were taken while finishing the bearing, but I do not have them handy at the moment, will add them later . 

 In the meanwhile a drawing would do. Green=shaft, brown+yellow = lower bearing. White = upper bear.... ...GRRRR!!!








I should have taken better care into centering the bearing on the parting line, I suppose.

Got a few ideas about eventually fixing that part, maybe making a new one (now I know how NOT to make it. 
By now Ill be using it to complete the cylinder block, just to see whether the assembled parts would work.


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## mzetati (Aug 2, 2011)

*The Bronze Bearing (continued)*

Heres the bearing on the lathe again, to turn the outside diameter to size and part off to length.













Done! 








*The Cylinder Block (again)*

On the mill, to saw off the upper portion of the bearing area: two cuts right below the scribed lines, as thin and precise as I can get them.







Milling the sides of the slot to a smooth finish







At the moment of test-fitting the bearing into the cylinder, I discovered the fit was a little bit on the tight side, more than I wanted it to be: had to enlarge the space between the external flanges of a few hundredths (of mm).
Not a difficult job, just a matter of fitting another couple of rings on the ends, mounting the thinghy on a madrel and then again in the lathe between centers.
This time, the rings were a bit too tight: and the press did the rest. One more item for the future projects box.


--

*The Cylinder block (take two)*
Got fed up with that al. block!!! Starting over with a large chunk of bronze: the usual sequence of hacksaw works, then file, and mill to have it squared and to dimension. No pictures - I was too nervous -.
Now the block is ok to restart on the cylinder, without straying too much from the drawings , this time.
Yeah! But what shall I do with the other block?  Spent a few days idling with some machine modifications while deciding what to do, then put the bronze back on the shelf.

--

*The al. Cylinder block  a different approach*

I milled a rectangular slot, and drilled 2 holes on its centreline, spaced 30mm, to be tapped M3







Drilled, and bored the cylinders 







To gauge size







I had no doubts the drawings were for 1 dia. cylinders... ..re centered, re boring.... and an off-the-shelf gauge.













A view of the steam ports







Ready for milling/drilling the steam passages (31deg instead of 28.xx  playing a bit on the safe side, now -. 







All done, but tapping. 








*The Brass Bearing*

Drillied two 3mm through holes and two 1.6mm holes on the sides of the lower part, the two matching holes (dia 1.7) on the upper portion, then cut a groove 3mm wide 1.5mm deep on the centreline of both of them












Will put special care into centring the tool on the parting line when drilling for the crankshaft, I kno I must.











Marcello


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## mzetati (Aug 2, 2011)

*The Brass Bearing (continued)*
Two short portions of a of a blunt 1.7mm drill bit shank were tapered on one end and rounded on the other, then lightly hammered into the undersized holes in the lower portion of the bearing, to aid keeping things aligned during the subsequent operations.

I aligned the bearing into the vice, and started the crankshaft hole with a centring bit, to prevent the 4.5mm from grabbing and wandering into the square slot.








It did not grab, but a check with a mirror showed the bit had gone through the workpiece all but straigthly ..the square slot idea did not help much into preventing that. Next time I will try with a small V groove.
By now, Ive gotta fix this one: I chucked a 7mm milling bit (the longest I have, in reasonable sizes) and carefully plunged it into the workpiece, taking advantage of the increased rigidity of the tool.

Another check with the mirror strip (graciously offered by a discarded laser printer) confirmed I was on the right way.








The next step with a blunt 10mm almost ruined the job sounds like drilling is not an option, here: rather mount the boring head and go with it. Had a toolmakers clamp added to the setup, in the meanwhile.








In slow steps to 11.8mm diameter.








And ream to 12mm (I know drawings call for 1/2, but aint got any stock in imperial sizes and do not yet know wheter the crankshaft will be cut from the solid or built up from barstock). 







A view of the reamed bearing fitting in place: still some lathe work is needed, to bring it to length together with tapering the ends. A test with the 12mm shank of a miiling bit showed I could easily insert it into the lower part, and fit the upper portion too!!








Now on the lathe for the final steps: the chosen tool were the faceplate in combination with an angle plate (aint much happy with using my 4 jaws...).
I chucked a 12mm HSS blank into the (recently overhauled  now it is at the correct height!! -) TS as a reference for the workpiece bore, shimmed it (25/100mm)and aligned so it could turn over the blank with no tight points.
(That aluminium faceplate I made has no, and probably will never have, T-slots for adjusting the angle plate. At the moment I had little interest into drilling another hole closer to the centre to raise the angleplate a little more)







1st side finished! 







Again, on aligning the bearing to machine the second side







Testing the results on the cylinder block







*The bronze cylinder...*
Tonight the shop radio was playing an old E,L&P LP without interruptions: did not want to mix the music with machining sounds, nor to spend my little shop time idling ... 
..whaddabout a lil scribing on that lump of bronze I had put back on the shelf some days ago, just for the fun of doing that? 






Obviously, answer was yes! I will do some more shop work tomorrow!


(P.S. Yesterday night they were playing the Doors... 
... fortunately, I had a cupful of used carbide inserts from a real workshop trash bin to examine, divide by shape, type, size...  
Gotta forget about that radio, if I want to cut some more metals on this project. : )

Marcello


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## mzetati (Aug 2, 2011)

*Could not resist to that bronze block!*
Here it is, sitting on the vise, being centered by ciggy paper & DRO. 








No pictures were taken during the making of the cylinders : anyway, that was just ordinary drilling and a little ..boring.
Here, Im roughing out the slot for the bearing, making use of a roughing mill: it cut like butter! 







Finishing the slot with a 15mm end mill: wandering a little from the drawings, I stopped at 17.something millimetres, to make use of some bronze offcuts for the matching part.







Cutting a V groove into the lower portion of the bearing to aid the drill stay in line.







On the left, the top portion of the cylinder block I had hacksawed, and the already cut piece for the upper bearing.







I milled the upper bearing .05mm oversize, then toyed myself for a couple of hours with engineers blue, files, sandpaper and stuff to get a nice fit of the cover into the cylinder block. 
In the end, I put a little grinding paste on the bottom to have a nice fit on the base, too. 







After drilling 4 holes in a 1.02 square into a small plate from the scrap pile, I added another 6mm drill in a convenient position, for another wandering from the drawings. 
Here, Im tapping the four holes Im gonna use next.
(While I was there, I tapped them all)







Eyespotting the 6mm hole, before drilling. 







After drilling, and tapping. 
Dunno whether is there any sense in that or not into that, but I do not want to have movements into those parts during the subsequent operations. 
Sure, the punchmarks I had put on them to prevent reverse mountings are now redundant. 







Flycutting the cylinder back, before drilling ...







..and reaming to 8mm 







PS: the V groove worked like charm! I had no means of checking how the drill was going, having the large workpiece mounted low in the vice. 
Got the bearing hole dead on center! 
Time to go on the ....

...mill again.  
I needed a 9mm hole, why did I ream it to 8??? 

Remounted on the vice, upside down for a change, re drilled and re-reamed.







Tapping the second end of the aligning jig for the faceplate 







The faceplate, the dismounted jig 







And the jig in use







Sure, it wont hold the workpiece steady when facing it on the lathe, some more holding (and counterweighing ) fixture will be in order.
Decided to put aside the faceplate for a while, taking advantage of the cylinder block squareness for the still missing operations.
Here, Ive completed milling the steam ports on one face, the other one Ill leave for another day. 






PS. One of the ports was made by plunging the 3mm mill a couple of mm and the moving it on the contour, then again , again, ... to 9.14mm depth. It took hours.
On the second port, I drilled five 2.2mm holes 9.14mm deep, plunged the mill into one of them and moved it on the contour, again. The work was completed in minutes.

Marcello


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## Groomengineering (Aug 2, 2011)

Nice work Marcello! I would think the split pieces would be easier to machine if they were soft soldered together instead of loctited, but whatever works for you. ;D Keep up the good work.

Cheers

Jeff


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## ShedBoy (Aug 2, 2011)

Beautful work there and good build photos. I will be following along.

Brock


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## mzetati (Aug 3, 2011)

Jeff,

loctite in my split pieces worked ...but I'm sure the iron wires and aluminium rings I had added to the setup played their part. 
And the loctite layer among the pieces was measurably far from zero thickness, something You should take into account when tolerances must be close.
I suppose there would be no need to remove the soft solder layer once You've done with the machining.
Definitely soft soldering was the way I would have chosen, had I had suitable soldering equipment and a bit of experience into using it.

Brock
Thank You for the kind words.

Marcello


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## mzetati (Aug 3, 2011)

*Some more work on the cylinder*


Now on the other port face of the cylinder: first of all, I drilled four rows of 2.2mm holes to the required depth








Next, I removed the bulk of the outtake port with a 4mm mill, then chucked a 3mm one, plunged full depht (9,14mm on the intake ports, 8.5 on the outtake) 








The ports face after being flycut







Marcello


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## mzetati (Aug 3, 2011)

Drilling the steam passages, taking again advantage of a built-up jig to have consistent angles. 
My procedure consisted into centring the workpiece on the Y and zeroing the DRO, eyespotting the Y diameter of a 4 fluted 6mm end mill on the cyl. bore, setting the Z zero on it. 
Then, I moved the table to the right, lowered the quill 2.20mm and set the X zero when I had one of the flutes touching the inner surface of the cylinder.
Next , I milled a slot 4mm long towards the ports face (X) and widened the opening +1 and -1mm (Y) and finally drilled two 3.3mm holes at X=4.84, Y=2.09 and -2.09. 








The aluminium block was recessed and drilled using the same procedure, but different readings for X, Y and Z





















All steam passages drilled 









Marcello


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## mzetati (Aug 10, 2011)

*Steam Chests*

Just ordinary drilling and milling, not worth many pictures. When machining the second one, I saved a little time by removing most of the unwanted metal by chain drilling







A couple of views of the cylinder with the steam chests temporarily fitted













*Flywheel*

The steam chests need a little more work, but I chose to put them aside for a while in order to spin some metal on the lathe. 
A bit of serious parting-off on a 4 rustium flywheel tyre blank from the scrapyard was doing for me, yesterday.









Heres the workpiece after facing, cleaning of the external surface and a bit of parting: did not mind that much about the finish at the moment moment as it is gonna be put again into the chuck at later times.







Had to stop the work before separating the parts: the parting tools did not appreciate the task, though I was using low speed and copiously applying cutting fluids. 
Not much of a surprise from the one on the left of the picture, tool material being a vanadium steel alloy, but also the HSS T-blade suffered the load. 
Time to pay a visit to the grinder. (And maybe to the bench vise, too: armed with a brand new blade in the hacksaw).








Marcello


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## mzetati (Aug 12, 2011)

Cutting that flywheel blank was only a matter of 59 of quiet, pleasant, nighttime hacksawing. ;-)







Back on the lathe, I faced & turned both the halves using an homemade insert holder , but was not particularly pleased with the finish. 
I supposed different rakes could do better  the quicker option to prove that laying into the long-postponed job of reducing the shank of a 30, maybe 35mm dia. ex-production insert holder .

Weapon of choice was a 20mm inserts mill I had never used before on steel. That thingy was all but brand new: had 3 inserts , of three different types, one of which was broken(*). Might say a two inserts and a balancing weigh end-mill. 

To my surprise(**), I reduced that tough shank (Sandvik holder) to 12mm in a few minutes, cutting 1-1.5mm deep at each passage: Im definitely happy with that mill! Will get around fitting some better inserts, someday.


-----

(*) My fault. Sometimes ago, the very first time I was chucking that mill, I was zeroing the mill DRO on a piece of bronze by and lowering the cutter till it touched the workpiece. The engine was not turning.
Moved the table a bit  click- and the insert was gone.

(**) I had already reduced the shank of an identical, but left handed, tool, using an homemade carbide flycutter: no way I could cut more than 10/100mm at each passage. 
Once more, rakes, design and quality of tools play their roles. 














Marcello


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## mzetati (Aug 23, 2011)

*The Crosshead*

Here, Im parting a 40mm dia. bronze tubing held among chuck and steady rest. 














The turning gave me a continuous shower of hot chips right on my head (not much pleasant though I was wearing safety glasses and also a hat) till I applied a brush right on the cutting edge of the turning tool, using a strong magnet I had salvaged from an old hard disk.









Heres the first part of the crosshead









Here, Im turning the upper portion of the crosshead, from 50mm brass square. 









The almost finished item hanging from the cross-slide handle.









A view of the plans Im working on.








Cutting the base, from the same 50mm square I had used before. I Roughly centered the workpiece and then milled the four sides at coordinates, using the DRO. 








Then, carefully bored it with the aid of a boring head. 








Drilled at coordinates, and parted using the biggest slitting saw I had.








Ready for the hydraulic press!









A bit of lapping of the bore, using Dremel polishing compound and oil.








The press, the workpiece and the two items from the metal shelves Im gonna use to get the job done.















Facing the upper side of the crosshead cap, held in the 3jaws by three short portions of 8mm al. square. (The 8mm al. rod held into the TS, going through the 3jaws is there as an added safety for a setup I did not trust that much).










Done.








And press-fitted.








The base was the used as a reference to mill the two 12.something slots square to its sides.







Now I have to center the bore into the mill, to drill the four tapped holes for the top support bracket and the two additional holes for the securing screws. Had the idea of making this small item to speed up the centering job.








It worked!








Had a bit of problems while cross- drilling the cross-head: I simply did not center the item carefully, with the obvious result of having the hole not in line with the slot, to the point that the crosshead pin could not be fitted.
No pictures were taken during the fix: I re centered (carefully) the crosshead, bored the hole a couple of mm larger and then press fitted a short portion of bronze rod, which I had already bored a bit undersize.
The finish of the bore was the definitely ruined when hand reamed it to size, but no one will ever know. 













Marcello


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## mzetati (Aug 24, 2011)

*The waterpipe crosshead*

Had the idea of making another crosshead out of a short water-pipe portion: the external turning gave an unexpectedly nice finish, not so much I can say about the internal boring: got a lot of chatter, maybe due to the tool being set way above the center line (a matter of millimeters) but it was either that or no way to have it getting into the bore. The smaller HSS boring bar I had tried had given worse results and I had no interest at all into reducing the section of this tool on the mill or grinder.








Now Im facing a roughly centered (trapezoidal) piece from the scrap box, to make the base, using the same tool as before.








With even poorer results
Tried a LH tool, mounted parallel to the lathe axis: got mirror-like finish!









The bore came out off center, as expected. Not much of a problem: with a bit of fiddling with marking blue and digital scriber on the glass plate I could mark the four lines I needed to bring the bore into the center of the square.


Milling to the scribed lines, aligned to the vise jaws.








Done milling, drilling








and press-fitting.







Marcello


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## mzetati (Sep 5, 2011)

*Top support bracket*

The (scribed) 4mm thick brass plate, a 5mm (supposedly) ergal blank, an 8mm gummy blank and a 3mm plate that will be used to protect the rotary table from unwanted slots. 







That worked for me last time I set the alignment of the lathe tailstock, cant se why it should not work for the rotary table, too. Wont be as much precise as checking with a DTI, but enough for the work at hand.









Once Ive had the RT aligned with the spindle, I set it exactly to 0deg, LOCKED it and drilled at coordinates 4 holes in the top plate, to be tapped M4. 
Then , I drilled the first hole at the lines scribed on the brass plate, a second hole in the 8mm gummy plate and locked them in place with the first screw. The second, third and 4th hole were pilot drilled, the assembly dismounted, drilled to size, deburred and re-assembled.







Starting from the left, milled (0.3mm oversize) the front of the workpiece full depth, till the mill got near the scribed circle, then took note of the DRO reading (it was zeroed on the centre of the workpiece) and exited perpendicularly. Re entered the workpiece at the same reading of the DRO on the opposite side of the center, to the same depth till the front portion was completed. 
Same as above on the rear.

The picture shows the setup at the moment Im gonna use the rot-table to make the rounded portion of the bracket: 
again, an oversize roughing cut to temove the bulk of the material,.










End of the roughing cuts: swarfs have gone everywhere!









And after the finishing cut: theres still some scars on the workpiece. They will go away later. 










Now, I need a pivoting point to round the brackets ends: I made it on the RT, from a short portion of brass from the odds n ends box.









After the usual roughing and finishing cuts, the two brackets are now ready to be polished.







Marcello


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## mzetati (Sep 19, 2011)

*Flywheel (continued)*

Drilling the hub to 10mm. then it will be bored to 11.85 and reamed to 12.








Parting stock for the ring. I rarely get swarfs like those while parting: I suppose the tool happened to be dead square on this occasion.






End of parting. Had to increase the tool overhang three times to get it done. The final 5 or 6mm portion was hacksawed.









Trepanning the ring.. 








The still unfinished hub, ring, and an aluminum sleeve I made to fit the hub.





Slitting the hub. The RT was really not a must for this job, but was handy for holding the workpiece and will be ready for the next operations.









..of milling the flats for the columns and drilling the holes for the studs.
 In the meanwhile I had drilled and tapped the hole for the locking screw, milled the pocket for the head and pressed the sleeve to hide the halfway cut as Chuck had explained into this thread 
 < http://www.homemodelenginemachinist.com/index.php?topic=11471.0 >
Thanks again, Chuck!





Still on the RT, to drill and countersinking the matching holes on the ring. Thats a 68mm Proxxon chuck I have mounted on a 20mm steel arbor to fit the largest collet of the ER32 series.








Having the five brass spokes turned, drilled and tapped M3, I cut portions of five of the ugliest M3 screws I had and used them as studs, with a bit of loctite to prevent unwanted unscrewing during the 

next operation.







of turning them to a nice fit into the rim. 








Again a bit of loctite on five cs screws and the rim is ready for the final truing on the lathe.









This barbell weight had resisted any previous attempt of machining: it simply ate the HSS bits like they were butter, and chewed the edges of the carbide tipped ones. 
Now Ive got some insert holders to try it with. 
First of all, I ground three notches on the circumference, for a better fit into the chuck: I really do not want the thing to chase me through the shop.








Guess what? They are working!









First side done. The material is really poor, rather rips instead of cutting. And some blow holes are appearing








An old picture of them tools, the lower two shown before I milled out the shank in excess.









The hub, Chucks design again. (If it were not for cutting the half way slit 90deg wrong, :- (  - It still works, anyway - )







And the sleeve, before press fitting.









The two, yet unfinished flywheels, waiting patiently for their tyres.











*The tyre problems*

When the external jaw #3 dropped on the lathe bed, I knew for sure I could not hold a 105mm ring into my 100mm chuck. Not a 100mm ring, too: the limit being somewhere around 90, I discovered later. 

Fonly I had some soft jaws!
The wiser option would have been fitting the thingy to the faceplate, for boring: but I really hate swapping workholding tools on the lathe, though it rarely takes more than a minute. 
Went for some creative machining, instead.

The ring was grabbed with the internal jaws and bored as deep as possible to a diameter 2mm shorter than the already completed part, with the exception of the initial 2.5mm that were enlarged to the 

final diameter. Then it was reversed into the chuck, grabbed by the inside jaws on that step and to press fitting diameter, leaving about 1mm on the bottom to act as a stop for the press.









This might clarify the idea.





















On the second tyre, I took a different approach: having the ring chucked by the internal jaws, I machined a small portion to about 90mm, with the tool at an angle so to have the inner diameter shorter 

than the outer: that should ensure it wont escape from the jaws.








A bit of paper tape stopped short chips from being thrown directly at me through the space amont chuck and workpiece.








Heres the two flywheels: when I mounted them on a mandrel for the final truing, I could get mirror finish on the external surface and the ugliest chatter when cutting on the sides, though the mandrel I 

used was rather stiff (a 12mm HSS bar)














I suppose they will go on the faceplate, someday. ;D




Marcello


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## kustomkb (Sep 19, 2011)

Your fly wheels look great! and heavy duty too.


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## mzetati (Oct 3, 2011)

*Cylinder Heads*

This steel rod gave me a few problems ending with burning the motor brushes.
Finish was ugly, anyway, whatever tool and speed I was using with it, unless I took deep cuts and cranked like hell to keep the feed rate well above the 0.1mm turn of my lathe. 
When I replaced the lathe motor, I realized there were no reasons to use a material so nasty to make some low stressed parts as the cylinder heads.








Went to the metal recycler, instead, and bought myself 18kg of these, for the price of 4euros and a coupla baskests of swarfs.









I removed most of the surface scale on a couple of them, using a well-worn insert, then moved to a much better one to continue the machining.

Here, Im making one of the upper heads: a few mistakes will become evident soon.






a)	the smaller diameter was made ¼ thick, as per specifications. Had I left it much longer, things would have been easier, later.
In fact, I had no ready made means of holding it for parting, the upper step of the external jaws being too large, the lower step too deep tried to put it into a collet, but the thingy went flying through the shop.
In the end, I tapped it for the piston gland nut, machined a threaded mandrel and screwed the soon to be parted heads on it. (See next picture)

b)	The chuck end of the workpiece had a blind hole in it, much like the hole the .0438 hole specified in the drawings for the lower head. What a luck, I will make use of that!!!
Wrong! I should have faced it to remove all that area, where I will find loads of cracks and blows (well visible into the items shown three pictures below)

Upper and lower heads, and the threaded mandrel I made to hold them to part them off.








A small fixture to drill the bolt circle on the heads: I zeroed the DRO, bored the central hole to size, drilled four holes at coordinates, and repeated the last operation for all the heads.
(Gotta do something with the rust on that boring bar: doesnt show well in pictures).














Marcello


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## mzetati (Oct 6, 2011)

*Cylinders Heads (again)*

Tapping the holes for the feet into the lower heads was a real pain! 

All my M4 taps were dull (time to buy myself some new ones) and the only way I could tap them holes was in careful steps: one thread with the taper tap, then with the second and the plug. Back with the taper, second, ..., , and again, and again

That steel was unexpectedly hard.
On the LAST hole (there were four) I lightly bottomed the tap: very - very - lightly.

Heres the results:









If it were not for some thin metal layer I had left around the bore, the whole area below the ring was a continuous blow!

There might have been reasons they were sent to the scrapyard.



The new, still unparted, heads (below): I had the material carefully faced till it was all clean and bright, before. 








As for the old ones, Ive not yet reached a decision about their final destination.


Marcello


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## steamer (Oct 6, 2011)

I have never seen a piece of stock come apart like that from a bottom tap!....clearly it is hard!....and probably cracked, though from what I can see in the photo, it looks like a brittle tensile break.......

Must be harder than woodpecker lips! ;D


YUCK!....find some nice free machining stainless Marcello!... 


Dave


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## mzetati (Oct 6, 2011)

Dave,

Yes, the whole area was cracked, but I did not imagine things were so bad int it, from the little lines I had sen into the bore.
I've attached an unresized (but cropped!) portion of the previous picture: the cracks should be more visible.
Marcello


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## EL-CORAZON (Oct 20, 2011)

Hi Marcello.sorry about little of topic!

you wrote"This steel rod gave me a few problems ending with burning the motor brushes."

is this motor construction weak?? 
what model do you have? 
I am about to by lathe so nice to know. 
Very interesting build by the way..inspiring


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## mzetati (Oct 21, 2011)

EL,

my next line was "...unless I took deep cuts and cranked like hell to keep the feed rate well above the 0.1mm turn of my lathe." 
A bit more about it here -> http://www.homemodelenginemachinist.com/index.php?topic=15962.msg163199#msg163199
And then there were all those pictures about turning barbell weighs....
No, I don't think I can put any blame to that motor. Not after six or seven years of berserking. 
The lathe is an Optimum D180x300: I'd buy another, especially if the new model were longer, larger ... ;D

Had some problems with the (same brand) BF20 mill motor, too: again, aint much sure I could put any blame to the motor itself, as I ran it continously, at maximum speed, in REVERSE, for an entire afternoon. And that was duriing the hot season, say about 35C in the shop.
As I understand it, those little motors with no independent cooling fans are not happy when run in reverse: a bit of care is in order.

Marcello


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## EL-CORAZON (Oct 21, 2011)

Thanks for reply


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## agmachado (Oct 21, 2011)

Pictures and more pictures... I love it!!!

Very nice job!

:bow:

Thanks for share with us!

Cheers,

Alexandre


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## mzetati (Oct 24, 2011)

Parting off one of the new lower heads: had to get a bit creative into holding it into the chuck: no way to close the workpiece into the normal jaws, no way to part it if held into the lower step of the external jaws









Heres the heads, before drilling the holes. (Theyre finished, now  but for tapping the foot holes). 










*Back on the waterpipe crosshead and al. steam chests.*

Spent too much time turning, lately: needed a little milling for a change.

Took no pictures of the works, heres the results, yet to be deburred.








As a side note, the opening into the first steam chest came out definitely tapered.  Strange! Sounds like a milling bit flex problem. I might have been feeding too heavily while milling. 
(...)
The second came out as bad as the first: this al. is definitely a bad alloy!!. 
(...)

When I started milling the slot into the steel, I realized there was again more than a fair share of play into the spindle: that recent session with the large flycutter (60mm, radius) more than 1mm deep cuts...

Bet I know what You will say.

Had to spend a little time into re-setting the spindle preload.









* and back to the bronze cylinders block.*

Gotta get that done, soon or later! (In other words, I could find no excuses to postpone this operation a little more).
Here it is, the, still mounted on the faceplate, first side already made:










It barely swung on the lathe: about 1mm of clearance between the lower corner and the V on the lathe ways.
The tool is an insert holder, with a carbide insert made for cast-iron: had to mount it into the holder as back as I could to reach the external end of the workpiece. 
Another option would have been a LH tool, turning the QCTP 90deg towards the operator.

Had to make a temporary chip shield extension, too.








Heres how I mounted the block:

The 8mm rod fits nicely into the faceplate hole and into the (still undersized) crankshaft hole of the cylinder block: that should ensure alignment.









The two aluminium rods will go through the cylinders bores, and the aluminium disk on the faceplate will accept the already machined bearing taper






A couple of pictures of the finished block, with the crankcase bore already enlarged to 11.85mm (drilled to 10 and then bored to the final size) and the tool I had used to face it.















You have probably noticed theres a counterweight, still mounted on the on the faceplate, if not its absence in the previous pictures: definitely, a must I should have added before. 
I could complete the first side without it, by turning the wp. at very low speeds, but it took soooOO long
Much more than what I spent into drilling a couple of holes, and tapping the one I had put on the faceplate.

Reaming the crankshaft bore, to the (chosen) final size of 12mm.







Marcello


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## mzetati (Feb 20, 2012)

*Small progress*

Had very little time left from work lately: the shop was freezing cold, and I figured that chopping woods, shoveling snow and occasionally giving heat to iced water pipes was much more fun than working at the lathe or mill. Sort of.

Anyway, I managed to make some bits and fittings: 

The piston rod gland nuts, turned from the 12mm hex brass bar, tapped M10x1, now being chamfered on the outer end.







*The feet*

made them in pairs from some al. offcuts.








*A nice surprise.*
Got a phone call from a friend, one evening: show Yourself at the pub, tomorrow. Got something Youll appreciate 







Theyre all finely grained cast iron!! but for the flywheel (gear) blank which is steel. Definitely appreciated.

I was a bit worried about scale, hard spots or blows (they were risers from castings) : turning and facing four or five of them revealed no flaws. 
But I dont think the lathe will ever get clean again, however hard I will scrub it.

Used one of them to make the pistons (though the use of CI pistons into bronze/aluminium cylinders makes me wonder). 








A temporary mounting of what Ive made so far.











*The piston rods.*

After drilling some holes into the steel block to remove the bulk of metal, I milled a pocket to (my) size and then slit the finished part.













As it goes, I drilled the first hole for the 6mm shaft using a 5.8mm bit: result, was a fit a bit too-tight. 
When I enlarged the hole with a 5.9mm bit I got it exactly how I wanted it to be. Drilling the next three holes using the 5.9mm bit (without pre-drilling 5.8 ) it brought an almost sloppy fit. 
Sure, not tight enough to hold the shaft in place. (GRRRR!!!) 
A bit of light knurling on the ends of the piston rods should solve the problem, maybe some loctite, a cross pin all the above options.

Marcello


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## mzetati (Mar 1, 2012)

*Connecting Rods*

The two items were sawed and milled roughly to shape from a 4mm brass plate 








Then, I drilled and tapped M5 four carefully spaced holes on a piece of scrap (thats iron, not even steel), three of which were subsequently counterbored 9mm dia. for a depth of 7.








After a few minutes spent on the on the lathe, the simple fixture was ready to hold both the blanks in place. 














Then, I chucked a 15mm end-mill and brought them near to dimensions, cutting full depth: they still need rounding the ends and tapering. That will probably be filing work, for a change. 






As for the making the bearings, which are plainly missing at the moment, I still have no clear ideas: will have a look into the metals shelf next time I will go to the shop.

Marcello


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## mzetati (Mar 21, 2012)

*Connecting Rods (continued)*

Here, Im chain drilling and milling two pockets on the top of a 25mm brass square








Next, came the splitting of the item, milling to size, polishing, and then filing the lower edges of the connecting rods. 
Here they are, together with the still unused filing buttons.









Tried to press fit the rods into the bearing area, using the bench vise, but they showed a tendency to bend: solution came through holding each of them upside down into the vise (aluminium jaws) and hammering the bearing area in place, having a piece of plywood interposed among the bearing and hammer face. 

Heres a picture of them, the bearings already split, ready to be drilled (and reamed?) for the crank.








At this point I realized I had forgotten putting a bit of loctite into that hammer-fitted joint: Im quite sure they would not move anyway, but decided to drive a few nails through them, just to make myself sure ...

Almost ruined the job when I broke a bit (1mm dia.) into one of the holes but with a lot of patience (and another sacrificial bit) I managed to get it done. 
After driving them into the holes, I cut those (soft iron) nails a little longer then needed and punched them into the brass forming some sort of head on each side. I suppose that will do for the entire five minutes working life this engine is gonna expect.









*Crankshaft*

However hard I tried to postpone this moment, time came: I definitely need one on this engine.
The blank is pure unknownium (hope thats steel, not iron) not large enough (only 35mm) and, worse of all, already to size. 









Milling the webs was easy: that Dormer 8mm roughing mill cuts steel like butter.








Working among the centers, for the first time on this lathe. I soon realize I have no lathe dog, nor driving plate. 








The driving plate came from the ER32 backplate I had made some Years ago, the dog.. ..well, I had that couple of car safety belts locks hanging around the shop for Years, hating the idea of throwing them away. 
Loda springs inside the plastic cases, too.









Had to content myself with turning the bearing areas, still oversize, for the day. I need to make myself a few more tools to get it done.







Marcello


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## mzetati (Mar 29, 2012)

A coupla quick question about the above cranckshaft: am I more likely to see it distort while milling/sawing the main bearing area or while turning? i/e should I roughly mill the whole shape and then go to the lathe or finish the eccentric bearings and then go for the main?

I'm slowly getting into the opinion I should have machined the larger bearing first.

TIA
Marcello


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## steamer (Mar 29, 2012)

Hi Marcello,

Well, if it were me.....and I hate crankshafts...for the reasons you state :big:

You started just fine, Now that the throws are done, I would perhaps clean up the cheeks a little and then glue in some steel filler blocks to support the part. The blocks need to fit well!...so spend some time fitting them.  Then I would rough out the stock on the mill and finish on the lathe.  A little heat from a torch will make the glue let go later and you can clean up with acetone.

I think your doing fine.....multithrow cranks are a pain in the )*@&$( !
Just my opinion, worth what you paid for it... ;D

Dave


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## mzetati (Mar 30, 2012)

steamer  said:
			
		

> clean up the cheeks a little and then glue in some steel filler blocks to support the part. The blocks need to fit well!...so spend some time fitting them.



There are faster(*?*) ways, BUT I DON'T KNOW WETHER THEY WOULD WORK OR NOT. ;D
Yet.

BTW, I plainly forgot cleaning three out of four cheecks before cutting away the main bearing area. :-[
Now I have nicely mangled surfaces everywhere I could make good use of flat ones.
Something to do with thinking about the next step while still in progress on the current one. 
Oh well, I have a few good files.

Marcello


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## mzetati (Mar 30, 2012)

*Crankshaft (continued)*

Heres the tool, shown into the temporary mounting I used while Im waiting for a skilled hand to come and solder a dovetail to the shank. 
It worked very well into cleaning one of the cheeks, not so into turning the throws. (The cutting edge being 8mm wide: a bit too much for my 7x10)
Some grinding work on the insert (a notch in the middle of it) should help when I will turn the main bearing, where traversing the cutter will be possible.







In the meanwhile, I experimented a bit with finishing cuts, on the still oversized throw bearings: my T-blades revealed to be too thin to be used with that overhang (they flex) 
but a cutter purposely ground from a 8x4mm vanadium bar brought decent results.

Now Ive gained some confidence into machining the throws, Im willing to see what happens to the main bearing area.
A bit of chain drilling (3.9mm bit, holes spaced 4mm).






The munched area on the top left being an extra hole to let the hacksaw blade turn 90 deg. when cutting the vertical area.
A few minutes later, I realized the little hacksaw I planned using for that part has no means of setting the blade at any angle but vertical.

Had to do without the frame.


Sawn.






And a bit of filing, just for the fun of doing that. 









Marcello


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## mzetati (Apr 3, 2012)

*Crankshaft (continued 2)*


With the throws bearings still oversize, I decided to finish the main bearing area.
First of all, I cleaned the cheeks to finish and then searched the scraps box for a couple of items to be used as temporary fillers for the gaps.

Two short portions of aluminium square wrapped into a strip of writing paper till they got a push-fit (finger force only) among the cheeks may solve the problem. 









Then it will only a matter of bumping the workpiece against the cutting tool for a long while. That cutter id definitely too wide for the job on my little lathe: 
ended with cutting a thin groove with a parting tool on the HS. side, subsequently enlarging it using only half of the big cutter. 
As You can see, the finish is ugly, and Im slowly tapering the bearing. But the job is getting done in seconds.







Later, I cut a second grove almost to depth close to the TS. cheek and traversed the tool back and forth till it was almost to size, 
switched the cutter to whatever material that bar is made of and finished the part to a close fitting with the bearing.







Had I been a little more confident into my skills of bringing it to the correct size, Id have left this finishing where it should be: the last operation.

Back to the throws, I filled the gap into the main bearing area with rod and screw, interposing a couple of strips of paper not to marr the surfaces.







Got curious about the eventual distortion into the workpiece after a good locking the screw: a few tenths of millimeter. Bet it would be too much. 
Filed a nut, turned the screw VERY LIGHTLY ad prevented unwanted motions by locking it in place through the nut.
In a few tries, I got a distortion of about 2 hundreds (of mm). I can live with that, but would not trust spinning the object without having taken some safety measure.







I realized I could make use of some gauge when bringing the throws to size. What about the connecting rods themselves?

One of them is shown into the vice, wrapped into paper so I can slid and screw the foot in place after finding the edge and centering the cutter among the vice jaws. 
Drilled a pilot hole and enlarged it using a plunge mill to whatever size it came.
It came out a bit less than the 12.065mm reamer I had, so that will be the throws size.







Heres the thing, I will break the sharp edges through filing.








*More Heads*

Some more shop time to spend, with no intention of working to close tolerances: just interested into filling a basket with coiled swarfs. 
Two head broke while tapping them, two are still missing
The steel blanks I used had a thick crust, which had to be removed before theyd give a decent finish: as it goes, I got six of them undersize, while making the four shown below. 

Left the hacksawing for another day, took the picture, cleaned the hands..







..and changed my mind.






Marcello


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## steamer (Apr 3, 2012)

Looking good Marcello! :bow:

Dave


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## ausdier (Apr 12, 2012)

I just virtually finished building my engine and thought I would share hope you all like it. 
Get it virtually.... 
PS. Keep up the good work Marcello.


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## mzetati (Apr 12, 2012)

Darren,

nice work on that model: now, get to the machines and show us the real thing. ;D ;D
Marcello

--
PS.
Does it 'move', if run into whathever program You used to make it?


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## ausdier (Apr 12, 2012)

Thanks Marcello. Yes it does run in Inventor 2012 Pro, but I don't know how to record it sorry


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## mzetati (Apr 12, 2012)

If You ever get around recording a movie, please, do not forget posting a link: I have ideas it would be nice watching at it.

Marcello


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## ausdier (Apr 12, 2012)

Will do


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## mzetati (Apr 17, 2012)

*Connecting Rods Bushings*

Had a small chunk of bronze rod with dozens of blow holes in it: the right material to make short bushings (providing Youre positive into discarding two third of the semi-finished parts) 









One of the bushings had a too light interference with the hole in the rod: at some point during the reaming it started turning. 
When the long line of self expressed comments finally ended, I went for a gentle squeezing of the part into the bench vise: 
the deformation I got (on second try) was enough to set it firmly. And that should do.

Then, the sixth of the bushing rings cracked partially while being driven in place: it took quite a while of fiddling with needle files and 
sand paper to realize I had that already turned and bored to size rod still set in the lathe chuck, even the hacksaw blade parting tool still 
in the post. One minute? Probably less.




*First assembly*

Now that thing starts looking like an engine! 
The two (long, You see) 6mm printer shafts were rather stiff into their bushings: after a while, I removed them one at a time and 
hand reamed the bushings in line. Another bit of oil ..hey! It turns smoothly!






Having (in hindsight, regretfully) spent most of the remaining shop time (and there was still plenty) playing with the moving parts, 
I found no points into wasting my dinner time into the same activity



*Connecting Rod Shafts* (..of course)


They were supposed to be made into two pieces only (to say nothing about the diameter reduction from ½ to 10mm) but I had 
a 6mm threaded bar just a little bit too long to fit into the so labeled box. Now, I can close the lid.









I left them slightly over length, just in case I got a bit creative with the dimensions of the parts they will be fitting to.
As for the missing runout groove clearly not visible on those threads, I decided to postpone that work till I will grind a thin round 
nosed grooving tool purposely made for the job, the parting tool being too wide and the hacksaw blade too thin.

As it usually happens on the (frequent) occasions I wander from the drawings, the single-piece crosshead pin and bolt cannot 
be set in place unless BOTH the connecting rods were disconnected from the crankshaft. 
Not sure it can be seen as an improvement.

Marcello


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## mzetati (May 2, 2012)

*Eccentric Strap*


Had no brass plate thick enough to make it, no better option than hacksawing a portion of a brass block.
Here it is, the first cut already made, scribed and ready for the second half.








Before cutting it, a second check on the metal shelf revealed a brass remnant large enough to make the lower part of the strap. Its thicker than needed, but not much.

Heres the two of them, already milled on all faces and drilled for the joining screws. 








The two parts fitted together and roughly scribed: I will probably use the DRO and ROT-table, but a visual check of what I will be doing... 








Had I checked twice the drawings before drilling the screw holes, I might have put the clearance holes on the correct part. 
Now, I will have to insert the mounting screws from the top, or drill again and make use of bigger screws.

Will face that the day it will come. 
For today, Ive really no interest into working with the rot-table, will use the remaining shop time to make some more small items.



*Piston Rod Inserts*

Material is 20mm brass square: I set it vertical in the vice, faced the top and drilled a 5.9mm hole through the center.

Next, I set it on a couple of stacked cheap man parallels and hogged a 12mm wide full depth (minus safety allowance) slot on the four sides, 
taking care to have the workpiece re-aligned with the vise jaw side anytime I turned it 90deg.






The four pieces were then hacksawed and filed to a nice fit into the matching area of the piston rods.


Machining the outer surfaces was no problem: I just fit them into the vice and face milled away all the unwanted material, maybe a little more, maybe a little less.
All I wanted was having the four of them as identical as I could.

Holding them inserts by the larger square to machine the roughly hacksawed inner surface is a bit different: aint sure the vice would hold the wp. on that thin surface.
I could figure a few safe ways to do that, but had to sit for a while in that (comfortable, really) armchair with a cup of tea to think for the best one.


It took a while


When I was awake again, I decided a mandrel in the lathe would do.

Made use of the already present hole in the items and screwed them to the mandrel, by interposing a paper washer not to marr the external surface should they slip. 
Then used a parting tool to remove the metal till it reached the screw head, and made the four of them in a row.







The little area that was under the screw head was then filed away. 








*Connecting Rod Shafts and Piston Rods*


Took no pictures at all, sorry.

Now I had the inserts finally brought to size and polished, I could take a few measures and bring the connecting rod shafts I had left a bit too long to the correct length. 
As simple as chucking them in the lathe and facing .55mm from each of them.

Then, I mounted the engine, measured more than carefully, and cut the piston part of the piston rods to a fitting length.
It came 5.5mm shorter than the 3.01 + ((0.90 - 0.504) / 2) shown on the drawings, but the piston travels the same amount of cylinder on both strokes* and that should be ok. 
Wont know for sure for another while.

Another dismounting and remounting (how many more???) of the whole engine to fit the heads gave the pleasant result of having the parts positively checked for smooth moving. 



Marcello

---

*) On drawing B1-D, I could not find a way to calculate the distance from the top centre hole to the bearing centre.
Bet I made some error when I took it from the graphics scale.


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## ausdier (May 2, 2012)

Is this what you got ??


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## mzetati (May 2, 2012)

Cannot say about the 3".25, I don't think I have the sheet of cheese paper I used to write it down, still.
Can still measure the distance between the centers, tho. But not at the moment.
Thank You for showing me how: NOW, it is obvious.

Marcello


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## JorgensenSteam (May 2, 2012)

That measurement is close, but the rod slopes down across the top, it is not flat.

The correct distance is 3.21".


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## kustomkb (May 2, 2012)

That is some beautiful work you are doing Marcello!

I enjoy seeing your nice set-ups.


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## JorgensenSteam (May 2, 2012)

CAD version.


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## mzetati (May 3, 2012)

UNIcastings  said:
			
		

> That measurement is close, but the rod slopes down across the top, it is not flat.
> 
> The correct distance is 3.21".



Oh well, I had written the measure taken on the scale on the drawing itself: 3" 7/32. Same value on the part itself: close enough, for my standards.
Not that I mind much about those missing 5.5mm (as long as the engine will run): as usual with my engines, from some point on the build has to switch towards the 'made to fit', taking the figures printed on the paper as general ideas about the parts dimensions. THAT'S DUE TO THE ROUNDINGS TO THE CLOSEST METRIC HUNDRETH WHILE CONVERTING FROM IMPERIAL MEASUREMENTS (and I dare You to believe into that. ;D ;D ;D). 
Please, do not ask why I'm rarely working on metric plans.

On that same drawing, the left and right bearing are quoted at two different values: 3.5" and 3.345": I chose the second, being the same value as the distance among the cylinder axes.

Marcello


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## ausdier (May 3, 2012)

Hi UNI.
Just wondering how you actually came up with the amount of slope for the top if that is the case ?
Also if it was to the top it would be to the top of what appears to be a web and that web should be shown on the side views.
If you look all 3 top bosses are in line and the measurement is to the top of the bosses.
Just MTCW.


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## JorgensenSteam (May 3, 2012)

The drawings were developed by disassembling and measuring the engine shown below, built in 2004 by Bob Jorgensen.

How he came up with the slight angle on the top of the rod, I don't know, but he tended to give a slight curve to things to eliminate the 'flat' look.

You are correct, the web should be shown in the side views, but was overlooked.
It was rather a pain to measure and draw this engine, but I knew people would have fun with this information.

The method was to measure each part exactly, and then the intent was to round of as many numbers as possible/practical. Looks like I forgot to take out one of the initial measurements on the rod when I rounded.

Jesse Livingston modeled a similar engine in Live Steam Magazine in 2006, but it was a smaller version of Bob's engine, and Jesse left out many of the finer details of Bob's engine, so I wanted an accurate set of drawings to be out there.

Took quite a while to develop the drawings, but well worth the effort in my opinion.


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## mzetati (May 16, 2012)

*Back to the Eccentric Strap *

My previous scribing was no good: rather wipe off and start over.








Now I have a visual check I can feel comfortable with, time to align the RT 








Setup the WP spaced from the holding plate by 4 washers not to ruin it and milled away all the unwanted material plus the uncareful machinists share.














4 cheap, ready made, commercial filing buttons








And a lot of polishing.








*..then the Eccentric*

Decided to turn the bearing area first, then offset the bore.
Here it is, being hugged off in the 3jaws, then grooved







..a bit too deep.








Another foundry scrap came out to a better fitting








Took a break from the eccentric: now, the 10.5 to 13mm step .5 drill bits will fit 10mm keyless chucks I have on both the mil and lathe TS!








Heres the eccentric in the mill: centered under the spindle then offset 4.76mm. Centre drilled and drilled in a few steps to 11.5mm. Next, its been reamed to 12.








Back on the lathe, held on the mandrel by the two grub screws, to complete the machining.









*Finishing the Piston Rods *

Them clips on the knurl wheels arbors had ever been a pain to remove, to say nothing about finding them again among the swarfs on the shop floor. 
Heres the result of 10 work on a 11.5mm rod and two nuts.






Switched the wheels to a medium coarse couple, and ruined the end of one of the top rods enough for press fitting purposes into a hole a bit too large. 


*..and the Top Support Bracket* 
where the bushing were still missing. Material is 21mm bronze, held in a collet mounted chuck to be faced and reduced to 20mm for a length of about 200. 
Then, I reversed the WP holding it into a 20mm collet, and machined the two bushes to be press fitted into the top bracket.








Some more parts going to place. A bit stiff at the start.







Dremel polishing compound mixed with oil made wonders, after a while.


Marcello


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## mzetati (May 22, 2012)

*Rocker arms support brackets*

One of the blanks as it came from the scraps bin, and two already skinned and scribed.







Parted to lenght








*Replacement heads*

I had left them uncompleted ages ago, I took the occasion of having the lathe in a mess of cast iron powder to bring them too to finish. 
Here, Ive centered the jig and Im drilling the bolt holes at coordinates.








The jig. With a total of ten heads, having made it paid well.














*Rocker arms support brackets*

Back to the C.I. risers, some facing to bring them to the required sizes. The blue clamp on the side of the vice will be used later as a wp. stop, 
so I wont have to find the edges more than once for all the faces.







Carving the shape with a 10mm four fluted mill, depth of cut being 1 / 1.5mm







Centre drilling, drilling and reaming the required holes.















Working on the sides, now with a 6mm end mill. The wp. is laying on parallels (HSS blanks) and held into the vice jaws through 
a short portion of steel rod. Not much of contact surfaces, but it did not move. I carefully avoided climb milling.







Here they are, all but finished. A lot of rounding, filing and polishing is still in order.
Gotta think something about the missing portion on one of the flanges, too: it came there on the last op. 
too simple to be worth bluing and scribing  Then, I turned the wrong wheel to the expected reading on the display.






Marcello


----------



## ronkh (May 22, 2012)

Hi Marcello,

I have watched this from the beginning and must say it's been a very good write up and build. 
I am looking forward to seeing it run!

On a side note:

Pat, your dad was a very clever chap.

Kind regards to both,

Ron.


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## JorgensenSteam (May 22, 2012)

Ron-

Marcello is doing a great job.
It is fun to watch his many methods and materials.
He is very creative.

As far as Bob J, it wasn't until I was able to disassemble some of his engines that I came to realize all the finer detail that he put into his work. He maintained the same level of quality inside the engine as outside.
Bob had an artistic flair, and was a very good machinist on top of that, so not only do his engines run well, they have a nice "look" to them, with just enough small subtle details to give them a finished look.
Definitely not museum pieces, but a good example of how you can quickly build some pretty nice scratch-built engines.

Pat J


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## mzetati (May 23, 2012)

Ron, Pat

Your words are much appreciated!
It will run someday, at the cost of being filmed while it is driving an electric drill. ;D ;D ;D

Still, sooo many parts to be made. 
But aint no haste so far: I'm really enjoying the travel.

Marcello


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## mzetati (May 23, 2012)

*Rocker arms support brackets(continued)*

Made this simple jig with the intentions of using it to bring the brackets to a higher finish. 






Then, I changed my mind (thats a habit!) and decided to go for a bit of hand work with files and sandpaper, 
maybe a coupla small grinding wheels on a Dremel..

Managed to STOP that right before the poor thing got mangled beyond recovery: the picture below shows it being set up on the lathe.

The second picture was taken while the lathe was spinning the second bracket, the chuck side already finished.

The pictures do not show the carriage stop I set on the lathe bed to prevent cutting too deep. 
The small parting tool I used is ¼ square with a huge overhang: took that into due account and never fed the cross slide more than .25mm.















It worked.







They are far better than what can be seen in this picture (others Ive taken are worse, btw), 
especially the one on the right which Ive polished using a wire wheel on the Dremel till I got it shiny. 
Im definitely satisfied with the job Ive done.

Next two will be made differently.

Marcello


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## blighty (May 23, 2012)

excellent build! excellent thread! 8)

it's threads like this one that makes me give my self a ruddy good kick up the bum........ to get on with building stuff.


thx


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## mzetati (Jun 5, 2012)

*Two more rocker arms support brackets*

Heres the starting piece: being already to the same length as the sum of the brackets heights, Ive gotta pay special attention into avoiding wandering cuts.








Managed to do a decent job with that hacksaw.









Flycutting the rough cuts, and squaring the faces. Love that finish!








Scribed








Drilled. Im now milling all what I can using a 10mm 2fluted mill. 
Just hogging most of the unwanted metal, will have to finish the work later with a smaller mill.








Forgot about a couple of holes (per bracket). Not a precision work, here: I could use an old drill chuck in held into a collet to speed-up the tool changes. 








Into the vice, to mill the brackets sides. Had to use a piece of al. square between the workpiece and the fixed jaw, to put holding pressure on a convenient point. 








The opposite face of each bracket was milled holding them into the vice through the flange only: was a little concerned about deflections 
and eventual breakages, so I clamped the top area to the big blue mill clamp Im using as vice stop. It worked.








Here they are: ugly as the picture can improve improve their look. Ive never found a way to get a decent finish when milling aluminium, except flycutting. 








Jig turned on the lathe. Too early: now, Ive gotta put many more attentions into polishing them flat areas.










*Constructed crankshaft*

Being lazy, looking for troubles. (Will get them).
Didnt want to waste time switching the lathe from collets to 3jaws to machine a short portion of the two blanks so I could hold them into a collet. 

Decided for an attempt with my collet held 3jaws for small works, no TS center: You guess what it's gonna happen.








Heres the workpiece after recollecting it from the floor, the insert cutting edge being completely destroyed.
But the lathe missed the throw: so, I learnt it cheap in the end. 








Put the chronometer at work: switching to lathe setup to the 4 3jaws took 315, and I had to hunt for the 14mm wrench. 
Getting back to collets took 310. Shop gremlins had hidden the 14mm wrench again.








After a short session on the mill, to drill 2 carefully spaced 11.5mm dia. holes on the face, back on the lathe to part off.








Facing. Scary setup again, though more reliable than the previous. Someday I will get some soft jaws for these types of works.








Heres the crankshaft cheeks. What I will choose among the thousand options for a built up crankshaft from now on, I still dont know.







Marcello


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## ProdEng (Jun 5, 2012)

It's a lovely looking engine and I am enjoying watching you at work, thanks 

Jan


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## ShedBoy (Jun 5, 2012)

A joy to see this beautiful engine grow, Fabulous work Marcello

Brock


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## mzetati (Jun 25, 2012)

*Al. Conn. Rods*


Heres the blank, not quality aluminium, but the plate should do for the job. 








Chain drilled







Using the vice as it were an angle plate 







Overtightening a toolmakers clamp: cracks among the marker lines.







Bearing areas completed. 







On the holding plate I had made before. A strip of paper (half circle) between the bearing feet 
and the rod secured a firm hold without affecting the distance among the centers.









*Constructed crankshaft (continued)*


Chamfering the holes, using a wood board as support: the tool would surely grab the hard material (it did), 
sharp edges,  : rather keep fingers far from that area. 







A quick test into hand reaming the 11.5mm holes to 12H7 convinced me to chuck an old 12.06 machine reamer 
from the purchased by weight bag.
Back on the holding plate, I screwed in a rod end I had turned to 11.5mm (added a clamp) and reamed one 
hole in each of the four throws. Then, replaced the rod end with a 12mm one, and reamed the remaining holes. 







12.06 holes and 11.98 silver steel shafts in need for a press fit joint: solution came throgh knurlink. 
Had ideas that straight knurlling would have been the way to go, but the wheels could not stand the work 
on silver steel long enough. Had to revert to diamond knurling to complete the job.







A bit of loctite (permanent thread locker - what I had) may do. Or may not, who knows.







Testing for alignment: no point! I had reduced the ends in one of the two shafts (the ones I will cut!) to 
whatever diameter they came, after having used them as test workpieces to try the knurls. Now it rocks, 
but thats obvious.







A visual test spinning on the lathe showed no visible wobbles, and thats the point I put it aside waiting for curing.









*Al. Conn. Rods(continued)*


On the rotary table, to round the ends of the bearing areas.
The single-screw hold worked better than expected: I had only one slip, when milling to full depth the arcs 
around the bearing area.







Rounding completed on both sides, end of workshop time. Will get back to them for finishing.









Marcello


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## mzetati (Jul 5, 2012)

*Constructed crankshaft (finishing)*

Decided to drill eight holes for some screws going from the webs to the bearing sections: not sure theyre gonna add any strength to the assembly, 
but they should prevent the parts from chasing the spectators, should it fall into pieces during the five minutes working life this engine is 
going to expect (providing it will run).

 Id have rather used some 1/8 tapered pins, but in all the years Ive had them in the box Ive never got around making the appropriate D-bit: 
Ive ever postponed the job to the moment I will need to use them and tonite.. 
Well, Im definitely not interested into grinding tapers.






Some hacksaw work (and a lot of file work) later, I could spin the thingy into the lathe, for a visual check of eventual runouts: nothing I 
could notice or feel by applying a wood bar to the far end. Had ideas about bringing the DI into play. It was late (reads: didnt want to 
spoil the satisfaction), maybe tomorrow.

Put a dab of permanent thread locker into each hole, instead, and here it is with the screws I will later cut and file flush with the cheeks.






Marcello


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## mzetati (Jul 10, 2012)

*Piston-rods* 

The printer bar material was a little too tight into the packing nuts, decided to try to get some clearance by interposing 
a strip of paper between the reamer and the bore. It worked.







Chain drilling a block of scrap to remove the bulk of metal before milling the rectangular pocket for the inserts and then 
a big 10mm hole in the middle of the area.







Took a file, then. And it wasnt a quick job.
The rectangular hole came out all but rectangular, centered and with parallel faces.







Put it back into the mill, the: faced the roughly cut surface as it can be seen into the previous picture, painted with 
blue and scribed a few lines.
Back to vice & files, till I got this. It was fun.








*Piston rod inserts*

They should be square, but I cannot see why they should not work if made round.








*Connecting rods*

Tried enlarging a coupla bearing holes to the 6mm bearing size I needed (they were made 5mm dia. for mounting on the plate) 
by hand drilling, but the idea was not good. 
Rather make use of the plate again, to bring them to straightness and squareness again. 
Took the occasion to remove some unwanted metal I had left on the body when I rounded the bearing areas on the rot-table.







The connecting rods will have brass bearings. 







The knurling gave a push fit only, so I put a dab of loctite and set them aside for curing.







Marcello


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## mzetati (Jul 11, 2012)

*Alum. Bernay Taking shape*


Had to solve a slight binding into the piston rods inserts, due to not enough side clearance into the rectangular slots : now I think of it, 
I never cared checking their dimensions with the drawings while making them () : 

A few strokes with a round file (green circles in the photo) and so much for my previous efforts into having them nicely finished. :big: :big:

A bit of work into cutting the rods to length, fitting the pistons, threading for the nuts, etc and here it is. 








Marcello


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## steamer (Jul 11, 2012)

Looking the part Marcello!  I'm a little confused with the crank...are you going to machine the journals now that it is all bonded together....?

Dave


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## mzetati (Jul 11, 2012)

Dave, 

now I'm confused (and worried) too!!!

Aint much sure about what parts You're referring to 






(A) Should be the journals, (B) the throws and (C) I cannot name them at the moment, but I'm sure I've come across that term before.

Whatever..
(A)s are already to size as are (C)s, while (B)s should be rectangular as per drawings, but I liked the shiny finish I've got while turning them and decided to let them be round.
(If I wanted to make them as per drawing, I'd probably fit an alu. spacer among the cheeks, put them into the vice then a bit of handwork with framed blades and files).

So, answer is "nope, aint gonna machine another anything on that crank nor touch it in any way with tools".
Unless... *? ? ? ? ? ?* Any bad news for me?

Marcello


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## mzetati (Jul 13, 2012)

*Steam Chests*


Yesterday I finally got around drilling and tapping the holes for the valve stems and steam intakes into the steam chests, wonder why I postponed this simple task so long.

Heres a picture of the two of them, patiently (not sure about that!) waiting for me to make and fit the valves and linkages.

Quite a pleasant view on my lathe bench, You know the feeling Im talking about.







Now I think of the missing parts, the pipe fittings and steam covers are also still hidden somewhere into the metals pile. Then the wooden bases, 
one eccentric strap, a hundred studs (if I decide to go for them in place of screws), some castle nuts, gaskets

Still enough work to do not to feel hastened into having it done. ;D


Marcello


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## mzetati (Jul 16, 2012)

*Another eccentric strap*

Heres the plates, already cut (and fastened) to the central line. Ive centered the RT under the spindle, then fitted the support 
plate and drilled four holes in it for the holding screws. Now, I will mill the bearing area to size, then cut the external shape 
adding new clamps when the lower screws will cease supporting the workpiece.









The task was completed successfully, the bearing having come out of the machine to a light fit with the eccentric. 
In a few minutes of handwork, I got the sliding fit I was looking for.

*Valve gear*

Quite a few parts in it! 
Started with cutting all the rods for the two engines to the length specified on the drawings and the diameter I had chosen when 
making the parts. Ive not been too consistent when converting the 0.185 measure to metric: sometimes it came out to 4mm and in 
some other occasion it came to 5.
Bright side is IF I manage to make them correctly, then there will be little chances to mount the improperly.

Just to make myself sure about what I was going to do, I cut all the arms from a strip of plastics, drilled the holes at the 
specified distances and press fitted (some light hammer blows) the rods into them.

Both engines accepted them without complains: the only item I had to make different is the one I could not find a drawing for, 
though Ive gone through the set a few times: thats #1 arm, the direct link from the bearing to the support bracket. Theres a 
slight difference of a few tenths of millimeter between them in the measurements Ive taken on each engine, for aesthetical reasons.







Though I has intentions of making them into metal as the next operation, I realized the press fitted arms on the brackets would have 
got into the way bringing them to the desired level of completion. Rather do that job first and make the links later.

A quick look into the scrap box showed a few filing buttons of the shape I needed







But not of the correct diameter. 

In fact







I had to make them, but took no pictures neither of the buttons not the finished brackets.


*Valve Rod gland nuts*

Had ideas about making them through a form tool, heres the results of my efforts with a Dremel on the second end of a 8mm lathe tool: 
it cuts on the front and on the curved portion (the second notch being a relief for the end of the curve)







Heres how it cuts, a facing cut on a test piece from the odds and ends. Of course, had I chosen the second end of a longer tool, 
the setup would have been easier, but so it goes
Not perfect, but the idea is not bad. Gotta work on it a little more.






Not having enough length of 14mm hex bar to make the four nuts I needed, I made only two out of it, and got the other two by knurling 
and doming some 13mm brass rod. Not that I had not thought about filing them from larger stock, but shop temperatures over 30C put 
little interest into doing that. Rather drill and hacksaw the valve arms, instead.

Marcello


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