# Double-Cross. Elmer's #34 Cross Twin Engine



## Sshire (Dec 14, 2013)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 1*

Other than polishing, the Liney RV-2 is done. So, here we go with the next engine. 
Ive always wanted to do a horizontal engine and Elmers #34 - Cross Twin Engine seemed intriguing.
After reading the drawings, so that I understand how the engine works, I called my neighbor, Fred, who has a virgin copy of the actual Elmers Engine book. The John-Tom drawings are fine but the pictures look like the result of someone who has a $3.00 scanner and has no idea how to use it. As far as I could tell, the picture was either an engine or a Koala in heat. Having the book, with Elmers very clear pictures, is a major help.

I started with the base. 6061 aluminum plate. My normal procedure is to mark the piece as a sanity check with the DRO.





After cutting a rough-size piece, squaring and sizing it from the 3/8 6061 plate, spot drilling, drilling and tapping commenced.
All holes were put in as SDM (sub data memory) in the DRO. This way I can do all spot drilling, then all drilling, then all tapping just by going to the 10 sub-data points.





When that was all finished, I flipped the piece over and did the counterbores.





And done.





Im going to do the bearing block next. The RV-2 was the first engine that I had done with bearings. Im a believer! Ive got some extra .25 ID Boca Bearings from the RV-2 build.

*So heres the question.*
Is there any reason that I shouldnt (or cant) increase the crankshaft ends to .25 (to fit the bearings) from Elmers .1875?
There seems to be plenty of metal available in the bearing block for this increase.





My thought is to only increase the crankshaft ends and leave the middle at .1875.


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## cheepo45 (Dec 14, 2013)

I'm looking forward to another great build log. Great documentation!
I'm hoping to get more shop time now that winter is here. I have so many works in progress I'm not sure where to start! 
                               cheepo45


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## GailInNM (Dec 14, 2013)

Stan,
No problem increasing the shaft to 1/4 and using bearings. You will be getting a little thin on the top of the bearing stand (1/32) but that is acceptable.  Because the step to form the simulated bearing cap on the top of the stand I just made the stand 7/16 wide and rounded the top. In your case I would make it 1/2 wide as per the drawing and put a 1/4 inch radius on top. This will make the stand 1/32 taller.

The only other change that I remember was I made ball joints for the valve rod linkage.  Mostly because I was into making ball ends at the time. I just pulled mine out of the display case to look at.  I generally put the completion date on my models and it was dated 1990.  Hard to believe it's been 23 years.  

If you need photos of any details on mine I can shoot them and email them to you.

Gail in NM


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## Sshire (Dec 14, 2013)

Scott
Start anyplace. Make an engine. 

Gail
I'm fascinated by the ball joint concept. Pictures would be great and I'd love to know how you machined them.
I had planned to slightly increase the bearing stands to allow for a bit more metal on top.


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## GailInNM (Dec 15, 2013)

Stan,
The valve linkage is a design flaw on #34. The actions at each end are at right angles to each other and move at fairly large angles. If the pins at each end are made a close fit then the valve link must bend. If the holes at each end are oversize so no binding occurs then there is a lot of slop when the valve is in mid position.  Neither was acceptable to me so I built ball joints for each end.

I found the old drawings and made up a couple today. So as to not dilute your thread I will post a tutorial on building them in a new thread.  Should get it done  tomorrow or the next day.  I shot the photos today and cleaned up the drawings some.  

Gail in NM


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## Sshire (Dec 16, 2013)

That's great, Gail. Looking forward to it.


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## GailInNM (Dec 16, 2013)

The "Making Miniature Ball Joints" tutorial is now posted at:
http://www.homemodelenginemachinist.com/f25/making-miniature-ball-joints-22392/

Gail in NM


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## Sshire (Dec 17, 2013)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 2*


In order to use the .250 ID bearings, I slightly changed the dimensions of the bearing blocks. 
Heres the CoC.





Squared up and sized the 6061 for the blocks. Im liking the finish on aluminum and brass with this high helix end mill.





The two blanks for the bearing blocks ready for drilling and milling.





Centered and the edge zeroed.





Ive drilled 11/32 (.3437) to make sure that the line reaming for the bearing OD (bearing specs say ream to .374) will be accurate.





Holes all drilled for the bearings and 4-40 threaded holes for the mounting screws.





I threaded and turned a locating pin for the ¼-20 center hole in the rotary table. Checking the bearing block for a good fit.





And the out-of-focus finished pin.





With the locating pin threaded into the rotary table, a quick centering and ready for milling.





Crank the rotary table to round the end.





And, two blocks.





Im using the 11/32 drill bit to align the two blocks for milling.





The top flats





And the side angle setup





With the milling done, the bearing blocks are screwed to the base.





And line reamed





That's today's parts. I'm trying for a part a day.


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## rebush (Dec 17, 2013)

Stan: Impressive as always. Pulling up my chair to follow along. Roger


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## Sshire (Dec 18, 2013)

Sorry, guys. Here's the one I forgot to take.


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## Sshire (Dec 18, 2013)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 3
*
Heres your part for the day, the cylinder block.

After staring at the drawing and calculating hole depths (which Elmer, for unknown reasons, neglected to include), metal removal began.
As with most of there parts, I did a layout just to stop myself from making some unrecoverable error. These usually happen on the last op of 426.

Entering the data for the 6-hole, 0.5 diameter circle into the DRO, I lightly tapped the spotting drill just to be sure all was correct. That done, I spot drilled the 6 holes.





The upper and lower pairs are connected with an air-passage; 3/32 end mill at a depth 0f 80 thou.





Then 3/32 holes, centered on the air-passages. These will exit in the center of each cylinder. The end holes, also 3/32, are intake and exhaust.





Ive been using spiral flute and form taps for smaller holes. Much less possibility of breaking a tap. You can see how the spiral flute pulls the chip out of the hole. This hole, which is tapped 5-40, is for the screw to fix the valve to the cylinder block.





Now to the end of the block. This hole, and its mate at the other end, are the intake and exhaust and intersect the holes at the top of the block. Its first drilled .88 deep (3/32 again) then counterbored .300 deep for the intake pipe thread.





Now some step drilling to get the cylinders just under 0.500. The hole is 2.125 deep.





Reaming to 0.500. Ive been using the knee power feed for boring and reaming and getting a nice finish.





An almost-finished cylinder block. Two mounting holes to be drilled in the bottom. The small triangular notch at the front corner was to keep my orientation correct as the block was flipped.Another sanity check which will disappear when the chamfers and finishing are done.





Tomorrows parts should be the support foot that goes under the cylinder and the valve. Im waiting for the Brown truck to show up with the .125 brass balls and an 0-80 form tap so that I can work on Gails microscopic ball joint technique.


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## artofpa (Dec 19, 2013)

Stan
I have followed two of your other builds and may I say you do excellent work.
Well except for that one part you that messed up on the water pump, but that build turned out to be museum quality. I'll be tracking this one.

Art


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## Sshire (Dec 19, 2013)

Thanks, Art. You obviously missed the upside-down PM Research Horizontal boiler build. Its a classic screwup. Don't miss it.


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## Sshire (Dec 19, 2013)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 4*

Todays activities were the cylinder foot and valve.

I thought a bit of profiling would make the rectangular foot better visually.
After squaring up the part and drilling the clearance holes, a ball nose end mill, flip the part, another pass and a part is done.









A test fit. Im happy with the profiling. Filing and sanding will come later.





Now the valve. A .125 through hole and this .250 counterbore.





Beveled and parted off.





The part goes back into the collet and collet block for a trip to the mill. The bolt hole circle is identical to the one on the top of the cylinder. 





Milling the connecting passages.





With that completed, it was back to the lathe to make a nut to hold the valve to the cylinder top.
I couldnt seem to find the correct specs in Machinerys Handbook for a 5-40 nut. It must be there and if someone can point me to nut specs smaller than ¼, Id be grateful. Im using the spiral flute tap again. 





Valve, stud and nut. Im not happy within the nut beveling so it will be remade.





And in position.





One part a day. Sometimes two. Sometimes the same part remade.


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## Nicolas (Dec 20, 2013)

Great progress Stan, looking forward to the next update


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## rebush (Dec 20, 2013)

Stan: Looks good. Pulling up a chair. Thanks for posting your build. Roger


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## Sshire (Dec 25, 2013)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 5*

After the annoying morning with the 4-40 die I switched to the con rods.
(if you missed the die episode, here it is)
http://www.modelenginemaker.com/index.php/topic,2908.msg50123.html#msg50123

Two pieces, rough cut. Elmer suggests tapered con rods as an alternative. Ive never (intentionally) turned a taper but Bogs once told me if you never try something, youll never know if you can do it.
Why not. Its only a bit of brass. My usual procedure is to think about how Ill hold a part and I think I have an idea on that one. 





The usual marking out as a double-check against the DRO.





Drill 2-56 tapping size hole.





Then the .02 slitting saw to split the part.





The bottom gets its 2-56 threads.





And the top (which was cut off) gets its clearance holes.





Then milled to final length and reattached.










I decided to make a third practice conrod to allow for a screwup on the taper turning.





I mentioned in the previous post of this build, that I needed a 2x3 piece of .125 thick aluminum for the crosshead guides. Nary a piece of .125 lurking anywhere. 
After the trip to Fazzios Steel and Metal Supply (Im always confused by the name. Thought steel was a metal but who am I to argue with the Great and Powerful Fazzio?), I returned home with this. Four feet should cover any screw-ups on the 2x3 part. The tubes are going to become holders for the air ratchet and die grinder.





The crosshead guides get two .25 channels for the crossheads.









Then marked out for drilling.





In machining the opening in the crosshead guides, I didnt make it back to 0,0 on the lower right corner. Oliver, fitted with a thin chainsaw file, fixed that.









Other than a bit of fettling and polishing, these are done.





Now, back to the tapered con rods.

Making a fixture to hold the rods to mill the narrow part to .1875 width. Since the rods already have holes, it wasnt a stretch to do it this way.













Now, the rods fit in a 3/16 5C collet.





No 4-jaw; no indicating. Worked as I had envisioned.





Elmer suggested setting the compound at 1.5 degrees for the taper. Done.





One completed. One to go.





A pair. The one without the screws was the test conrod.






Havent decided what part to start tomorrow, but, Im leaning toward the crankshaft. Ive an idea for assembling and taper-pinning the crankshaft which will require constructing another fixture.
Stay tuned.


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## Sshire (Dec 30, 2013)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 6*

Heres the round carbide insert cutter. Its something I heard about from Bogs. When it gets dull (not likely with the amount of aluminum and brass I cut with it) the insert is rotated a few degrees and you're cutting again. Cuts left and right and makes nice curves at the ends.





Now, a short break while I make a tool to make a tool (Klotz Level 2).

Every time I use the tapping head, Im setting up mag bases and strange setups with T-nuts and threaded rod to keep the Tapmatics arm in position. And, everytime I do this, I swear Im going to make a proper torque arm stop.





I did look at Tapmatics device that clamps onto the quill. I couldnt imagine anyone buying this, given that they just might have a machine shop.





So I made this.





So I could make this









So I could hold small parts. And speaking of small parts and overkill.





Onto the studs. The new, Made in USA, 4-40 die arrived from McMaster. I turned the end down to the 4-40 major diameter of .112





I managed this.





But only after wedging the die open to turn the screw in and reducing the diameter to .101.









I couldnt get a factory-made 4-40 SHCS to even start in the die. Its going back to McMaster. On to Plan B.





















With those done, it was on to the rocker shaft bearing.

The stock, squared up and milled to size.





Just some milling and drilling.





Another part is checked off.





This is the progress so far. Doesnt seem like much, but with the holidays and the DRO issues (another thread) Im back on track. Richie (my UPS guy) picked up the DRO scale a few minutes ago and its on the way to the hospital in California.


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## Sshire (Dec 31, 2013)

*Double-Cross
Elmer&#8217;s #34 - Cross Twin Engine
Part 7*

Today was  Rocker Crank Arm day. (only celebrated during odd-numbered years in which February has an even number of days.)





I&#8217;ve milled this part and tomorrow&#8217;s rocker shaft to size, then did some marking out and drilled the .125 and .0625 holes.





After precisely measuring the angle (&#8220;That looks sort of close&#8221&#8230;..





Mounted in the angle fixture for milling.





That split the line. As Keith Fenner says, &#8220;I&#8217;m happy with that.&#8221;





Recalculated the angle, for the other side and reset the vise.





I was going to set up the rotary table and turn the locating studs to round the ends, but that would be about an hour I&#8217;d never see again. Actual time at Oliver was 5 minutes.





Another part gets added to the &#8220;done&#8221; pile.





Thanks for stopping by.


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## Walltoddj (Dec 31, 2013)

Nice job looks great! I see you are buying brass studs I did much the same on Ebay for stainless steel 4-40 5/8 set screws to use as studs on my 9 cyl and 18 cyl Radial from Lee's plans. To me it's a lot easier than trying to thread long studs or tie bars. Keep up the good work I'll keep watching to get some pointers. 
Thanks 
Todd


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## chucketn (Dec 31, 2013)

Stan,
More info on the 'Angle Fixture', please? Is it home made or store bought?
Nice work!

Chuck


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## Sshire (Dec 31, 2013)

Chuck
Got it at Shars. Very nicely made. Vernier angle scale. I use it a lot.
Link is here
http://www.shars.com/products/view/2207/4quot_x_134quot_x_1316quot_Precision_060_degree_Angle_Blocks


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## vascon2196 (Jan 1, 2014)

Stan...how's things?

I just did a search for "centering a rotary table" and your thread came up first...awesome build!

Also, now I have to buy one of those angle blocks from Shars!

Keep plugging away!


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## Sshire (Jan 1, 2014)

Hey Chris
Thanks. I got that angle block not knowing if it would be useful. Turns out I've used it a whole lot. 
How's the Bridgeport


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## Swifty (Jan 2, 2014)

I see that you were using a tapping head for all the holes in the plate, I don't have one but often just put the tap in the drill chuck and use the forward and reverse switch to make tapping easy, of course not with tiny taps.

Paul.


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## Sshire (Jan 2, 2014)

Paul
Agree. This is the small tapping head (max 1/4"). When I built Elmer's 3 cylinder radial, I used it to tap the many 2-56 holes in the cylinder block. Balax form tap. No broken taps. 
For over 1/4" taps I just chuck the tap in the Bridgeport. Run the tap in. Hit reverse and the braking on the VFD stops the tap rotation in less than 1 rev. and out it comes. For power tapping I use either form taps or spiral point taps. I keep these separate from the hand taps.


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## vascon2196 (Jan 2, 2014)

Sshire said:


> Hey Chris
> Thanks. I got that angle block not knowing if it would be useful. Turns out I've used it a whole lot.
> How's the Bridgeport



The Bridgeport has been great...I've been fighting rust ever since I got it though. Every time I turn my heater on the machine starts "sweating" and before long rust. I hit it the areas with a scotch-brite pad and then apply white grease but it's getting old.

I'm be watching your Elmers build...good stuff!


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## Walltoddj (Jan 2, 2014)

vascon2196 said:


> The Bridgeport has been great...I've been fighting rust ever since I got it though. Every time I turn my heater on the machine starts "sweating" and before long rust. I hit it the areas with a scotch-brite pad and then apply white grease but it's getting old.
> 
> I'm be watching your Elmers build...good stuff!



My shop does the same when it warms everything sweats, I'm in the process of adding a furnace to help control the temp swings. What I've done in the mean time is keep a bottle of light spindle oil and a rag handy to wipe things down after use. I learned years ago it's not just sweat but acid from our hands that cause surface rust so I just try to wipe everything after I'm done.


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## Sshire (Jan 2, 2014)

Might be off the wall, but I read about a guy who covered his mill with an electric blanket on low when not in 
use to stop the sweating. ???


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## motoseeya (Jan 3, 2014)

I use wd 40 it is a water displacement oil will let the water go throw it and hold the water to the steel and will rust water won't go throw wd 40 it's what's it's made for. just my 2 cents


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## Sshire (Jan 8, 2014)

*Double-Cross
Elmer&#8217;s #34 - Cross Twin Engine
Part 8*

I&#8217;ve recovered from the Rocker Crank Arm Day festivities, so onto the crankshaft. This is a built up crankshaft. I needed three pieces of 12L14 and the small bits are a PITA in the horizontal bandsaw. I have a vise that clamps into the saw base, but these were too small.
The cutting fluid is like a smokescreen.





Winter wonderland outside of the shop. 72 degrees inside.





For my next experiment in cutting small bits, I clamped a standard hacksaw blade in Oliver. Worked very well.





I ended up with these three pieces.





Early on, i decided to use the ball bearings that I had with a .25&#8221; ID.  So two shaft sizes. The connecting rods are .1875&#8221;. Drilling and reaming for both sizes.





Three pieces for the crankshaft.





The angle for the crankshaft center part is marked out.





Then lined up against a parallel in the mill vise.





Milled to the line.





And it looks like this





Very rough test assembly to make sure I hadn&#8217;t milled the angle wrong.





The crankshaft end pieces and the shafts.





Elmer&#8217;s plan is to Loctite the whole thing together so that all stays in place for the roll pins to follow. The spacing for the connecting rods is .194&#8221;. Two gauge blocks wrung together to get the correct spacing.





A little extra Loctite 609 can&#8217;t hurt. Love those toothpicks.





When the Loctite cured, the part was clamped to the new plate. I should have made this long ago.
1/16&#8221; drill bit for the roll pins.





The first 3 pins were cut off with the fiberglass reinforced cutoff disks.









Then back to the plate for the other holes and roll pins.





The connecting shafts are next removed (again, the Dremel disk in the Foredom flex shaft.)





Then cleaned up at the mill.





Polishing to follow.





Onto the stuffing boxes. Drilled and tapped.





A .125&#8221;x.125&#8221; recess is milled.





Don&#8217;t get excited. I didn&#8217;t break a 1/16&#8221; end mill. I got a few stubby end mills which, for shallow slots (this one has a .125 depth of cut) is much less likely to go &#8220;snap.&#8221;





Full depth, very slow feed, speed cranked up. One pass. Done.





A matched pair of stuffing boxes.





Most likely the pistons, rods and tubes will be next.
Thanks for watching.


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## Philjoe5 (Jan 8, 2014)

Nice work as usual Stan.  I like the drilling plate you've shown in the figure where you're drilling for the roll pins.  Why use roll pins instead of solid pins, I'm curious?

Cheers,
Phil


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## Sshire (Jan 8, 2014)

Thanks,Phil
I have 200 1/16" roll pins and no solid pins. Easy choice.


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## artofpa (Jan 9, 2014)

Love the crank Stan.
You make it look to easy.

Art


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## Sshire (Jan 9, 2014)

Thanks,Art. Much appreciated.
This is the 2nd built-up crank I've done. The first was IIRC on Elmer's open column twin. His was easier with the new fixture plate for drilling.
On the last build, the Liney RV-2, it was a turned crank. That was my first and it was not as difficult as I thought. I probably spent more time making the offset fixtures than I did turning the crank. Since I've only been doing this machining stuff for about 2-1/2 years, there are a lot of "firsts"


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## Philjoe5 (Jan 9, 2014)

> I probably spent more time making the offset fixtures



One of the reasons I often make a 2nd or even a 3rd copy of an engine.  Once all the fixtures are made you can add other details to those builds or experiment doing new things without thinking you're in a rut 
(at least, I can).  

Cheers,
Phil


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## Sshire (Jan 10, 2014)

Phil
No more crazy than remaking a part until I'm happy with it. Sometimes more than twice. On the Liney RV-2 build, I was almost finished but the 4 cylinders were bothering me. The "cooling fins" weren't spaced precisely. If you looked carefully, each cylinder was slightly different. Turns out the Y axis DRO scale mount had loosened enough to screw with the readings. So, I now have a spare set of cylinders. 
Good thing this isn't my real job. But, since I'm the boss, shop manager, QC dept, CEO, floor sweeper, etc., doesn't matter how many parts are scrap or rejected.
I keep a container for NO-GO parts to remind me to pay attention.
BTW, where are u in South Easterm PA? I grew up 30 miles south of PGH.


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## Walltoddj (Jan 10, 2014)

Sshire said:


> Phil
> No more crazy than remaking a part until I'm happy with it. Sometimes more than twice. On the Liney RV-2 build, I was almost finished but the 4 cylinders were bothering me. The "cooling fins" weren't spaced precisely. If you looked carefully, each cylinder was slightly different. Turns out the Y axis DRO scale mount had loosened enough to screw with the readings. So, I now have a spare set of cylinders.
> Good thing this isn't my real job. But, since I'm the boss, shop manager, QC dept, CEO, floor sweeper, etc., doesn't matter how many parts are scrap or rejected.
> I keep a container for NO-GO parts to remind me to pay attention.
> BTW, where are u in South Easterm PA? I grew up 30 miles south of PGH.



We all make mistakes as my Dad told the Foreman one morning I can't screw up If I don't do anything that's part of being human and learning from them. If you ever get the chance to go to a plant tour in Buffalo,NY GM Powertrain Plant you would be amazed at what a part looks like before we get done machining it the cranks look a big cast chuck of iron other that the basic shape they look like they could never be a crank but with in three operations they are just about done.

Todd


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## Sshire (Jan 10, 2014)

Todd
Your Dad was right on the money.
Now, how do I get a plant tour? That would be excellent. In the spring. I'll pass on Buffalo in the winter


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## cheepo45 (Jan 10, 2014)

Nice Job on the crank, Stan. I've never made a built up crankshaft,and your pictures and description make it look easy.
                       cheepo45


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## Sshire (Jan 10, 2014)

Scott
With the rods going through all parts, alignment is pretty much guaranteed.
The fixture plate helps by keeping everything flat for drilling.


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## Sshire (Jan 10, 2014)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 9*

I cut the oil grooves in the piston [.015"x.008"] and then spot drilled.





Elmer has the piston rods silver brazed in the piston. I set up the parts and soon after the torch hit the 3/32 rod, it bent to one side. The torch was not that hot.





I love making parts twice. The piston was a 10 minute job so no major loss. Heres Plan B.













The short rod is threaded for the stuffing box. Test fit here.





Then drilled for the 3/32 rod to slide through.





The rod is flipped, end for end, and drilled .125





Ready for Loctite 609. Parts cleaned in acetone and then Loctite primer painted on.





Waiting until tomorrow for the Loctite to cure.





Looks like the crossheads are on the schedule for tomorrow.
Stay tuned.


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## vascon2196 (Jan 11, 2014)

Great job Stan...keep her going.


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## Sshire (Jan 15, 2014)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 10*

Crossheads

I machined both crossheads on one piece of brass and then cut each to length. I started with enough material to make three crossheads (just in case)

Elmer has a four step procedure which eliminates the which cut do I do first so Im not backed into a corner issue. The first two are done without moving the part









And after those cuts, we have this.





Then the part is flipped in the vise to machine the cross cuts. The slot will accept the crosshead link.





Then another turn for drilling and tapping for the piston rod.





Now, with the crossheads separated, the part is turned again for another hole . This one is for the 1/16 retaining pin for the crosshead link. 
In standard Elmer design, the pin gets a #70 hole cross drilled to accept a piece of wire to keep the pin in position. Ive never liked this method of retaining pins. A few engines ago, I discovered 1/16 e-clips and a neat tool to snap them onto a .053 O.D. groove on the 1/16 shaft. When I make the pins, Ill be sure to show that tool again. Its used by RC airplane and car people.





Two crossheads, hot off the mill.





I had left the pistons a few thou large and this seemed like a good time to fit them. Various grits of paper and some Scotchbrite with many test fits. 





With the pistons fitted, I needed to Loctite the bearings into the housings. The people that I spoke with at Boca Bearings said finger press fit.  I also had the same advice from some folks at MEM when I built the RV-2. (I believe they speak from experience about tight fits on these bearings)

Originally, I had the bearings on the inside of the housings but didnt like the big, empty clearance hole on the outside. So, those were relocated to the outer face. Loctite 609.





Finger press and





I now had enough parts made to do a trial assembly to find any places that needed attention. I had lots of binding. I just love following the builds which go So I machined the 834 parts, put it together and it runs on 2 PSI. A bit of running-in should get that down to running on a light breeze.
OK. That NEVER happened on any of my builds, but after some fettling, sanding, more fettling, more fettling, more fettling, I can turn the crankshaft with my fingers and its all moving with nary a bind.
Im quite sure that as I add the rest of the parts, Ill have some issues but at least I know that its not the pistons, rods, crossheads, crankshaft, bearings or con rods.





A pair of pack nuts for the stuffing box.









I really should have just taken a picture of my fingers yesterday when they were squeaky-clean.

Installed in the stuffing boxes.





Now onto the crosshead links. I laid them out on 1/16 brass sheet, rough cut on the bandsaw, on finished by milling to the line.





Then a 1/16 hole in each for the retaining pin.





Then they are silver brazed into the slot on the stuffing box.





More polishing to do, but these are done.





Thanks for pulling up a chair.


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## Sshire (Jan 19, 2014)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 11*

Getting near the end of the line. Except for one little glitch.

I had been running the engine (powered by the Bridgeport) with Timesaver in the cylinders to smooth out a slight bind. After about 10 minutes, it was turning by finger power smooth as silk. Binding gone.

I figured since that went so well, Id install the crosshead links and run it in a bit more on the mill.
Links installed, I hand turned the crankshaft about a half turn forward and a half turn back. Felt good.
Note to self. Turn the damn crank a full turn to check. 
The VFD on the Bridgeport was set very slow.

Question: What happens when you make the links from a 2 wide piece of brass and layout the crosshead links perfectly except you forget to mill the 2 long piece to the correct (shorter) dimension?

Answer: This is what happens.





They did end up at precisely the correct length after the Bridgeports correction.

I was able to unsolder the links from the stuffing boxes and remade the links. This time at the correct length. I also decided to bag the soldering and fix then to the stuffing boxes with 0-80 screws. These will be replaced with 0-=80 hex head brass screws when they arrive from Microfasteners.

So, the new links were attached to the crossheads and I clamped the other end in position and drilled, tapped and made a clearance hole 0-80.









The new links were fixed in place and I tested the movement with a number of full revolutions of the crank.

[ame]http://www.youtube.com/watch?v=gxKml5m2gIs[/ame]

I had mentioned that I was less than happy with Elmers retaining parts on shafts with a hole and wire. If you missed the magic E-clip tool in one of my past builds, heres a rerun from this engine.
The 1/16 shaft is grooved to .052. Im using a Warner grooving tool although Ive heard good things about the Kaiser Thinbit tooling.





Heres the 1/16 E-clip.





This is the tool. Although its metric, the imperial clips work just fine. I got it from one of the model RC airplane/car sites. Seems to be a pretty standard item.





My technique is to grab the clip with tweezers and push it into the tool. 





And you just push it into the groove. To remove a clip, you push the tool against the clips open end.





With the grooves and clips done, I moved onto the other two links. Rough cut on the bandsaw and milled to the line.





The link ends were rounded at Oliver. and then drilled.









The link from the crankshaft to the  crank is 1/16 thick soldered into  a &#8539; built-up end. Using a .062 slitting saw to cut the &#8539; end piece.





So, the valve linkage tomorrow and a temporary flywheel, and hopefully, a first run on air.

Just to hold you over, heres a run-in with the new cross links.

[ame]http://www.youtube.com/watch?v=wsDF4q39ijs[/ame]


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## Philjoe5 (Jan 19, 2014)

Looking good Stan.  Lots of good photos and techniques shown here.

You'll have a runner before me

Cheers,
Phil


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## Walltoddj (Jan 20, 2014)

I like your little E-clip pliers they look very handy, I loose a lot of them because they try to fly off. Nice job on the engine it looks great!!

Ps. I'll have to see when GM has another open house they just did a 75th last fall.

Todd


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## Sshire (Jan 20, 2014)

That would be great let me know


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## Heffalump (Jan 20, 2014)

Stan this build is great! I'm really enjoying it so far, high quality work like this is very encouraging to newbies like me.

I'm also very jealous of your angle jig.


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## Sshire (Jan 20, 2014)

Thanks for the kind words. 2 ½ years ago, I hadn't ever seen a metal lathe, didn't know 6061 from Reynolds Wrap and thought coolant was something the HVAC guy put in my central A/C if it was too hot.

It is consuming and I love it.


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## Sshire (Jan 20, 2014)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 12*

The link that connects to the valve has a 90 degree twist. It seemed like a good idea to anneal the link before bending.





and the twist went without incident (amazing in itself)





Now, a tricky part and a story.

My son sent me this for my birthday last August.





In it, I saw these. I had never seen (nor heard of) Key Seat clamps, but after reading the old catalog, I went to Starretts website to see if theyre still made because it seemed like they could be useful for something.





So, there they were, although the price has gone up a bit. $134.00 the pair!

Hell, I thought, I can make those. I couldnt get a real sense of the size from the catalog (and paid no attention to the size which was clearly on the Starrett website.)

So, here they are.





But wait, theres more to the story.

I was on a recent aluminum buying excursion to Fazzios in the wilds of New Jersey, In addition to the supermarket-like aluminum and stainless building, Fazzios has a secret building with the most amazing collection of used stuff from machine, welding and fab shops. Need a 4 end mill or a circa 1960 stick welder? Thats the place. Its a rabbit warren of room after room of absolutely neat stuff.
Now, imagine this block-long building, marginally lit, filled 20 feet high with shelf after shelf of stuff.
I was quickly passing an aisle of vises when my Starrett Detector went to full alert. I carefully looked at the shelves in front of me and something was calling my name. Stuffed between 20 beaten-to-death Bridgeport vises was this tiny box.





Of course, they came home with me and went into the toolbox.

So, now Im trying to figure out how to transfer a line from the bottom of the valve to cut an aligned slot on the top of the valve for the 90 degree twisted link.

KEY SEAT CLAMPS!!!

First scribing a line with the center head to bisect two ports.





Then the key seat clamps to scribe a parallel line down to edge.





My friend, Fred, who got me into this stuff, suggested the parallels to get the centerline closer to the edge of the ruler.





With the scribe line perpendicular to the face of the collet block





the slot was easily cut.





The valve crank (which goes into the slot) was rounded over at Oliver. 





The plans call for silver brazing this piece into the slot. I really wanted to leave my options open because if there was binding, I was going with Gails ball joints. I decided to insert the crank with a 1-72 screw and then, if all is well, Ill either replace the SHCS with a brass hex head bolt or silver braze it in.

So, a 1-72 clearance hole and a tiny, shop-made 1-72 transfer punch (wire brad).





Then, a 1-72 tap, turned with thumb and finger.









Now a 1/16 hole for the crank pin, .50 from the valve center.





I found an aluminum plug in the scrap box for a temporary flywheel, so theres nothing for it but to plug in some air.

[ame]http://www.youtube.com/watch?v=D1bboqTd3lM[/ame]

ITS A RUNNER!!!

Now I have to take it apart for some finish machining and polishing.


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## cheepo45 (Jan 20, 2014)

Your progress in the model engine building hobby has been nothing short of amazing, Stan. Thanks for your great pictures and descriptions! Another great model. 
       cheepo45


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## Sshire (Jan 20, 2014)

Thanks, Scott. I really appreciate that from you.
It is an addiction.


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## vascon2196 (Jan 20, 2014)

Another great Elmer's engine...awesome job Stan!


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## Sshire (Jan 20, 2014)

Thanks,Chris. Still some machining and polishing to do plus the flywheel.
Will you be at Cabin Fever?


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## vascon2196 (Jan 21, 2014)

I would love to attend the show again...I have to take another look at the dates to see if I can. I drove down there by myself a few years back and it was amazing to see how many people in this hobby under one roof.

I know your going...its right in your backyard isn't it?

We'll see...


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## Philjoe5 (Jan 21, 2014)

Nice work Stan.  I appreciate your efforts to show how some of the less common tools can be used.  

Cheers,
Phil


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## Sshire (Jan 31, 2014)

*Double-Cross
Elmers #34 - Cross Twin Engine
Part 13*

I was thinking that this engine was done. The cast iron flywheel (solid, with recessed center and drilled through with 5 holes) just looked wrong. Two things were bothering me. First, it looked too small (made to Elmers plans) and second, I felt that a heavier flywheel would allow the engine to run a bit slower.
After checking the engine for clearance, it seemed that a spoked, 3 flywheel would be a better choice. I do have a 3 round bar of C.I. and Marvs flywheel program does the spokes dead on. Then, I remembered how nice the PM Research cast flywheels were when I saw them at Cabin Fever last year. Ordered 2, 3 bronze, spoked, 7.5 oz flywheels on Monday and Richie, my UPS guy dropped them off on Wednesday. Id never machined a flywheel casting (or any casting) but, what the hell.

Mounted the three-jaw and bolted a set of home-brew soft jaws. I preloaded the jaws and bored a 0.25 deep recess and mounted the casting.





I was able to face the rim and hub and then turn the hubs O.D.  Did a bit more than half of the rim O.D.





Then flipped around and repeat on the other side.





It was easier to see what was happening by cutting the inside of the rim from the rear with the lathe running in reverse.





Good so far.





Drilling and reaming for the shaft.









I pressed a tapered mandrel into the hole and went back to the 5C and the thin live center. 
There was some wobble, but a bit of facing and turning had it running wobble-free.





I had ordered two flywheels figuring that I might screw one up, but it was less stressful than I thought.
Now, Ive got one for the next engine.





Oliver made short work of removing the flash, then 1 rolls of abrasive, small files, and about an hour finished the spokes.





Self-etching primer (2 coats) and paint (3 coats) and Im definitely calling this one done.
Thanks for following along.









Since I have that extra flywheel, watch for this build in the next few days.


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## crueby (Jan 31, 2014)

Nice work on the flywheel - the one picture where you are filing the spokes though - what kind of machine is that? Is it a jig saw with a file mounted somehow? 

You called it Oliver - must be a favorite tool....


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## Sshire (Jan 31, 2014)

Thanks, Crueby
Oliver is a 1970 Oliver of Adrian (Michigan) S-4 Die Filer.
Some info here but unlike these pictures, mine has the optional 16" table, the roller and spring- loaded file support and looks like brand new.

http://vintagemachinery.org/photoindex/detail.aspx?id=12190

Here's mine


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## vascon2196 (Feb 1, 2014)

Once again...awesome job Stan.

I especially like the segment on the Starrett keyseat tools....very cool.


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## barnesrickw (Feb 1, 2014)

I have a worthless jig-saw I might try to convert. 


Sent from my iPad using Model Engines


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