# Potty Simpson and Shipton Short Stroke Engine



## SBWHART (Dec 18, 2011)

I've not bin Idle these last couple of weeks I've bin doing a bit of research on an engine that caught my eye. Its a bit of a strange beast it has a rotary action that I can best describe as a captive eccentric. The original was first displayed at the great exhibition and was shown powering some textile machinery, as far as I can find out only two were made, though there is very little documentary evidence for the second.

I've got enough of the drawing done to show you an assembly, but I still need to do more detailing of the parts, but its enough to give you an idea of how it will look.







I'll slowly work on the drawing and start to get material together ready to make a start and cut metal in the new year.

Stew


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## Jasonb (Dec 18, 2011)

Looking good so far Stew, to you have Anthony mounts articles on teh one he did?

Pat over on Classic steam is doing something similar with a Dake engine

J


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## SBWHART (Dec 18, 2011)

Hi Jason

The club have copies of engineering in miniture with Antony Mounts article, I had a quick look at it to try and understand the valve arrangement, still couldn't get my head round it, I'm doing mine with a piston valve arrangement, I didn't read the full article, as I didn't want to be influenced to much by it, not that there is anything wrong with it, far from it, its a very nice engine.

I'll be using bar stock as far as posible and it will be about 4/5 the size of Antony's 

I'll have a Look at Pats Build thanks for the information

Stew


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## SBWHART (Dec 18, 2011)

Hi Jason

Just done some research on the Dake engine and i must say what a wonderful engine it is, worth doing a google on william dake, 3 or 4 page in there's a link to high pressure steam engines, that has some great animation of the engine.

Thanks for bringing it up

Stew


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## SBWHART (Jan 6, 2012)

Started to cut metal on this engine, first job cut the cylinder out of a chunk of brass and square it up






Next using my new digital height gauge from Santa mark it out and light centre pop the lines.






Then in the mill with a wobbler find the edge of the lump and bring the mill onto its centre, and set the vice stop.






Then working to the marked lines chew out the edge to start forming what will be the port face flip it over and do the same on the other edge.

Turn it on its end a chew out the end edge, flip it over and do the other end






Sit it level on parallels check that we are still on centre, and drill a couple of 13mm on holes on the what will be the centre for the cylinder.






I was getting a bit cold at this point so went in for a warm, I'll pick it up again tomorrow.


Any one who would like a copy of the drawing just send me a PM with your email adress on.

Stew


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## SBWHART (Jan 6, 2012)

Ok Guys big red face time I dropped a bollock with the drawing 

 :'( :'( :'( :'( :'( :'(  

I've made the cylinder too long, it should be the 30 + 15 + 1.5 = 46.5

I drew it as 30 + 30 = 60 it was only after I had drilled it that I started to think that looks too long better check it out, 

Just measured things up and all is not lost I can still fit the correct length of cylinder in, but I need to chase the change through the drawings as it will impact on the con rods, cylinder covers and the valve chest.

So it's back to the drawing board.

Stew


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## Lesmo (Jan 9, 2012)

Like your flash new height gauge Stew, nice present, much better than a tie or socks.
Sorry to hear about the wayward gonad, just goes to show, that it happens even to the best of us. 
I am really looking forward to this one when you are back on track.

Les


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## SBWHART (Jan 14, 2012)

Cheers Les

Things have bin a bit slow on this over the last week, what with having to redraw some of the parts, and other things getting in the way:- plus I went down with the dreaded puckes.

All fit now and bits redrawn.

First job was to put the bollock right.

So plugged the holes and respotted in the correct position.






In order to get things in the correct position I had to use a boring head, just opened the holes up just enough to give a good register for a mandrel.






Then turn a mandrell up a nice fit in the hole.






Then transfer chuck and mandrel over to the RT and bolt the cylinder to it.






Then machine the rads around the rim






Turn the RT onto the horizontal and machine the pocket around the top.
First with a radius cutter






Then take the meat away 






Then do the same with the base but leaving a flat for the foot to solder too.







Your probably a bit baffled as to where I'm going with this, well I'm baffled as well :lol:

Stew


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## SBWHART (Jan 16, 2012)

Got a little done today: made the cylinder base this will be silver soldered to the cylinder.

Started life as a bit of 12mm thick brass sqaured up and milled to size.

Then first with a end mill and finishing off with a 10mm bull nosed cutter machined out a plinth in its middle.






It fits on the flat like this






I'm not going to solder it just yet the cylinder covers will need soldering as well so I'll do them together.

Stew


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## SBWHART (Jan 18, 2012)

Thanks for you interest Guys

Any way got the base soldered to the cylinder, it took two goe's my first atempt the nozzle was a bit small and I wasn't getting enough heat into it, swapped to a bigger nozzle and it went like a dream, at the first attemp I tought should I swap to a bigger nozzle, but I was to lazey and went with what was fitted, came out ok in the end its slightly skiwiff, but a light skim of the base should sort that.






Next up the covers, I'm making these out of 1/8" thick brass, first job cut then off the bar and square the ends, then carfuly drill the centre holes 3mm to take dowels and a couple of 1/16 for brass pegs to locate a thickening peice.






Then cut out the thickening peice square them up and drill them for the 1/16 pegs






File a rad on each end






And this is how they fit on the cover for silver soldering






Job done:- the pic doesn't do it justice its a very neat joint.






The covers have a curved slot that the piston rod runs in this has to be on a 75mm rad, and the covers have to fix centraly on the cylinder bore. so I made a fixture to hold the covers on.

A 10mm hole was drilled and reamed in the jig 75mm from this two 3mm holes were drilled to take 3mm dowel pins, and a hole drilled and tapped to take a clamp. I also made a 10mm clamp bolt with a 10mm register dia a neat fit in the 10mm hole in the fixture, this bolt screwed into the surface plate that I made some time ago to increase the capacity of my RT.






and how it all fixes together.






Stew


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## kjk (Jan 18, 2012)

I'm still baffled. Perplexed even.


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## SBWHART (Jan 18, 2012)

Hi Woodguy

This animation and explination you will find her Doug.
may help.

Thanks
Stew


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## metalmad (Jan 18, 2012)

Wow what an interesting engine
This will defiantly be on my watch list 
Pete


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## Path (Jan 18, 2012)

*Wow* ... Santa was nice. You are going to really going to enjoy working with your new 
digital height gauge. 


Your project is going to be another learning experiencing for me,
will be following closely. 


Pat H.


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## danstir (Jan 19, 2012)

Love the build so far. Thanks for sharing.


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## SBWHART (Jan 20, 2012)

Thanks for your interest Guys

Things should start to make sence from now.

I can now start treating the cylinder like a casting, the trouble with this design of engine is that its so weird, its difficult getting your head round feature that are important.

I figured that it will be important getting the slot that the piston rod moves in central with the cylinder hence the fixture I've made.

So to mill the slot first centre the RT on the mill spindle zero things up then, using the bolt secure the fixture to the table, but first clock it up level with the Rt set on zero deg.






Then index 75mm bolt the cover to the fixture and with a 8mm slot drill mill the slot.






Next drill the 2mm holes on the PCD, both ends






Onto the cylinder centre it up on the mill zero the dials. and using a boring head bore out the cylinder vertically down, advancing 1mm vertical down again advance 1mm etc etc until its long enough.






Did this for a couple of rouging cuts, then to finish advanced it 0.5mm/cut , this left a slight ripel in the bore but that will soon clean out with a bit of fine emery cloth wrapped around something flat.

Then on the centre line drill a couple of holes each side to take 3mm dowels.






Locate the covers on the dowels and spot through 2mm followed through with M2 tapping drill.






Centre the jig back up on the RT and radius the end of the covers.






And this is what the covers look like on the cylinder, only got one finished before domestic duties called, I'll finish the other off tomorrow.






Hope things are starting to look a bit clearer.

Stew

PS for some reason the Preview button doesn't seem to work ????


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## AussieJimG (Jan 20, 2012)

Interesting engine and really great construction techniques and photos. I will be following along with mouth open at the way you achieve things. :bow:
Thank you

Jim


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## SBWHART (Jan 22, 2012)

Thanks Jim

Her's a pic of the covers the right way round, I think it looks happier the other way 






With both covers fitted i put a length of 8mm silver steel through the slot and measured the height side to side and front to back, and it was within 0.06mm:- not alf chuffed with that      :ddb: :ddb: :ddb: :ddb: :ddb:






Back on the mill and drilled and milled the air ways, and drilled m2 tapping for the valve chest.






Then tapped the holes M2 using the tapping stand to get them square, these holes are on both side of the cylinder, on the model they don't do anything, but on the origonal the cylinder sides were spring loaded to take up wear hance covers both side.






On with the valve chest now, first square it up to size, then centre spot where the bore is to go for the spool valve.






Then in the four jaw chuck clock up a wobble bar centred on the spot centre.






Centre drill then drill and ream 8mm.






Swap it round clock the centre spot up on the face.






Drill through into the 8mm bore and face the boss for the air coupling.






Over onto the mill using centre the work and with the DRO drill the holes on the PCD for the coupling.






Flip it on the back find the centre and drill the feed ports and 2mm for the studds






That was a good morning work    

Any one know where I can buy some M2 studding in the UK.

Stew


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## Blogwitch (Jan 22, 2012)

It just so happens Stew, I have some 2mm stainless studding sitting here on my computer desk.

Call round and pick it up.


John


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## SBWHART (Jan 22, 2012)

Thanks John

I'll give you a call

Stew


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## SBWHART (Jan 23, 2012)

Got the stream chest finished off, today.

Drilling the holes for the sealing gland.







Next up the little top hat to take the graphite cord.

Turned the OD and reamed through 3mm parted off flipped it round then used a slot drill to cut the flat bottom hole.






Then turned up the spool valve from some silver steel bar, 
Drill and tap and acuratly turn the gap and over all length as these are important to the valve timing.






Camera went flat at this stage, and couldn't be arsed to get the spare out of the house.

Finished of the rest of the bits for the gland, this is how they all fit togethere






Then onto the valve cross head bar, made this from a bit of 1/4 square bar, so in the four jaw self centring chuck, rough out the steps.






Then with a thin tool and with the compound slewed over 5 deg turn the taper bits.






Over onto the mill and find the midle of the bar and drill though 3mm index to the outside bits and drill these through 3mm as well.






Then with an end mill thin the end bits out.






Time for an hows it looking.






Stew


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## ref1ection (Jan 23, 2012)

It's looking real fine from my angle. ;D

Ray


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## danstir (Jan 24, 2012)

Very nice so far. Thanks for sharing.


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## SBWHART (Jan 25, 2012)

Thanks for your interest Ray/Danstir

Things will slow down over the next week as I'm on domestic duties 

Decided the cross head would look better with the end bits rounded off so made a filing button and nibbled away with files, I think that looks better:-- less clumsy.






Used the rest of the morning making the link bars.

First cut off a length of bar enough to make all three links, then drilled some pairs of 3mm holes 12.5mm apart, the DRO on the mill gets the pitch for each one very accurate.






Cut each link from, then turn a 3mm mandrell on the lathe, bolted each link to it and faced it off to form the arm.






With the same filing button finished the ends off, then drilled and tapped M2.5 for a grub screw.






Job done











Stew


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## AussieJimG (Jan 25, 2012)

It looks obvious when you do it Stew, but I guess that is the mark of a true craftsman. :bow:

Jim


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## RonGinger (Jan 25, 2012)

Nice work, and I really like all the photos.

You seem to make great use of a stop in your vise. It looks like a simple stop block, but it a couple photos it appears to be rotated and have a double stop.

Could you please show a photo of the stop itself and offer a few words on how it is used?


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## steamer (Jan 25, 2012)

Decided the cross head would look better with the end bits rounded off so made a filing button and nibbled away with files, I think that looks better:-- less clumsy.



I absolutely agree!...nice!

Dave


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## Blogwitch (Jan 26, 2012)

Ron,

In all honesty, a good, rigid mill vice stop should be one of the first bits of extra tooling you should make. I made the mistake of using a mobile one for many years, but eventually I realised I needed something a little more permanent.

I showed how I made mine here. Very long winded in the beginning, but it might give you a few ideas, as it did for Stew.

http://madmodder.net/index.php?topic=1007.msg7615#msg7615

No need to go to the extremes that I did, but do take time to make it rigid and square.

John


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## SBWHART (Jan 26, 2012)

Thanks for all your comments Guys

Ron:- I pinched the stop design from Bogs, he showed me his design on one of my visits to his shop, it's a little gold mine for ideas.

Stew


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## RonGinger (Jan 26, 2012)

Thanks, I will read the madmodder topic.


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## SBWHART (Jan 26, 2012)

Hi Ron

I'm not at home at the moment, this is the best pic I've got, it shows the stop on my old vice.






Hope it helps

Stew


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## SBWHART (Feb 16, 2012)

Thanks Guys

Started back on the engine for a little while at least.

Finished off the rest of the linkage






Made the piston today its a job I've been putting off don't know why I guess I just had a funny for doing it.
I liked the idea of making the piston out of PTFE, the main reason is its slippy plastic and quite soft, and I figgured that if I made it just a coulple of though longer than the cylinder it would act as a good air seal against the covers ??? we'll just have to see how it works out the bottom line is to change it for steel if it don't work out.

I used very sharply honed tools it cut like butter with a great finish.






Set it up in the mill and drilled the off set holes.






Back on the lathe and resessed the faces.






Then parted off a length of 8mm silver steel (drill rod) and put a rough straight knurl into the middle.






Sorry its such a crap pic

Then gently tapped the rod into the cylinder the straight knurl acting as splines to give it grip.

Mounted it back in the lathe a carfully skimmed the cylinder to width

The cylinder covers wern't sitting flat so gave them a bash wif me ammer, and a rub on emery cloth on a flat surface.

This is how it looks in the bore






Stew


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## HS93 (Feb 17, 2012)

could you have a perspex end cover for the odd run to see it working ? :bow:

  Peter


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## steamer (Feb 17, 2012)

Hi Stew,

I've used teflon for piston rings on my launch engine, and it's held up nicely

I think that should work great!

Nice work!

Dave


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## SBWHART (Feb 18, 2012)

HS93  said:
			
		

> could you have a perspex end cover for the odd run to see it working ? :bow:
> 
> Peter



I've got one tucked away Peter.

Cheers Dave that good to know

Had a couple of sucessful days in the shop.

Made the crank webs, they are of the pinch clamp type so you can get them on and off due to the design of the engine.

First drill the holes 2 with 8mm crank pins 2 with 6 mm crank pins






Cut off with slitting saw






With two drill through the holes across top of vice, mill off so they are central, for the two cranks with the 6mm crank pin holes had to use a drill imm smaller






Drill and tap and open up half with a clearance drill






Cut the split.






Then with filing buttons file to shape, they still need a bit of tidying up and a rub with emery, but her they are with the buttons






Think they look a bit on the heavy side may thin them out a bit.

Next up the con rods the engine has four using 9/16 free cutting mild steel first cut off to length face them up so they are all the same and centre drill and turn up a lost centre.






With a part off blade put a couple of grooves into them to show where to stop and to give some clearance to the turning tool.






The with a running centre chew the meat out of the middle.






Slew the compound over a couple of deg and with a radius tool form taper toward the chuck, swap it round and tune the other end to form the barrel.











Cut the centre pips off then over on the mill cut the flats.






Called it a day at that and went for a brew and a snooze.

Stew


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## SBWHART (Feb 20, 2012)

Finished off the con rods

Drilled and reamed






Then turned up the bearings I needed eight of them I didn't want to P*** about to much, so turned a length of bar for a good fit in the con rod ends and parted off.






I'm using my independat four jaw that chucks up very true, this allowed me to drill and ream right through the bar.






Then it was just a matter of parting the bearings off to length, fitted into the con rod with a spot of bearing retainer.

A bit of work with filing buttons to shape the ends and this is they fit to the cylinder






Things comming together well 

Stew


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## bearcar1 (Feb 20, 2012)

"coming together well....." Boy, I'll say! You make fabricating oddball shaped pieces seem so effortless and easy, Stew. I like the overall lines of this engine, art deco-ish in a way. Whatever style it is, I LIKE IT! Thm: Carry on.

BC1
Jim


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## SBWHART (Feb 22, 2012)

bearcar1  said:
			
		

> "coming together well....." Boy, I'll say! You make fabricating oddball shaped pieces seem so effortless and easy, Stew. I like the overall lines of this engine, art deco-ish in a way. Whatever style it is, I LIKE IT! Thm: Carry on.
> 
> BC1
> Jim



Thanks Jim you'll enjoy this next bit:----- I did ;D

Eccentric strap:- I've had it in mind to make the strap silimar to an eccentric on an 1850 ish beam engine I saw in a museum, it was a lovely cast iron job with a delicate latice work of circles, this will be too small to do the cirlces but I fancied doing something in that flavaour.

First part the strap end, cut off a sliver of brass 5mm wide drilled an hole up the middle and mounted it on a mandrel in the rotary tabel, and generate the strap end out. 






Then drill and tap M2.5 






Split it in half bolt it back together and grip it in the self centering four jaw and bore it out.






I've spent ages thinking how to do the next part, I've had all sorts of complicated plans, in the end i decided to go the simplest way as i'm a bit of a simple bugger at heart.

So milled out a couple of 3*5mm wide strips of brass and with a big chunk for the other end to give me plant to machine to get it squared up after soldering.

Filed an angle on the end of the strips and butted them up against with a bit of flux and a few nuggets of silver solder, and a few weights to stop it moving:- and solder it together.






Onto the mill and sit the strips on a thin bit of strip and gripping the chunk mill the chunk up square to the strips.






Cut the strips up to length, and file a chamfer to but up against the strap end.

Then back on to the soldering hearth and solder






A couple of hours in the pickle, drill the cross hole and cut the slot






A bit of attension with files and it's not looking too bad.







 :big: :big: :big:

Stew


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## Captain Jerry (Feb 22, 2012)

Stew

Three cheers for simple!!!

Jerry


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## AussieJimG (Feb 22, 2012)

I am following in awe and amazement. :bow:

Jim


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## cfellows (Feb 23, 2012)

It's fun to follow your posts, Stew. Love seeing pictures of your progress and techniques.

Chuck


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## SBWHART (Feb 23, 2012)

Cheers  Jerry/Jim and Chuck

Got the eccentric finished off today

With a bit of bar in the lathe face and turn OD, then with a parting blade turn the 20mm dia * 5mm groove for the strap. 







Tranfer the chuck over onto the mill centre it under the spindle and off set 3.2 and centre drill.






Back onto the lathe this time with a independant four jaw chuck and with a wobble bar clock the centre true






Then drill and ream 8mm and turn the boss down.






In the three jaw chuck and part off.

Drill and tap M3 for a retaining grub screw






Job done

Time for a lose assembly of the parts made so far.











It looks more like a knitting machine than an engine, i wouldn't be suprized if it knitted me a pair of socks when it starts up, would any one like to place an order for a pair


Stew


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## ozzie46 (Feb 23, 2012)

Excellent work Stew. That is sure one interesting looking engine. ;D ;D

 This is one I really want to see run. Not that I don't want to see them all run,but this one is, I don't know, just so different. I hope you put the perspex on one side so it can be seen.


 Ron


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## Brian Rupnow (Feb 23, 2012)

Stew---You do amazing work. I am always impressed by your posts and your machining ability. I'm watching this develop, and admiring it all the way.----Brian


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## Captain Jerry (Feb 23, 2012)

I'll have a pair Stew. Nothing fancy, plain black with a red pinstripe will do.

Jerry


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## SBWHART (Feb 24, 2012)

Thanks Guys

Ron The Perspex safely stored away 

Jerry:- Order is accepted :big:

Stew


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## SBWHART (Mar 2, 2012)

Things slowed down durring the past week while a did a little commission work  ;D

Started on the base, first I squared it up to size, then drilled and tapped the cylinder fixing holes for M3 studs.






This was so I could set the cylinder down and get some idea of whare the cut outs were to go and how much to cut out.

Then marked them out with the height gauge centred popped the lines and hatched them out some, so I didn't get mixed up.






Then drilled the coners of the cut out first.






Then chewed them out with a slot drill.






Quick look see






Now on with the columns, I'm fabricating these out of ally bar, for the fluted column I'm using 9/16" bar, first cut the bar down into handy lengths than face and centre drill one end. In the spin indexer with a 1/4" ball nosed cutter mill the 12 flutes.






This is whare the power feed on the mill pays for its self, whist it was doing its thing, I fired up the lathe, and parted off the bases from some 20mm square ally bar.






I'd have got these roosters finished today but my boss dragged me out of the shop to go the Docs for some injections for our visit to Africa. :-  Now got a sore arm  

Stew


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## SBWHART (Mar 3, 2012)

As these parts will have a delicate edge that will be easily damaged by the chuck jaws I made a split collet, to hold them.






Using the split collet part the flutted collumns off to length.






Then as its important that the collumns are all the same length I fitted my back stop into the spindle nose, this is it with a few of the interchangable ends i've made for it.






Then using the back stop face, drill and tap M3, I though I had a picture of this but no.

Here they are done they are all within 0.05mm






Again using the back stop face off the square bit so they are all the same thickness

Got a pic of this 






Her they are with the columns






Stew


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## AussieJimG (Mar 3, 2012)

It's looking good, I am still following and learning.

Jim


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## zeeprogrammer (Mar 3, 2012)

Beautiful work Stew.
A fascinating engine and an excellent thread.


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## SBWHART (Mar 9, 2012)

Thanks Guys

Bit more done on the engine the pillar parts was more about mass production than anything, made the roundels from 20mm brass bar, i'm going to paint the columns mat black and leave the roundels shiny brass 

Used a form tool to form the rads drill and parted off






Sorry about the crap pic.

Then with the back stop faced them all off the same.






Then turned up a mandrell a blended things in and gave them a polish.






This is how one looks like.






And time for an interest boosting assembly.






Not looking too bad.

Stew


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## metalmad (Mar 9, 2012)

looking great Stew :bow:
Pete


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## SBWHART (Mar 9, 2012)

Thanks Pete

Its bin a good day in the shop finished off the fly wheel.

In the independant four jaw true it up so the inside of the rim is running true, then clean up the hub and the inside of the rim, face and turn a register on the OD.






Turn it round clock up the register true, and clean up as for the first side.

Then griping on the inside of the wheel clock the register true and clean up the OD, and drill and ream 8mm






Job Done






Stew


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## Jasonb (Mar 9, 2012)

Stew, is that an RDG casting or Stuarts?


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## SBWHART (Mar 9, 2012)

Jason

Its an RDG Casting,

Quality quite good, not to much flash and running resonably true only needed a couple of mill skimming off it. It had one hard spot on the rim from a chilled flash, but that came off OK with a TC tip tool.

Stew


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## steamer (Mar 9, 2012)

RDG as in RDG tool?

Dave


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## HS93 (Mar 9, 2012)

sbwhart  said:
			
		

> Thanks Guys
> 
> Bit more done on the engine the pillar parts was more about mass production than anything, made the roundels from 20mm brass bar, i'm going to paint the columns mat black and leave the roundels shiny brass
> 
> ...



Stew do you make wedding cakes?? :big: :big:

Peter ;D


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## SBWHART (Mar 10, 2012)

steamer  said:
			
		

> RDG as in RDG tool?
> 
> Dave



Yes Dave Her's the link http://www.rdgtools.co.uk/acatalog/Fly_wheel_Casting_.html to the fly wheel page they do a range of different sizes i used their 7" for my Over Crank Engine fly wheel' quite happy with the quality and price is not bad either.

Wedding cake :big: :big: :big: it did remind me of something but I couldn't quite put my finger on it I recon your spot on with that one Peter.

Stew


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## Jasonb (Mar 10, 2012)

For the price the RDG ones are quite good, I've just done one of the 10" ones and apart from a small hole in the hub that can easily be filled it was very good. I did sort through them at a show and that was the third one down the pile the others having small faults in the rim.






J


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## SBWHART (Mar 18, 2012)

Fine looking fly wheel their Jason.

Things have been real slow on this build over the last week due to domestic duties.

One of those duties was solving the aviane housing problem in Glasgow where our son is moving into a new/old house, with a big garden, he asked if i could make him some bird nest boxes, yes I said, he proptly ran through a list of boxes with diferent hole sizes, and shapes, plus a box for Bats and a block of flats for sparrows.

This is the score minus the sparrow tower I ran out of wood for that, which I will buy at B and Q on their old git discount day.






Made some acorn nuts for the engine, ground a form tool up to form the dome.






This how they look on the engine.






Then made a start on the bearing housing, I'm going to try and emulate Jason, and Ramon's method using JB weld. First square up to size a chunk of ally, then run a 3mm rad down each edge.






Cut off and skim them off to all the same length, then rough drill the hole for the bearing.






Drill through M2.5 tapping.






Her desaster struck :doh: I broke the drill and failed to get it out, tried nocking it out from the other side it moved a bit then i got the punch stuck, so gave it up as a bad job I'll just have to make another, in fact this may not be a bad thing as the flywheel bearing could do with being a bit wider.






Cut the caps off with a slitting saw.






Tap M2.5 and bolt them together, and then giving the scrws a bit of support pass a 11mm end mill vertically down through to form the bearing bed.






Now for the bases as before clean up and square the ally to size, cut them off and mill to the same length.






Then using the sine bar angle the edge of the base.






This is what they look like so far, the main bits needs sortening to get the centre height so they will look more in proportion.






The next couple of weeks will be slow weeks as well which is a bit frustrating as there isn't that much to do to the engine.

Stew


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## SBWHART (Mar 20, 2012)

For those of you who don't know what a sine bar look like hers mine:







The bar is made to a very accurate length between the rollers and you just pack one end up to give the desired angle, that you calculate using the sine function.

Finished off the base by drilling the holes, the outer holes were countersunk flat bottom to take the bolting pads and the centre hole for countersunk for the cap screws.






Then turned up the pads.

And the bearings.






I like to push the reamer through with a centre with a drive carrier, that way it floats and you cut a true size.

This is how it all assembles together.






Then stuck the lot together with JB weld gave it 24 hrs to cure then cleaned them up.






Now they look good:- a big thanks to Jason and Ramon for sharing the method its one I will use again in future.

One more bit made the drive half shaft. I was going to make it from 12mm bar, but didn't have any so used 15mm and turned it down to 12mm with an 8mm step for the fly wheel threaded M8






Stew


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## SBWHART (Mar 28, 2012)

Managed to sneak a couple of hours in the shop this morning thanks to my grandson, the little darling had been playing with my bed side clock and put it forward 1 1/2 Hrs so bright and early I was up at my usual time, it was only when I looked at my shop clock that I noticed how early it was 

 : : : : : :

Made the fly wheel drive for this I needed at 36mm dia * 10mm slice of mild steel I hadn't got any bar but I did have some 1/2" thick *
 1 1/2" steel bar, so I cut of a 1 1/2" length put a centre drilled the middle and then used a friction drive to turn it into a disc.






Then skimed the faces up.






Set it up central on the mill and put a 12mm off set and drilled 9mm











Then drilled and reamed 12mm through the middle






Drilled and tapped M3 for a fixing grub screw.






Then made a 6mm bush for the crank drive and pressed and pressed it into the disc.

Time for a few hows it looking shots.











Stew


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## AussieJimG (Mar 28, 2012)

It's coming along nicely Stew, and those supporting columns are outstanding.

Jim


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## SBWHART (Apr 11, 2012)

Thanks Jim

Things have been real slow on this engine due to family commitments but have managed to steal an hour or two her and their.
I had to do a major sculpturing job on the base, it was my own fault instead of following the drawing I changes the hole centres for the pedestal as i thought they would make thing look more symmetrical, but I forgot about the impact on the length of the crank.

Any way with that sorted I've spent some time getting my head around setting the timing:- not easy as you can't get at anything.

But I have had it running for short time, but it will only run with lots of oil in the cylinder, I think I have to reduce the clearance of the piston, which will be a major strip down, but the positive thing is that It will run, as soon as I get a longer run out of it I'll post a video.

Stew


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## SBWHART (Apr 15, 2012)

[ame]http://youtu.be/0KZoRF8AhRU[/ame]

I think I may have run up against the limitation of the design it will only run for a few seconds with my small compressor before it runs out of wind.

After all they only ever made two of them i guess thats why.

Stew


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## AussieJimG (Apr 15, 2012)

Great stuff. It runs well and looks great. Who can ask for anything more. Congratulations.

Jim


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## Brian Rupnow (Apr 15, 2012)

Very nice Stew--Up to your usual standard. Congratulations on another great build.-----Brian


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## SBWHART (Apr 18, 2012)

Cheers Jim/Brian

Still a bit along the learning curve to go with this engine.

To days lesson:-

I made the piston from PTFE it seemed a good idea at the time, I know PTFE has some strange properties and that it has a high figure of coefficient of linear expansion, but I though that shouldn't pose any problem, I measures the width of the piston and the cylinder up and made them so that I had about 0.2mm clearance fit, I reduced this down to 0.05 to try and get a better run, but as I was doing this I was having problems getting a repeat size for the piston, this morning I stripped the engine down and measured things up the clearance was size for size, great i thought, tried it for fit and it all rolled over smoothly I fiddled about a bit, tried it for fit and things had tightend up, measured up again and I had an interferance fit ???

Time for my morning coffee, so stuck the piston in the fridge for 1/2 hr measured up again and it had shrunk by 0.15mm.

Just done a google search on the properties of PTFE and as far as I can tell it has coefficient some 5 times greater than brass.

Time for a change of material i have some nice shash weight cast iron that John gave me I'll give that a try.

Stew


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## steamer (Apr 18, 2012)

Hey Stew,

I use teflon piston rings with a stepped lap joint to allow for differential expansion. in my launch engine

Like this







I know your engine doesn't use rings in the traditional sense, but was wondering if there was a way to allow for the thermal expansion mismatch......

Dave


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## SBWHART (Apr 27, 2012)

Thought I'd better update the build log

1st making the cast iron cylinder.

Turning to size after drilling off set hole






The trepanning a groove for some packing,






seems to work ok without packing tough, still nice to have the option.

Shaft assembly using same method as for the PTFE






Also pinned the crank journal using soft nails.






Then whilst waiting for deliver of new 7" fly wheel made the stop valve, body fabricated in two parts silver soldered together.






Get to use the new ER32 indexing blocks to cut an hex for the valve pillars.






Worked a treat :thumbup:

Completed valve






And on the engine






Stew


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## AussieJimG (Apr 27, 2012)

That valve is a work of art on its own Stew :bow:
Jim


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## SBWHART (Apr 29, 2012)

Thanks Jim

I'm sorry to miss you at Harrogate this year I usualy go, but family commitments make it dificult this year, unless their is a change I won't be able to make it.

On Friday I took delivery of a 7" flywheel casting from RDG.






Good quality a few blow holes on the rim but nothing that couldn't be skimmed out or filled.

This morning I finished off machining it and tried it out on the engine.











It's more in proportion to the fly wheel in the etching of the original.






Its improved the engine running considerably, it now runs at about 10 - 15 psi at about 100 RPM at full pressure of 60 psi it runs at 550 down from 850 for the 4" wheel. Still got an horrendous wobbly on the wheel but that's down to the single bearing support, I'm hoping to get some plate delivered next week that will allow me to double up the bearing supports on the fly wheel that should smooth things out even more.

I'm now about 99% happy with this engine

     

Stew


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## AussieJimG (Apr 29, 2012)

What a pity you are not going to Harrogate. But how about turning on Skype and we can have a chat when our time zones coincide.

Jim


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## Blogwitch (Apr 29, 2012)

Stew,

Those RDG flywheels really are a very good buy, especially when you look at the crap that comes from the big casting retailers, theirs are usually almost unusable, with massive inclusions and misaligned spokes. It is easier to make your own than to try to use one of theirs.

I keep a few in stock, just in case I get the urge to make an engine.


BTW, nice gumbeating session on Skype last night Jim, as I said, it's good to put a face and a voice to a name.


John


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## Blogwitch (Apr 29, 2012)

Just a suggestion Stew to save you having to wait for plate to be delivered, but only if you have a block of something to make it out of.






It would save a lot of work in the long run.


John


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## SBWHART (May 9, 2012)

Bit of an update

Got the new base for the larger fly wheel made and the bearing housing plus one or two other bits, cleaned it all up and got it prepaired for painting but bin held up on this front due to the rain we've had the last couple of days. Taking the base round to men in sheds to have it planed and edged.

With a fair wind i should have it compleat next week.

Stew


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## SBWHART (May 20, 2012)

Well got it all together











I'll show some smatter pics and a vid later, at the moment i've got my Boss breathing down my neck, I've bin a bit obsessed with this engine, and the jobs are building up.

I think it looks great but my boss said its a bit too Tarty for me 

 :big: :big: :big: :big: :big: :big:

Stew


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## steamer (May 20, 2012)

That looks awesome to me Stew!

Great Job...looking forward to the pictures!

dave


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## Jasonb (May 20, 2012)

Thats turned out nicely Stew, I do like the understated black and you have just anbout the right amount of exposed metal so it does not look too blinged up.

Look forward to the video.

J


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## vcutajar (May 20, 2012)

ooooww.

That's very nice Stew. :bow: :bow: :bow:

Vince


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## SBWHART (May 20, 2012)

Thanks Vince/Jason and Dave

I've posted some pics and a vid elsware but her's the vid any way.

[ame]http://youtu.be/kxpAIlInObk[/ame]

Stew


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## vcutajar (May 20, 2012)

It looks even better in the video. Thumbs up also from the wife who also liked the black colour.

Vince


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## steamer (May 20, 2012)

Theres only one way to get them to run that slow build them accurately!
 :bow:

Dave


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## ShedBoy (May 20, 2012)

That is some awesome looking engine Stew. Black goes with anything. Runs nice too.

Brock


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## Maryak (May 20, 2012)

Another masterpiece. :bow: :bow:

Best Regards
Bob


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## Blogwitch (May 21, 2012)

That's turned out very well indeed Stew, and MIS did a very nice job of the wooden base.

Black & brass, my favourite classic combination.

Are you going to bring it round to show me in person? The last time I saw it was when you had just done the cast iron piston.

John


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## Lesmo (May 21, 2012)

That is just beautiful Stew and the brass rail finishes it off nicely, its good to know we have something to thank the weather for. 

Les  :bow: :bow: :bow:


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## d-m (May 24, 2012)

Stew 
Hats off to you, got to be my Favorite of all ! And a vary good wright up to boot I learned a few things THANK YOU 
Dave 
 :bow:


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## SBWHART (May 25, 2012)

Thanks Guys

I've just completed updating the drawings, so if any one wants a copy just send me a PM with you're email adress.

Stew


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## gbritnell (May 25, 2012)

Hi Stew,
This is another engine that matches the high standard off craftsmanship of your other engines. As was mentioned the understated black really sets off the brightwork. Beautiful!
gbritnell


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## fcheslop (May 25, 2012)

Hi Stew
     Stunning work and many thanks for taking the time to post the build
kind regards Frazer


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## Ramon (May 28, 2012)

Hi Stew, I'm late for the party as usual but would just like to add to the already very favourable comments on your latest build. 

A lovely piece of work yet again, you certainly have pushed the boat out with this one. Well described and superbly finished in what seems an amazingly short time, it's a real credit it to you. Stunning paint job to boot too. :bow:

Truly inspirational Thm: Thm:
Regards - Ramon


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## SBWHART (May 29, 2012)

Thanks for your comments and support Chaps.

Stew


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