Potty Lads and Dads Engine

[vtsteam]

What a great looking little engine this is going to be! I love the horizontal mill engines. 

[sbwhart]

My offering this morning are just a few of the fiddly bits that need doing.

Drill and tapped the eccentric for a M3 grub screw



As I drew the engine up I relised that there was no provision for setting the valve event, I scratched my head on this one for some time then I had a look through the pic I took of the origonal engine to see how they did it.



So decided it would be best to try and copy this arangement.

This require some 3mm dia cross holes drilled. The parts are made from 6mm dia stainless first off I drill and parted off a thick washer with a 3mm hole, I then used this to locate for the cross holes.





It was just a mater then of turning up the parts.



This is how the orangement looks on the model, that cap screw gets in the way so I'm going to replace it with a grub screw.



I'm keeping my fingers crossed that it hase enough movement to activate the valve.

Stew

[Stilldrillin]

That should give a good range of adjustment Stew!   

You can always mill a couple of flats, to slim the clamp block for extra clearance....... 

David D

[Dan The Man]

HOW QUICK!!!!!  I have made 6 easy bits in the time you have almost finished it! Top Man Stew

[sbwhart]

Cheers Dan

You and your Dad are going to have to get a move on 

I'm waiting on some steel tube to make the fly wheel so decided to get on and finish the bed plate off, I carfully marked the position for the crank bearing and drill them out 2.7mm clearance on M2.5. The bit of ally I made the bed plate from was 3" wide I wanted 2" but that was all I could get so had to cut it down, using a hack saw and a guide plate, so that things didn't wander off.



Then filed the cut off level, noting too fussy just as long as it doesn't offend the eye.



The drill 4 corner holes and filed some fancy rads on the corners.



Assembled the engine back to the bed plate, and fixed a carrier to the crank shaft to try and turn it over, turned over ok, but the valve rod thing fouled, did a bit of adjustment, phew ther's enough clearnace for it travel its full movement, I roughly set the valve and spent 1/2" turning it over by hand it nows turn over nice and free.

Can't wait for that steel to arrive.

Decided to make the base, these sort of engine often stood on stone plyths, so got hold of some chip board, cut two bits off to size and rounded the edge, then cut and filed some nicks along the edge to simulate the stone courses.

This is what it looks like.



I'll give it some licks of paint I'm hoping that it will keep its rough texture to look like stone. I aplied some wood glu and clamp them together, I'll see what they are like tomorrow.

Stew

[sbwhart]

Still waiting on some material to finish this engine off, in the mean time visited our local hobby craft shop and they were having a bit of a clearance and picked this stuff up to have a try at staining the wood chip



Its water based wood stain and some felt tip pens, after a bit of a play I found that the tips were next to usless dried out that is why they were cheep, so instead I had some white emulsion paint that I added some of the wood stain to and added that with a thin paint brush to show up the cement bonding, I aint no Rembrant when it comes too paint. I then sealed it off with the PVA watered down a bit.

I don't think it looks too bad.



Now where is that post man

Stew

[vtsteam]

Where do you get bricks that small? What type of mortar did you use? Did you use a tiny string level? And how do you get a running bond to come out even on the end like that?

Excellent job! 

ps. a little muriatic acid on that mortar will clean it up nicely.

[sbwhart]

Cheers 

Well the posti dropped off the material for the fly wheel. 

So first job was to cut off a 1" slice from the tube its 100 od with a 4mm wall.



Then face to length 3/4"



Skim up the OD



Then clock up the OD in independent four jaw chuck because the tube is relatively thin and it distorts some what with the internal stresses it a bit like trying to clock up a bit of jelly, just get it as good as you can as long as it doesn't offend the eye.

And skim up the bore.



And turn a step for the hub to but up against.

Next up the hub this is made from a chuck of 1/4 ms plate 100mm square. first mark up the centre and draw a circle 100mm dia and trim off the corners with a hack saw.



The drill and 1/2" hole in the middle



And mount it on an 1/2" mandrell and turn up the OD for a nice push fit into the rim.



On the original Bolton museum engine the fly wheel doesn't have spokes just 4 holes I don't know if this is the original fly wheel or one the Bolton lads have knocked up. So drill 4*22mm dia hole in it.



Turn up the inner hub a nice tight fit it the outer bit.



And stick the lot together with high strength Loctite.



Its doing its curing thing now until tomorrow when I will finish it off, I have a few domestic duties to do this afternoon. 

Stew
 

[Stilldrillin]

Looking very good from here Stew! 

Hope your "homework" goes as well....... 

David D

[Bangkok Mick]

Looking great, learning a lot from this thread.

Cheers Mick

[vtsteam]

Love the flywheel method!

[sbwhart]

Thanks Chaps

This mornings task to complete the flywheel, just griped it in the three jaw to see how it was running, and it looked good so drilled and reamed 6mm for the crank shaft.



Then spent the next couple of hours striping down and adding studs and sealer where required and chasing out tight spots then I wen and lost one of the main bearing searched every ware, brushed the floor, I gone though the cussing stage into despair, so went and asked the Boss to help me do a CSI search of the shed, "what are we looking for" "one of those", I said pointing to the remaining bearing, " so there should be three she said", "No", I said a little tetchy, " there's two" "well she said there's two there pointing"

Can you spot the missing bearing



 

I can play a mean pin ball

 

So with that mystery solved a roughly set the timing, and with not much hope gave it some air.

 

Stew

[doubleboost]

Very nice
Makes good sounds
John

[Stilldrillin]

That runs very well Stew! 

Relative simplicity, and a good finished size....... 

Blummin well done! 

David D

[sbwhart]

Thanks all for your replies and support Chaps its very kind of you.

I must say its been a fun build.

I'll take her along to the Harrogate show this coming Saturday so if you a re there you can eye ball her.

Spent sum time fine tuning her, tightening and loosening nuts to see what happens as a result I've packed one of the bearing up a little, they weren't quite level, and I've also packed the cylinder up a little, I recon it wasn't quite lining up with the slide bars.

I'm going to have another fiddled with her today (the engine that is ) I still think there are few improvements to make to her running.

Then its time for a bit bling, acorn nuts on the top of the slide bars, I think I'll increase the size of the hold down bolts on the bed plate to M4 and add some bolt down pads so it looks a bit more like a casting, then its a strip down and a bit of paint:- apple green fro the engine and red for the fly wheel and I'm going to had some wooden cladding to the cylinder, and finally a nice hardwood base, and that should be just about job Done.

Ho and a nearly forgot, bring the drawing up to date and write it up for the Model Engineer.

Stew

[vtsteam]

Looks and sounds great! I make it out to be running 545 RPM in the video. 

[sbwhart]

Thanks vtsteam

I've been running it know for about 4 hrs chased a few tight spots out of it and reset the valves a few time so that it will run forward and reverse its getting nicely bedded, had the tacho on it and at full pressure 50psi it licks along at 1500rpm and it will throttle down to about 15psi at 400 rpm.

Stew

[garym]

Thanks for this excellent thread Stew. I'm building a Stuart S50 as my second project and threads like this are very educational. I'd like to have seen it at Harrogate but I'm going on Friday. 

Gary

[GordonL]

Looks good. I do not understand why the special valve rod arrangement. Wouldn't the threads on the two clevises as shown on the original design have allowed valve adjustment?

[sbwhart]

Looks good. I do not understand why the special valve rod arrangement. Wouldn't the threads on the two clevises as shown on the original design have allowed valve adjustment?

Hi Gordon

Yes there would have been adjustment on the clevises, that was the plan, but the more I thought about it the less I liked the idea, it would have been limited and awkward to use, and not as easy to make as what I ended up with.

I also found this info on the engine that I saw at Bolton

extract from NMES http://www.nmes.org/

When a steam engine with large cylinders became worn, so that the piston no longer fitted properly, it was common to re-bore the cylinders, making them a fraction of an inch larger. However, since the casting often weighed many tons and removal to a workshop would have taken too long and been too expensive, the work was frequently carried out on site. This small engine would have been used to provide power to the re-boring equipment which was clamped to the cylinder being re-machined.

The slide valve is driven by an eccentric on the crankshaft that can easily be moved to another position to alter the timing so that the engine can run in either direction.
End


So apparently this valve arrangement had practical uses.

Thanks for you interest

Stew

[GordonL]

Thanks Stew. That makes sense. Actually by putting a collar/stop/mark  on either extreme it would actually be easy to reverse the engine and set it back to the other direction.

Actually I started to build this engine as kind of a fill in project and was just at the point of making the valve actuator rods. I think that I will probably use your method.

[saw]

Nice work, thanks for showing us 

[sbwhart]

Thanks for your replies chaps.

I've been busy revising the drawings, if any one wants a copy of the revised drawing just drop me a PM with your email address and I'll send them.

Stew

[ozzie46]

Great job on the engine as always.

PM sent

Ron

[Joules]

What a great little build series.  Another PM on its way...