"A Beginners Engine" From Model Engineer.

[ParCan]

 

We after the first engine attempt last year (Puddleduck)  I have some workshop time again.

Model Engineer have just started a "Beginners Engine" series.
As with most things, I'm impatient and have started to get some of the bits underway (With minimal dimentions)

It requires a 4" flywheel. I put an inch thick round slab in my 3 Jaw and it was .2 mm or so out.
Out came the 4 jaw and the centre of one side is well under way to being hollowed out. (More Details in the Tools Thread)

Last week a couple of sheets of Perspex arrived. I decided they would be good to make the Base.
8 bits, 9 1/2"X 2 1/2" were cut and superglued together to make it 1" thick.
I have trimmed it down to the correct(ish) size on the mill.

This looks like it'll be a fun engine and maybe i'll stand a chance of getting it to work...

[sbwhart]

We after the first engine attempt last year (Puddleduck)  I have some workshop time again.

Model Engineer have just started a "Beginners Engine" series.
As with most things, I'm impatient and have started to get some of the bits underway (With minimal dimentions)

This looks like it'll be a fun engine and maybe i'll stand a chance of getting it to work...

I think I'm guilty for you getting 

You can find my build log her http://madmodder.net/index.php/topic,8438.0.html

Pleased you're having a go, hope you enjoy the build.

Stew

[NickG]

Hi there, i'll be watching as i am also building Stew's engine. It has stalled lately but hope to get back to
It tomorrow night.

[ParCan]

Stu: 100% guilty.

I'll have a read of your log over the coming days

Alex.

[Stilldrillin]

I've seen Stew's original. It's much larger than I imagined, from his postings. 

A nice engine! 

David D

[ParCan]

I now have the Drawings from Stew. Thank you

I have been looking at the Cylinder and valve.

Forgive me, but where does the exhaust go ?

[ParCan]

ok - ok I see.
2 X 4mm holes shown 20mm apart under the valve chest.

 

[NickG]

I asked Stew the same question a couple of months ago! Don't know how I missed it.

 I do have another question for Stew though - how do you go about setting the valve timing when you cant see the valve and ports? Measure depth to back valve face through hole?

[sbwhart]

I asked Stew the same question a couple of months ago! Don't know how I missed it.

 I do have another question for Stew though - how do you go about setting the valve timing when you cant see the valve and ports? Measure depth to back valve face through hole?

I did it by looking through the single inlet port, when the crank at the 12:00 oclock position you adjust the eccentric so the valve is not quite covering half the hole. second drawing from the top of the valve events on attached drawing shows this.

Hope this helps

Stew

[NickG]

Thanks Stew, way off yet but good to know.

[ParCan]

Ok: Both sides of the Flywheel are made.
Centre is reamed to 8mm and fits like a glove on my Stainless steel shafts.

Just need to chuck it up again to skim the outside edge.
I do however have concerns gripping a 9mm deep shoulder / 20 mm dia (I still have a mm to remove if need be) and turning the edge off something 100mm dia.

Are my concerns unfounded ?

Suggestions welcome as always.

Then it's off to the Mill and rotary Table to make nice holes in it.
Never used the table (Bootfair find) It's the same size as the fly wheel (100mm) so clamping clues welcome.

[sbwhart]

I do however have concerns gripping a 9mm deep shoulder / 20 mm dia (I still have a mm to remove if need be) and turning the edge off something 100mm dia.


That's how I do it, should be fine, just don't run the lathe fast or it will chase you round the shed if it comes off  and take small cuts.

Stew

[ParCan]

Hi Guys.

Flywheel is now complete.
It's on centre, and looks like it's going to be ok.

Started on the Cylinder yesterday, I'm making it from Cast Iron (Sash Weight) cos I have some of a suitable size.

You know it's getting hot (Drilling it to 12mm) when your squirt of coolant boils as it touches the work !

I'll complete the bore today.

My Boring tool is rather small but it seems to cut the Iron nicely.

[NickG]

Cast iron will be good, i am using cast gunmetal for mine as have a bit the right size. Is your drill blunt or were you running it too fast? Slow cutting speed for cast iron and it doesn't usually get hot in my experience.

[ParCan]

Hi.
Apologies for the Picture size in my last post....

The drill was brand new when I started. It's now somewhat 'used'
Cutting speeds were slow (slowest on an ML7 without the back gear) and I believe appropriate.

Cylinder is bored to 16mm (tight fit on a 16mm Milling tool shank)
Made a Hone out of some Plastic, Probably Nylon, 50mm long X 16mm dia to make it a sliding fit. Tapped one end blind M8.
Starting with Course grinding paste, then fine, I ran the bore up an down the hone for around 10 mins.
Clean down with White Spirit between each paste.

A Quick final with Solvo Autosol (Very Fine) I now have a smooth bore with a fine crisscross of light scratches.

Now it's time for a thorough clean down of the lathe. (to get rid of both the Cast Iron and the Grinding paste)

[NickG]

Looks good.

[ParCan]

I now have a flywheel with 6 decorative holes in it.

Rotary Table is, er , well - um: not good
Put a Centre into the Mill (had to take the Draw Bar out)
Centred the table and bolted it down.
Checked the runout on the edge - looks good to me.....
Dropped the same centre into the flywheel.
Bolted the flywheel through the centre hole, Checked the runout - 3rd time I got lucky !

Then you encounter the lash. About 1/4 turn of the handle each way.

Centre drilled 6 places (60 deg apart), then 5mm and 13mm drill. (The largest I have)
That all went well.

The only thing I have 16mm is an end mill. That would have to make said 16mm holes.
The lash coupled with a VERY poor clamp screw has confirmed which side is the outside !

Anyway, 6 X 16mm holes in the flywheel sorta 60 deg apart....

[sbwhart]

Fly wheel and cylinder looks good 

I drilled with four 22mm holes but it made my old drill sweat a bit, so drew it up with 6*16mm ish holes near enough is good enough for position I just marked mine out and went for it 

I know of three engines being made out there 

Stew

[NickG]

Yeah nobody will be able to tell. I always mess them up the lightening holes!

[ParCan]

Hi Stew

You have probably gathered that I'm not an experienced Engineer !
Finding Documented projects out there is always hard. The ME Article got me interested in this one, then your write up on here gave me the missing bits I need to get going.

The Puddleduck I built was in reality beyond my ability. It was and was supposed to be a challenge. I knew that the chances of it working were slim.
Saying that, John's Docs were easy to follow and gave me enough info to really learn how to do this stuff.

Your Engine looks like I can both build it and it will work at the end of it all.

Looking at your Youtube Ch I'm in awe of the stuff you have built. I looked at the Dake Engine but decided that would be beyond my ability. The Simpson engine is a work of art.
 
Oh - and where do I get a Wobbler Bar (used to center the Piston Valve ). Does it have another name ?

[sbwhart]

Oh - and where do I get a Wobbler Bar (used to center the Piston Valve ). Does it have another name ?

Hi Alex

I'm not sure if it has another name I think its one of those things that people sort of call it different things I've just always known it as a wobble bar.

Where you get them from:-

You can make one all you need is a length of 10mm ish diameter silver steel clock it up in the lathe so that its running as true as you can get it, you may get away with the three jaw if its a good un, if not use the independent four jaw, then put a female centre in the end with a centre drill, swap it round and clock the other end true then slew the compound over 30 deg and turn a cone on the end, you can use it as it is or you can harden the pointed end by heating it up to cherry and quenching.

Or:- you can use a solid morse taperd centre, check that it has a female centre in the end.

Her's a picture.



Hope this helps

Stew

[ParCan]

More progress today.

Valve and Piston made. Body was easy enough, piston not so. Got it on the 3rd attempt.

Then I decided it was time for Small holes in Cast Iron time.
Centre punch did sweet nothing so I used a centre drill in the mill to mark each hole before drilling.
Drilled the Ports and used a small milling cutter for the Bore cutout.
Drilled the holes for the Valve. They both wondered a little so opened em out to 4mm.
The 8 X 1.6 mm holes were not fun, neither was the Tapping of said holes.
Just to note, I didn't have a suitable clamp, I Super Glued the Body to the Cylinder then spotted through with 2 mm and drilled 1.6 before removing the valve body and tapping the holes.
I'll leave you to guess where the rest of that tap is !

Piston rod is also done. I may do the piston later.

[ParCan]

And more progress.

Brass Piston is made and attached to the piston rod. I turned the last bit with the piston mounted on the rod.
Lump of 35mm dia Brass arrived today so made the end caps. Still need to drill them for the mounting holes.
Piston almost runs freely in the bore. I'll knock a tiny bit off the locating 16mm dia.

I'm trying to work out the lesser of the evils for fixing the end caps.
I either drill 3mm all the way through the Cast Iron and mount the caps with studs.
OR I can drill and Tap M3 as per the drawings.
This lump of iron is darn hard in places.....  Comments and ideas welcome.

[NickG]

Alex, good progress there. Would be bit unorthodox drilling right through the cylinder but can see your point if you had a long enough drill and 3mm studding - Could get away with drilling only 4 holes rather than 8 and tapping 8 threads. Or if you could do with both covers clamped in place that's another 8 holes you don't have to drill!

[ParCan]

After another day in the workshop, the assembled list now includes.

1 X Cylinder : Complete
2 X Cylinder end caps : Complete
1 X Piston Valve : Complete
4 X crosshead rails : Complete
I need to do cleaning and filing bits to make thing look nice.
A blow in the requisite hole moved the piston appropriately.

I decided to Drill & Tap the cylinder holes as per the standard method.
8 holes tapped with no breakage though some are rather shallow. I can't get 10mm long screws in at the moment.
I have nice screws for the final build but it's all gone together.

I Super Glued the End caps to the Cylinder and used the Mill to position the holes.
(8.5mm each way from centre seemed to be close enough to work)
I then centre drilled the end cap, Drilled 2.5mm for M3 then knocked the end cap off.
Turn it over and repeat for the other side.
I then drilled the end caps 1/8 " (3.2 mm) on the pillar drill.

I'm rather pleased with the outcome so far.

(edit) Um - I have just seen a problem in the photo's.
1 Brownie point to anyone else who can spot the mistake......