First mini lathe project, oscillating steam engine.

[DaveH]

Ross,

Perfect 

 
DaveH

[doubleboost]

Looking good
Ross
It wont be long before it is a runner
John

[Divided he ad]

Very interesting reading through this Ross.

It's easy to forget the amount of things that just "don't go right"  when you first get your machine/s. 

We've all had and still often do have those arrrggg! moments where it takes a great deal of self control not to throw your work at the nearest wall!   

Glad you persevered and obtained the good results 


Looking forward to the "it's running" post.... but not as much as you are eh?   



On the taps and die front.... Are you using split dies or die nuts? Makes quite a difference.

Just to add my 2p worth.... I always undersize a part to be threaded "male" and oversize a part to be threaded female.

It depends on thread dia and pitch as to just how much it really makes a difference. My torches M12x1.5 are quite forgiving. model size stuff I make using M2 threads are not! Time and experiences (stressful as they are) will let you know where the detail is required 




Ralph.

[Ross]

On the taps and die front.... Are you using split dies or die nuts? Makes quite a difference.

Just to add my 2p worth.... I always undersize a part to be threaded "male" and oversize a part to be threaded female.

It depends on thread dia and pitch as to just how much it really makes a difference. My torches M12x1.5 are quite forgiving. model size stuff I make using M2 threads are not! Time and experiences (stressful as they are) will let you know where the detail is required 

Ralph.

Hi Ralph,

Ive got a mixture of split and nut type dies, the smaller ones are split type.

I'm getting there with the threading I think, it's all trial and error.

[Ross]

Hi everyone. 

Today I put the final pieces together for this engine, 

I marked out the holes on the base and the engine post. 





I then drilled and tapped the holes in the post to M6 I drilled the hole for the crankshaft too. 



And drilled the holes in the base with sunk holes for the bolt heads. 





Next I assembled the base and post. 





And finally I assembled the other bits and bobs. Just the flywheel ad pipe work to do now!





I tried machining the recess on the flywheel with no luck. The tool rubs alot has anyone got any further tips on this? 

[Divided he ad]

Hi Ross,

Glad you're getting the threading under your belt. It'll still bite you now and again... Well it does me!


Looking good on the engine front.

Flywheels are notoriously annoying to cut out/ trepan or what have you...

You might find it easier to build one from 2/3 parts?

I'll pen a C-o-C for you to help explain 




Does this make sense?

You make a displacer disk (bottom bit) and then the 3 parts of the flywheel are assembled with a smear of loctite (the .9 measurements are to show a smaller fit... Might need to be nearer .6 to allow for easy assembly?)

Anywho, loctite the outer edge of the disc and the hub. install onto the displacer disc and lower the outer ring over and make sure it's all flat (I'd assemble on the surface plate.... There should not be enough loctite to drip down. And it can be wiped up easy enough)

Leave over night and then it should have bonded well enough to be able to drill the centre hole (using soft jaws if you have them? for greater acuracy. )

You could make it in 2 parts but the hub is easier to make and bond I'm thinking!

As long as the bits are a sliding fit and you have a reasonable strength loctite it's a relatively easy way to make a flywheel 

Hmmm... Thinking about it you could even machine a  micro step in the ring (at 6.5mm in this drawing and it's sizes)  and centre so the parts sit to a shoulder?
Cat skinning and all that!


Hope that helps? I'm sure someone will go into the trepanning side of things?


If you need any further things to be drawn out, over complificated and long windyfied just ask     







Ralph.

[Ross]

Hi everyone,

I ground up the tool today an made a start on the recess in the flywheel. 

This is how far I got; I'll finish it tomorrow.  



one thing I need a bit of advice on I'd the best way to secure the flywheel to the crankshaft. 

The drawing says it should be a screw fit. I've got a crankshaft with an m6 thread on the end I can use. Or should I use. Grubscrew to  Secure it instead?

[Dean W]

Flywheel is looking good, Ross.  : )
As for the threads on the crankshaft, if you were to thread the flywheel for the same thread, then screw it onto the
crankshaft, you can get a pretty noticeable wobble due to the clearance in the threads, and when it bottoms out on
the unthreaded part of the crank, it will often cause it to seat cockeyed on the shaft.

If you make a plain hole in the center of the flywheel that is the same diameter as the crankshaft, you can push it on
with a little Loctite and it will hold quite well.  A set screw is fine, too.  Either way, you need a close fit between the
crankshaft and flywheel to avoid the wobblies.   A wobbly flywheel is quite noticeable, so it's something to work at in
keeping it straight.

Best of luck.  You look to be getting close to the first run!   

[Stilldrillin]

Ross.
A plain shaft, with a close fitting flywheel bore. 

I hate to see wobabbly flywheels............. 

David D

[Ross]

Ok that's a a better idea.... Off to the shed now thanks!

[Ross]

Today I finished up the flywheel, and drilled it 6mm. 




It took a bit of fretting to get it onto the crank, once it was on there I glued it In place. And left it for a while. 

Then I assembled everything and gave it a polish;








We should have a runner next weekend I think! Just the pipe work to do now. 

[Stilldrillin]

That looks terrific Ross! 

Blummin well done! 

Looking forward to the all action video...... 

David D

[DaveH]

Ross,

Very smart indeed,  very nice
Turned out really great - well done 
 
DaveH

[doubleboost]

Ross,

Coming along very niecly
Looking forward to some video of it running
John

[Ross]

Just an update guys,

I rigged her up to one if my steam engine boilers,

And she is having a bit of trouble turning over, it seems there is a tight spot near bottom dead centre, I've cleaned the piston and cylinder and I've had no luck.

Ideally I'd want to rig it up to a compressor an run it in but I don't have one, it's on the 'to get' list.

I'm off on holiday next Monday and I start a new job straight after, so I'm wondering if any of you guys have any advice you could give me to get her going?


Thanks

[Stilldrillin]

Is there a garage nearby, with air for tyres Ross? 

Or, borrow Dad's spare tyre.
Take the hose and valve connector from his old footpump, and adapt as an air reservoir.......

Doesn't Dad have one of those electric, tyre/ airbed inflators?

Handy things, Dads. Often! 

Good luck, with engine, holiday, and job, Mate........ 

Defor.

[NickG]

Ross,

Out of interest, have you tried connecting the steam to the other port and running in the opposite direction? It may be better one way than the other and because you've made 2 air connectors you have that luxury!

Also, your ports looks slightly different heights, you may need to elongate the port hole on the cylinder slightly up and/or down so they line up properly with the holes in the stand.

I've just skimmed back through your posts and a have a couple more questions - have you lapped the port faces of both cylinder and stand? If not, it's definitely worth doing.

Why did you only drill the air adaptors 2mm when the port dia. in the cylinder is 1/8" - more than 3mm? This will be restrictive as well as potentially causing a timing issue - don't think it will do the latter in this case but it's certainly better to have them matched.

Hope this helps.

Nick

[mzt]

one thing I need a bit of advice on I'd the best way to secure the flywheel to the crankshaft.

I see I'm coming late to this, anyway this is an idea I like a lot:

http://www.homemodelenginemachinist.com/index.php?topic=11471.msg125602#msg125602

It's easier to make when shafts are bigger, but worked also on the 6mm shaft of my #29.

Marcello

[Ross]

Ross,

Out of interest, have you tried connecting the steam to the other port and running in the opposite direction? It may be better one way than the other and because you've made 2 air connectors you have that luxury!

Also, your ports looks slightly different heights, you may need to elongate the port hole on the cylinder slightly up and/or down so they line up properly with the holes in the stand.

I've just skimmed back through your posts and a have a couple more questions - have you lapped the port faces of both cylinder and stand? If not, it's definitely worth doing.

Why did you only drill the air adaptors 2mm when the port dia. in the cylinder is 1/8" - more than 3mm? This will be restrictive as well as potentially causing a timing issue - don't think it will do the latter in this case but it's certainly better to have them matched.

Hope this helps.

Nick

Hi Nick,

I haven't tried switching the ports, Something I'll try soon. 

The ports being a different height Is a mistake I made, one of the ports is drilled diagonalu as I didn't endure the workpiece was flat in the vice.  Where the hole meets the cylinder it lines up fine. If that makes sense.

I have not lapped the faces, something to try it is pretty free running part from the tight spot.

And that point s something I never thought of at the time, the port holes on the stad were drilled to 2mm as that was the I/D of the 1/8 pipe. Something to think about next time.

[Ross]

Also, just an update to those wondering. I've made an air raptor to fit onto the regulator and tried it with one of those electric car tyre pumps, it just hasn't got the lungs to sustain the pressure.

Can anyone recommend a mediumly priced small tanked compressor? I've been meaning to get one for ages and now seems the time.

[philf]

Also, just an update to those wondering. I've made an air raptor to fit onto the regulator and tried it with one of those electric car tyre pumps, it just hasn't got the lungs to sustain the pressure.

Can anyone recommend a mediumly priced small tanked compressor? I've been meaning to get one for ages and now seems the time.

Hi Ross,

I have a small tankless compressor which is free for the asking if you're ever in the Stockport area.

 

Phil.

[Ross]

Also, just an update to those wondering. I've made an air raptor to fit onto the regulator and tried it with one of those electric car tyre pumps, it just hasn't got the lungs to sustain the pressure.

Can anyone recommend a mediumly priced small tanked compressor? I've been meaning to get one for ages and now seems the time.

Hi Ross,

I have a small tankless compressor which is free for the asking if you're ever in the Stockport area.

 

Phil.

Thanks for the offer Phil, but I can't think I'll be in the area any time soon, but I'll keep you in mind if I know anyone that is going out that way.

[andyf]

Phil, if you can't find a use or a more deserving home for it, I'd appreciate the compressor until such time as Ross finds someone who is coming up to our area and can act as courier for him.

Andy, in Sale.

[philf]

Phil, if you can't find a use or a more deserving home for it, I'd appreciate the compressor until such time as Ross finds someone who is coming up to our area and can act as courier for him.

Andy, in Sale.

Andy,

PM sent.

Cheers.

Phil.

[Ross]

Will this do guys?

http://www.ebay.co.uk/itm/170870089449?_trksid=p5197.c0.m619#ht_1796wt_689