Potty Popcorn Engine

[SBWHART]

Thanks George/Dan/Brian/Bob

Brian

I think Marv would point out that you have turned "Ogives". I never heard that term before, but on one thread last year somebody was turning egg shaped balls with pointy ends, and thats what Marv said they were.

Good eye site that man, they are 12.3 dia about 1mm undersize from being a true ball, I needed to bring the tool forward a touch to make them a ball at 1/2".

But hey they are close enough to do the job :big:

Bob

Do you know where the rest of the monkey is

Probably holding up the rest of the balls,

"Cold enough to freeze the balls off a brass monkey" is an old navy expression, a brass monkey was a square of brass they used to stack the cannon balls on in a pyramid, when it got gold it contracted and the balls fell off, hence the expression.

Thanks for the interest guys,

I've bin busily drawing up the governor and things, I'll post the drawing when I've got it done.

Stew

 

[Lesmo]

Those are an almost perfect set of goolies Stew and I like your lateral thinking in their production. 10/10

Les :big:

 

[mklotz]

"Cold enough to freeze the balls off a brass monkey" is an old navy expression, a brass monkey was a square of brass they used to stack the cannon balls on in a pyramid, when it got gold it contracted and the balls fell off, hence the expression.

Balderdash...

http://www.snopes.com/language/stories/brass.asp

 

[SBWHART]

Ho well thats another ball story dashed to peices, but I like the story ;D

Stew

 

[SBWHART]

Things slowed down on this over the last week what with visiting our son up in Glasgow, and i wasn't too happy how it was running far to sluggish, so I've spent a few days tinkering with it, the engine that is. Slowly chased the stickiness out of it, final part was to make a new front cover, for some reason or other it was nipping the piston rod and slowing things up, so made a new one making sure, everything was correct, that did the trick its running great now.

Also spent a bit of time drawing up the governor

Your probably thinking how the hell is he going to make that, well I've no bloody idea also ???

;D

But you don't know what you can do until you try.

First part the swiveling bit.

Rough out a chunk of brass bar.

Then form the domes, things were a bit tight so I had to finish off the back dome with a file and Mk 1 eye ball.

Looks ok

Tomorrow I'll start to mill it out.

Stew

 

[bearcar1]

Well done Stew, I thought that ball turning tool would come into play here, BRAVO! A bit of silver solder here and there and I can see a governor that would be the envy of the Cretor's Co. ;D

BC1
Jim

 

[SBWHART]

Thanks Jim


Good mornings work in the shed, finishing off

Keeping the job in the chuck transfer over to the spin-indexer and fly cut the flats.

Then find the centre of things and zero the DRO.

Drill

Then off set and drill the 1mm holes fly the fly ball arms.

Turn it through 90 and mill the 2mm slots for the fly ball arms with a slot drill.

For those of you who don't know what a spin-indexer is here's a pic of the set up.

Then still keeping the job in the chuck put it back in the lathe and finish off the diameters so that everything is nice and concentric just in case anything moved under the mill.

OK again keeping it in the chuck back onto the spin-indexer and mill the 3mm dia groove for the drive belt I just turned the indexer by hand to cut the groove.

Back onto the lathe to part off.

The reason I left the big bit sticking out at the front is to give me something to chuck onto to finish the back end.

So holding onto the chucking piece, clock up true.

Drill through for the spindle then open out to 12mm with a boring bar for the bearing.

Then protecting the finished dia, turn it round in the chuck and skim the chucking piece down and dome the end.

Job done, needs a bit of tidying up with a file and the shape is a bit off but it will do the job fine.

Need to buy a new tank of propane for the next bit.

Stew

 

[Captain Jerry]

Stew

This is the part that I have been anticipating. A thing of beauty and a joy to behold.

Jerry

 

[peatoluser]

Now thats a well thought out machining sequence.
I think we can all learn something from the way you approached the job.
really enjoying the build thread

peter

 

[Path]

Stew ...

Thanks for the sharing.

Love the way you transfer from the lathe to the mill and back ... great stuff. :bow: :bow:

Will be watching for other neat things.

Pat

 

[SBWHART]

Thanks for your kind comments Guys

Love the way you transfer from the lathe to the mill and back ... great stuff. :bow: :bow:

Pat

Pat:- Swapping things over like that is a little trick John Bogstandard showed me, its all about having a system of tooling, with the Chinese cheep chuck mounting, its quite easy to make adaptor plates so you can swap the chuck or ER collets for that matter from lathe to spin-indexer- to rotary table and back again, it saves a lot of clocking and if you make the adaptors accuratly you keep consistency spot on.

Johns based his sytem on the Myford Chuck mount.

Stew

 

[SBWHART]

Got on with the fixed part of the governor, this is the bit that has the packing gland in the real job its sit in the little loop so you can replace the packing without having to strip everything down, well thats what I think it does, I'm going to cheat with this as I cant think of a way to get in and tap the hole and at the same time screw it onto the steam chest, so I'll just fiddle it and make it look like the real thing.

Fist job rough it out.

Then with the ball turner form the rads it was a bit awkward get the back rad done because of hitting the chuck, so I had to eye ball some of it.

Looks ok

I scratched my head on how to do the next bit, doing the out rigger for the belt jockey wheel. In the end I just filed a lump of brass to match the radius and screwed it to the body with a 6ba brass screw.

Then silver soldered it.

I left plenty of meat on so it was over to the indexer for milling.

And locating and drilling the holes.

So this is how it came off the mill

Then I turned up a filing button and using this as a guide whittle the unwanted stuff off.

Then back onto the lathe and parted it off the bar.

Then it was a matter of using the chucking pieces to finish off each end.

Time for a hows it looking shot

Not bad

Stew

 

[maverick]

Just like icing on the cake. Wonderful job. Looking forward to the rest like a kid waiting for christmas.

Regards,
Mike

 

[JorgensenSteam]

That is impressive work Stew.
Thanks for posting.

Pat J

 

[ozzie46]

Well done Stew. I learn more every time I look in. Thanks :bow: :bow: :bow:

Ron

 

[Captain Jerry]

How's it looking? Looks great from here! But I suspect that you are holding something back. Where is the air line?

Here is a suggestion for the gland, if you don't mind. Instead of the threaded spigot that you have at the bottom, use a nipple that threads up from the bottom, and rises a few threads proud of the oval opening. You can then use an external, cap type gland nut. The lower end of the nipple will then screw down on the top of the chest or whatever you have planned to fit between the chest and the governor.

Jerry

 

[Path]

Stew ...

Another winner!

How did you silver solder on that chunk of brass ... that's impressive.

Thanks for sharing.


Pat

 

[SBWHART]

Thanks for your comments and suggestions Chaps.

How did you silver solder on that chunk of brass ... that's impressive

Pat

As well as fitting the chunk to the rad, I filed a flat down the screw to allow the solder to wick in, applied some "tenacity flux" before screwing it together.

I just stood it on the hearth like this

The chunk of brass wasn't going anywhere the screw kept it in place.

Then I just heated it up with a propane torch, you have to look out for temperature clues:- the flux goes a powdery white then black and then sort of glassy when you see that your getting close, then I just touched on with the easy flo solder, both sides and watched the solder melt in and stopped feeding it in when I though there was enough, let it cool to black and quenched it in water, I didn't bother with an acid pickle as I was going to machine so much of it away.

After machining you can see a faint 1/16" arc of soldered joint.

Cheers

Stew

 

[tel]

Not that it makes any difference to the finished product (which is excellent, btw) but wouldn't it have been easier to mill a slot in the side of the 'ball' to accept the block?

 

[SBWHART]

Thanks for your input Tel.

I did contemplate that but as the block would be milled down to 6mm wide the same as the ball it would mean that their would only be a little bit of solder keeping it in place at the ends, which may have been enough, but I went to the Forth Rail Bridge school of over engineering, so went for the extra security.

The rail bridge is standing firm after 100+ years and good for another couple of 100

The road bridge is falling down after 50 years

:big:

Stew