Monitor Steam Engine

[90LX_Notch]

I'll second Jim's suggestion of an expanding mandrel.  I've made several over the years.  They are straight forward to make and run dead true if you turn the final od of the mandrel after slitting it.

-Bob

[Don1966]

Looks like Zee toke a 'left turn in Albuquerque again'".

You guys lost me about 6 posts ago; but that's not to hard. 

Dave

It happens with these programmers Dave, they were lost 6 posts ago also. It's called a "bug" or "glitch".

Don

[zeeprogrammer]

Sometimes we fall into an infinite loop.
Without a watchdog...we're toast.

[Don1966]

Sometimes we fall into an infinite loop.
Without a watchdog...we're toast.

More like embedded system fault, so corrective action is needed to get you to a stable state .

Don

[Kim]

Zee, your thread takes the cake (or maybe the cookie).  I've missed a couple days in keeping up with the forum and I'm suddenly 5 pages behind.  I read them all and you've bored one hole.  That's a pretty impressive feat!  What a fascinating thread!

Keep up the good work.  I'll be following.

But man, I have to keep up.  This thread moves fast!
Kim

[zeeprogrammer]

I've missed a couple days in keeping up with the forum and I'm suddenly 5 pages behind.  I read them all and you've bored one hole.  That's a pretty impressive feat!

  Yeah, sad isn't it?

Not to worry. Soon we'll return to our regular programming. 

Thanks Kim.

[mklotz]

Zee, your thread takes the cake (or maybe the cookie).  I've missed a couple days in keeping up with the forum and I'm suddenly 5 pages behind.  I read them all and you've bored one hole.

... and a dozen people.

[Alan Haisley]

I have no hysteresis.

I'm surprised.  I think you're absolutely hysterical.  Oh, wait...

He can't -- no hysteresis.

[zeeprogrammer]

Zee, your thread takes the cake (or maybe the cookie).  I've missed a couple days in keeping up with the forum and I'm suddenly 5 pages behind.  I read them all and you've bored one hole.

... and a dozen people.

Ouch!

[zeeprogrammer]

So talking about this 'turning' business and expanding mandrel...

I've attached a drawing of the approach I'm thinking.

As you can see, one cover is held by the chuck, and the cylinder and other cover is pressed by the live center.
Then turn both covers and cylinder as one.

I only intend to take off enough to give a good finish. As I'd mentioned earlier...sandpaper/brillo, etc. won't do it.
Although it shouldn't take much to clean up...it is a few thou.
Light cuts.

Happy to take warnings with this.

One concern I have is getting the one cover true enough for the hole that has to be drilled later. Which will take out that dimple for the live center.
I'm thinking the 4-jaw will come into play. The outside should be good (after the above) to measure true.

[crueby]

Turning it like that should be fine - careful about marring the finish on the cover plate.

When the cover plate was being turned originally, that was the time to drill the piston rod holes since you know it would be concentric to the part you were turning. As Marv probably made you a post-it of, always do max operations on part before removing from the chuck. Going back to center it up again, use the 4-jaw and a dial indicator to true it up, both concentric and the face true to the jaws.

[zeeprogrammer]

careful about marring the finish on the cover plate.
When the cover plate was being turned originally, that was the time to drill the piston rod holes since you know it would be concentric to the part you were turning.

Yes. Most concerned about the cover held by the chuck. Hopefully some sodie-can aluminum will help. That side's not critical so if necessary I can chuck and sand.

I had wondered about drilling first. My concern was only an edge would be in contact with the live center. (Although truth be told...I haven't thought much yet about how to get more contact beyond wondering if using a center drill would give more contact on the live center. But I don't know if it really matters.)

I'm thinking to do the piston rod gland, attach it to the cover, and drill through both at the same time. Sane?

Doing things in batches. Have four covers faced. Have turned one-half of one down. The outside 'hub?' on the cover is the same dimension as the inside hub so was able to use the cylinder to bring to size.

I was pleased to see both ends of the cylinder are very close. Don't know if close enough.

Broke the blade on the horizontal band-saw. Replaced with a better blade. Wow.

[mklotz]

Light cuts.

Happy to take warnings with this.

Do you have enough material for two new cylinders and covers?

Also, how do you propose to "turn both covers and cylinder as one" if one of the covers is held in the chuck?

[zeeprogrammer]

Light cuts.
Happy to take warnings with this.

Do you have enough material for two new cylinders and covers?

Material for one cylinder and one or two covers. 
Would have had two or three covers...but I messed one up.

Also, how do you propose to "turn both covers and cylinder as one" if one of the covers is held in the chuck?

The benefits of drawing this up.  It's apparent I need to machine a thin washer to go between the chuck and the cover. 1/16" should do to give clearance between the tool and chuck. That leaves 3/16 for the chuck to hold onto.

But I must confess...I wouldn't have known this now had you not asked. (But I think I would have seen it when I went to turn.)

Thanks.

[crueby]

Light cuts.

Happy to take warnings with this.

Do you have enough material for two new cylinders and covers?

Also, how do you propose to "turn both covers and cylinder as one" if one of the covers is held in the chuck?

The bottom cover has the smaller diameter section for the gland, so can grab there, with spacer as zee mentioned.