Monitor Steam Engine

[zeeprogrammer]

4 days to bore a 1" hole. 1/4" a day. 0.0104" per hour. 

It may be too early to say...but I'm thinking I'm happy.
A little oversize. 1.008 but both ends seem to measure the same.
I took the last pass at what I thought would be pretty slow and the cut was better.
The bore feels smooth. It still looks a bit choppy but hard to tell.
I may hone but that decision is later.
I don't believe I'll ever run this on steam so I expect it's a bit more forgiving.



It's going to be fun figuring out how to turn the outside.
I'm thinking of making two plugs. One plug in the chuck. The other plug pressed up by a live center. Small cuts.
Make the plugs sort of like a piston...that is, turn until the cylinder fits.
(If plugs is the right term.)

Feeling okay about this. Time to stop tonight.
Not time to stop thinking though.

There's a few jokers 'friends' on this forum I need to pay some attention to. 

Thanks all. You've all been very helpful.
It ain't done yet though! So neither is your job. 

[crueby]

Nice!   

Hope the second one goes easier than the first one.

For the plugs to turn the outside - if they have a slight taper, you can use the tailstock to put some pressure on, and basically you are turning between centers. Or drill/tap the holes for the end caps, and use a bolt in the head end for a driving point. Just take light cuts so you are not putting a lot of pressure on it. Assume you are turning the outside down since the cylinder stock was oversized to what the plan calls for? If so, on next engine turn that down first on longer stock, one end in chuck, other on live center, then cut the cylinder blanks from that piece.

Looking good!   

[zeeprogrammer]

For the plugs to turn the outside - if they have a slight taper, you can use the tailstock to put some pressure on, and basically you are turning between centers. Or drill/tap the holes for the end caps, and use a bolt in the head end for a driving point. Just take light cuts so you are not putting a lot of pressure on it. Assume you are turning the outside down since the cylinder stock was oversized to what the plan calls for? If so, on next engine turn that down first on longer stock, one end in chuck, other on live center, then cut the cylinder blanks from that piece.

Thanks friend. Yeah that's the idea. Use the tailstock to put pressure on.

Hm. The plans call for 2.25 diameter. I bought stock at 2.25 (but is slight smaller). So after turning it will be smaller still.
I have to be careful but the idea is to adjust height (the flat on the bottom of the cylinder) so I still meet the plan's dimension of where the center line is.
Same idea for the flat where the steam chest goes.

I had wondered about turning the outside first. Wasn't sure how I would cut the blank off without ruining the turning. Since then though I've seen some ideas of how to use the bandsaw.

[crueby]

Lost me on that, if the stock is already a little smaller than the plan calls for, why do you need to turn it down more? The bore is centered, the flats come in from the side. What is thete to turn?

[mklotz]

If so, on next engine turn that down first on longer stock, one end in chuck, other on live center, then cut the cylinder blanks from that piece.

Perhaps Zee could convert this excellent advice into a mantra for entry into his shop notebook.  Something like...

NEVER REMOVE A PART FROM ITS PARENT STOCK UNTIL ABSOLUTELY NECESSARY.

Hmm, where have I heard that before?

[Jim Nic]

Zee
Presumably you have 2 cylinders to machine so you could hold fire on the first until you are ready with the second and then make an expanding mandrel (I would think it would be as quick as making two tapered plugs).  Do both cylinders without removing the mandrel from your chuck and you ensure concentricity.   
Jim

[crueby]

Zee - back on the A2Z toolpost moving issue - a friend of mine had a simaler problem on his, saw what I had done, and did a variant on it - just did a single arc rather than the 4 that I did, is working very well for him. Below is a picture of his.

[zeeprogrammer]

Lost me on that, if the stock is already a little smaller than the plan calls for, why do you need to turn it down more? The bore is centered, the flats come in from the side. What is thete to turn?

The outside of the cylinder is unfinished. I just want to turn it a tad to clean it up. Whether I did it first or not...the result is the same.
Right or wrong...I thought doing it this way (using the bore to center) would improve my chance of keeping the outside parallel to the inside.

I was about to start boring the 2nd cylinder but it occurs to me by making the plugs for turning the 1st cylinder, I can use the plugs to help bore to size the 2nd cylinder.

Happy to take suggestions.

If so, on next engine turn that down first on longer stock, one end in chuck, other on live center, then cut the cylinder blanks from that piece.

Perhaps Zee could convert this excellent advice into a mantra for entry into his shop notebook.  Something like...

NEVER REMOVE A PART FROM ITS PARENT STOCK UNTIL ABSOLUTELY NECESSARY.

Hmm, where have I heard that before?

Probably on every thread I've started. 
You may recall, that mantra is on a card pasted above my machine. (Per your suggestion if I recall correctly.)
(But I did it in crayon.)

In any case, going back to crueby's suggestion...

Method 1: As he suggests: turn with live center, cut, face, bore.
Method 2: What I did: cut, face, bore, turn with live center.

For method 1, I think I'd have to go to 4-jaw to bore. (I haven't checked if my 4-jaw can hold that diameter)
I'm not sure of the downside to my approach. Sure I have to make the plugs. But it's dawned on me that I can start making the covers and use them as plugs. (The hole would be drilled later after mating the one cover to the cylinder.)

As an aside, seems method 1 would result in more waste and more facing to size.

Thanks Jim. I've never made an expanding mandrel...at least of that type and size. I had  thought about it early on...but I thought my chances of success are better with the plugs (now the covers). As in MY success.

I think I have to give my approach a try. If it fails...so what?

[zeeprogrammer]

Zee - back on the A2Z toolpost moving issue - a friend of mine had a simaler problem on his, saw what I had done, and did a variant on it - just did a single arc rather than the 4 that I did, is working very well for him. Below is a picture of his.

I think I'm missing something. Wouldn't the toolpost rotate on that plate?

[crueby]

Lost me on that, if the stock is already a little smaller than the plan calls for, why do you need to turn it down more? The bore is centered, the flats come in from the side. What is thete to turn?

The outside of the cylinder is unfinished. I just want to turn it a tad to clean it up. Whether I did it first or not...the result is the same.
Right or wrong...I thought doing it this way (using the bore to center) would improve my chance of keeping the outside parallel to the inside.

On mine, I just held an abrasive pad (like a kitchen scouring pad) on the side while it was spinning in the lathe chuck, gave it a nice clean look without taking off much of anything thickness-wise. Then reversed it in chuck to do other end. Not too picky on alignment either, since your fingers will follow any bumps. Just be sure to stay back from the vise jaws, or you'll be making up some new words about the lathe's parentage.

[crueby]

Zee - back on the A2Z toolpost moving issue - a friend of mine had a simaler problem on his, saw what I had done, and did a variant on it - just did a single arc rather than the 4 that I did, is working very well for him. Below is a picture of his.

I think I'm missing something. Wouldn't the toolpost rotate on that plate?

Nope - plate is held on to the bottom of the post with some countersunk screws. Sorry - forgot to mention that part (it was left as an exercise for the reader - isn't that how the textbooks skip over something the author didnt understand either?!)

[zeeprogrammer]

The outside of the bar is pretty crappy. Dents and weird crap that's pretty glued on. ScotchBrite won't do it.
I have no doubt I need to take a few thou off. You'll see when I do it.

Ah...the exercise for the reader.

I have a line in code that's been in the field for the last 10 years and continuously supported.
It was only last week that someone finally mentioned it.
Goes something like...

   eCurrentEngineState = eCurrentEngineState ;

When he asked, I just said..."There's a reason for that"...and went into a meeting leaving him to figure out 'that'. 

Part of my job is mentor/teacher. Gives me a lot of flexibility in covering my boo-boos. 

[PStechPaul]

That should be ignored by an optimizing compiler. 

[zeeprogrammer]

That should be ignored by an optimizing compiler. 

It was. Otherwise I would have caught it when I wrote it. 

[crueby]

That should be ignored by an optimizing compiler. 

It was. Otherwise I would have caught it when I wrote it. 

One time saw a subroutine called fakeStuffHack()...