4-Jaw chuck back plate

[NPKenny]

I need a lathe...

...and a mill.

At this exact moment, the lathe is more interesting than chainsaws. I figured I needed a lathe few years ago when I realized I was obsessing over items others were showing. I have always admired folks who were excellent at their crafts and an entry level lathe is very inexpensive.

Of course, this is a tool that does not make the man. As shown above, I have many miles to travel.

 

[mettee]

Ya, I kept looking at them and I would find one that I liked, the lowest I saw was 4K.

It was a nice lathe but a little more than what I thought it was worth.

I think if I had one I might never sleep I would be in the garage non stop

 

[NPKenny]

We are in the same market. Mine was $1K with a bunch of tooling, jaws, rests, etc. I picked it up in Tempe.

I decided I wanted a Taiwan lathe or better, wanted a 10" swing or larger, and a shorter bed so I can fit it in my shop. This lathe is a 12"x24" with a back gear, has cross-feed, and quick change gears. I am happy to have it.

 

[srcarr52]

No!!! I punched through the chuck holes with a drift punch. Looks like I need to upgrade my method. Thank you.

If I didn't have the correct transfer punch I'd find a drill bit that just rides on the ID of the threads and use it to spot the new holes.

Either clamp it together so there is no chance of it rotating or drill/tap one hole first to keep it from rotating.

On your picture you can see your spots are off since you have a nice witness mark from your over cut on the shoulder.

 

[NPKenny]

Funny, I saw the obvious witness mark as I posted the picture…. Then had the idea to cut a groove in the bolt hole circumference on the next try. It will at least center the hole in one dimension.

On a related observation, what starting point for feed rate and cut depth should I be looking at. I was making “sand” on my face cut and presume I was being timid with the cut. The over it on the shoulder was the result of actually making small chips instead of dust.

I recognize I am getting a lot of hand-holding here. Thanks for the lessons.

 

[mettee]

We are in the same market. Mine was $1K with a bunch of tooling, jaws, rests, etc. I picked it up in Tempe.

I decided I wanted a Taiwan lathe or better, wanted a 10" swing or larger, and a shorter bed so I can fit it in my shop. This lathe is a 12"x24" with a back gear, has cross-feed, and quick change gears. I am happy to have it.

Moore tool or someplace else?

I can never find one that fits the requirements it seems.

 

[NPKenny]

Moore tool or someplace else?

I can never find one that fits the requirements it seems.

No. Private sale. I scoured CL and Offerup for a few years.

I hate to admit it, but I like the chase on "unnecessary" tools. I don't fool around on these sites for items within my professional skillset, but on the hobby side, I enjoy hunting the deal.

 

[NPKenny]

I procured transfer punches and proceeded to mess-up another hole. I rotated to the third spot and figured out the correct marking and drilling method. The holes tapped cleanly and the 4-jaw is ready to go. I took a few additional passes on the face to increase the index ring depth.

I then re-installed the 3-jaw and turned a 54mm mandrel for an 066. Worked face and turning cuts figuring out runout, feed, and backlash on each operation.

I did all of this in back gear at less than 300rpm. I’ll need to pick-up some confidence to get out of back gear. It’s tough to work the parts and check run-out manually turning with back gear engaged. I think this lathe will easily pull all of the cuts I want to make and make smoother cuts at a faster feed rate.

 

[NPKenny]

I continued to gear up for this cylinder by building a back plate out of 3/4” aluminum. The holes are drilled and tapped to 1/4-20, but I did not tap all the way through so the all-thread could shoulder in the block. I don’t have a bottom tap, so I improvised

The 1/4-20 all-thread was cut to 5-1/2”, cleaned-up, and installed. I used shouldered lock nuts to help with contact area and possibly hold the nuts in place.

The cooling fins on the top of the cylinder were trimmed to allow flat mounting in the block. The base was surfaced so I could get accurate timing numbers. (Really, I couldn’t resist cutting something since the cylinder was mounted and runout was dialed in.)

I’m making progress here.

 

[Moparmyway]

The longer your mandrel, the more deviation its going to have if you have any runout, or if it shifts during use. I run longer mandrels, between 10-12 inches and I'm considering cutting a couple/few inches off on the smaller diameter ones, how long is that one ?

 

[NPKenny]

The longer your mandrel, the more deviation its going to have if you have any runout, or if it shifts during use. I run longer mandrels, between 10-12 inches and I'm considering cutting a couple/few inches off on the smaller diameter ones, how long is that one ?

It’s a 12” mandrel. It’s the length of the blanks I have easy access to. I was thinking I could use it for two cylinder diameters if I left it long.

I didn’t have any sense for how much space I would need behind the back of the cylinder.

What have you found to be a more ideal length?

 

[srcarr52]

It’s a 12” mandrel. It’s the length of the blanks I have easy access to. I was thinking I could use it for two cylinder diameters if I left it long.

I didn’t have any sense for how much space I would need behind the back of the cylinder.

What have you found to be a more ideal length?

I make most of my mandrels from 6” of stock. I buy 12” and cut it in half. I like the cylinder as close to the chuck as possible.

I also spin them around 500 rpm when cutting the base or squish.

 

[Al Smith]

There are a number of methods to hold a cylinder .Some use steel round stock,some aluminum round stock .One I saw used a large wooden dowel .
I can't find the picture but I use a piece of finished 1" hard cold rolled stock mounted in a Hardinge Jorgenson collette chuck threaded to take nylon arbors for whatever size cylinder .Theses set deep enough I have enough room to cut the chamfer on the bottom .I have five so far 48-50-52 and what ever size an 020T is .If I need another size I just turn one out .These fit tight enough I have to give it a little tap with a dead blow hammer on and off . I might add all this stuff is for a Monarch 10" EE tool makers lathe that uses a D 1-3 pin mount .

 

[Al Smith]

It seems the last few years the trend seems to focus on cutting down the combustion chamber to produce a hotter "hot spot ".I've never tried it myself but if I did it likely would be with a face plate and rods .Then it might take 2 hours to tram it in and ten minutes to make the cut For what I do I'll most likely stay with my raised dome pistons and "sweeps " on the upper transfers .