Workholding - 19mm Wheel Blanks

[Wongster]

I've been googling "step collets" and "emergency collets". Lots of pot roast shown instead... lol... Have you folks came across anything other than 5C? I've an ER32 collet block and my tools are mainly for ER or MT.

I'm trying not to buy new stuff if I can. The housing market took a turn 2 odd years ago and I've not recovered from the drastic reduction in income (was doing mortgages). This job will not make me enough money to pay for the collets and the holder, so I try to make do with what I've on hand. No more free job for anyone who writes to me on my website. Was doing that for a while.

Saw someone posted on making one with MT1 shank (http://northbranchreels.com/2012/05/28/pot-chuck/). I wonder if I try making one with straight shank and use it with my ER32 collet block, will it have enough clamping force to hold something about 2.3mm thick and 19mm in diameter?

[Vinny]

I had a bunch of plastic gears that needed to be faced off. I made pot chucks (out of plastic but you can make them out of anything) and used them to hold the gears. My suggestion would be to make pot chucks with a straight shaft to hold in an ER32 collet then use a hose clamp to clamp the part in the pot chuck. At least I'm ASSUMING this will work, I'm sure someone else will chime in if it won't. I don't know how much clamping power is needed to hold these things during machining. I can see pouring some sort of resin or something that holds them in a block like the pic you posted earlier, but I'm not sure which material I'd use for it due to the clamping power comment I made above.

[Wongster]

Hello Vinny,

This may just work for me. I was contemplating the use of double sided tape with my original setup. Will try this weekend to see if it will work. Otherwise, I'll try my hand on making one pot chuck and use hose clamp like you suggested.

Thanks man!

[Roadracer_Al]

If you have a lathe with a removable chuck, you could make a mounting plate, and soft jaws which get bored exactly to the size of the wheel.

[Wongster]

Can't visualize how the setup look. My lathe chick is mounted from the front with 4 bolts.

[Mayhem]

Hi Wong - nice to see you back here!

You could try something like THIS. The last post on page 2 is what Al is thinking (if I understood his post).

First, you make the aluminium soft jaws and then bore them on your lathe (as shown in the link above), so they hold the wheels. Then you remove the chuck from your lathe and set that up on your mill, so the chuck holds the wheels.

[Roadracer_Al]

Yes, exactly. Although I was thinking more of two-piece chuck jaw which have bolt-on jaw faces -- these can be replaced with bare aluminum blocks which can be turned to suit your needs. However, I ** really** like how the soft jaws in the link work with one-piece chuck jaws: that's a very clean solution.

Wong, your description of 4 bolts sounds ideal - when I had a Seig 7x14 mini-lathe, I upgraded from a 3" to a 5" chuck. The chucks were held on with 3 six mm studs and nuts. I made a 1/2" thick aluminum plate about 1" larger in diameter than the body of the un-used 3" chuck, and milled pockets into the back of the aluminum plate to conceal the chuck-mounting nuts so the plate would lay flat on the mill table. This plate doesn't need to be aluminum, of course. I used it extensively to move parts between my lathe and mill without de-chucking the parts, and it was especially handy when using the rotary table.

I sold the mini lathe last year, and the 3" chuck and base plate went with it.

I may actually have to buy myself another 3" chuck - I have, on occasion, chucked the small 3-jaw inside the large 4-jaw on my new-to-me 16x40, dialed it in, and found that it could be made to run extremely true, like a collet, only a a lot easier to install and operate

[Wongster]

Thanks guys!

If I don't have enough "meat" with the soft jaws in closed position, I can put a rod in between and bore the required size.

[Good Mann]

Hello WS.
I'm thinking Dallen has a point.
I used a tar product to hold delicate jewellery parts prior to drilling and polishing.
No clamping involved. Warm up the medium, press your metal into the soft product.
However, it's been a few years since .
Would it hold for your project? Not certain.
The centering? Guess that's time and patience.
Would you like me to persue this on your behalf?
GM.

[Wongster]

Hi GM,
May I know more about this tar product? I can still use the fixture I made to locate the part and use the product you mentioned to hold the part. If it's strong enough, the screw can be left out.

I don't mind trying whatever methods thrown my way. If it didn't work for this job, it may work for another, most importantly, knowledge is gained.