Thread: Ideas for work holding small round parts

You could attach a bent leg lathe dog to the 25 mm section and the leg could rest against the chuck jaw.
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Phil

Grip it with two "V" blocks ?

Rob

Originally Posted by Steamwhisperer

You could attach a bent leg lathe dog to the 25 mm section and the leg could rest against the chuck jaw.
Like these LATHE DOGS, MINI LATHES, Lathemaster.com offers mini-lathes, milling machines, chucks & accessories
Phil

Thanks Phil. I have never seen lathe dogs before. They look like an interesting option. If I could screw them in tight enough on the part they may do the trick.

Originally Posted by nearnexus

Grip it with two "V" blocks ?
Rob

Rob, I had thought about using one of those V blocks with the little arm over the top and screw clamp. I am thinking though that I would rip the thread out of the arm before I got enough purchase on it. I have a set of standard V blocks but they are far too large to grip between. I need to find some micro V's.

Probably better to drill and tap the rod before you machined the two diameters onto it.
Would give you greater purchase area, and you can machine off any jaw imprints.

First how critical is the threaded hole?

If only for holding and not under undue pressure,tension or load drill the tapping hole a little bigger.

If the finish is not that critical which it may not seeing it has already spun,have you considered using a piece of emery wrapped around your job with the rough side towards the job

Have you tried holding the larger diameter if possible?

I would clamp it in a bench vise , between two bits of wood, and tighten up the vice . It always works for me . You could profile the wood to match the diameter of the piece . You have to be careful to run the tap in dead straight , takes some practice

Mike

If the "V" blocks are too big, put the part in a drill chuck (sans the drill) and then put the drill chuck in the "V" blocks

Rob

Do you have a set of normal taps? If so you can try going round in circles taper, int, bottom repeat.
Are you using tapping fluid of some sort?

Stuart

Perhaps if it was griped in the larger part, and several size drills used up to tapping size ,there would not be much pressure in the drilling stage and do not think by then that the tap would move the part in the chuck, and by the tapping size drill it would show if it was going to move. I would think.


Eddie

A gun nose or spiral point tap would work better than the tap you are using but as suggested earlier it might be better to tap the hole before turning the smaller diameter for a better grip.

Maybe I have collets on my mind at the moment but that is one way to approach it. may involve more expense than desired but will be available for the future.

Dean

Originally Posted by Oldneweng

Maybe I have collets on my mind at the moment but that is one way to approach it. may involve more expense than desired but will be available for the future.

Dean

If i had to do it i would have the part on the lathe in the ER collet chuck. Bet it wouldn't slip then.
But since you don't have a lathe, maybe look at a 5C block and collets, you could either clamp a square block to an angle plate or a hex on in the 3 jaw.

Ew

Pipeclay: I will give the emery cloth a try. The thread is rather important as it is holding a stud that makes up my milling machine leveling feet. It will hold (compression) up to 450kg across 4 x m12 studs.


Morrisman: The bench vise would certainly hold the part. I am however a notoriously bad "hand tapper". If can tap anything but straight.

Rob: I am thinking I hunt down some smaller V blocks. I can clamp them between my anglock vise which will exert enough pressure to hold it nice an tight. If I am not 100% on that, I will drill a small relief to ensure the clamping screw bites..

Stuart: I have a few M12's but not a full set of T-I-M. I am pretty sure they are all intermediates. The spiral was for my tapping head and at first glance the "get er done" tap. I am using Tap Magic tapping fluid.

TKO: I tried gripping the larger part. Because it is so small, and the vise is so big, it only gets a couple of teeth purchase on the part. The drilling stage, and even the cutting down to size on the rotary table went perfectly. It is just this tapping stage where the pressure is just a bit much and it breaks loose.

I almost considered grinding some serrations in the chuck jaws!

Originally Posted by Oldneweng

Maybe I have collets on my mind at the moment but that is one way to approach it. may involve more expense than desired but will be available for the future.
Dean

Originally Posted by Ueee

If i had to do it i would have the part on the lathe in the ER collet chuck. Bet it wouldn't slip then.
But since you don't have a lathe, maybe look at a 5C block and collets, you could either clamp a square block to an angle plate or a hex on in the 3 jaw.
Ew

Dean and Ewan, I like the idea of an ER collet. I have ER32's which have a 14mm. I considered this but came full circle in how to then hold the ER TTS holder without it turning... Given the length of its arbor it may well not slip in the 3 jaw..

I am a bit surprised no one has suggested a 4 jaw. I read that they get much better clamping pressure. I figure it is probably swatting a fly with a sledgehammer..