Thread: How do you hold round parts for axial operations?

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barrel vice - Google Search

Originally Posted by Michael G

Based on a picture put up on the homeworkshop site some time ago, I made a scaled down version of the photographed part to see if it could be done without CNC (apparently it's the starter pinion for a marine diesel)
Attachment 186925
It was an interesting exercise with the dividing head to try out the concept but when I tried reaming the internal bore the part rotated in the vice and scratched up the outside - this was with soft jaws in the vice. I've also tried thin card and copper strips but I can't hold the part firmly enough. A similar thing can happen when I tap larger sizes (say greater than M10) in round parts too.

Anyone got a good way to hold these round parts so they don't rotate (and aren't distorted out of round)?

Michael

Hi Michael,

More jaws, like a 6 jaw, or a collet.

Regards
Ray

Vee block in vise, with soft jaws?

Originally Posted by Bryan

Vee block in vise, with soft jaws?

or two

3 jaw or 4 jaw chuck.(6 if you have one like Ray or a maybe a clever little four pad vice thingy if you have one )

Apart from that (and with out knowing exactly, you may have your reasons) I'd question your order of operations, why are you reaming the bore last? Can't it be done in a lathe first? How much material are you trying to ream?

Stuart

Thanks guys - I hadn't thought of gun equipment (or using V blocks in the vice).
In answer to Stuart's question, I can't ream it in the lathe because the tap handle I have for my larger reamers is too big for the lathe bed - the hole in question is around 3/4". I was only taking out a few thou, but the hole is about 3" long, so the reaction forces build up. I also wanted to preserve the centre marks in the ends of the blanks for alignment purposes so I elected to do the hole last. In this case the scuffing did not matter (being a learning piece to try out an idea), but it's one of those work holding things that I haven't got an answer for, so I thought I'd ask the question.

Michael

Yesterday some round bar spun in my bandsaw's vice, even though it was done up tight. Putting oil on the screw and bush fixed it - allowing more torque I suppose.

Jordan

I thought you'd have your reasons.
Going to show us some pictures of how it was done?
If I ever run out of things to do I might make a drivetrain for my rotary table

Stuart

Do you have a centre in the end of your hand reamer?

I'm not sure I'd dignify the what is present with the title 'centre', but there is a small hole in the ends of the reamers. I did once read about someone using an adjustable reamer as a mandrel but I've never liked that idea as I suspect it is far easier to put a bend in one than the writer realises - and there is the risk of marking the bore.

Stuart, the set up is simple enough not to need pictures (and the set up is broken down anyway - I'll have to recreate). The normal vertical head was used and to get the rotary motion I removed the hand wheel off the end of the mill table and replaced it with a gear. It was then a matter of building a gear train into the back of the dividing head. The dividing head is a universal type with an input shaft - I picked it up as a wreck for $300 and have spent most of the last 12 months cleaning it, repairing it and making up gears.

Michael

Hello Michael,
I have a set of gears for a universal dividing head, nothing else just the gears which are module 2 from memory. Let me know if you are interested in organizing something.
Mm.