Thread: machining flat bar on the mill

hi guys

i need to machine approx 1mm off a piece of 50 by 3mm flat bar and was wondering the best way to secure it to the lathe bed to prevent it springing ideas??

thanks everyone

Can you post a sketch or something? Which dimension are you wanting to reduce and are you securing it to a mill or a lathe?
Have you got a vertical mill or horizontal or...?

Michael

Weld it to the mill table? seriously for that size just use a file. Works for me and you get some good practice. Though if you really wanted to machine it use some 5 min araldite and glue it to a piece of thicker steel wait till set and go for it
Pete

fittermachinist I would lay it on top of another piece of flat with 5 or 6mm hanging over the edge and place another piece of flat over the top and set up several clamps along the length, make it parallel to the table and tighten the clamps.

Lathe or mill ?

How long is the length ?

I'd super glue it to a thicker piece of stock, like some keysteel, and then clamp the thicker piece in mill vice and mill off the 1mm. Make sure both pieces are thououghly clean before gluing. To release the super glue either use some gentle heat or soak in acetone or nail polish remover that contains acetone. I've also read that you can use double sided tape to stick metal directly to the mill table but I suppose that this would only work with a larger piece of material.

GLUE !!

Do not use glue under any circumstances fittermachinist.

If you have any job that is difficult to hold then you make a jig or clamp/s to hold it securely !

Often this can take much longer than the milling but it is actually part of the job, work must be held securely because otherwise you will/can damage the job, tooling, machine or a fleshy thing.

I don't know whether you know guys know ?

fittermachinist is an apprentice I think ? hence the correct method

Has he been in contact to advise its the edge and not the face hes taking it off.

Wouldnt it be advisable to tell someone the correct method all the time if possable no matter what experience.

Originally Posted by fittermachinist

hi guys
i need to machine approx 1mm off a piece of 50 by 3mm flat bar and was wondering the best way to secure it to the lathe bed to prevent it springing ideas??
thanks everyone

Are you using a mill?

I would sandwich it between two pieces of 10 X 40 holding it down with tee bolts, clamps and stepped blocks from the far edge at regular intervals. It is then raised 10mm off of the table avoiding any brown pants moments.

hey guys,

it was the face i was taking it off as i needed 2mm flat bar instead of 3 which you cant buy, i needed to machine 1500 mm long in total, so in the end i cut 3x 500mm bits and put it on the magnetic chuck and used a facing insert tip cutter

thanks

oh and i meant mill! not lathe

Your answer could of come more quickly if you had given all your machining information.

Hi guys,

This is an interesting discussion. Me being relatively new at the milling game I had a similar issue when I wanted to face a piece of 10mm plate for a bracket I was making. I don't have low profile clamps, only the standard clamping kit. I wanted to face the entire plate surface so I faced up to the clamp position and then moved the clamp to the machined surface and continued. Is this not the done thing?

Simon

There is nothing wrong with that method,you may strike a problem if your machined area was not clamped before releasing the unmachined section.

Agreed - nothing wrong with clamping and then moving the clamps. That's how I did the material for the fabricated gears I'm making.
While it seems to have worked, I wouldn't have suggested a mag table and milling as you are relying entirely on the magnet to hold the material and the forces while milling can be high (grinding is comparatively lower force). Once a part moves on a mag table it seems to go completely most of the time (and the holding force will decrease with thinner material)

Michael

Little late now but is there any reason you couldnt have used 2mm sheet?