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dr pepper
05-23-2010, 07:52 AM
Is it a good idea to weld up damage in a mill table, or would it screw up the table and distort everything?

recoilless
05-23-2010, 08:38 AM
Is it a good idea to weld up damage in a mill table, or would it screw up the table and distort everything?

I'd say typically no...then again, how bad is the damage?

I'd think the table should be flat, move square wrt to travel axis, t-slots clear, etc. If you have a 1/2" hole mistakenly drilled in middle of table .250" deep, it is unsightly and will collect swarf in it but if the edges of hole aren't dinged or have raised burrs on edges, is it really hurting the functioning of mill?

SGW
05-23-2010, 09:02 AM
I think I'd try to find some steel-filled epoxy and fill them that way.

JCHannum
05-23-2010, 09:18 AM
Mill tables are generally cast iron and, as such, are not easily welded. Steel filled epoxy can be used with some success. Smaller individual drill or mill spots can be repaired by drilling, threading and installing a machine screw. Cut off the head and finish file or mill flush with the table.

gwilson
05-23-2010, 10:17 AM
I'd think the best,most camouflaged repair would be to make the repair screw out of cast iron. Make it a flat head,and cut it off a little above the table's surface. Peen the edges down,and carefully mill down. File off the last bit so the milling cutter doesn't touch the table,of course.

The worst things are holes on the edges of T slots,or long grooves milled into the table. You might stress relieve the table if you get the top reground,and warp it out of true.

Carld
05-23-2010, 10:56 AM
It depends on where and how much your planning to weld on the table. Can you give more details as to where and what is broken and needs welding. Your question is to open ended to answer.

alanganes
05-23-2010, 11:12 AM
Don't bother with all of that. If it is a hole in the table just take your letter stamp set and stamp "OIL" near it with a little arrow pointing at the hole.
Job finished.*




* Before some sharp-eyed forum reader nails me for plagiarism: that idea (joke) is not original to me, I shamelessly lifted it from one of Guy Lautard's Machinist's Bedside Reader books.

lazlo
05-23-2010, 11:13 AM
I'd think the best,most camouflaged repair would be to make the repair screw out of cast iron. Make it a flat head,and cut it off a little above the table's surface. Peen the edges down,and carefully mill down. File off the last bit so the milling cutter doesn't touch the table,of course.

That's the method that's described in Connelly's book. I can't imagine you'd be able to get a bead to stick to ancient, oily, dirty cast iron, and there'd be a very high risk of cracking and warping.

Even if you were successful, you'd be using NiRod, so you'd have a bright shiny silver spot on your table.