Repairing drill rack..

[robwizard]

So I got this drill press.. it's great.. but the rack is smashed to bits on it

Looks like someone has used it to pry and press something in and its all busted up. I plan on welding it, turning it and then milling new slots into it.. the only thing is I don't know how to go about it. I have read in a couple of places that you can MIG cast steel (which is what I think it might be?) but also things like this seem to get done with ARC more often. We have a TIG set in work and I would feel more confident using that.. would I need special filler rods etc?

Cheers

 

[shenion]

Without knowing if it is cast steel, pot metal or cast iron, it is hard to recommend a filler.

I'd lean toward brazing it. Maybe you can pick up some TIG brazing rods.

If it is cast steel, you can MIG it. I'd look at bolting it together similar to how it was done in the tutorials.

The reason for using arc is you can get NiFe filler rods easily and they will work without preheat.

 

[robwizard]

How could I identify it? It is not sheared off in any way.. more the rack has worn off and I want to cover it in weld then machine a new rack out of it.. if that makes sense..

Cheers

 

[Hitch]

One problem I can envisage Is keeping it straight, if you build up one side of the shaft with layer upon layer of weld, you might well end up with a bit of a bend in it.

 

[Bsmith]

Test with file.
If its a dull silver/dull white colour, its most likely a cast alumium alloy (a magnet would not stick to it).
If its dull grey and teeth snapped off the rack, its cast iron.
If its shining silver and teeth bent or chewed, its a steel.
I would be thinking of just building the teeth up and shaping again.
Whats the gear like if the rack is in that condition?

 

[robwizard]

The gear is surprisingly good actually.. a little worn but very usable. The teeth snapped off I would say as it's sort of showing the grain of the material.. It's a sort off shiny steely looking material.. I will check it with a magnet tomorrow.. I hope it's not cast iron..

Cheers

 

[mi3gto]

Sorry for digging up a old thread, but what was the outcome? I have a sim problem only one tooth broken.

 

[awemawson]

Can you not simplt replace the gear and rack as a pair - that way they don't have to be identical to the original, just suitable. Of course it is just possible that you could identify the rack and buy a length of it.

 

[robwizard]

Returning to this like a million months later and it is basically in the same situation.. sat on one of the benches waiting to be fixed I did make a start welding it and it seemed ok.. bit porous despite being super clean. Havn't had a go at machining it yet but I did run a file over it and the welded area is hard as ****. I should have explained that the rack cannont be replaced as such because it is a part of the shaft if that makes sense.. I intend to finish this soon.. along with about fifty other things..

 

[penfold]

What method? If you've used MIG, stick might be worth a try to see if the flux will lift the crap out of the weldpool better. Should be softer too, even with mild steel rods.

 

[graffian]

the rack is machined into the back of the quill isn't it?
I have welded up the teeth on a lathe rack and recut them with an angle grinder, sounds a bit gruesome but it worked and was still working 20 year on, it was a load better then a rack with teeth missing.

 

[Pete.]

I thought they meant the table-rise rack?

 

[graffian]

I thought they meant the table-rise rack?

I wasn't sure which he was on about,but "using the drill as a press" lead me
to think he was on about the quill, no idea why I thought that;-)

 

[Pete.]

Oh yeah - 'turning it' would be a giveaway I guess