What alloy of aluminum for this part?

[HarryJM]

A little help please. I just finished taking apart, cleaning, and putting together my Burke #4 mill and need to make a broken part. Its one of the trip rod bearing brackets (one on each end of the trip rod). Looks like pot metal to me and the rod only rotates a few degrees to disengage the automatic table feed. The bracket on the right has a location pin which the broken one on the left does not.

So what alloy of aluminum would be a good choice for making a new bracket?

 

[Joeman77]

I'd probably go with 6061, mostly because I've got a few pieces laying around, but also because it machines pretty well. Shouldn't be too bad a project since you've got a couple of patterns to work from.

 

[Ulma Doctor]

6061,6063,7075
would all be suitable for your needs as bracket material.
7075 is the strongest of the lot

 

[HarryJM]

Well that was fast and I really appreciate the suggestions and will order a piece tomorrow. This will be my first metal working project and it seems simple enough, which is a good way to start.

 

[ericc]

This is really interesting. I have a mill like that and I had to rush out to take a look at it. On mine, the brackets are steel, and are kind of blocky. I suspect that the ones in the photo above are not original. This is a low stress item, and I think almost anything would work, even 3d printing.

 

[HarryJM]

I suspect that the ones in the photo above are not original.

Who knows as old as it is. Date of mine is 10 44 and the other bracket is stampede 474 and the broken one is broken right where the stamp mark would be.

 

[ericc]

Mine is certainly not original. It has a jackshaft instead of the gear motor, and it is clearly a retrofit. I got it off a farm, and the farmer hit the mechanism with his tractor and decided he didn't want the mill around any more. It's OK, these mills can certainly do some work.

 

[HarryJM]

Mine also has a jackshaft with pillow block bearing on a very sturdy welded assembly.

 

[GunsOfNavarone]

Not that 6061 isn't strong, its just that part really isn't taking a lot of beating. Based on its machining qualities and availability...I'd agree with the 6061 suggestion.