How to mill a slot without a mill?

[dml66]

I've got a piece of round aluminum which has a 1/4" wide by 1/4" deep slot axially milled into it. I need to make the same size slot 180° on the other side, problem is I don't have a mill .

I could try it on the my drill press using a chucked end mill or mortising bit, the spindle does have a DIY drawbar so it won't fall out, but it's hard on the machine, even with lots of light passes.

I have a mini lathe with a milling attachment, not sure if the vise is big enough to hold the workpiece, and there's barely enough cross slide travel, I may have to stop and and move the piece in the vise.

My best bet is having someone with a mill do this, I'll keep trying to locate someone.

Suggestions solicited, thank you!

 

[Eddyde]

I assume you have an X-Y table on the drill press or some means of holding and moving the part? If so, you should be fine milling that slot.
In my "Dark ages", before I had my own mill, I milled on a drill press, end mill held in the chuck, a shop made X-Y table and it worked, even in steel. I still have the same drill press and it is fine.

 

[derf]

Is that for a rifle rest?

 

[dml66]

I assume you have an X-Y table on the drill press or some means of holding and moving the part? If so, you should be fine milling that slot.
In my "Dark ages", before I had my own mill, I milled on a drill press, end mill held in the chuck, a shop made X-Y table and it worked, even in steel. I still have the same drill press and it is fine.

Yes, I have an X-Y table on the drill press, I may try that approach first.

 

[dml66]

Is that for a rifle rest?

Yes.

 

[derf]

Why do you need to mill an additional slot?

 

[dml66]

Why do you need to mill an additional slot?

Flexibility.

 

[GrifterGuru]

...

 

[derf]

You mean you want to shoot off it backwards? There is a reason that the rear leg is in the middle. If you are left handed, drill and tap another hole in the opposite side for the knob.

 

[dml66]

You mean you want to shoot off it backwards? There is a reason that the rear leg is in the middle. If you are left handed, drill and tap another hole in the opposite side for the knob.

It's not that simple, there's an internal slot which locks into the coaxial top.

As far as backwards is concerned, that's debatable, something I'd like to determine for myself, which is why I'd like to have the flexibility to try it both ways.