Milling alluminum

[mikey74063]

I have another question. I have a photo below of what I am attempting to do.

I have 1/4" thick 6061 aluminum and wanting to mill out a slot 1/4" x 1"

I have a Craftsman 12" drill press and I am looking at buying a compound milling table 18-5/8" table surface



I think I need to attach a quick clamp vise to the table to hold my work..



I want to mill out this slot.. what type of bit will I need to use that will attach to my drill press?

I will later buy milling machine but I am wanting to start off and see how this goes..

can anyone give me advice if this setup is do able with what I am wanting to do? it seems like a simple milling issue.. but I want to wait before I spend a bunch of cash..

Thank you for the advice.

[spoiledbrat]

Drill presses are ill-equipped to handle any sideloads. You may have limited success doing that.

If I were you, and did not have a milling machine yet, I would opt for using a hand-held router, rigidly fixed in place above the X-Y table. You could use the router base to adjust the cut depth between cuts. I would make light cuts (0.050") or less in depth, using WD-40 or Kerosine to prevent the aluminum from welding to the end-mill. Use a two-flute endmill, bottom cutting.

Remember, this is just an opinion. Hopefully many others will chime in, and give you more ideas. I have cut aluminum plate (0.500" thick) using my CNC with porter cable router, set to 10,000 rpm. Making light cuts, it is usually not a problem, just messy.

Good luck,

Rob

[Geof]

Milling on a drill press is not a good idea and can be downright dangerous.

Drill chucks are secured to the spindle by a Jacobs taper which is a short steep taper that provides enough friction to drive a drill and is self-locking to the extent that the chuck will not spontaneously fall off.

However, the Jacobs taper will come loose if the chuck is subjected to a side load when it is spinning. It might take quite a while but it will come loose, and then you have a spinning chuck with a sharp milling cutter bouncing around near your hands.

Even if the chuck was secured in some way so the taper could not work loose most low cost drill presses have poor quality chucks which will not grip a milling cutter firmly and accurately. In addition the bearings on a drill press are not designed for side loading and normally the spindle is quite loose to side loads.

It is much better to [ut the money into getting a small benchtop milling machine with a proper R8 spindle.

[stevespo]

I completely agree with the previous advice. Even trying to lightly mill wood had done a number on the accuracy of my drill press.

Another option is to drill close/slighly overlapping holes and then clean up the sides with a file. If you have a (power) jigsaw you could also clean up the slot and then file by hand.

Steve

[Andre' B]

Yep save your money and by a small mill.

To make the part in the pic, use the drill press to drill a chain of holes.
Then use a jig saw to remove the webs between the holes and clean up the slot with a file.
Edit: Like he said.

[mikey74063]

Thanks for telling me about the hazards of using a drill press. I will look at buying a R8..

Does anyone have a recommendation on a unit for $500 to $800 that will work with what I am wanting to do with 1/4" thick aluminum.

Thank you,

[arizonavideo]

Send me the part and I will cut a slot for free....

Do you only have one slot to do?

A jigsaw and file can get you close for a low price. If you just want to do some milling then you need to buy a mill. You might want to look at the G0704 thread.

Welcome to the Zone.

[Andre' B]

At the upper end of your price range is the Taig manual mill.
Three weeks ago I got one of their CNC ready versions, before I ordered the mill I had a computer setup with EMC2 and a G540 spinning the motors on the bench, within an hour of uncrating the Taig it was making chips. Only bad thing I can say is at higher speeds there is some belt slapping noise.

I am a bit leary of some of the China mills, but I have had an RF-30 for over 10 years that has been OK. From day 1 it needed a spindle rebuid, which I have yet to do, as it spins the spindle slowly moves up and down about 0.0003", leaving a less then perfect finish.

[TonyAllen]

Hi Mickey
with the compound slide and vise U will be fine to make the slot in 1/4 alum.
the way u will want to do this is tighten the end mill good and plunge down like drilling a hole but move axis only 20 or 30 thousands at the time for each plunge U R only going 1 inch with no side pressure and will not require any clean up or secondary work......Although if you will be doing more machine work in the future other than simple slot in Alum.. U may need a mill ..

Good luck
Tony

[Geof]

Originally Posted by TonyAllen ...... tighten the end mill good and plunge down like drilling a hole but move axis only 20 or 30 thousands at the time for each plunge U R only going 1 inch with no side pressure...

No, do not do this. The cutting action alone gives side pressure because the tool is only cutting on one edge of the slot.

It is possible this procedure could work and give a very rough slot, rough because the spindle and chuck will deflect sideways during the cut. It is also possible, indeed probable, the chuck will come loose at some point.

[Med-Pac]

My 2 cents.

I agree with the advice from above and can add one more. Most of the end mills we use have a flat side to accept a set screw. I've actually had a guy set up a job with a jacobs chuck and an end mill.....hit some hard stuff and twisted the 3 holders inside of the chuck. He no longer has a job here. After reading this, I'm glad the damn chuck didn't come out of the spindle. That would've probably put him on disability.

Mike

[TonyAllen]

Originally Posted by Geof No, do not do this. The cutting action alone gives side pressure because the tool is only cutting on one edge of the slot. It is possible this procedure could work and give a very rough slot, rough because the spindle and chuck will deflect sideways during the cut. It is also possible, indeed probable, the chuck will come loose at some point.

An open mind is a virtue...so long as all the common sense has not leaked out.
mikey74063 ask for help to make 1 slot in Aluminum .250 thaousands wide and only 1 inch long in a 1/4 inch thick material SO it is obvious you don't know how little .030 step overis ...it will have very little side preassure...and a very smooth slot ..You are intitled to your opinion but you are showing your lack of expereince in the machining feild ....I was helping mikey74063 .. with all the negative advice I don't see how anyone gets anything Accomplished.....Mikey if you try to make your slot let us all know how it turns out ! best to you ..
Tony