MDF Machine - Cut Aluminum?

Just a quick question. Can a well made CNC machine using servos and a good router, but built from MDF, handle milling Alum?

See, I was thinking of ordering high-quality parts (Servos, Gecko drivers, Ballscrews and Linear Rails) for my machine, but saving some initial cost by building it out of MDF. I have a few reasons for this:

1) MDF is easy to work.
2) MDF is cheap enough that I can tinker with the design.
3) If the MDF machine can cut Alum, I can use it to remake the machine from Alum once my design is final.

So, any thoughts?

Maybe,
My machine was bought. Made of tubular steel frame for stand and aluminum plate and extrusions for the machine itself. I usually use it for contouring graphite for glass molds. As sturdy as it is, it's still a challenge to get good work in aluminum. No match for a proper mill.

Quote:

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Originally Posted by keithorr

As sturdy as it is, it's still a challenge to get good work in aluminum. No match for a proper mill.

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Is that more of the Servos/Steppers and/or drive system problem or a construction problem though??

The machine is too light. The position accuracy or motive power is not a problem, but vibration is. If I mill aluminum plate with an appropriate 1/4" end mill, I can get pretty good cuts. I can't hog anything and the swirl marks in finish cuts is more than you would get with a good mill. The router bearings aren't up to the job, and the 12" Z axis isn't rigid enough when extended. I have to use a tall fixture block to raise the workpiece so the Z axis is only hanging down a couple of inches. The uprights are of 1" aluminum plate, the crossmember is 6" square tube. The base plate is 1/2" aluminum plate with 5/8" plate rabbited on edge and screwed to the base to form T-slots. The ballscrews are rolled.

I cut dry just to keep the machine clean. I could probably get better results with proper coolant. I don't think you would want to use coolant with an MDF machine.

Many of the members here have milled aluminum with their MDF machines. Balsaman is the only one that I can think of off hand. Good luck.

Hi. This is no claim to fame but I did most of my hard aluminum alloy cuts on a machine that was held together with a couple of 2x4s. I noticed that using the right cutting tool for aluminum, slow feedrate and, yes, WD40 meant that there was little load put on the frame. Now that I switched to 8020 extrusions, I'm cutting the same alloys at a much faster rate and the edges come out much smoother.

Not to knock off MDF but when I cut it, I get tons of a fine 'talc' that gets everywhere including the screws, rails, lungs, etc. Check the 8020 forum out and post your frame requirements - maybe they can help you as they did with me.

Later,
JR

I don't have a problem keeping the speed down to save some money initially. Once I start selling some parts, I can always upgrade the machine.

So MDF will work if:
1) Keep the ipms down.
2) Use some sort of cutting fluid!
3) Use the right bits (and keep them sharp!).

I'd say so. See the video here when I cut my router's base. I used a plain PVC clamp I got from the hardware store to hold the router while cutting the real holder. Because the whole setup it was so flimsy and my then router was only 1/2 HP, I did that cut very slowly. But, it worked.

Regards,
Julio