Benchtop model for routing small 1/4" thick aluminum signs

[robert56@mindspring.com]

Hi,

I just started reading the list and am thinking about placing an order for a benchtop model shopbot. I will be using it to route out small (11" x 3.25") aluminum signs out of of 6061-t6 aluminum stock. I will be working with 1/4" thick extrusion flat stock and milling it to around .100" to .125" deep. Is the benchtop model up to this? I have read some posts by people saying that their larger models are capable of such tasks, but at slow and shallow feed rates. I will be using the 2-1/4 horse makita router with a 1/8" or 1/4" end mill diameter. I realize that a misting system will be necessary. Thanks

Rob

[flyboy]

T-6 will be hard to mill though right? You could use some softer aluminum for a sign couldn't you. Also, you will need a speed control to keep from heating up and wearing out your bits prematurely. Aluminum is pretty abrasive and the correct feed rate and rpm will go a long way to your sucess. If I were you, and all I was going to do was mill aluminum of that size, I would go get a nice used Bridgeport or other cnc Mill. A mill is a mill for a reason. I have both and can see where the limitations are for both. The larger router is mostly compromized in it's size. Great for what it's intent is for though.

[ggressel@cinci.rr.com]

Robert,
I use an older PR-32 machine which is dimensionally similiar to the benchtop model. i machine 1/16" thick 24x24" 6061-T4 with 1/4, 1/8 and 7/16" ball end mills (actually router bits) with a depth of about .040". All this is done using a small PC router, not the 3.5HP and it works wonderfully. There are many tricks to make this successful including getting set up for coolant and how to make the z-zero work with both aluminum and coolant. If you have any questions e-mail me and we can arrange a time to talk. No use for you going through the learnings that I did.

[larry]

I routinely mill aluminum. My setup is an 18,000 RPM spindle and misting system for cooling and a .25" dia single flute spiral upcut carbide bit with a .75 cutting length. I run full RPM at .5 IPS setting each pass to less than .125". Using this setup I cut up to .75 thick 6061 aluminum.
Larry