Dumpster T-Slots =/

Out behind the local Pier One and leaning up against the bin was this really neat looking T slot material. Not real wood mind you, but still fairly stout and it should work for the kind of small stuff that I have been cutting. This is what it looks like installed.

and a close up of the slot

So now, I needed some hold downs this is what I was able to hack out with my sawsall not very pretty

This took about a 20 min of sawing, grinding and drilling around on a piece of steel, then I got the wild idea, hey I have a CNC machine, duh, why don’t I make the hold downs with it.

Here they are side by side just for comparison

I was amazed at how efficiently the machine cut these out. Took about 15 min each. I had a hard time setting up the program to cut more then one at a time, step and repeat so to speak. It was also tricky to hold them down without hold downs. I did not cut completely through the material but left a small sliver at the edge. I broke the piece off the main aluminum block and then filed off the rough edge. 5 min or so per piece spent on clean up.

I ended up cutting at 12000 RPM spindle speed and 7.5 inches per min with .020 depth passes.

What follows are some more shots of the process, the messy shot at the end is where the hold downs failed at the last moment and the work kicked out. Lucky for me the job ended at the same time.  Also on another dangorous note I miss set the height to the top of the work at one point and plunged all the way through a piece aluminum and into the bed of the table.

Ouch, it was in the center of one of the parts so again, luckily I hit the emergency stop in time enough to save it.  It let me know that the spindle does indeed have the ability to do more work, but I think I like keeping the work load light and the time frame long, at least for the moment.

Next I may try and make some T-nuts and also I might machine a few more hold downs with a V in the nose so that I can hold 90 degree corners more securely.  So far I only have 3 of these made, but hey, I can make more.

The Rhino File

The Gcode file


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