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View Full Version : Newbie CNC Newbie (or) Bigbear CNC style machine setup



gdgeorge
09-01-2010, 11:05 PM
Well the new machine finally arrived on Friday.

The back-story: I purchased this machine as new from a seller on eBay who apparently builds them as he sells them. The transaction itself was straightforward and the seller and I corresponded. He estimated three weeks to build and ship. Meanwhile, I bought a used Dell GX280 tower, installed and worked with software, and made space in my garage.

After a minor shipping issue the great day was finally upon us. The machine arrived in two boxes. I assembled the gantry to the base within about 20 minutes and then hooked up the electronics. I didn't have a parallel extension cable so I had to park the computer right next to the machine for the time being. I had pre-configured Mach 2 and had the motors turning within an hour.

I had the machine cut a very rough USMC logo (Semper Fi, Mac!) and then hit the first problem. Actually I hit the hard limit of the machine. The Y-axis came loose. The machine has simple all-thread screws to drive it. They are connected with collars and set-screws to the motor shafts. When I hit the hard limit (i.e. the machine itself) it pulled the all-thread off collar. I went to re-tighten in and the set-screw was actually a bit stripped out. (Or I stripped it out...) In any case I couldn't get it tight enough and it kept pulling free after a couple of minutes. Made things interesting. Caused me to turn the air blue with my language a couple times too. Quitting time. (To be continued)

gdgeorge
09-02-2010, 06:46 PM
So a trip to the local big-box for a replacement setscrew and a bit of loctite seems to have resolved the loose drive screw issues. I had another issue where the machine simply stopped functioning. Tried lots of things including reinstalling Mach 2 but no dice. Finally realized that I had somehow turned the jog rate to 0... Reset and voila! We're cutting again.

I had set up my shop vac hose to ride along with the router. It worked fine until all of the magic blue smoke came out of the shop vac. The hose was easy to adapt to my dust collector, but I think Im going to get some copper wire and ground the shop vac hose just in case. Any suggestions?

I also got some limit switches that I'm going to install this weekend, I think. Note: I sometimes think that the seat/keyboard interface unit is going bad as I seem to have an almost scary ability to make the machine do unexpected things.

Last night I played around with some simple engraving on scrap Luan. I've got to check but Im not sure that an inch on the drawing is an inch on the machine. I remember seeing something about that....

So much to do. More to follow!