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DICKEYBIRD

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I’m starting this thread to (hopefully) keep moving me forward on this long overdue CNC machine for my shop. The thread was named after Vederstein’s post about his saving several linear slides from the dumpster at his day job. He made me a deal I couldn’t refuse on three of them that he had left over. Thanks Ved, you're awesome!


It all started with a plan to upgrade my old homemade MDO plywood & drawer slide CNC router built way back in ’94. I started doodling around in TurboCAD to best utilize the slides to improve the router. One thing led to another & the decision was made to build a new machine utilizing a heavy-duty table I stumbled onto on ebay.

It’s aptly called a “Brute” machine base made by the American Grinding & Machine Co. in Chicago. I got this one for $315 which I think is a steal. It came with 1 large electrical box and a smaller one on the other end. When I opened the boxes I found a bunch of DIN rails, cable tracks, wiring, a 3A 24vdc power supply, a 30A contactor, a bunch of 12ga stranded wire, DIN mount fuse holders and a ton of DIN mount terminal strips. It was way more than I bargained for.

That stuff is just icing on the cake though. Man oh man, is this thing is SOLID. It’s an all-welded design made with 3” square, ¼” wall tubing with blanchard-ground ¾” steel top & feet. I feel pretty sure it’s stress-relieved before the grinding is done and the fit & finish quality is great. The specs say +/- .001” over the entire 24” square top & it checks out with the straight-edge we have at work for checking cylinder heads. It weighs over 400 lb. What better foundation for a CNC machine! I don’t know if I should call it a heavy-duty CNC router or a medium duty CNC bridge mill. I’m thinking the latter until proven otherwise.

I had it delivered at work where I had some help flipping it over so I could drill the mounting holes for the casters. (Rated for 900 lbs. each) I have been accumulating other stuff for the project: 6 - THK linear slides, 3 - 425 oz/in stepper motors & 4amp drives, a 36v switching power supply (probably build my own 48v linear supply later especially if I build up a 4th axis) a dual parallel port card to go in the Dell XP PC I fixed up for it, an LMS Sieg X-2 mill head/R-8 spindle to be powered by my trusty treadmill motor & KB speed control. The gray posts in the background will be used as part of the fixed y-axis bridge. They’re 3” square ¼” wall tubing with welded 3/8” flanges on one end. I’m still working on the bridge design and my plan is for the whole thing to be bolted & doweled together so I won’t have to deal with welding/stress-relieving/issues. I’m sure I’ll hear complaints about the Mach3 P/Port control & that it should have servos instead of steppers but at the sad state my hobby-budget is now in, it’s all I can afford. It’ll be a slow process over the next 6 months to a year but at least the process has started, yay!

Brute4.jpg


Brute Casters.jpg


Brute Stuff.jpg


Brute Top.jpg
 
I'm looking forward to your progress.

...Ved.
 
You are correct American puts there bases in the oven to normalize them. Back in the day when I was building special machines we used them quite often. There grinder was big enough to set a full size pickup on and grind it down to nothing.
 
Thanks Jack, that's good to know. With as many heavy welds as there is on this thing & as straight as it is I figured it had been cooked thoroughly before it was ground!

Starting to make a little progress on it. Some more metal arrived & I hope to move forward on the fixed bridge a bit this weekend

. I finished the "Po' Man's Mag Drill (enough to use it anyway) & drilled the 1st 20 holes to mount the 1st linear stage assy. It has a pair of 12vdc security door electromagnets wired in series powered by a 24vdc power supply. It really locks down well to the table then I climb up on a step-stool & bear down on it. Eze-peazy, no pain no strain & very straight holes! Next comes mounting the pair of 20mm THK linear guides beside that stage & mount the work-holding table on top.

I attached a couple pics & a crude CAD sketch showing the basic structure. The bridge gussets are 1/2" steel plate & the top of the bridge where the other stage & pair of THK's mount will be faced front & back with 3/16" steel plate and a zillion bolts. The bridge vertical post are 3"x3" square steel tube with .290" wall thickness. When it has all been trial assembled & squared up, I'll tear it back down & & smear on some structural epoxy & final assemble it. Once cured & drill & ream for dowels in the important spots. Sound like a plan?

RobertL2 Post2.jpg


Drill Stand Use.jpg


RL2 Step 1.jpg
 

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