PRT ShopBot upgrades

[Brady Watson]

Nice find on the Vrollers...even cheaper than the ones I posted when you factor in shipping, if you have Prime.

You might want to consider starting with some hex stock. I believe they take a 7/16" wrench, so: 360 Brass $9/ft It's way cheaper/easier than trying to put flats on round stock.

[pro70z28]

I'll probably end up using what I can find laying around the shop.

[Chuck Keysor]

Thanks Brady for the bearing and eccentric supplier information! I just got done ordering the bearings and eccentrics from the sources you provided.

If I may, since this isn't my thread,,,, when I get my 2 1/2" x 1 1/2" steel tubing welded on my X-car, would it help to weld some gussets or struts into the corners between the new tubing and the existing 3"x3" tubing?

Thanks again, Chuck

[Brady Watson]

Chuck,
The tubing you add will be butted up to the 3x3 ends of the gantry. It should be welded on all 4 edges. It is important to understand that welding is not gluing and it's not brazing or soldering either. Welding means that the both pieces to be joined together are melted to a semi liquid state under controlled conditions and filler material is dipped into the molten puddle whereas both pieces are fused together into one continuous piece or, welded together. So no, I don't think you need any gussets on the gantry itself. Put them on the frame if you don't already have them.

[Chuck Keysor]

Thanks Brady. My adjustable eccentric bushings and V rollers have shipped...……. Chuck

[pro70z28]

V Bearings came today. I went out to the shop, just to see what the job would entail. I obviously haven't paid enough attention to this part of the CNC for awhile. I noticed just how worn the t-rail is. I think I'll leave it as is until I get the other upgrades done, then tear it down and address the t-rail issue last. By then I'll have installed the 4th axis, so I'll have a better idea about Z clearance. Then I can tear it down once for both issues and be done. As bad as the t-rail surfaces look I'm surprised there isn't more play, hasn't been much noticable chatter. I haven't cut metal for a long time, I'm guessing it'd be noticable then. Since the V-bearings I bought come as an 8 pack, I'll probably just replace them all when the time comes. BTW, they look pretty well made for the price. Thanks for the heads up on the t-rail issue Brady.

[pro70z28]

Another thought I had. I have an old Multi Cam 4'x4' CNC that I retired, when an out of production Chip on the control board was fried by lightning. Fried the socket in the board too. It has an extruded T-slot table top, belt driven X stepper motors and a ball screw drive Y motor and screw Z motor. Could those stepper motors be used, they worked fine at retirement? Just wondering if a ShopBot control board would drive those motors? Is it just a matter of matching up a driver to the motor plate information on the stepper or is it more complicated than that? If I could drive those steppers with new electronics, I think I'd be inclined to leave the ShopBot alone and modify the Multi Cam as a dedicated 4th axis. Before the gears in my head get spinning too fast, I thought I better find out if it's even feasible. I didn't go the upgrade route with the Multi Cam at the time for a couple reasons. One, I really wanted a 4'x8' table and second, the people I talked to 15 or so years ago, made it sound like the bare chassis was about the only salvageable parts. Any thoughts?

[Gary Campbell]

In the "step & direction" world, and as long as the drives match up with the motors, you can put any motor drive combo on any control system and any control system on virtually any machine. Of course, there are a few caveats, like many of the controls using legacy parallel and USB connections are speed limited, so you cannot use many of the high resolution combos and expect speed from them.

[pro70z28]

Thanks Gary. I may have to pull the old CNC out and see what I have to work with before I get too far into working on the ShopBot. I bought 2 - 4'x8'x.75" sheets of plywood yesterday. I set them up with parts to make the base for the Jet vac & dust collector. What was left I set up brackets for the south wall of the shop to hold the coropast inventory. Leaning against the wall doesn't do much for keeping the sheets flat. These racks will take care of that and keep me a little more organized. I'll probably get the racks built first, then go back to the CNC upgrades.

[pro70z28]

I got the parts cut out for the CNC Vac platform and brackets for material racks for the shop, on the ShopBot today. I spent the day building the racks to get the shop a little more organized. Easier now to get at what I need, when I need it. By the time I finished the racks the ambition level had dropped below a functional level, so the CNC upgrade will have to wait 'til I get another gap in the schedule.