I currently have a 4 x 8 cnc router, and I feel like I've reached its limits. I'm working on upgrading it piece at a time, but I would really love to just splurge and buy a hands down better machine. That's probably not in the cards at the moment, but I'm keeping my eyes open for deals, and something local has popped up.
I'll post what few pictures I have below, but basically it's a pretty beefy welded steel frame 4 x 8 machine, with U.S. Digital nema 34 motors geared down about 3:1 with a Bison reducer (this guy: https://www.bisongear.com/catalog/pr...95/category/4/ ). Rack and pinion drives, but the gantry is driven by only 1 motor - instead of an A-axis motor, it has a 3/4" or 1" steel bar running under the table, over to a rack and pinion on the opposite side of the motor. It has gecko drives, but I couldn't tell what models without tearing the box apart.
The current owners were using it to cut relatively thin aluminum, and had it set up super slow. They expressed concern over whether it could corner rapidly.
Here are some pictures:
Do the experts out there have any opinions about how well this might perform? My current machine has Nema 23s, not geared down at all, direct drive onto rack and pinion and I rapid at 400 ipm, and cut up to 200 ipm, depending. My motors might be able to move everything faster, but there are design issues which introduce flex into the system, so it's not as accurate as it needs to be. I get quite a bit of play at the router bit, making it hard to cut as accurately as I need. Do you think the above setup will be a significant upgrade? Do you guys have any guesstimate as to how fast something like the above could cut? I know it's hard to tell from just these pictures and my description, but I'm hoping some of you guys can give me some recommendations.
Also, with the above machine, I tried grabbing the gantry or carriage and shoving it - I could get some movement, but it sort of just wanted to not move and would flex back to where it was trying to live. The motors also sat there making a ticking noise, and changed pitch when I pushed on stuff. That is different from my current setup - my setup has some backlash in it, but otherwise seems to be more 'solid', and the motors make a high pitched noise that's hard to hear, but don't change pitch at all if I shove on them. Does that make any sense? I just don't know what's normal and what isn't with these things... Any help would be much appreciated!
Opinions on this machine please...
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