Xylotex
Originally Posted by
MechanoMan
Well, this is what I've picked up so far. I've been using them for a few weeks and have not worked with other CNC drivers.
Xylotech is prone to making motors resonate in the mid-range, that causes then to stall far below their max speed and torque. Supposed to be caused by the Xylotech's not being capable of micro-stepping, maybe also because they've got lower maximum input voltages. I'm dealing with the pain now. It can technically jog at 40ipm "sometimes" but without consistency, and if there's ever a risk of losing steps you can't ever run or jog it at that speed. Losing steps makes an unrecoverable loss of understanding of its position, it'll ruin your work, may break the bit, may drive the bit into the table or vice. Well it doesn't damage the motors or anything but you'll have to recalibrate the XYZ position in Mach3 and start all over with it slowed down or it'll simply ruin the next job too.
So I have found 15ipm seems like it is absolutely guaranteed never to stall. Which, well, I just broke a very fine point engraver on an acrylic block at ~15ipm. So I can't do the job faster anyways. I can't hog out aluminum faster than this either, not without flood cooling I think.
It seems to be a problem when doing finishing work where there's a curve that was initially cut with steps and the only way to smooth it down is go back and forth over the cusps thousands of times, removing only a speck each time. Chip removal and cooling are not an issue. The aluminum could only take 5 min to initially route out (which can't go any faster even if the driver could do it) but then an hour or two or three to try to smooth up the filleted curves. If I change the speed to say 40 ipm and simulate in Mach3 then the finishing time goes way down proportionately.
People have said that running the Taig at "high" feedrates will wear out the leadscrews and nut sooner. Frankly I am unsure if this is actually the case or not, people said they shy away from 50 or 60 ipm as too fast based on "feeling". Well, in any case, I don't think anybody said 30ipm was a problem at all.
There's threads out there showing that with mechanical vibration-dampening flywheels on the motor, the resonance problem may go away and the Xylotech can then drive at high speeds reliably. However, the thing is- and I didn't know this before- GeckoDrives are simply not all that expensive to begin with.
Xylotex drives micro step, the problem is that they don't have mid band resomance compensation and the other killer is that they are normally run on 24v-30v with IIRC 35v absolute max including bemf.
The mechanical dampeners apparently do a good job but if I had to do it again, I would go either g540 or g251's depending on exactly what I needed.
The g540 is $299 and the Xylotex plus the breakout board that you really should get to go with it is $50-$90 extra. Then if you want to have 0-10v that is extra but included in the g540.
Plus the g540 will run at 50v all day long making the machine fly. And not loose steps until a much higher speed, like 4 times faster.
My Taig is limited to 10ipm. This is the maximum reliable speed that I can get out of it with the current motors and such.
If I wanted to go faster and I do, I could get rid of the 425's and go to 387's or even smaller as with the stock 20tpi lead screw torque is not a problem.
If my machine would rapid a 60 ipm, I would probably let it go that fast, of course proper lubrication is a must. There would be an increased wear rate but that is the trade off of time vs wear.
Mike
Warning: DIY CNC may cause extreme hair loss due to you pulling your hair out.