not sure where to post this. I am cutting a series of holes ( about 300 its a cribbage board ) 1/8 in to a depth of .4 in after 15 or 20 noticed the bit getting closer to the surface, eventually it doesn't clear and plows. I have torn apart the Z and tightened everything and tested, but when I go back to drilling it does the same thing. I know its not a software issue, its mechanical. This is on a Sphynx 1050 with a dewalt 611 any suggestions?
What control board are you using. I had this problem with mine when using an underpowered CNC shield and not having $1 set to 255. Mine looked like this Lead Screw Driven Ox Derivative (850x1500) and would eventually start cutting deeper and deeper. Read that and then following posts to #14. The gnea/grbl explains it. Basically, your motor may be slowly lowering due to gravity. If this is not your problem, then we will have to keep digging.
It has an Xpro V3, and has worked well for the past year. Ihave had problems with the collars on the leadscrew not tightening properly. The setscrews are tiny and the allan wrench wants to strip the screws
Or an oddball case, could be the endmill pulling out of the collet. Happened to me a couple months back (accidentally had some 6mm shaft tools, that fit snug into the 1/4inch (6.35mm) collet, but while cutting, slowly worked their way out of the collet.
Could be, I’ll check. Its an 1/8” ball nose. Problem feels like a clutch slipping only on the upstroke, eventually plows into the surface.
Finally found it. Turned off the power and tried to pull a bit out with a wrench, couldn't do it. So tried to manually drive the bit into the spoil board by turning the gear on the stepper motor by hand to see if I could get the bit to move. The bit hit the spoil board and I kept turning the gear, it wasn't easy but the timing pulley and the 8 mm clamp collar turned, but the lead screw didn't. Have to figure out how to tighten it, maybe roughen up the surfaces first. Thanks for the all the help, especially Peter, you got me looking in the right area. I think it was the rapid retract on the drill sequence that was causing the slipping.
I use longer 3mm socket cap screws with locktite. I also drilled into the screw shaft and tapped that as well, but that may be overkill.
After switching to direct drive on the Z axis everything is working great again. It took a little while but I'm slowly getting my faith back in the machine. ( so you don't cringe every time you try to cut something ) Even gone so far as to use my new dust shoe ( one where you cant see the tool at all ) and boy am I making sawdust. Thanks for everybody's help, its appreciated. Then I ran into other problems... My stupid el cheapo laser that I use to sign and date my work started acting up. It was a software glitch that I have been living with for a couple of years. I finally started to look around for a replacement, and saw the Laserweb4 so I thought I try it. After putsing around for a couple of hours I got it going, and I'm impressed! I like how you can control everything. Now I can print really small in what ever font I want. Thanks Peter this stuff is good.
(; glad you like it, LaserWeb was my baby before I joined OpenBuilds (; so should feel kinda familiar hehe
