Motors sound as if they are binding???

[dubliner]

I just tried out my new BT32 standard with a 2.2 spindle on it. I was trying some 3D files and the second one ran fine, but 1,3,4,5 failed in roughly the same spot. The X motor sounded like it was grinding hard to get past something. Nothing in the way though.At that point it lost its XY position by an inch or two.# 2 had no dust coll. neither did 4 & 5. File was Chisel & Mallet, set up in C3D, imported into VCP, 3 ips xy, 1 ips z, 13000 on the spindle. Any ideaas, & no I havent got it grounded fully yet :-(

[Gary Campbell]

Neville..
Pull the motors and see how the axis' move thru the full range of motion, pay special attention to the area where you lost position. Check all 3.

Check to see if any bolts are loose anywhere near the motion areas.
Gary

[wberminio]

Neville

Check your driver connections.
Any loose wires in the Wago connectors or in the control box will cause grinding sounds.
Pull the motors as Gary says and check each motor individually.

Erminio

[dubliner]

Gary/Erminio ~ I'll check the connections. As for pulling the motors, do you mean pull them & push the table & gantry by hand to see if there's any binding or run the file with the motors pulled to see if the motors themselves exhibit any anomalies?

[wberminio]

Neville

Loosen the allen bolts so the motors are pulled down and disengaged from the rails.Test each motor
separately so you can isolate which is causing the problem.Most likely you'll find that there is a loose wire at some connection.

Erminio

[Gary Campbell]

Neville...
Part 1 as Erminio says.
Part 2 while the motors are off check the mechanical axis movement as I posted above.
Livin' in the cone!
Gary

[GlenP]

Hi Neville, have you done a comm check to makes sure your computer is communicating with the controller at a good speed. I wonder if you are trying to cut faster than your computer is sending info to the controller and making the motors skip and act erratic. Do a search for comm speeds to find some info. I have a prs standard and don't cut at 3ips for the 3d. Have you tried cutting it at a slower speed? I like to cut slower and get a better cut then going fast. Just some thoughts, good luck let us know how you make out.

[tparr]

I have the exact same machine and spindle and had the same experience, until I slowed down the feed-rate to ~1"/sec. I think that the weight of the table (alum) causes the servos to miss pulses when it chages direction and thus the XY position loss.

[dubliner]

hey guys, 3 IPS is perhaps too fast for 3D, i'm new to the standard so I havent got it dialed in yet. 1 ips seems slow. I wonder could you bring that up somewhat by adjusting cornering & ramping? Another question on tensioning the X motor. I thought the spring handle was used to pull the pinion up against the rack, but I see a bolt that can be lowered to push down on the motor mount. Its clear of the mount now & the motor seems to be nice & tight against the rack. TIA Neville

[kivimagi]

I was having lost steps on the a bt48 standard up until Friday. IT seems that I had the motor too tight against the rack, and things were binding.

I pulled the motor up against the rack, and then backed it off with the screw on the bracket. I backed it off until I heard ticking, and then slightly retightened things so there was no slop.

This has solved my missed steps so far.

Regards,

[dubliner]

Well I'll have to try that tomorrow. What was throwing off the scent was it moved & jogged without noise, but I did look closely as it cut & it seemed to happen in roughly the same place on the table & the same place in the file. The motors increased in sound by at least 3 times, and shuddered as if you were pushing against the stops. I'm used to the alpha motors not losing steps so this is a new one for me with the standard. I cant understand why it doesn't happen anywhere else so I may also have something out of square. Thanks for all the suggestions - Neville

[dubliner]

Well Gentlemen, it appears the X rack & pinion was too tight and it would bind in roughly the same spot ( of course ) so thanks to you all for your suggestions. Much appreciated - To Thomas I cut the file 3 times without error at 3 ips, so perhaps you might push yours a little faster & check if the same thing is happening. By all accounts a Standard should be able to handle that with the right material & bit. Neville

[tparr]

After reading the above comments, I adjusted the X servo to the minimum contact compression and retried the file that was giving me trouble, which was the "roping" 3D file on a 15" circle. This file has the machine moving or reciprocating within 3/4'. It ran at 2"/sec quite well. The test was to re-enter a hole made with the cutter at xy at 1,1 without making it larger, after running the file. It did great. I am interested in what "ticking" is. Maybe I could improve the set-up.

[dubliner]

Thomas, With power on & x table towards the back turn the bolt that will loosen the X motor until when you push & pull the table the pinion will click against the rack, then back off the bolt so it allows the motor to engage the rack again,when you have it loose the table will click , but when you tighten it the click will go away. So not too tight as to bind but not loose enough to tick or click. After all that though it turned out my V rollers on the Y were way too tight, so not sure ix X was at fault originally.