oval holes with perfect x,y alignments.

[myths420]

If you can see either end of the Y axis ballscrew I'd put a dial indicator against it and jog the machine backwards and forwards and see if there is any play there. Also check the bolts for the ballscrew unit attached to the underside of the machine bed are actually tight, I've seen them loose before.

the way its put together its compressed between the machine and the locking thing for the motor so no way to test it while its together. i have just again completely taken apart the x and y axis, made sure everything was tight and it was. any more and id be more afraid of the threads snapping. i dont feel any play anywhere so completely at a loss of what it could be. as far as the video to calibrate backlash i have literally done this at least 70 different times sense ive had this and lashes are what they are, but the way i do it now is by cutting lots of squares and adjusting untill the transition is seamless form where the cut starts and where it stops after cutting the rest of the square, that just makes me think its something with the kit.

[RJS100]

There are three points that directly affect backlash with your current setup:

1. The connection point between the ball nut and the saddle. If your mill is a PM833, this is done with an M8 screw. Be sure it is tight and use lock tight.

2. The bolts that fasten the bearing block to the mill. Also must be tight.

3. Most importantly, the bearings are angular contact bearing and you need to adjust the preload. I will try to find a video that illustrates how to do this

[RJS100]

Here it is

[myths420]

There are three points that directly affect backlash with your current setup:

1. The connection point between the ball nut and the saddle. If your mill is a PM833, this is done with an M8 screw. Be sure it is tight and use lock tight.

2. The bolts that fasten the bearing block to the mill. Also must be tight.

3. Most importantly, the bearings are angular contact bearing and you need to adjust the preload. I will try to find a video that illustrates how to do this

ty ill watch this. i just finished reinstalling my 3 axis dro to help tune this thing so i can get accurate measurements.

[myths420]

well im leading towards possible bad bearings, i tried multiple times yesterday, first was with vid and have it free spinning when loading, the problem is if i put any load on the bearings it doesnt free spin. run out was still high. i put maybe 1/8 turn of preload and removes about .002 of the .007 runout but then i get chatter when moving the y axis. cant pinpoint if its the bearings but not sure what else it could be. ordered some replacement bearings and going to see if its any different when i preload it. looks like im still running down this rabbit hole. doesnt look like my dro kept calibration after taking it off the mill a few months ago so need to calibrate that first.

on a side note does anyone know how to speed up probe speeds? i want to keep the actually probing speed slow to be more accurate but i dont want to wait 5 minutes for it to move across a part to get to the other side. any way to just increase its travel speed and not probe speed? if i increase fast probe speed both travel and probe are faster but id think those 2 settings should be separate. not sure if i should make a new post but will see if anyone knows in here first.

[centroid467]

Fast probe rate is the travel and initial surface detection feed rate. The measurements are taken at the slow rate.

From your report dated 4/11/2025, your fast rate is 30 inches/minute while your slow rate is 1.

If the probe is well within its overtravel limits at 30 inches/minute fast probe rate, then you can try incrementing the fast probe rate by 5 IPM to reach a suitable speed. You'll need to watch and make sure it does not overtravel.

Setting the fast rate to 50 inches/minute should get you across a 5 minute (150" of travel at 30 IPM) part in 3 minutes!

[suntravel]

Slow and fast Probe speed is configured in the Wizard.

Do you have angular bearings or just normal ball bearings?

Uwe

[RJS100]

The bearings that Dave sells are angular contact bearings. Did you confirm that the bearings are oriented in the correct position? If my memory is correct, the video demonstrates this as well.

[myths420]

ty for the info, in regards to the travel speed it looks like im just stuck with the slower speeds as i dont want it to ping the probe to hard would just like it to travel to its next point quicker.

for the bearings yes they are angular, think 7202b 2rs if i remember correctly. i made sure they were oriented correctly but ordered some more to be on the safe side. running into another weird issue now, same as when i first started this conversion with backlash. with my dro installed ive gotten all my rotations pretty close, backlash has jumped to .0019 on x, z has stayed the same .00145 i think, as for y i just have no idea whats going on. spend all day yesterday. taking apart trying different preloads on bearings and getting backlash measurments. when i stopped for the day current backlash was back at .006ish doing some more fine tuning today with my dial indicator and dro to make sure everything matched i notice my y axis moving inconsistent. rechecked all the settings disabled backlash comp and after testing for about 30 minutes as of this moment my backlash is completely 0. according to dial indicator and dro. im 100% sure it will be different tomorrow. ive taken this machine apart so many times i could do it blind fold im fairly confident every point of connections is completely secure. does this sound like a bearing issue. not sure what signs to look for if a angular contact bearing is going bad. does it just lock up or does it cause play.

[myths420]

ok i think the issue was just crappy bearings from dave. just got new ones in from bearings direct and been testing. have y axis at a steady .00114. ty for all the help and info. now need to order some new ones for x as well. sucks spending so much on a kit just to have to replace bad parts. think maybe even y. they have held solid at .0014ish but they seam to be going out as well i guess. not touched them and no they are over .002