Bed probe issues


So I am in the process of assembling the last bits of my wilson 2. I noticed however the the rack and pinion mecanism has a funny or 2. When disassembled the rack and pinion can sit at a 90 degree angle when in the activated position however when I fit it to the carriage it doesnt actually do that its slightly off even though the motion is smooth. Also when I fit the springs for the pinion it seems that there is now alot of tension needed to activate/deactivate the probe. Anyone have these issues before and how did you address them?


I had the similar issue… here is my fix I changed the part slightly and it worked for me. If you try it let me know if it works for you.

Just as a check… is your X carriage traveling enough? you could add a bit of bluetac to the end of the rack to make sure.

Marty I actually cant remember how much different but building the second Wilson II I had the same issue and reprinted my fix. I can give you my Inventor files for the part or convert them into something you can use (other than the stl)


will give it a shot thanks


The axis is traveling enough its just that the pinion becomes rather tight to move once the springs are added. Are they really needed


I had the same issue at first with mine. I found that my first issue was the springs getting caught on the screw on one side. this caused it to not be perfectly set. After that I had the same tightness issue and found that I just had to back the screw off that the z-probe pivots on. you could try loosening it a half turn or so. Once I did those 2 things my probe pivots without a problem.


Ok so just to be sure it has a bit of tension when you move the pinion right? It doesnt seem to set to a point where its rigid always has a tiny bit of wiggle


yes… there should be some tension, but to much can cause it not to have enough force to move it.


Ok all sorted. I have however come across a few gotchas with this build which might be useful to other members. When you go by the bom for a 200x200 bed and intend to use the rack and pinion abl you will lose about 20-30mm in build volume. I found this out when everything was assembled. Easy fix thought is to extend the 4 extrusions parallel to the x axis by 40mm and also the x rods although my rods were bought to the spec of the bom and were a bit longer when everything was said and done. I think the bom calculator doc needs an update to accomodate the rack and pinion mount. I also found that the y axis calculations were way off as i have about 300mm travel endstop to the end of the axis although you can limit the travel in the firmware without much hassle


I am running into the issue where it is not traveling far enough. Originally I was using different springs than Marty used, but I found the mcmaster part # in one of the comments on the video and replaced them thinking that would fix the issue. I did this along with sanding the teeth on the pinion thinking that would help. When it hits the 400mm max, it moves just a little bit back, but does not “snap” and retract. It just nudges it basically. It’s almost as if I need to add 5-10 mm to the build area for the homing/ bed leveling process just for the pinion to know to retract or maybe just make the rack on the max side a little bit longer like you said with the bluetac. I was also interested in seeing if there’s a way to manually level the bed as an alternative because I did not see an option to do that.