Z Motion Problems

[backyard_cnc]

Hi All,

Have a strange problem that I have been unable to resolve. I have a PRT standard with 4G upgrade running 3.6.44 software. Was running a job and after it started normally for the first few cuts it seems the Y axis started to only go only negative and crashed into limit. I shut everything down to reset and once up the XY axis both jog normally but now the Z axis will only move down regardless of direction commanded. I swapped the Z motor onto the Y driver and it moves normal both directions on there and I also swapped the GECKO drives from Y and Z slots and is still ok on the Y position, so that tells me my MOTOR, Cable and GECKO are good. I reconfigured to have Z on my A position as I have a 4th axis GECKO installed but not used and that port also give same results only downward motion. Can't see what I might be missing other than it has to be a hardware fault on my relatively new low hours 4G PCB.

Comments or advice appreciated.

Gerald

[Brady Watson]

Go through your motor wiring with a fine toothed comb. Turn box off. Use Wago tool to release & re-seat each motor wire in the connector at both ends, both male & female.

Pull the Geckos out of the board. Remove the screw blocks that are attached to them & reseat them. Then replace them on the board. I've seen the connections between the Geckos and board pins fail for whatever reason (and screw terminals to Geckos fail as well) Pulling & reseating usually does the trick.

-B

[backyard_cnc]

Thanks for reply brady. Pretty sure motor and wiring are good since they work fine both directions when connected to the Y driver and the gecko from the Z position also works fine in the Y slot. Looking like its a hardware fault on the 4g pcb. I found another thread on here where another user had similiar issue that required a hardware fix (replacement hex inverter IC) on the board so hopefully I can source the parts and repair it here without sending it to Shopbot since I am in Canada.

gonna try calling Shopbot tech support tomorrow and see what they say.

gerald

[backyard_cnc]

well looks like a fault on 4g pcb so after some talk with Shopbot tech support I am gonna try to repair it here in my shop. ordered up parts from DigiKey and they shoukd be here tomorrow. in the meantime I got running again with my old pc and original v3.54 pcb. you realize how good the current software and 4g hardware is when you fall back after a year!

sure hope the parts fix the problem!

gerald

[backyard_cnc]

Well I breathed a sigh of relief when my Z axis started to worked in both directions after I swapped out 2 IC's on the motherboard. Not a task I would recommend for a neophyte in soldering but certainly doable by a well practiced tinkerer!

glad to have the Shopbot back at full capacity after finishing up a project on the old driver PCB. Got me to thinking though that I should build a complete spare control box so swaps are easier and maybe get a better PC configured to run it. Going back to WIN98 on my original PC was better than reinstalling the software on new PC but still a nuisance. Oh well alls well that ends well I guess. If anybody has this issue I can send you along pictures to show the parts that need swapping if needed but sending the controller to Durham is certainly an easy and affordable object if you are in US but since I am in Canada.....................

thanks to Frank at SHOPBOT Tech support for answering my questions.


Gerald