NordicCNC's build log

[NordicCnc]

Home & limit switches

Z-axis home switch at the top end of the travel. Soft limit will be used for the lower end of the travel.


X-axis home switch & limit switch on the moving part. Adjustable bolts in the t-slot in the lower right and upper left of the picture. The lower right will be used for home & limit switch and the upper left will be used for limit switch.


Y-axis home and limit switch on the moving part. Adjustable bolts in the t-slot on the left side of the base frame. Upper left one is used for limit switch and lower right one is used for home & limit switch. On the opposite side (right side) is the second home switch. The purpose with 2 home switches is to be auto to auto square the gantry when homing the axis.


Alternatively I could have all the proximity sensors fixed and not on the moving parts. Then I could use soft limits for all axis's in the opposite end of the homing position, same way as with the Z-axis. Would that be a bad idea? It would be less cable routing of the sensors in the cable drag chains,

[AndyUK]

I'd recommend having the homing positions on the dual screw axis finely adjustable - like how your Z position can be adjusted by turning that bolt. At the moment you'll have to loosen that bolt and t-nut and just hope you can push it accurately back and forth. It'll help when trying to square the gantry, where you need (ideally) sub-mm changes to switch triggering position and I wish I'd thought of that earlier. I've had to do quite a bit of back and forth trying to get the gantry squared.

You can work around it in software (I can't remember what controller software combo you're planning to use - but generally speaking its possible), but easier done once in hardware.

[NordicCnc]

I'd recommend having the homing positions on the dual screw axis finely adjustable - like how your Z position can be adjusted by turning that bolt. At the moment you'll have to loosen that bolt and t-nut and just hope you can push it accurately back and forth. It'll help when trying to square the gantry, where you need (ideally) sub-mm changes to switch triggering position and I wish I'd thought of that earlier. I've had to do quite a bit of back and forth trying to get the gantry squared.

You can work around it in software (I can't remember what controller software combo you're planning to use - but generally speaking its possible), but easier done once in hardware.

Extremely good point, thanks for letting me know. I will make some changes to the design to allow for fine adjustment.

[Clive S]

Z-axis home switch at the top end of the travel. Soft limit will be used for the lower end of the travel.

I personally would have the switch fixed and have the target moving

[NordicCnc]

I personally would have the switch fixed and have the target moving

Yes, that is how the Z-axis switch is planned in the picture.

[Clive S]

Yes, that is how the Z-axis switch is planned in the picture.

Yes sorry I was looking at it wrong.