NordicCNC's build log

[NordicCnc]

Regarding spindle, I didn't realise it was an ATC spindle, which are a lot longer. Clamping high up may not be appropriate (though with a decent tolerance clamp I doubt you'd be crushing the spindle). The point is the longer the clamping area (or the further apart the clamping points) the better.

Yes, that's what I meant about the ribs. You don't need 15mm thick plate, even 5mm would be fine. The stiffness comes from the dimension in the direction of the force.

You should also add stiffening ribs to the carriage .

Machines only as strong as its weakest point. Currently what is keeping the back of your Z axis still? Its those carriages, which are attached via a 90 degree but-joint. So I'd say those two or so screws are the weakest point! That's why I created the side plates on my Z axis to give some support to the joints.

Thanks both of you pippin and Andy! I took your advice and now I've added 10mm aluminium ribs bolted to the front plate. I've also added 10mm side plates that are bolted to the rear plate, motor bracket and top bearing plate.



New total weights did not change much, while I think I have added quite a bit of stiffness!

Z-axis moving weight: 26.8kg -> 26.4kg
Z-axis total weight: 39.7kg -> 42.4kg



I am now debating, should I do something of the following things:

1. Remove the spacer plates used for the linear rails completely and add machining (on both the rear and front plate)? This would reduce weight (maybe 3-4kg?) and fewer parts needed. More machining though.



2. Move the spacers from the rear plate to the front plate. Linear rails would then go directly on the rear plate. Shorter spacers would be added behind the guide carriages and the front plate. This would increase the Z-axis moving weight by like 1kg, but reduce total weight by 1kg. I would gain some stiffness on the front plate, but lose some on the rear plate. Not sure where the weak point is and where the spacers are needed the most.