Building My First CNC Router, Looking for Advice & Other Info

[AlexDoran]

...now you must practice how to set the orientation right. The pictures are nice but they are all (even the videos) turned 90 degrees... ;) I mean, the videos are supposed to be taken with the phone in horizontal orientation otherwise you are wasting image surface area.

Anyway, it is really a very nice machine you are building. The only thing I notice is that you seem to have made the same mistake I did regarding the Z plate. The linear bearings should be the other way round, the rails moving up/down and the bearings fixed. If not too late you should change that. For me it is too late now, but it sure will be the first thing I'll correct next time I upgrade my CNC.

Lol I took the photos portrait and they are portrait on my PC, so not sure why they have uploaded rotated! Schoolboy error on the video though haha

That's an interesting point about the Z Bearings, so is the point of this to be able to spread the bearings further apart?? Maybe I could change the design, I'll have to have a play around with the CAD model.

The machine looks good, it seems you are getting close now!

Thanks, still a way to go yet I feel!

Thanks

Alex

[Neale]

If you look at the geometry of the Z plates and imagine both ways of positioning rails and bearings, you will see that you get better support of the moving plate through its full travel if you put the bearing carriages on the fixed plate. It feels wrong at first, but it's the right thing to do! The rails also provide a slight stiffening effect on the moving plate as well, although if you use the usual 20mm plate, that's not going to matter much.

[Zeeflyboy]

While I agree, it was pointed out to me that it can make the Z-axis less versatile... it can limit the ability to retract the Spindle and tool above the gantry base height which can cause problems when using long tools and/or tall stock.

Just worth considering if that sort of thing is on the agenda.

[Neale]

No argument there - good engineering is all about compromise, and understanding the trade-offs so you pick the right compromise is important.