Second CNC table build, here we go again....

[Davek0974]

Reclaiming some motion distance....


After building the base frame and motion, I decided to build a new floating head using Hiwin and a single carriage - pretty much a standard design. However, this moved my torch 30mm closer to the front of the table than I had planned which left very little over-travel on a full 1250mm sheet - not good.

The first pic is a cross-section of the average torch mount with the Hiwin at the bottom and the circle being the torch clamp.




Now, as I am using wide/stable Hiwin rail, could this idea work?? It regains a valuable 30mm of spare travel on the Y axis.

[Davek0974]

Here we go, down to 27mm distance now, thats a little less than my existing unit




The side effect is that to get the torch back on centre, I have to shift the Hiwin carriage to the left a fair bit, luckily this will be over the machine side beams and will not affect anything at all - perfect

[njhussey]

That should be fine Dave I would have thought, it's not carrying any weight and ther are no forces acting on it after all. For complete ease of maintenance could you not turn the torch mount through 90° (gap facing the front) and use one of the fixing bolts (now coming in from the right and tightening into tapped holes in the 5mm steel plate) to tighten the clamp? I'm not sure from the drawing if there's ease of access to get to the torch mount?

[Davek0974]

Yes, but then there would be a risk of losing the torch alignment when the torch clamp is released to remove the torch. Hopefully with the clamp mounted firmly from the base, it will stay fixed once aligned.

[Davek0974]

Got the floating head mount fitted to the Z-axis, probably work better when i fit a means to stop the carriage and torch falling off the bottom

[njhussey]

Dave, I'm probably being a bit thick....but how are you moving your Z axis up and down? From what I can see you've got your Z stepper mounted on the profile behind the fixed Z front plate? Is there something on the bolttom of your Z front plate that connects to the stepper behind the plate?

[Davek0974]

No, the round object sticking out of the top is the coupling for the stepper, it's just not fitted yet :)

It means i can move the z up and down by hand easily.

Inside its a standard screw type affair.