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

[njhussey]

I get that Dave, but not how the block and torch mount connect to the stepper?

[Davek0974]

Ah, right.

Behind the plate lies one of these -
http://www.ebay.co.uk/itm/NEMA23-75m...item4881441268

Its a standard Z-axis unit, screw drive, 2mm pitch, 75mm travel - the motor sits on top and drives the screw direct, the middle block is fixed to the gantry carriage and the upper/lower blocks move with the motor/screw.

Works well.

[njhussey]

Ah ok, so why do you need the rail and block on the plate that's moving up and down? Fine adjustment? Surely mounting the torch holder on the bottom of the plate will be enough?

[Davek0974]

Ah ok, so why do you need the rail and block on the plate that's moving up and down? Fine adjustment? Surely mounting the torch holder on the bottom of the plate will be enough?

The second rail/block you mention is the floating head, it only moves a few mm, just enough to trip a switch as the torch probes the metal surface before cutting.

You can't do initial height sensing without one.

[njhussey]

Ahhh...ok I get it now....said I was being thick!! I know v little about plasma cutters....and it shows!!

[Davek0974]

Little bit slower now, onto the small fiddly bits....

Got the Axis hard-stops and beam end-covers designed, cut and fitted..



Fitted the floating head, torch mount and probe/limit switches...



The front Y & A axis limit/home switches...



And the Y far-end limit switch...



Started work on fitting the cable chain to the X axis now.

[njhussey]

Looking good, it's the little bits that seem to take the most time....

[Lee Roberts]

Looking sweet Dave, nice bit of metal work there!

[Davek0974]

Thanks,

another slow day today, had a few orders to make then fitted the cable tracks and trunking and started planning out the bed support frame.

[Davek0974]

had a couple of hours today, fitted the last of the limit switches and started on the slat support frame.

I thought a seperate frame would be best to avoid putting any heat into the side frames and make replacement easy.

50 40 x 5mm angle fitted into bed opening and a strip fitted to its bottom edge to support the slats vertically.



Quite disappointingly when i did the heavy tacks to secure the bottom return strips, the angle warped and is now 4mm high in the middle

Not good, not sure what to do about it - ignore it and let the THC tackle it, maybe slit the angles vertically in two or three places, press it flat and weld up or something else.

I didn't think angle that heavy would warp!

Apart from that it s all going to plan