Gathering ideas for a new CNC router-mill thingy

[Davek0974]

Too much metal on the Z axis?

I have ordered a bit too much metal and linear rails for the front plate of my Z axis, the back plate is 320 tall but for some reason i ordered 400mm plate and rails for the front plate where the spindle mounts.

Should i leave the extra or cut it down to match the back?.

Is it generally a good thing to have maximum space between the linear carriages on the Z axis?
I had originally sketched around 30mm but after drawing it up fully it lookalike i can go to about 70-80mm apart.

[Clive S]

It might be a good idea to post up your sketches so that they can be commented on

[Davek0974]

Backplate attached, not shown but its 160mm wide, 20mm thick aluminium machined tooling plate, same for the front plate.



Blocks are HiWin HGH20CA narrow, screw is 1605.

[Davek0974]

If i use full 400mm front plate i can space blocks much wider which i think is generally a good thing?

[Davek0974]

If we bring in the plates that are fixed to the rear side which connect the X axis carriages to the gantry rails, it works out very nicely i think - the plates are directly connected to the z axis carriage positions.

Plates are dimensioned as 15mm. bottom two are the gantry lower/upper sides and top one holds the z motor

[Davek0974]

Metal arrived today, will be on the mill this weekend i think :)

Ballscrews - with a stepper drive system and 1610 screws, is it allowable to let the nut hit the BK/BF blocks as a means of hard-stops or do i need to also fit physical stops before they hit?

The machine will have full limit switches so will not be ploughing into the ends too often hopefully ;)

[JAZZCNC]

If we bring in the plates that are fixed to the rear side which connect the X axis carriages to the gantry rails, it works out very nicely i think - the plates are directly connected to the z axis carriage positions.

Plates are dimensioned as 15mm. bottom two are the gantry lower/upper sides and top one holds the z motor

Dave Think you have been got by Classic Gotcha.?
How are you going to access the holes for fastening the rear plate to the bottom bearing plate.? The Z bearings fasten from back side so can't fit when rear plate is fastened. You'll need to Lift the bearings so can access the bolts.

[Davek0974]

Dave Think you have been got by Classic Gotcha.?
How are you going to access the holes for fastening the rear plate to the bottom bearing plate.? The Z bearings fasten from back side so can't fit when rear plate is fastened. You'll need to Lift the bearings so can access the bolts.

....Scurries off to grab the drawings............