Gathering ideas for a new CNC router-mill thingy

[jamesgates1000]

Even with smaller cutters if you want decent speeds and doc you will need rigidity. The heavy builds are to deal with vibration and resonance that the tool generates as it cuts.

[Davek0974]

Ok, i have the basic design sorted with the generous help of a forum member.

I have a nice lump of ground cast iron 18mm thick for a bed, what is the preferred method of fixturing - a matrix of holes or built-up T-slots??

This will be a multipurpose machine metal through to wood being used.

Any preferences???

[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