CNC Router V1.0 (For Cutting Multiple Materials)

[biketrialsdave]

I know what you're saying, that is a concern of mine. At the moment I'm using a thk kr33 assembly as I bought it a while back. However, I am planning to use the excess thk linear rail that I'll have left in the future. Perhaps I should design that in now...

[JAZZCNC]

Perhaps I should design that in now...

No perhaps about it Dave needs to be done. The Z axis is KEY area don't matter how well built rest of machine if Z is shite or weak.!!

[biketrialsdave]

No perhaps about it Dave needs to be done. The Z axis is KEY area don't matter how well built rest of machine if Z is shite or weak.!!

OK, I'll get onto that tomorrow! I assume 2 linear rails with the ballscrew in-between them sitting in a slot to reduce the overall depth? I'm using THK HSR15 carriages for the other axis, I assume these will be OK for the Z too?


The drop brackets on the rear are 5mm steel at the moment. I can increase this and also add some kind of right angle bracket perhaps.

[Neale]

OK, I'll get onto that tomorrow! I assume 2 linear rails with the ballscrew in-between them sitting in a slot to reduce the overall depth? I'm using THK HSR15 carriages for the other axis, I assume these will be OK for the Z too?

Even if you don't really need them for strength, this is one place where "20" rails and carriages can be useful to give just a bit more clearance between Z plates for the ballscrew and nut. If you have to buy them and don't have something in stock already, this might be something to consider.

[JAZZCNC]

OK, I'll get onto that tomorrow! I assume 2 linear rails with the ballscrew in-between them sitting in a slot to reduce the overall depth? I'm using THK HSR15 carriages for the other axis, I assume these will be OK for the Z too?

Yes more than enough regards forces etc but has pointed out by neale 20mm can work better regards spacing etc. Personally I use 20mm on all axis for simplicity and hardly any difference in price.

The drop brackets on the rear are 5mm steel at the moment. I can increase this and also add some kind of right angle bracket perhaps.

Yes you need more bracing to stop deflection. 5mm steel isn't really upto to it without being braced.

[routercnc]

I have 15mm rails on Z and they work ok but they use M3 bolts on the rail and carriages which look very small compared to M5 on the 20mm rails on my Y axis. When cutting I can feel vibration across them especially the top ones and for this type of machine I would go with 20mm on Z.

[biketrialsdave]

Thanks for all the feedback guys. I think I'll go with Hiwin 20mm for the Z axis. What would be the "minimum" recommended centre distance between the two rails? I want to keep this as small as possible to maximise the effective Y axis length but without compromising rigidity. At the moment my whole Z axis assembly is 130mm wide..

[Lee Roberts]

Thanks for all the feedback guys. I think I'll go with Hiwin 20mm for the Z axis. What would be the "minimum" recommended centre distance between the two rails? I want to keep this as small as possible to maximise the effective Y axis length but without compromising rigidity. At the moment my whole Z axis assembly is 130mm wide..

Well generally I always suggest 250mm minimum, obviously this harder to achieve on smaller machine with smaller z assembles...

.Me