Game on!

[Voicecoil]

Tramming's not such a bad thing as might appear - the vertical blocks that the Z-axis Hiwins are attached to have increasing clearance hole diameters from 6.1mm (bottom) to 6.6 mm bot( top) to allow some side to side movement at the top to get it square. And they make the Z-axis plate seriously chuffing rigid top to bottom-wise. Front to back tramming (which would always seem to be a bugger on a gantry machine to me) was done using the end fastenings on the gantry and a bit of shimming As regards the bearings being on thin plate, that was a result of me not having much in the way of machining facilities, the top plate and a few other bits are due for a re-make once I have it making chips, with thicker material and better alignment once I can sink the bearings and the motor into the plate.

[JAZZCNC]

Tramming's not such a bad thing as might appear - the vertical blocks that the Z-axis Hiwins are attached to have increasing clearance hole diameters from 6.1mm (bottom) to 6.6 mm bot( top) to allow some side to side movement at the top to get it square.

In that case, you are bending the ball-screws because they are fixed to the top plate while the bottoms are fixed to the upright plates which your moving causing a twist on the screw. Also, the ball-screws must stay aligned perfectly parallel to the rails which they cannot do this way because you have them fixed to the top plate.

This design fails the golden rule of DIY to me.? Which is build-in Adjustment, adjustment, adjustment and bit more adjustment just for good measure?

And they make the Z-axis plate seriously chuffing rigid top to bottom-wise.

Pointless if they cause vibrations through the spindle, which they will do compared to if they were fixed directly to backplate like on conventional design. You could also use a similar supporting strip on the rear plate if felt it was needed on conventional design but without causing vibrations.

[Voicecoil]

In that case, you are bending the ball-screws because they are fixed to the top plate while the bottoms are fixed to the upright plates which your moving causing a twist on the screw. Also, the ball-screws must stay aligned perfectly parallel to the rails which they cannot do this way because you have them fixed to the top plate.

This design fails the golden rule of DIY to me.? Which is build-in Adjustment, adjustment, adjustment and bit more adjustment just for good measure?
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Well, the holes that secure the top plate to the back plate are a bit oversized to allow the bit of L to R adjustment whilst the idea is that the top of the side blocks and bearings stay fixed relative to each other - and after all the position where tram is spot-on should be when everything is perfectly aligned at 90 deg. If I were to do it again I would likely split the back plate into 2 stacked thinner plates to make assembly and tramming easier, but right now the important thing is to get this one up and running.And whilst it took a couuple of goes round the loop to adjust it all to get it running smoothly, it does basically work, it goes up and down quite happily apart from a slight wobble on one of the pulleys which I seem to have managed to bore out slightly off-centre, that's a job for tomorrow.