[RodMcM]

Hi I have a 6040 and mainly use it 3-6 mm acrylic, have had it for about 9 months and generally impressed for the level of work I need. I have recently, for fun, put on a standalone 3D printer head and connected to A drive in Mach 3. All goes well, except for a totally repeatable lean on the Y axis, towards the Y zero ( print center is 100,100). Have read all the references I can on lost steps, but this is strange as it is going on one directlion only.
So after all sorts of experiments with rates, acc, puls times etc I get no change to the slope. The most telling is that by changing the Port settings for the X and Y on Mach 3 I get no change ion the slope ( accept that it goes a different way), so that tells me that there is nothing wrong in the parallel break out board, nor the CNC dfrives.
The attached photos show the front view (X axis) is almost square sides, the Y axis slope and the shot with three together shows the repeatability.

For interest I have included a shot of the 3D printer attachement as well

[RodMcM]

The question is of course, why is this happening?

[MarcusWolschon]

Is your Z axis perfectly normal to the print surface?

[RodMcM]

Not wonderfully, but quite accurate. Why?

[MarcusWolschon]

Not wonderfully, but quite accurate. Why?

isn't that obvious?
if it is not normal to the XY plane, every layer will get an offset until you get such a slanted result.
that's why I asked.

[RodMcM]

I can see that, but wouldnt the slope be the same as the offset from the horizontal plane? The slope on the parts well exceeds the offset I have on the horizontal plane of the bed.

[MarcusWolschon]

I can see that, but wouldnt the slope be the same as the offset from the horizontal plane? The slope on the parts well exceeds the offset I have on the horizontal plane of the bed.

yes, it would.
do get the same slope with different objects?

[RodMcM]

Yes I do get the same slope on different objects as you can see from the photographs. Thats the annoying thing about it, it is repeatable but I have yet to find out why. It looks like there are steps missing in only the Y pos direction, but the lay in the y neg direction is correct so I get the overlap each time... Annoying!

[tgdavies]

Do you get the same slope with objects of different *designs*?

If you make that block twice as wide in the slope direction, do you get more slope?

That is, is the slope a function of the total Y distance you move, or is it just a function of the Z distance?