I have a strange situation with my TronXY X1.
I have designed a circular standoff (20mm x 7.8mm) in Fusion 360 with an internal hole diameter of 4mm. When I print this I get resulting diameter of ~3mm. Diameter varies from 8.3mm (z=0mm) down to 7.30mm (z=19.35mm)
The overall height is not 20mm but 19.35mm.
I use repetier-host v2.1.3 witn integrated Curaengine and Slic3r. Both slicers show this strange behavior although not to the same extend.
Any idea someone?
Thanks a lot,
It could be that the x axis isn't perpendicular to the y axis. This happened to me after I printed the z axis stabilizers. They must have been warped or something because they were pushing the x axis out of place. The effects of it were that circular prints turned into oval-ish shapes. I fixed it by heating up the brackets while they were installed and when they got soft I manually pushed the x axis bar into alignment (90 degrees from the y axis) and when the brackets cooled they held alignment perfectly. As for the height of the print, I don't know. Even if you didn't print the stabilizers just check by looking at the printer from up top and making sure that the x axis bar is at a right angle.
Is the hole circular, or does the diameter vary round the circle. It sounds like you may have slop in the belts or they are catching on the edges of the aluminium channel.
Alternatively if the model looks odd once sliced (take a look at slic3r's preview and zoom in to see if the slicing has resulted in a cone rather than a pipe), try a different program (FreeCad perhaps) and see if you get similar strange behavior.
Also look at the amount of play in your Z rod, is it straight? Does it wave about in the breeze?
There are a couple of models here on Thingiverse that will fix the slop in the Z axis, the belt tension, and the slop in the X and Y axes.
On my version, I fixed all of these issues with careful adjustment of the existing hardware.
I also had to shim the Z rod in the flex coupler with a bit a nylon tubing to get it to run straight, true and vertical.
Once I had it all trued up, it is quite accurate, I printed an M25 fine pitched thread and an M10 fine pitch thread with it (with a layer height of 0.1mm and an add on part cooling fan). So persist and you should be able to get pretty accurate results.
Most of my modeling so far had been done with FreeCAD, which I'm impressed with.