X Drift

In recent prints I have noticed my layers drift by about 1mm per 20-30mm of Z movement.

Not sure what other details to give, but anyone seen this before?


-Nick

Posible Causes to Investigate:

1. If using printed pulleys, make sure the pulley is not slipping on the motor shaft. Also check the temperature of the motor, but BE CAREFUL! It can get really hot, if the driver current is too high.
2. Driver current is a little too low. A cold motor during print might indicate this. You will also notice this if there is little resistance from the motor when you try to prevent it from moving.
3. If you do not have a fan, or heat sinks on the stepper drivers (Pololu, StepStick, etc), it could be that you are Temperature Limited.
4. If the X-Carriage bushings/bearings are binding occasionally, this could lead to missed steps, but I think this is the least likely.

1. No printed pulleys. Motors get quite hot, but not untouchable.
2. ^^
3. Bout a ~10" fan blowing on the whole machine from ~2-3 feet away
4. Using LM8UUs. They seem good.

Btw its a pretty consistent/constant rate of drift.


-Nick

Edited 1 time(s). Last edit at 02/06/2013 08:24PM by N314.

A photo showing the problem might help.
Parallel walls drift at the same time by the same amount? I assume it is 1mm in one direction only

-Nick

What type of printer do you have? It looks like the Z axis is just ever so slightly out of square with respect to your X and Y axes. On the the older Prusas I always found it tricky to square the Z axis, so if this is your type of printer that would be my first guess.

Prusa V2... so yeah... It crossed my mind that that could be the problem.

Any special trick for aligning them?


-Nick

If that is indeed the problem, it's quite simple actually: level your bed. As long as the Z has the same height against all 4 corners of your bed, it's fine.

Not true! The z smooth rods need to be perpendicular to the plane of the print. You can tweak the frame nuts to get everything square but I don't know of an easy way to confirm it

Hm.. yeah, I was kinda hasty on that. You would get a parallelogram with a slanted Z, even if the bed is leveled.

If you can fit a small speed square on the bed with the vertical edge against the z smooth rod, that should allow you to make sure they are 90 degrees exactly. You may have to remove to x axis assembly to get it in there though...

Hence Mendel90.

---

[www.hydraraptor.blogspot.com]