I printed the piece the first time rotated to 90 degrees, causing it to print upwards. After wanting to go for a reprint, I decided to print it on the bed laying flat with no rotation. I used the exact same model with the exact same Slic3r configuration file, but the finished print was noticeably larger than the first print. In both prints I didn’t change the scaling whatsoever. Anyone know what might be causing this? Here’s pics of the models in Repetier and the finished print. Anybody notice this problem before or have a solution to it?
To summarize, the flat print (Repetier Pic 2) was the larger/correct size.
did you change anything in your firmware?
maybe your steps per mm of the x/y ax is off?
this could cause it to get larger prints in the x/y direction
No its just the Marlin V2 from Vellemans download section. The only things I’ve changed is the extruder steps to accurately calibrate it. Other than that everything is standard.
i think there is a problem with the steps/mm settings.
Which object is closer to the designed measurements?
So the one printed upright got too high?
What are the steps/mm for your z axis?
Using the stock threaded rod they should be around 2560 steps/mm.
sorry for the delay. The object printed flat (Repetier Pic 2) was the correct dimensions, the object printed upright (Repetier Pic 1) was significantly smaller.
Here’s my EEPROM configuration. Anything look like it might be causing it?
Well, your steps/mm seem quite ok.
I think your Z axis motor is losing/skipping steps.
Did you oil the threaded rod well?
Does ist wobble around if spun, or turn niticebly hard at some angle?
This may cause the thread to bind, keeping the motor from rotating as it should.
What Vref did you set for the Z axis stepper driver?
All of the rods are well-oiled. I tend to re oil them lightly after each print.
Its spinning with fairly even pressure. No noticeably harder turning.
I just switched out the flex coupler to see if perhaps it was slipping. I’m going to attempt a reprint of the same part with the same (upright) settings once I’m back home.
The thing that is confusing to me is that the overall dimensions of the (upright/incorrect) part are fairly accurate. I can still slide it over the other main piece quite well. It’s overall length just seems off. I think you may be right about the Z-steps. I’m just surprised it squeezed the model so consistently. Could it be a Slic3r issue when rotating the model? I have little experience configuring Cura so I haven’t attempted that yet.
I don’t think it’s a slicer issue.
i had to calibrate my steps/mm for the Z axis also, to get correct height.
Have you tried to print a calibration pyramid, to find out how much it is off and if it’s evenly off?
Have you tried to reduce Z axis jerk?
Hmm alright then, I’ll give that a shot and see how the pyramid comes out. Once it’s done I’ll post a pic and the measurements.
Right now my maximum Z-Axis jerk is at 0.30 mm/s. I lowered it to this a little while ago, do you think it needs to be lower?
[quote=“pwalsh117”]Hmm alright then, I’ll give that a shot and see how the pyramid comes out. Once it’s done I’ll post a pic and the measurements.
Right now my maximum Z-Axis jerk is at 0.30 mm/s. Think it needs to be lower?[/quote]
Not normally, but just give it a try.
If the rod is sticky it might help.
Well I printed a calibration cube (part link below). I switched out my coupling for the stock one, re-oiled, and used the same configuration as before. Didn’t change any settings just to test. everything printed okay, within 0.25mm, I want it to be a little more accurate. Maybe my coupling was off somehow. Any advice on the accuracy?
thingiverse.com/thing:37869
Well, which axes are off?
all three, or only Z?
X and Y may need some fine calibration because of the belt drive.
Z axis should be almost spot on, putting the shrink of the printed object aside.
How is your Z axis mounted on the top end?
Still with the stock mount?
If so, is the bearing tight or loose within the mount?
If it’s loose that may be a cause for shift in Z axis.
