Item Deformation

I have been printing with my Taz 3 I recently acquired.

Have had some issues and most of them I have found answers through here , reading blogs or through my supplier.

But, I was trying to print a Small Herringbone gear for the extruder, but when it prints its always deformed and higher on one side of the print whereas the rest of the print is very nice.

I have leveled the bed to .254 using a feeler gauge all around, it pretty much measures .254mm anywhere in the bed between the nozzle and the bed, i test 16 different points on the bed and all are the same height.

Yet i print this herringbone gear and it gets higher always on the same side towards 00 on the bed.

I have tried to make the bed higher and lower on either end and i still get the same result.

Any suggestions?

This sounds like your Z axis motors are not in sync for some reason. I would test this by marking a spot on both sides (either on the smooth rod or threaded rod) and then move the Z axis up 100mm and measure both sides again to see if they show exactly 100mm

There are no separate adjustments for them so if they are not the same then it’s likely you have a hardware failure like a bad stepper motor or (since I assume you got the printer second hand) if someone replaced the threaded rod on one side with one that has a different pitch (teeth per inch).

Another possibility if the measurements don’t match up is one motor is not getting enough current and it’s skipping this could be due to the driver or wiring.

Do the test I mention, come back and post the results and post a photo of the part (a photo can sometimes tell the story better).

I resorted to level the Extruder bars but measuring from the stepper motor to the bar, gave me a much more accurate reading than from the aluminum plate on the bed.

Then I re leveled the bed.
I also leveled the Extruder nozzle by making sure the distance around the heater block was the same all around the bed at all point in the bed. I moved the nozzle to 16 different points in the bed and measured form the bed to the nozzle using a feeler gauge. I measured from the bed to the heater block and made sure the measurements are the same all around.

I have been getting much better prints since i re leveled everything using this way of measuring.

I had some more pressing parts to print so I have not tried the herringbone again.

I suspect it is a heat issue and instead of printing one gear i will make a print of 9 of them to allow cooling time between layers.

I printed several items on the bed at different locations and all measurements came out perfect.

So I am hoping it boils down to heat.


Thanks!

Get a dial depth guage (digital is nice). Attach to the x-rods. Makes taking quantitative readings much easier.

Check Z height on both edges of the bed. Raise a constant distance (20mm) and check that the height reads the same on both edges of the bed. This should confirm the z axis is square.

Check the levelness of the y-axis also. Also check the levelness of the bed… Is it bare glass or is there a film? Of the latter, check for air bubbles. Lastly, make sure your feelers aren’t deflecting the bed when checking the gap.

Heat contraction shouldn’t cause a noticeable deformation…