SoliForum - 3D Printing Community — Hot motor + Printer skipping along the board

Re: Hot motor + Printer skipping along the board

2015-10-14T04:51:10Z

Search VREF or particularly my posts on tuning them by ear and feel. Carl is correct you need to find that sweet spot. I say over extrusion for many reasons.
First is experience, SD never set the steps per mm on E. It'll be set at 138 and should be closer to 105. Look at EEPROM in RH and you'll see for yourself.
Second is more experience, this is experience with new users in general. The first clue was you didn't know what I was referring to when I mentioned calibration. This is not an insult in any way, how would you know.
So to sum things up your machine was set up to over extrude right out of the box. Then SD worked around this by manipulating the extrusion multiplier in their "stock SD Slic3r" profiles.
Set these two things properly and you'll be happy you did.
The reason this causes skipping is the added resistance of the nozzle dragging across the previous layer because it was too thick. Couple that with poor cooling on the control board and overdriven motors, toss in some poor alignment and you'll get skipping.
We are here to help
Happy Printing.

Re: Hot motor + Printer skipping along the board

2015-10-13T21:55:11Z

carl_m1968 wrote:

You want the value to be closer to the .350 or even lower as possible. The ideal is to get the lowest possible value while still allowing the motor to run dependably. There is line where you get too much current and over heating but not enough current and skipping so both ways can lead to skipping. You have to find the middle sweet spot. .6 is way to high and will cause excessive heating and even stalling.

What you're saying makes sense. Solid Doodle recommends 1v on all axis, though...do you/others find that this is often bad advice??

Re: Hot motor + Printer skipping along the board

2015-10-13T21:11:24Z

You want the value to be closer to the .350 or even lower as possible. The ideal is to get the lowest possible value while still allowing the motor to run dependably. There is line where you get too much current and over heating but not enough current and skipping so both ways can lead to skipping. You have to find the middle sweet spot. .6 is way to high and will cause excessive heating and even stalling.

Re: Hot motor + Printer skipping along the board

2015-10-13T20:59:39Z

Update:

I re-checked the voltages, and both X and Y motors were about .6-ish V. If I turn the pot as far as it will go, this is where it maxes out.

Am I doing something wrong or is this a thing that happens? Is my mobo fried??

My multimeter is set to 2v, and I'm placing the probes as suggested by SD troubleshooting found here: http://support.solidoodle.com/hc/en-us/ … ip-Voltage
Also, the power supply itself is reading 12.7 v

Re: Hot motor + Printer skipping along the board

2015-10-13T20:10:44Z

wardjr wrote:

I'd put money on over extrusion.
http://www.soliwiki.com/#Calibrations
Put a fan on the board even a desk fan pointed in that direction can help.

Thanks, I will look into this. I'm curious, why would you guess that this is an over-extrusion issue? I.e. why can that cause the skipping?

Re: Hot motor + Printer skipping along the board

2015-10-13T19:35:00Z

I'd put money on over extrusion.
http://www.soliwiki.com/#Calibrations
Put a fan on the board even a desk fan pointed in that direction can help.

Re: Hot motor + Printer skipping along the board

2015-10-13T19:26:20Z

Thanks for the replies!

I greased the rods a while ago, and I checked the belts as well -- that all seems OK.

Wardjr: Can you elaborate on what you mean about calibrating the extruder, and "checking the binding?"

I haven't heard any unusual sounds when it's moving, but I'll try to print something again and I'll pay attention to that and get back to you on it.

Re: Hot motor + Printer skipping along the board

2015-10-13T19:19:00Z

Check for binding.
Put a fan on the control board.
Put a fan on the motor or at least a heat sink.
Ensure proper calibration especially extrusion.
Lube up the rods.

If the motor is getting that hot you have the VREF set incorrectly. What's it sound like when it's moving?

Re: Hot motor + Printer skipping along the board

2015-10-13T19:18:14Z

Reduce the voltage on that axis regardless of recommendation. Recommendations don't account for inherent differences in each printer such as rails being parallel and such.

Hot motor + Printer skipping along the board

2015-10-13T19:11:12Z

Hi everyone, I'm pretty new to 3D printing and I'm hoping to get some help.

I have a Solid Doodle 3. I am currently unable to print much, because after the printer prints a few layers (of anything at all) the extruder head will skip ahead an inch or so on the X axis, and continue printing the next layer there.

I've noticed that the motor gets very hot to touch, much more than the other 2. It is my suspicion currently that it prints the first few layers OK, because it takes time for the motor to overheat, and then once it gets too hot, the print head jumps. I don't know what to do.

I've checked the voltages for every axis and they are all within the recommendations from solid doodle's troubleshooting.
Any ideas of what I should do?