Extruder Reversing

Why would my extruder be reversing while printing. I have cleaned the heatend and my extruder has been calibrated. I am printing a test cude with PLA at @220C.

I think I have seen posts with this type of problem before but I cannot find them on the forum.

Thanks in advance!

Mark

When you manually extrude does it reverse like when you are trying to print? If so then you need to reverse the extruder motor in your firmware

Reversing completely, or just backing up on occasion? If the latter, check your retract settings in your slicer . . .

Otherwise, perhaps a bad connection/solder joint on the direction select line from the Arduino to tne Pololu module . .

-Tim

I made a video of the reversing during my last print

[youtu.be]

I adjusted the pot but that did not make difference

Edited 1 time(s). Last edit at 07/28/2015 11:58PM by MarkIngle.

That is stepper missing steps. If it can exteude other times it is not for lag of power but because of jamming in the hotend or wrong bed height ( nozzle too close to bed with no space to exteude plastic.

Can it exteude other times? Is it only when printing first layer?

220 is too high for pla and can give problems. Try 200.

It reverses through the whole print of the cube. the faster the print speed the more it reverses. It does the same thing at 200C.

I am gonna give my nozzle and heat end a good cleaning to see what that gives. Currently I am printing a 7mm/s to get good prints with the extruder acting like it is. How fast should I expect to be able to print?

Quote
MarkIngle
It reverses through the whole print of the cube. the faster the print speed the more it reverses. It does the same thing at 200C.

I am gonna give my nozzle and heat end a good cleaning to see what that gives. Currently I am printing a 7mm/s to get good prints with the extruder acting like it is. How fast should I expect to be able to print?

50 mm/s should be no problem. Also much faster but where you are now I think 50 mm/s is what you should aim for.

Cleaning the hotend again will not help. You need to find the root cause.

It is still unclear for me if your printer have ever worked? If not, then you maybe just need to set the potmeter correct. Get a multimeter and set it to measure DC. Attache the black (negative) in a permanent way to ground so you will not need to hold that while you do the following; set the screw driver on the potmeter and put the positive probe to the screwdriver steel part. You should turn until you have 0.9V.

Also - Please confirm if you have already calibrated your extruder - By calibration I mean that you have tried to manually extrude for example 10 cm out in the air, and then measured by measuring tape that it actually extruded that?

Next, try to print again, this time when it is up and running, after a little while, put your index-finger on the lower part of the heatsink (the part close to the heating block, but not the heating block obviously). How hot is it? Can you leave your finger without it getting uncomfortable hot?

I have printed a decent test cube. I can post a picture and video it you like.

The pot has been adjusted to determine if it is the cause There was no improvement.

Calibraion was doen as well....G1 E100 spits out 100mm

Its like the extruder is pushing more that can exit the nozzle but I am not sure how to reduce the load.

Ok, some things is still unclear - when it starts skipping - does it then entirely stop putting out plastic or does it still put out a little? Can you pause it for a minute and then if you start again it will work just fine for a little while ?


Do you have cooling on the ramps board ( the electronic s)?

I found my problem. I had partially clogged nozzle. The way to clear it is remove the nozzle from the heat end. Heat up the brass nozzle a little until you can insert a small strand of copper wire. I used a strand from 12 guage wire. The the wire strand will only insert once the nozzle hole is expanded.