Hi Everyone,

I am new to the board and the 3d printing world (but I do know the 12v area kind of well). I have about 20+ hours into assembling my Prusa i3 and finally got it up and almost running. Everything is working great on the printer except for the extruder motor. The large gear on the extruder BARELY moves, I looked at other videos with the Prusa i3 to make sure I wasn't going crazy and I see the gear moving quite quickly in other videos. I know the extruder has power because it make make one click on the gear every 30 seconds or so. The gear and motor are free to move as I can't see any physical resistance on anything when the machine is powered down. I can heat the extruder up, move the gear, and filament comes right out. My printer has a built in LCD board and the setting for the extruder speed reads 100. I tried to max it out to see what would happen and the actual extruder speed did not increase at all.

I did my research and found the Pronterface software and tried to extrude something crazy, like 100mm as a test, and the large gear maybe clicked over two times at a VERY slow rate. I am LOST as to how to fix this and I am in desperate need of help.

Any help you could offer would be great!

Thanks,
Mike

Edit: In case anyone wants to know the printer has RAMPS 1.4, Marlin software, and I use slic3r to prep the files and adjust any settings I need to (haven't yet though as the company I got it from make a configuration file for slic3r)

Edited 1 time(s). Last edit at 02/03/2014 09:01PM by trdcelica.

You need to calibrate the extruder there are many posts on this. You have to set steps per millimeter going through the extruder

Okay - I did more research after you mentioned that and I found an article mentioning how Pronterface can do that. The printer came with preconfigured software to load it on and go... I am guessing the software was wrong.

Couple of things come to mind:
1. Misaligned pins plugged into the ramps board
2. Bad wire to the motor
3. Stepper driver current too low.

From your description I am guessing most likely 1 or 2.
If you plug another motor into the extruder stepper connection does it turn when activated?
What happens if you plug the extruder motor into another connection?

Appreciate the reply - I'll answer these the best I can.

Couple of things come to mind:
1. Misaligned pins plugged into the ramps board
A - I'll triple check this. Everything else signal wise from the board is working great, but who knows, maybe the connector isn't in.
2. Bad wire to the motor
B - Always a possibility but I doubt it only because I soldered all the wires.
3. Stepper driver current too low.
C - The manual sent to set it to 1.1v and I hit the mark right on the money.

When I am using Pronterface and hit the Extrude button the signal from the board to the motor is flowing because I see and hear the motor engagng. It is just SUPER slow. It could be a software issue, but with "pre-configured" software you would imagine the developer would noticed that, but who knows!

So I believe I found the problem. I believe the port on the board is faulty. While it maintains voltage, I feel it is not sending the signal for the motor to move correctly. When I take my Extruder motor and put it on the Y axis port it works fine BUT when I take my Y axis motor and plug it into the Extruder port on the board it does the same thing. I checked the Pronterface settings and playing with the extrusion rate didn't do anything.

So I guess my question is, how do I alter this preconfigured software to send the signal for the Extruder out of the additional port on the board??????? The vendor said "just swap the port".... that didn't really help me.

I attached a picture for the wiring diagram they supplied me. On a side note, the Y plug is reversed in the picture........

So, how would I modify the software to send the signal for the Extruder out of the port adjacent to it on the right? (the one that is vacant in the pic...)

Definitely sounds like steps per millimeter in other words calibration sounds like yours is set up for direct drive extruder. That's why you have to alter it for the wades type believe me this is what you have to do. Steps per millimeter set it the firmware to each one of the driver outputs for the motors so it will actually do what your say nothing is bad has to be set

Edited 1 time(s). Last edit at 02/05/2014 03:15AM by cnc dick.

Use M92 to set the E value of the steps per mm.

When you first connect to the printer, you'll see those numbers on the log window.

By log window are you referring to the Arduino software? I tried cranking the steps/mm in Pronterface and nothing happened.

Based on what I read, would this be found in the configuration h file of the Marlin software? Sorry for all the questions, but I'm 25+ hours into this project and I feel like I'm so close to getting it to work!

Confirmed PCB driver port was bad. Someone was able to walk me through to get it corrected.

Thanks!

Okay but you're still going to have to calibrate the extruder it is one of the most important things to do with a 3-D printer steps per millimeter going through the extruder. And it would be less steps per millimeter which would be faster or more extruded. You mentioned earlier that you jacked it up in one place which is the reverse of what you should of done. Read up on it it has to be done. Even if you knew what the steps were for your particular extruder everyone of them is a little different you have to calibrate the extruder for anywhere near good prints or even set up the rest of your machine calibration of the extruder comes first. In your other post you just asked to change the port which he did but this isn't going to help you you still need to calibrate the extruder. You should post and ask about how to calibrate it on the i3 with the geared extruder

Edited 4 time(s). Last edit at 02/05/2014 09:18AM by cnc dick.

Quote
trdcelica
Confirmed PCB driver port was bad. Someone was able to walk me through to get it corrected.

Thanks!

did you print anything yet you're still going to have to calibrate the Extruder when you use your slicer it it tells it to use a certain amount of filament volume of plastic if your steps are not correct the software doesn't know this and will extrude too much or too little

Quote
trdcelica
By log window are you referring to the Arduino software? I tried cranking the steps/mm in Pronterface and nothing happened.

Based on what I read, would this be found in the configuration h file of the Marlin software? Sorry for all the questions, but I'm 25+ hours into this project and I feel like I'm so close to getting it to work!

No. The right side of Pronterface window after it connects to the printer shows a lot of the parameters that you can change using M commands.

How did you fix this? I was just watching a video on calibrating extruder and noticed how much faster the herring bone wheel turned in comparison to mine (which is ridiculously slow). Now I wonder if I have the same issue.

Thanks!

Edited 1 time(s). Last edit at 04/25/2014 02:55PM by BlaiddDrwg.

Quote
trdcelica
Confirmed PCB driver port was bad. Someone was able to walk me through to get it corrected.

Mmmm. More than one year later, no solution to this post... I have to guess that trdcelica gave it up. Or forgot to share? Anyway, same problem here, big gear moving half a millimeter every second, like an old clock...

@IMShogun,
Did you ever resolve the issue?

I've just finished building mine and have exactly the same issue. I've not played about with the calibration of the extruder yet, but this will be my next plan.

Thanks.

This is my first post to the forum I’ve built a Prusa i3 from scratch: box frame, Greg J head extruder, Arduino mega 2560 with Ramps 1.4 electronics, DRV 8825 stepper drivers, Sprinter firmware and Pronterface and Sic3r software control. While calibrating the Extruder feed, I was narrowing in the 100mm extrusion steps per unit feed value at about 900 (close to the calculated number for my system). At one point the extrusion feed was very close to the 100mm requested, however, the speed of the motor suddenly decreased by a factor of 5 –it took 3 minutes to feed the 100mm into the extruder (extruder hot end was disconnected for this calibration).

From that point on I started monitoring the time per revolution of the small gear on the extruder. One revolution is equivalent to about 8mm filament feed. So the time per revolution changed from about 3 sec per revolution to about 15 seconds per revolution. Then upon further testing, the seconds per revolution of the small gear changed again to so it was dramatically even slower.

Experiments with these conditions showed that the time of a “5mm” extrusion request from Pronterface was constant at about 150 sec. no matter the E_Step value chosen but the motor speed increases with the higher E_Step value. A calibrated extruder under these conditions would have the E-Step value set to about 4000 but it would take 2.5 minutes to feed the extruder 5mm.

I have swapped stepper drivers, motors, Ramps and Arduino boards, and E_0 to E_1 extruder ports. The test program for motors shows that all motors work normally. Any suggestions on how to fix this?

Check the mm/min setting right under the reverse button, you may have accidentally lowered the speed.

That was the answer, stephebrc! I guess I was assuming it was just for backing the filament out since it is right next to the Reverse button. Thanks so much.