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greenplease

Trouble with extruder "grabbing" filament, lag in controls

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Hi guys! This is my first post here. I just got done assembling my Ultimaker. I'm trying to do a "test" print but I can't get the filament to move... at all! A few notes:

-the wooden gear turns freely (no interference with the housing)

-the large screw that goes through the center of the housing (the one that is meant to "grab" and "drive" the filament)is firmly connected to the wooden gear. The two turn in unison.

-the PLA is rather snug inside the wooden housing. I have a great deal of difficulty driving it by hand. As a note, I live in Florida where the humidity is rather high. I had a great deal of difficulty putting the entire machine together as everything was very tight. I wonder if the humidity has caused the wood to swell just enough that the extruder's housing is too tight for the included PLA?

Thanks in advance for any help.

Edit: I also forgot to mention that the controls in ReplicatorG are rather laggy. It takes as much as 30 seconds for the extruder to respond to commands such as "forward" or "stop". I have a Netfabb license but I have not installed it yet.

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1. Make sure you can push the filament in by hand (if the temperature is too low, it wont print at all.) Just unlock the screw mechanism, and push the filament by hand. If nothing gets out, then something is wrong with your setup.

2. If pushing by hand works, but not mechanically, then look at your filament. Sometimes, the filament tends to get "grinded", this means that the extruder was running too fast or the extrusion was too cold. This can cause the extruder to "grind" the filament off. Just cut the end off, and it should work smoothly again.

3. Turn the adjustment screw a bit more.

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I don't have a lot of experience with RepG, but the controls should act pretty quick. You might have a case of motor driver overheating. Which causes the motors to go on/off when the driver shuts on/off because of overheating and cooling again.

http://wiki.ultimaker.com/Electronics_b ... or_drivers

Is the gear turning? Because it's impossible for the filament to really stop the gear. If the bolt is not grabbing the filament make sure you have the pressure screw is tight enough. And the quick release is "closed"

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I don't have a lot of experience with RepG, but the controls should act pretty quick.

Surprisingly not.

RepG was really designed for pre-5D machines and 'Extruder On' wants to just send a simple M gcode saying to turn the extruder on until you poke 'Extruder Off'. Somebody (Erik?) changed that on 5D machines to do (what I guess is) a series of G1 E commands that simulate the same thing.

With volumetric 5D, the extrusion length E suddenly means something different - extrude a lot more, in particular. If the firmware is buffering up commands, which a G1 can do, you can end up sitting around for a while, watching it extrude and waiting for the queue to drain.

So.. GreenPlease: the repg stuff is normal repg weirdness.. Don't worry about it.

As for humidity, I just went through about 5 pounds of PLA that I bought almost 2 years ago. I'm in New England, not Florida, so the humidity here is a lot less but it was just sitting on the shelf for nearly 2 years. No bag, no desiccant..

Have you measured the filament with calipers? Average diameter, how much diameter varies and if it's circular or oval are the things to look at.. Usual numbers are around 2.85 and circular is better than oval. If you're far off spec or it varies a lot, that can cause problems.

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Hey guys, thanks for all of the replies.

@Mr. Seeker: I can push the filament by hand. I don't see any evidence of grinding. My adjustment screw is turned as far to the right as I can get it to go by hand.

@Daid: yup, gear is turning, pressure screw is maxed out, quick release is closed. Filament doesn't move.

@DDurant: I'll measure it this afternoon. I'm assuming that Netfabb doesn't have the lag problems of ReplicatorG?

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The "Extruder On" command is something that I frown upon. Its quite laggy, and was originally designed for makerbot/BfB. Erik made it work with the Ultimaker, but when I check it, it means a lot of sending G1 commands.

What I do (and I think its much better) is just turning off the stepper motors and turning the wheel by hand. Much easier & much more control.

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