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Hi guys,

i am having a new issue with my printer since switching to the e3d v6. My filament is jamming during the print. The filament is over a year old. Could that be the issue?

i've tired lowering the retract. But the extruder grinds down the filament no matter what. The first time the filament was broken off and wrapped all the way around the grub screw. I've also thought that the berdAir might be causing the hotend to get too cold, but it stays around 200c. I've verified the temp with a meter, it is actually running about 5c higher. I've also turned the cooling off, just in case.

The extruder gets too hot to touch. The Bondtech says it should be set at 1.2 amps. Initially i had set the current level to 210, but i thought maybe it was too high, so i lowered it to 190. The extruder still gets hot. i've placed a fan on the extruder but i wasn't able to test that yet.

I'm getting some new PLA filament tomorrow, since i've only been buying ABS recently, but i was wondering if there was something else i could try in the mean time?

thanks!

It likely is not your filament You need to systematically go through the extrusion path.

Bring the to end up to temp and disconnect the bowden. Push the filament in by hand and see if you feel excess resistance.
Make sure filament will pass down the entire length of the bowden disconnecting both ends.
Test the path through the extruder. Is this a new Bondtech or were you using it before? You might not have the cogs adjusted for the feed path.

i was using the bondtech before. It seemed to work with ABS fine... I printed a large print in white ABS before this without issue.

I never adjusted the cogs... i don't know how to do that?

Someone mentioned a "100mm" test awhile back. Whenever i try to extract 100mm i always get some skipping.

I'll do the tests you mentioned and report back.

Did you calibrate the steps/mm for the Bondtech when you installed it? This extruder is a tank, if you get skipping extruding 100mm you have some problem you need to fix! The adjustment is in the assembly instructions on Bondtech's site.

Thanks for your responses.

Yes, I did calibrate it. I just repositioned the extruder to get rid of a 90 degree turn at the top of my Rostock but jt didn't seem to have much of an effect.


I can smoothly push the filament through the extruder and Bowden tube with ease. When I get to the hotend, I can still push it through, but it requires a moderate-to-hard push to get the filament through. How much pressure should I need to apply?

Here is a video of the extruder:

https://m.youtube.com/watch?v=j4k1BdYc5A0



Also, I noted my jog speed for the extruder was 1850mm/min (~30mm/s)... In order to get no clicks, I have to reduce it to 200mm/min (~3mm/s)

Also, the bondtech was fully assymbled when I bought it, should I take it back apart?

Here is a picture of a a failed print. This is supposed to be about 22cm tall. It starts getting clogged around 1cm off the bed and completely jams about 5cm off the bed.

If I heat up the hotend again, the filament will extrude....

Check your Bondtech drive wheel alignment as per page 4 & 5: https://drive.google.com/file/d/0B7A1ME ... dYcXM/view

This is a user serviceable and maintenance operation and you should learn how to check it. It does not go out of whack usually but it does happen so best to check. I don't think that's your issue though.

There is a practical maximum volume that can be extruded and that can be easily calculated. You then use this to calculate your maximum print speed. I created a spreadsheet to do these calculations for me and to fine tune for various filament types, etc.

For an E3D V6 with .4mm nozzle, the maximum extrusion volume is about 15mm^3/sec and it is considerably lower than that for PLA (due to its properties). I suggest that your maximum extrusion volume target for PLA with this setup is 10mm^3/sec - you need to stay below that.

Now we can do some calculations to figure out what that means in terms of print speed and extrusion rate:

feed rate (mm^3/sec) = nozzle width (mm) * layer height (mm) * print speed (mm/sec)

let's rearrange so we can calculate print speed:

print speed = feed rate / (nozzle width * layer height)
substituting your values:
print speed = 10 mm^3/sec / (.4mm * .2mm) = 125 mm/sec - this is the absolute fastest you should be able to print under ideal circumstances.

Now let's see how that translates to your extrusion feed rate.

10 mm^3/sec / *pi * (1.75mm/2)^2) = 4.2 mm/sec and this would be the maximum extrusion feed rate you should expect

So your observation that you need to set extrusion speed to about 3mm/sec to prevent skipping is indeed below that maximum. And depending on many factors (like melt temperature, actual filament diameter, etc) that might be your upper limit. It is right around 3.7 mm/sec for my E3D V6s running a .4mm nozzle and most of my PLAs.

What control application are you using? The default extrusion rates in the "jogging" display for most are pretty bad.

By the way, you can use gcode.ws to analyze and calculate this stuff automatically: http://gcode.ws

I am using s3d..

I am printing at about 60mm/s, I left my jogging extrusion rate at 200mm/min

It looks like the bondtech is aligned well? I took a look at pages 4 and 5 and it looks the same....

Ok, that's off the table. By the way, how tight are you screwing down the release lever on the Bondtech?

About half way usually, but after this problem I tried going full tight, didn't seem to make a difference.

I just attempted a cold pull with ABS (I don't have any nylon) and this is what I got..

I think i might have potentially found an issue.

It turns out that the connector plug to my accerometer board was not fully seated. I had noticed that when i moved the thermistor wires around the temperature swung wildly around a 20c difference in temp.

I dont want to say this is the issue (because i thought i was monitoring temps before) but we'll see. The connection was definately raised up on the side opposite the LEDS.

That looks like it was the issue. I'm about 90% done with the print i was having issues with and other than some stringing due to underretraction (trying to solve the extrusion issue) it is looking great.

Thanks for helping me troubleshot this, McHackney, and especially the information about the BondTech extruder and the extrusion calculations, i didn't know that 200mm/min was considered "reasonable" for the extrusion rate.

successful print, and $9.00 in the bank!