After receiving the sample pack of @ColorFabb filaments, I wanted to test out the BambooFill first on my Printrbot Simple Metal. I’ve run into some issues that I cannot quite figure out how to fix and I am sadly out of my sample to continue testing (will buy more in the future).

My first problem is the tension for the direct drive extruder. The BambooFill is very soft compared to ordinary PLA or ABS and flattens under less pressure. This was an issue when setting filament diameter in CURA, but was more easily remedied.

The thing I am still having troubles with is the drive gear sheering the filament before getting to the hot end which causes a jam similar to NinjaFlex type filaments. The normal tension is use on my printer is when the nut is about flush with the aluminum piece it is “housed” in.

Prints work fine for about 20 layers and then it jams or cannot feed the filament through the hot end anymore. If anyone has a fix for this it would be greatly appreciated.

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Hmm… BambooFill works out fine with my Printrbot Simple Metal.

Have you tried adjusting the extruder drive tension by turning the nut on top of the extruder spring?

Or you could try increasing the feed rate. Maybe the filament is burning inside the extruder

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Its mainly the combination temperature x feedrate x extrusion width. Did you play with those settings? My experiences with bamboofill/woodfill from colorfab were ok after a bit of tweaking.

Probably you checked the page, but just in case. There is quite some info there about different types of special filaments.

I’ve had some problems with filament prematurely melting within the upper part of the hot end, then jamming. That produces symptoms similar to what you’re seeing, a good print for X number of layers, then jamming. When I pull the filament out the end looks like there’s an elongated teardrop shape that’s jammed off axis to the rest of the filament. My fix was to mount a small fan blowing at the tan plastic/ceramic part of the hot end, below the extruder, but above the red insulator. That seems to keep the upper portion cool enough to solve my feed issues.

You can test this by putting a small house fan blowing at the entire print area, including the hot end. This this should cool the hot end sufficiently to fix the feed problems (though you’re going to get major print warping). I’ve have designed a duct channel to mount a 40mm fan on the right side of the print arm, and bring the air output to the proper location on the hot end (which I can post on thingiverse if you’re interested). However, the airflow is incredibly inefficient, and turbulence around the fan tends to blow on the print, again warping it. You’d be much better off mounting a 10mm fan directly in front of the top of the hot end. It seems like printrbot is aware of this issue, as they not stock a redesigned hotend with integrated fan.

http://printrbot.com/shop/metal-ubis-hot-end-2/

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Hi, try increasing the temperature and loosen the tension on the drive gear so that when you tug on the filament there is just enough tension that it doesn’t slip out. Too much tension might be deforming the filament before it can get to the hot end causing it to buckle. Increasing the temperature will relax the filament and allow it to get through the hot end. I would try going up to even 250. Take the print speed down to their lowest recommendation of 40mm/s too. You might even have to take the speed down to 30mm/s or even 20mm/s. Hope this helps.

Hi there,

Yeah I’ve experienced similar issues with flexible filament. The three most popular fixes are:

1. Replace your extruder with a Gear Head Extruder (http://printrbot.com/shop/gear-head-extruder-v0-01/)

2. Print Printrbot Simple [2014] Ninjaflex Helper by adafruit - Thingiverse

3. Print PrintrBot Metal NinjaFlex adapter by dubi - Thingiverse

I’ve tried all three options. Personally I’d recommend option 3. It’s not very sophisticated, or maybe sustainable, but it’s quick and easy. I got the Gear Head Extruder, but the replacement is a bit of work, and I didn’t want to risk my printrbot not working for a week or two, in case the upgrade failed. Option 2 didn’t work for me. Tried printing the part several times, but it always breaks during installation.

Good luck, and let us know how it goes!

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