<p>When I started printing ABS with my Prusa i3 MK3 MMU2+ printer, I started experiencing jams on some longer prints, which was heat creap, possibly combined with old filament.</p>
<p>I improved the cooling by filling the gap between the sides of the heat sink and the plastic extruder body. I think I stuffed it with some soft foam rubber, but anything that can handle the (what should be fairly cool) temperature should work.</p>
<p>My hypothesis is that with gap allowed too much of the air to pass without engaging the heat sink, compromising the cooling.</p>
<p>With that change, I haven't had heat-creap jams.</p>
<p>You aren't printing ABS, but the temperature is high, and PLA softens as a low temperature. IMO, it would still be worth making the change.</p>
<p>It is the gap on the front and rear sides that I blocked.  The heatsink fins are fully open for air flow.</p>
<p>Some people here have changed out the Noctua fan for one that is noisier and pushes more air, which should also work. I appreciate the quiet fan, so I tried to get more work out of the fan I had.</p>

CC BY-SA 4.0
2021-01-18T00:27:53.180Z
I found the answer was the maker geeks formulation of PLA requires much hotter temperatures. Great idea on the airflow. Did you let Prusa know?
Jay
CC BY-SA 4.0
2021-01-17T20:49:32.683Z
2021-01-17T23:01:40.483Z
2021-01-17T23:01:40.483Z
cmm
<p>The maker geeks formulation of PLA requires much hotter temperatures. The plastic was not melted enough for good flow.</p>

CC BY-SA 4.0
2021-01-18T00:28:35.190Z
2021-01-18T00:28:35.190Z
Jay
<p>While printing a <a href="https://www.thingiverse.com/thing:3932302" rel="nofollow noreferrer">paint rack from thingiverse</a> I keep getting jams. Other prints (shorter) work fine. Can anyone give me a clue?</p>
<p>Here's a <a href="https://photos.app.goo.gl/PQuJwqNdYWSMTiwm6" rel="nofollow noreferrer">video of the printer</a></p>
<p>I thought it was heat creep so I increased the speed and decreased the hot end temperature. It generally prints for several hours then jams.</p>

CC BY-SA 4.0
2020-12-20T18:55:52.897Z
I hear extruder clicking. What's the material and the temperature you have set?
Trish
CC BY-SA 4.0
2020-12-20T19:05:17.163Z
I set to 0.3 layer height, changed the temperature to 205 from 215. Increased the print speed by 10 mm/sec. These were suggested for reducing heat creep. The filament is Maker Geeks Maker Series PLA. I just noticed this filament recommends 235. Much hotter than any other PLA I've used. I'll try running it at that temp
Jay
<prusa-i3><extrusion>
Help fixing Prusa i3 MK3 print jams
Jay
# Help fixing Prusa i3 MK3 print jams

(Asked by: username_0 on 2020-12-20)

While printing a [paint rack from thingiverse](https://www.thingiverse.com/thing:3932302) I keep getting jams. Other prints (shorter) work fine. Can anyone give me a clue?

Here's a [video of the printer](https://photos.app.goo.gl/PQuJwqNdYWSMTiwm6)

I thought it was heat creep so I increased the speed and decreased the hot end temperature. It generally prints for several hours then jams.

**Tags:** prusa-i3, extrusion

> **Comments:**
> **username_1**: I hear extruder clicking. What's the material and the temperature you have set?  
> **username_0**: I set to 0.3 layer height, changed the temperature to 205 from 215. Increased the print speed by 10 mm/sec. These were suggested for reducing heat creep. The filament is Maker Geeks Maker Series PLA. I just noticed this filament recommends 235. Much hotter than any other PLA I've used. I'll try running it at that temp  

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## 2 answers

### Answer by username_2 on 2021-01-17. Score: 1

When I started printing ABS with my Prusa i3 MK3 MMU2+ printer, I started experiencing jams on some longer prints, which was heat creap, possibly combined with old filament.

I improved the cooling by filling the gap between the sides of the heat sink and the plastic extruder body. I think I stuffed it with some soft foam rubber, but anything that can handle the (what should be fairly cool) temperature should work.

My hypothesis is that with gap allowed too much of the air to pass without engaging the heat sink, compromising the cooling.

With that change, I haven't had heat-creap jams.

You aren't printing ABS, but the temperature is high, and PLA softens as a low temperature. IMO, it would still be worth making the change.

It is the gap on the front and rear sides that I blocked. The heatsink fins are fully open for air flow.

Some people here have changed out the Noctua fan for one that is noisier and pushes more air, which should also work. I appreciate the quiet fan, so I tried to get more work out of the fan I had.

> **Comments:**
> **username_0**: I found the answer was the maker geeks formulation of PLA requires much hotter temperatures. Great idea on the airflow. Did you let Prusa know?  

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### Answer by username_0 on 2021-01-18. Score: 0

The maker geeks formulation of PLA requires much hotter temperatures. The plastic was not melted enough for good flow.


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