Extruder barrel length

I've noticed that some extruder barrels are 50mm in length, such as ones sold by some of the online suppliers, while the wiki calls for a 32mm barrel length.

Does it matter? I'm currently having are hard time getting anything to extrude out the nozzle (0.5mm), so I was wondering if this makes a difference.

I'd like to know what barrels/nozzles people are using successfully on Mendel. I think some kind of poll would be useful to see what setups are most effective.

The longer barrel does work, I used it for some time on my Mendel. You have more molten plastic, and since it is a bit compressible that gives more ooze. Also there is slightly more viscous drag, but not much as the plastic is well molten inside the barrel.

The problem area is usually where it transitions from cold to molten, which is in the insulator. The plastic is very viscous there so if there is a gap it can expand into it will lock solid. Also if the transition area is too long the plug of softened plastic can simply have too much friction against the sides to move.

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[www.hydraraptor.blogspot.com]

So, shorter is better, but not required? Is it worth cutting the barrel to a shorter length to reduce the chances for problems?

Yes it is better shorter but works OK longer. I wouldn't bother shortening it. The problem is more likely a gap were it meets the PTFE.

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[www.hydraraptor.blogspot.com]