Hollow filament?

I've been having a lot of trouble getting the extruder to work for any period of time since the filament will always stop pushing through and the hobbed bolt will just carve a half-circle out of the filament, and it'll go nowhere. However, when pulling the filament out (and accidentally snapping a small piece off) that it's hollow on the inside. I've got the screws with the springs on them fairly tight as I've seen reccomended, but I think that it's collapsing the filament into the hollow part in the middle, making it get stuck. Did I get a bum spool of filament, or is all 3mm filament like that? If so, what am I doing wrong? Thanks in advance

-Brit

The filament definitely should not be hollow. The extrusion calculations rely on having a known cross sectional area based on the diameter of the filament; if it was hollow the machine wouldn't be extruding as much plastic as the software thinks it is.

Try breaking a few more pieces off to see if it really is hollow. It's probably just bubbles in the filament, which is indicative of low quality filament. What are you using, PLA or ABS? And where is it from?

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I'm using ABS. I broke it in 5 places spread out across about a meter of length, and four of the five breaks had hollow spots that were about 1 - 1.5 mm in diameter. This is what I ordered. Do you have any suggestions for places to order better filament?

-Brit

I have no idea where that filament comes from. Here are some reputable suppliers:
[www.protoparadigm.com]
[ultimachine.com]
[www.makergear.com]
[www.printbl.com] (PLA only)
[store.makerbot.com]

I have purchased from Ultimachine and ProtoParadigm before, both have good quality filament. I have a few samples from Printbl too, and it is very high quality.

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I've been getting good results with abs from makerfarm.com

Quick shipping and great service.

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Thingiverse ID Alan1279

Yeah, my Prusa is actually a makerfarm kit, and they do have absolutely awesome customer service and ship quickly, but they've been out of stock of the filament for a while, otherwise I would have just ordered from them I think

Update: I've ordered new filament from Protoparadigm and it's working great! I guess you get what you pay for sometimes....

The hollow filaments as you describe are in fact shrinking voids caused at the point of manufacture, this is a common error by the less skilled producers.

have you tried KDI Filaments yet?

www.kdipolymerspecialists.co.uk

[www.amazon.co.uk]

Late to the thread but FWIW I just had 3mm ABS Protoparadigm filament with bubbles/hollow bits in it.

Pretty disappointed.

I had some hollow from Maker Shed that ended up costing me a hotend. Severe jam that I could not get undone without disassembly and some parts broke while disassembling it so I ended up buying a new hotend.

Can you post pics of the failure? tmorris9 I just want to see how things broke.

Thank Mike

This was almost a year ago. I was using a budaschnozzle and the air pocket somehow caused a serious jam I could not undo (never had a real jam in 3 years of printing with it) While trying to remove the nozzle the tube (aluminum) broke. I tried removing the heater block and it was fused to the tube as well (aluminum on aluminum with heat is a bad combination and can seize) So, 90% of my hotend was useless and I bought a new one.

At the time I took some photos of the hole in the filament to send to Maker Shed but those have long since been deleted. I never took photos of the hotend.

An update on my hollow filament. Protoparadigm is going to send me new spools when they get their in house filament line up and running! Very happy to have good support from Protoparadigm.