Andy Gough

@kmanstudios Printer is only 1 month old probably no more that 20 prints total. I did notice some small bits of debris in the Bowden tube on extruder 1 and removed and cleaned it. Spools are new to me (around a month) but I take your point about warehouse time, though they printed fine when I first got them. The spool is still fairly full, but being conscious of the issue I did regularly loosen the spool during printing, enough to reduce friction when unspooling but not enough so it could tangle. Where I might have gone wrong is using the same nozzle for PLA and ABS, when changing filament I've just been letting it feed through until the new filament is clearly running through the nozzle. Is using the same print core for PLA and ABS generally a bad idea? Incidentally, after a failed print due to grinding, I can unload the filament fine, cut off the section from the grind onward and load it again and it will extrude fine every time during load, and start to print the first few layers fine. I'll do some more reading on nozzle cleaning, thanks for the advice.

Thanks @DidierKlein yes using the standard 0.4 AA print core that came with the printer. I'll try 40mm/s and see how I get on. I'll also try cleaning out the feeders, but as I said I've tried both extruders and I'd never had an issue with grinding before on either of them. Thanks @gr5 as @DidierKlein said fan speed is 5%, line width is the default of 0.35mm. Point taken about strength of ABS/PLA and to be honest I'm just really printing these for fun with my son who is a massive Robot Wars fan, so unless he wants to start competing, PLA is probably fine and does seem to be a lot easier to print. Thanks for all your advice.

Last night I upped the temp to 245dgC and it did get to the first layer of infill before jamming, the previous 3 attempts didn't get past layer 3 so still on the bottom layers. What speed would you recommend for ABS?

I have had an Ultimaker 3 for about a month now and so far am really enjoying using it. It's my first 3D printer so I am a novice in the 3D printing world. All my prints in PLA for the the most part have worked great, but in the past week I've been having real issues with ABS prints. I'm printing an Antweight fighting robot so need the need the impact resistance of ABS. When I got the printer initially the same model printed perfectly first time, but now a few weeks on I am having consistent failures where filament stops extruding between layers 3 and 8, at this stage of the print its pretty much a flat plate of around 10cm x 10cm (nothing fancy). I can't tell if it is the nozzle getting clogged that causes the feeder to grind down the filament or the feeder just manages to do that itself, but essentially the feeder grinds down the ABS and it stops extruding and the print fails. I'm using new original Ultimaker ABS filament which is open less than 4 weeks and has been stored in a zip lock bag between prints. I've tried two different rolls, black and white. I'm using Cura with Recommended settings with a layer height of 0.15mm, most prints have been at 235dgC but in case it helped I up the temp to 245dgC for the one print (same result). The feeders tension setting is right in the middle. I've tried with both extruder 1 and extruder 2, same result (therefore different feeders and print cores). I'm really at a loss as to what else to try. The only thing I can think of is I haven't manually levelled the print bed and am using the active levelling instead, but as I said PLA prints are coming out perfect. Cura settings from last attempt attached. Any suggestions welcomed.