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Topic: Slow extrusion and heating issues

I've had my pre-assembled filastruder for a month and a half so far and I just seem too keep running into issues.  I do have my filastruder mounted vertially using Ian's vertical hopper.  I did test the issues out in horizontal mode as well just to rule that out.  I get the same issues vertically and horizontally.

I first started off with an extrusion speed of about 3 inches per minute (1.75mm nozzle), no matter the temperature.  (180 up to 200 degrees).  At first I tried cleaning out the nozzle with a drill, that did not help.  I then bought a melt filter, that did not help it either.  I had then contacted support and was sent a new motor as it was thought that might be the problem.  Put in the new motor, still 3 inches per minute.  I did verify that the motor/auger is rotating at ~1.5 RPMs.  To give perspective on the speed, I was able to extrude 160g of ABS in 30 hours.  I then took the whole thing apart and soaked the pipe/auger in acetone so that I could pull the auger out more easily.  Apparently half of it was just jammed up as half of the ABS in the auger was a dark gray while the other half was white.  Cleaned it all out, soaked both the pipe and auger in acetone get rid of all the ABS.  Up to 4.5 inches per minute... still no where near the 7 inches per minute it should be.  I am still getting debris in my extruded filament (and it's coming out gray), but I'm currently chalking that up to be fully cleaning it out, so I may need to just run half a pound through to get out the residue.

My 2nd issue that seems to have come about is a heating issue.  While debugging the issue above, at some point I heard a loud pop and thought nothing of it.  Eventually the whole thing stopped heating.  Part of the controller was melted and a wire was completely burned through.  Re-wired it back up and it seemed to be operating normally.  This was about 3 weeks ago.  Then last night as I went to turn it off for the night (ran for about 4 hours) I noticed the temperature had dropped from 180 to 165.  Did not think much of it.  Turn it on today, heated it up to 180 and left it there for ~15 minutes then turned on the motor.  Stepped out of the room for about 15 minutes only to come back to a lot of smoke and the motor off and the temperature at 150.  Apparently the whole thing seized up.  Thankfully the motor seems just fine after I removed it and tested it. 

At this point I'm hesitant to run it again, especially if the heater dies out while the motor is running.  It has been a bit disheartening to have put so much effort into it with little to show for it.  Any feedback or suggestions would be greatly appreciated.

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Re: Slow extrusion and heating issues

Oh man. First of all, let me apologize for the issues you've dealt with so far. Truly.

~1.5RPMs is right in the ballpark of what I'd expect for the Kickstarter motors. What resin were you using? Where'd you get it from?

Debris in the filament is likely due to needing to finish the purge cycle, like you said - though you may want to use the melt filter after finishing the purge cycle.

The controller malfunction is much more worrisome. After the initial pop and observation of the melted controller, did you contact support? They should have sent you a new controller immediately. Using a damaged one was asking for trouble.

It sounds like the controller failed, but I am curious why that happened. If you get a chance, can you measure the resistance of the heater with it disconnected from the controller? At this point, in my opinion, OSP should exchange a known good, tested unit with yours. I'll send them an email about it right now.

Thanks for your patience. I know it is frustrating - I would be as frustrated if not more if it were me! I'll work to find a resolution.

Tim

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Re: Slow extrusion and heating issues

I am using OSP ABS MG94 from the open source printing store.

At the time when I had mentioned it I was talking to support about my slow extrusion.  I might have passed it off as just an air bubble at the time as the heater started back up when I turned it on or off.  It was my miss to not make more of a deal of it.

It has been a while since I've used my multimeter but I believe I'm reading the numbers right.  I am getting 2.5 ohms on the heater with it completely disconnected from the controller.

Thanks for getting back to me so quick.  If you need any additional information from me, let me know.

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Re: Slow extrusion and heating issues

2.5 ohms seems low. It could cause excessive current draw through the controller. I have heard of only one other case of a heater failure though, in over 900 units total.

I think the right answer here is to get you a tested unit, and have the problematic unit returned for a teardown. I emailed Rob at OSP this thread, so this should be sorted relatively soon.

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Re: Slow extrusion and heating issues

Soynuts,
I am sorry your unit has caused such a headache. I would be happy to send you a tested unit to replace this machine. This way you are comfortable with running it. I will email you and we can set this up. Once again, I am sorry for the inconvenience.

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Re: Slow extrusion and heating issues

Thanks for the awesome support!  I really do appreciate it.