***PLEASE HELP- MY BOX+ STOPS EXTRUDING***

Share your experience with UP BOX and UP BOX+
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DCSConcepts
Posts: 5
Joined: Sat Jul 07, 2018 1:47 am

***PLEASE HELP- MY BOX+ STOPS EXTRUDING***

Post by DCSConcepts » Tue Mar 19, 2019 10:17 pm

Hi, I have an BOX+ that for months printed perfectly. In fact I wrote a glowing 5-star review on Amazon. I'm using UP's ABS filament which I keep in the bag and in the box when not in use.

Recently after several perfect several-hour prints I started noticing lifting and decided to lubricate the machine as per videos at YouTub, replaced the nozzle and did numerous manual leveling rounds. Afterwards I was able to successfully print a small calibration cube test. There were some leveling issues with the perimeter of the perf board but I got that squared away too.

Then I returned to printing something larger thinking all was OK. This model has curves. But the machine stopped extruding during the print, although it extrudes and withdraws fine when the button is pressed or via the software. I tried printing different models (also curved) but the same thing happened.

So I followed posted suggestions on this forum and thoroughly cleaned the extruder gear. I also checked and all cable connections which are secure, but the extrusion issue continues. But what is strange, and I hope helpful, is that I am still able to print the calibration cube successfully.

PLEASE HELP. I NEED TO PRINT FOR WORK. THANK YOU!

bjorn
Posts: 172
Joined: Fri Aug 10, 2018 6:00 pm

Re: ***PLEASE HELP- MY BOX+ STOPS EXTRUDING***

Post by bjorn » Wed Mar 20, 2019 9:15 am

You say you changed the nozzle and cleaned the gear, did you also clean the heat break between the gear and the nozzle?

I used a hot air gun and heated it until I could pull out the scorched plastic stuck to the walls, and then pushed some clean filament through without the nozzle. Asking the printer to extrude without the nozzle may achieve the same thing, I just liked to see what was happening.

DCSConcepts
Posts: 5
Joined: Sat Jul 07, 2018 1:47 am

Re: ***PLEASE HELP- MY BOX+ STOPS EXTRUDING***

Post by DCSConcepts » Wed Mar 20, 2019 1:58 pm

Thank you for reaching out and offering help. I've cleaned the area that you mentioned and in doing so I noticed a small (plastic or metal, not sure) plate that appears to fit vertically between the extruder motor and the mount (with mated notches) was out of alignment. So I lined everything up properly and tightened. Testing with prints shortly.

DCSConcepts
Posts: 5
Joined: Sat Jul 07, 2018 1:47 am

Re: ***PLEASE HELP- MY BOX+ STOPS EXTRUDING***

Post by DCSConcepts » Wed Mar 20, 2019 4:46 pm

Thank you for your help. It's now working perfectly again (at least so far).

omsgregg
Posts: 2
Joined: Mon Feb 11, 2019 3:31 am

Re: ***PLEASE HELP- MY BOX+ STOPS EXTRUDING***

Post by omsgregg » Sun Sep 15, 2019 5:29 am

Here's the cause: Tiertime uses a cheap extruder mechanism that has a fixed location wrt the extruder spline. Most other printers employ a spring loaded mechanism that maintains a constant force between the bearing, filament, and drive gear.

The UP Box's fixed gap results in reduced pinching force as the heat upstream from the hot end warms and softens the filament. At this point, since there's no spring pinching it tighter, the gear just chews a groove in the filament and air printing ensues.

To further exacerbate the design flaw, that little pusher bearing is of poor quality and the inside ball bearings chew up the bearing race. I discovered this when I popped mine off the nylon post only to find shrapnel shards behind it. So now that bearing's OD has slop effectively reducing its diameter and hence pinching power.

You might buy back a little time by purchasing new 7mm x 3mm bearings on Amazon.

I took a more drastic route and modified the nylon filament guide block with my dremel so that it now can slide in and out a little allowing me to bias the pusher bearing towards the drive gear. This little bit of extra pinch got me back in operation.

What we need to do is pressure Tiertime into a redesigned head mechanism or even a retrofit fix with a spring loaded wheel.

Please reply if you need more info or wish to collaborate on a community solution.

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