Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
New guy with ThreeUp startup issues
#1
Found a ThreeUp kit deeply discounted which became my birthday present. To say that this is a low price entry level printer is certainly an understatement.

So, I've got it all assembled, Repetier talks to it, and I can slew it manually on all 3 axes. Alas, the extruder drive seems to be dead. By way of troubleshooting, I've done the following so far:
  • Swap the connection to another axis. Manual slew of that axis moves the motor as expected.
  • Swap the driver bridge from a known good axis. No motion on the extruder, works ok on the other axis.
  • Examining the RAMPS/AT-Mega assembly revealed 2 pins bent so as to lie on the outside of the header. Put them back in place, but no change in operation.
I'm going to try moving the connection to the Extruder 2 slot to get some functionality. If that doesn't work I fear my RAMPS board will need repair or replacement. Does this sound like I'm on the right track?
Reply
#2
Hi ChuckP,

Just wanted to check if you missed the reply from arocketguy to your other post. He said:

"2 things... Software won't let you run the extruder motor unless the hot end ... is hot.  and 2nd, even if you have turned on the hot end - and it is truly hot - if the thermistor is not working then the software will still think it's cold and not let you turn on the extruder motor. "

We can hope that this is the issue so you don't have to replace your board. Kudos to arocketguy for the response!

Stan
Reply
#3
(2017-12-08, 06:58 PM)MisterAcoustic Wrote: Hi ChuckP,

Just wanted to check if you missed the reply from arocketguy to your other post. He said:

"2 things... Software won't let you run the extruder motor unless the hot end ... is hot.  and 2nd, even if you have turned on the hot end - and it is truly hot - if the thermistor is not working then the software will still think it's cold and not let you turn on the extruder motor. "

We can hope that this is the issue so you don't have to replace your board. Kudos to arocketguy for the response!

Stan
Thanks for the heads-up. I hadn't checked the introduction thread yet. Let's hope this is what's needed.
Reply
#4
That did the trick! I suspect I'll be full of questions here, and I'm very glad to have y'all to lean on.
Reply
#5
I was right about having many questions: The extruder motor appears to be running backwards (Extracting when it should be feeding.) I can't find a setting to reverse this: Can I safely flip the connector on the RAMPs board? That should reverse polarity on both phases. Is this something I should even consider?
Reply
#6
Hi ChuckP,

I think it might not be a hardware issue. I found this thread:

https://www.thingiverse.com/groups/prusa...topic:5575

Looks like there might be some g-code manipulation needed, depending on the cause. You could check first if the problem goes away if you power down and restart the printer - that would suggest the g-code changes might work.

Stan
Reply
#7
I like the added G code just for safety's sake, but it didn't help here. In the end, I reversed the servo connection on the Ramps board, and now it at least feeds in the right direction.

I think I'm down to temperature issues now: What little plastic comes out doesn't stay put on the (heated) platen, and the extruder is feeding filament far faster than it comes out. I'm using the sample filament from the kit, which they politely neglected to tell me the composition of. I'm beginning to suspect its ABS, not PLA.
Reply
#8
(2017-12-09, 11:47 AM)ChuckP Wrote: I like the added G code just for safety's sake, but it didn't help here. In the end, I reversed the servo connection on the Ramps board, and now it at least feeds in the right direction.

I think I'm down to temperature issues now: What little plastic comes out doesn't stay put on the (heated) platen, and the extruder is feeding filament far faster than it comes out. I'm using the sample filament from the kit, which they politely neglected to tell me the composition of. I'm beginning to suspect its ABS, not PLA.

Hi ChuckP,

I was just curious if you tried to manually feed some filament once the hot end was hot, to see if that was backwards as well. In any case, if it's working now, it's all good Smile.

I guess I can ask some basic questions - forgive me if you know this stuff already. Have you leveled the bed, and have you set the height of the hot end above the bed? It looks like the ThreeUp has the same bed material as a TwoUp - I don't have a heated bed, but I have always used blue painters tape on the bed to improve adhesion.

So first, I would put down a layer of painters tape (I do mine so I can get it off easily when it needs to be replaced).

Then, run the extruder down close to the bed - perhaps not too close if you're never leveled the bed before - and then move it to each of the 4 corners of the bed. At each point, adjust the height of the bed so that it's the exact same distance from the extruder at each point. You adjust the height by using an Allen wrench on the screws coming up under the bed with the springs around them. I would also check the center of the bed. The bed can actually be warped, but you should be able to get it close enough to work.

Finally, when you go to print, get a piece of paper and slide it between the extruder and the bed. Run the extruder down manually using the smallest movements until the extruder applies pressure to the paper - but you can still slide it in and out.

That should be the height where you put down your first layer. I've never had a problem with things not sticking this way - in fact, it's much more difficult to get things off when they're done.

Lastly, regarding the feed rate, of course all of those things are adjustable through the software - are you using Repetier Host? I would still do the above before adjusting the software parameters - plenty of time for that later Smile.

Hope all of this helps. Let us know what happens.

Stan
Reply
#9
Hi ChuckP,

I re-read what you said, and I wanted to ask about "...the extruder is feeding filament far faster than it comes out...". Does this seem to mean that the filament is slipping as the extruder stepper motor tries to drive it into the hot end? Obviously, if that's the case, you can try to ensure that the bearing is squeezing the filament tightly enough up against the drive pulley.

Also, I saw that it can appear that there is too little plastic coming out if your slicer settings do not match your filament size. You likely are using 1.75 mm filament, but the slicer settings could have been changed to a higher number.

Just guessing at this point Smile.

Let us know what you've been able to try.

Stan
Reply
#10
Yep, turned out to be the filament diameter parameter. Now I'm down to just run of the mill tuning. thanks for all the help.
Reply
Topic Options
Forum Jump:




Users browsing this thread: 1 Guest(s)