Clearing printhead clog question

[DonHanson]

What's am I required to remove in order to clear a printhead clog?

Is unscrewing the nozzle a possibility?

Trying to isolate possible variables in my print quality issues... printed same model on gMax and Vision. Not sure if clog came from end of print using included ColorFab filament (see below) or from SainSmart filament I swapped in from other printer.

Is this a clogged head, overheating head or ...? (rest of object printed ok)


Haven't clogged Vision3D printer in over a year using SainSmart, but I typically print at 185 with it.

 

[RPz376]

On the initial setup of my gMax, I had to adjust the extruder stepper driver's potentiometer. I also had some difficulty getting the filament to feed correctly and after updating the idler lever arm that holds the smooth bearing, I had to trim off a portion of the spring to reduce the pressure on the drive wheel. I also had an instance when a thin sliver of cooled filament was pulled out of the hotend when changing filaments that fell back down and blocked the upper end of the hotend, preventing the new filament from being inserted.

I unbolted the hotend, cleaned the loose pieces out and put it back together without any problems while it was in place on the smooth rods.

To check if the actual hotend is plugged, I just raise the extruder about 30 mm on the z axis, preheat it using the LCD panel menu under "prepare", and then push filament through manually while squeezing the lever arm down with my other hand's finger to release the pressure on the drive wheel. If it extrudes, it isn't plugged.

Rick

 

[DonHanson]

To remove the hot end do I remove the two nuts (A) holding the piece of wood in place, or can the nozzle be unscrewed (B)?

Thanks

 

[RPz376]

There are 4 bolts that have to be removed to pull the extruder stepper motor bracket off the carriage. Two of those bolts are the bolts you show in your photo that pass through the wood wedge plates that secure the hot end. Once the motor bracket is loose, the wood plates will be as well, and you'll be able to separate all of the components. Unless you wish to change the nozzle, you shouldn't need to unscrew it from the hot end.

There is a clear acrylic plate that makes up the extruder carriage base and is sandwiched between the motor bracket and the wood plates that hold the hot end. Just pay attention to how all the pieces are oriented as you pull them apart so you can reassemble them correctly. If you have thick fingers, it may be difficult to hold the nuts and get them threaded back on the bolts, so you may have to get creative with some sticky tape.

 

[DonHanson]

Have the hot end out. Nozzle was definitely plugged. Couldn't push filament through when its heated up.

Should I attempt to unscrew the nozzle from the heater block (very hard to get grip), or the heater block from the black plastic tube?

 

[DonHanson]

I got the metal bits unscrewed from the black plastic tube but am unable to extract the nozzle or threaded rod from the heater block. (ignore nozzle on left, from different 3D printer)

I suppose the right way to prep for cleaning would be to uncover/find the tension screw holding the heat element in the heater block to get down to metal pieces for propane torching/cleaning.



Should these pieces come out of heater block?
Is there better way to clear clogged nozzle?

Thanks

 

[GORDON.LAPLANTE]

To remove the hot end do I remove the two nuts (A) holding the piece of wood in place, or can the nozzle be unscrewed (B)?

Thanks

Don, yes remove those two screws. Refer to this post as well
viewtopic.php?f=12&t=7

 

[GORDON.LAPLANTE]

I got the metal bits unscrewed from the black plastic tube but am unable to extract the nozzle or threaded rod from the heater block. (ignore nozzle on left, from different 3D printer)

I suppose the right way to prep for cleaning would be to uncover/find the tension screw holding the heat element in the heater block to get down to metal pieces for propane torching/cleaning.



Should these pieces come out of heater block?
Is there better way to clear clogged nozzle?

Thanks

I was hoping to get a write-up about clearing a clogged nozzle soon we've just been swamped. I plan on adding images or making a video to demonstrate this process. After many tests, the easiest way for us to clean the nozzle is the following:

Note: In some cases you can simply clean the tip without removing the hotend so try that first since it only takes a few seconds. It's step #4 below.


1. Remove the two screws you mentioned and as seen in this post
http://www.gmaxprinter.com/forum/viewtopic.php?f=12&t=7

2. Pull off the nozzle/basswood assembly but don't unplug it.

3. Using the LCD screen go to "Control > Temperature > Nozzle" and set it to around 195. BE VERY CAREFUL NOT TO TOUCH THE HOTEND. The basswood end should be cool to the touch. Use "helping hands" to hold the hotend.

4. Using a piece of wire or a piece of miniature piano wire (smaller than the diameter of the nozzle which is either 0.5mm or 0.35mm) insert it in to the tip of the nozzle. We used this for our 0.5mm nozzle http://www.amazon.com/gp/product/B0013891I0/ref=wms_ohs_product?ie=UTF8&psc=1. This will unclog the tip.

5. Using a piece of wire or steel rod (http://www.mcmaster.com/#1257k19/=rksail) push out what you can from the top of the hotend.

6. Cut about 12" of PLA from your spool and feed it from the top of the hotend for about 1 second. Pull it out and cut off the melted part. Reinsert it in the hotend pull out and cut the melted part. Repeat this step several times. The point is to melt the end of the filament and have it "pull" out any glassified filament which is already in the tip.

Basically repeat steps 4-6 until the hotend is clear and filament easily pushes through. I've found this can take anywhere from a single try up to 10 minutes but it seems to be quite effective.

 

[RobTorres]

I just had my first clog. I've been running my printer about 12 hours a day. I swapped out the printers hot end with my spare.
Thanks for posting these instructions. The forums have been very useful for troubleshooting!