Rostock Mini Pro Issues

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This thread is quite long and split over 2 pages now, and has covered several issues. Can you remind us what the current problem is, and what you have done to try to fix it?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Sure. Currently, the three main issues I'm having are as follows:
1. A J-Head MK V hot end that seems to be constantly jammed
2. A noticeable bowling effect that causes the hot end to rise around two millimeters near the edge of the print bed
3. A bowden tube that always pops out of the plastic holder after a few seconds of extruding

I tried lowering the hot end temperature from 200C to 160C, and it worked for roughly three seconds. Then the bowden tube popped out of its holder.
The bowling effect has been around for a while, and it's much better than it used to be. I lowered the offset height from 5 to 2 mm by increasing the DELTA_RADIUS parameter in Repetier Host.

PS I'm on spring break week so I'm trying to get as much done as possible.

Thanks!

Edited 1 time(s). Last edit at 04/02/2015 08:34PM by andychang28.

1. I can't help with the jamming as I have no experience with J heads.

2. To get the printing height the same at the edges of the bed in front of the towers at the centre, adjust the delta radius by approx. 2.2 times the height difference. Re-measure the heights, and repeat as necessary.

3. If the plastic holder you are referring to is a push fit pneumatic connector, replace it.

Edited 1 time(s). Last edit at 04/03/2015 03:27AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have not installed the fan that came with the Czar delta.
It prints well without :-)

Thomas

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

@dc42
I'm not particularly sure what you mean by "push fit pneumatic connector". I have a printed plastic part with the end of the bowden tube screwed into it. Is this what you were referring to?

The push fit pneumatic connector is the brass end of the bowden tube that you are screwing into the extruder. It is a push-fit connector because the PTFE tube is simply pushed into brass end and held in with pressure. I had mine pop out of the extruder that came from 3D Printer Czar as well, ended up just using a lot of super glue to reattach the brass end (not the tube) to the extruder. Held well until I could eventually replace the extruder.

The "bowing" of the bed is likely due to a poor calibration. Essentially what you want to due is adjust the endstop screws for each tower one-by-one so that they just touch the bed at Z=0. You then adjust the delta radius (using the 2.2 factor) so that Z=0 at X=0 and Y=0. You will then need to repeat the endstop calibration until the bed is entirely flat. A good guide on the process can be found here...[minow.blogspot.com]

I had troubles with my cloned J-Head, eventually replaced it with an E3D v6, though now the V6Lite might be a great option. If you can easily feed the filament through at temperature by hand (not using the extruder / bowden tube), then I am not sure what might be happening as if you can pop your push fit, you should have enough pressure. If you can't though, try taking the whole hotend apart and cleaning it out. I used a hot air gun, though you might try putting the nozzle in the oven. Perhaps google some methods for cleaning the hotend nozzle before taking it apart.

Hi again, I believe I have spotted another problem with the printer. The extruder motor pushes the plastic forward like it's supposed to, but every once in a while it seems to pull the plastic back as well. Over about thirty seconds, the motor will pull the plastic back so far that there is no longer any filament inside the hotend! Is this due to poor calibration, or is my extruder wired backwards?

Also, will an E3D fit my Rostock Mini Pro?

Thanks!

Check the retraction settings in your slicer. It sounds like you have speed and distance transposed

As AndyCart mentioned, you want to double check the retraction settings in your slicer. The default retraction distance in Slic3r I believe is 1mm. So far I have increased mine to 2mm, but you don't want to go much beyond that in most cases. The default speed I believe is 60mm / sec, and again, so far I have upped mine to 90mm / sec. Still trying to dial in my settings, though I also started getting some filament jams over the weekend.

As for switching to an E3D, I am currently running a v6 on my Rostock Mini, using a 6mm groove mount mounted on the bottom of effector plate (?) to accommodate the hotend fan. It wasn't the miracle fix I was hoping for when I bought it, but it did "eliminate" one point of failure for me to have to worry about. However, unless you are really planning to print anything other than PLA and occasionally ABS, the new E3D v6Lite might be a better and cheaper alternative for a replacement hotend.