Rrepetier firmware issue?

[Cobraphx]

I'm having a new problem since I started trying to use the Repetier firmware with my Rostock Max. I have an Onyx bed and a glass plate covered with Kapton tape. When I painstakingly level the bed, everything looks good. I slice my part using Slic3r from the Object Placement tab. When I start printing, the head digs into the tape and tears it. This has happened multiple times. I level the bed again and try printing again, same thing. Figured I wasn't leveling it precisely enough.

So... I watched it very carefully on the last print attempt. The head is moving up and down by at least .4mm as it moves around the bed while printing. Looks like the steppers aren't stepping properly to keep the head height uniform as it translates around the bed. I'll try switching back to the Marlin firmware and see if that clears up the issue. I can't think of a hardware problem that would cause this kind of issue.

-Matt

[mhackney]

I've not had my Rostock working - just built it last week - but in the process of trying to calibrate it I've seen the same odd thing several times and it is sort of like yours. Using the Repetier firmware. When attempting to print the calibration cube, after the first 3 layers (solid) the print shifts about 1 to 2 cm in the -X direction (cartesian, not the X tower). Then I notice as its printing at this new location that the nozzle is moving up and down about .5mm as it prints in this location.

I haven't trien other items and haven't dug into this issue deeply since I can not extrude properly yet. I have an H-1 and an H-1.1 so I am very familiar with Steve's extruder. When extruding into air, I see the filament move 1cm when I tell it to extrude 1 cm. However, when attempting to print continuously, it seems as if the nozzle is blocked and nothing comes out and the extruder is unable to push the filament.

regards,
Michael

[Polygonhell]

The shift and vertical motion is what deltas do when they lose steps.

On the OP's post are you setting the ZHeight in the EEPROM settings or in configuration.h?
It needs to be in the EEPROM settings in repetier host, setting it in configuration.h will have no effect after the firmware is run for the first time.
If you are seeing convex or concave motion of the head you need to adjust the delta radius in the firmware, it's pretty much trial and error, but 0.5mm is a lot to change it by. This is the same in Marlin.

[mhackney]

I could see a shift in the direction of one of the towers but a shift along a Cartesian dimension involves all 3 towers doesn't it?

On the EEPROM, if you have that disabled in the firmware (set the directive to 0) then the values would come solely from the firmware. You can't even view the EEPROM if it is disabled.

In my situation the first 3 layers would be perfect (if extruding worked) and the I get a shift in Cartesian X dimension. It's like something happens when going from printing the bottom shell (3 layers) to printing the perimeter and fill.

Thanks!

[jesse]

It needs to be in the EEPROM settings in repetier host, setting it in configuration.h will have no effect after the firmware is run for the first time.

Are you saying that the z-max can be set in repetier without uploading new firmware? I've been uploading the firmware and entering the height in the repetier printer settings. It would be nice to be able to send the z-max number to the RAMBo EEPROM without waiting a minute to upload the firmware.

[Polygonhell]

I could see a shift in the direction of one of the towers but a shift along a Cartesian dimension involves all 3 towers doesn't it?

On the EEPROM, if you have that disabled in the firmware (set the directive to 0) then the values would come solely from the firmware. You can't even view the EEPROM if it is disabled.

In my situation the first 3 layers would be perfect (if extruding worked) and the I get a shift in Cartesian X dimension. It's like something happens when going from printing the bottom shell (3 layers) to printing the perimeter and fill.

Thanks!

It does seem unlikely, but I think it's more unlikely it's the firmware, and vertical motion accompanying the skew is exactly what missed steps do.
I'd try the following independently to see if they fix, reduce jerk/accel, reduce speed of travel moves, decrease digipots values.

[Polygonhell]

It needs to be in the EEPROM settings in repetier host, setting it in configuration.h will have no effect after the firmware is run for the first time.

Are you saying that the z-max can be set in repetier without uploading new firmware? I've been uploading the firmware and entering the height in the repetier printer settings. It would be nice to be able to send the z-max number to the RAMBo EEPROM without waiting a minute to upload the firmware.

Yes if the firmware is compiled with EEPROM enabled, you must make the changes in the repetier host EEPROM settings menu. Or you have to send additional GCode commands to save the configuration.h values into the EEPROM.

[mhackney]

A thought comes to mind is that the speed of printing the infill is much higher than the first 3 solid layers and this is where I see the problem. So I think you may be onto something. I'll do some tests.

I am still struggling with the extruder though. Driving me bonkers. I have 3 other Steve's extruders but all direct and not Bowden. I've pushed filament by hand and it moves easily up the Bowden tube into the hot end. It then takes a lot of pressure to push it to extrude (ABS at 235 deg C). When the extruder is pushing, the pinch rollers turn but the filament does not move. If I tighten the adjustment screws, I still don't get enough grip to push the filament and the filament gets badly squished into an oval. I suspect the roller grooves are not toothy enough. I haven't had a chance to check/change this yet though.

[barnett]

Hi Michael,

Two questions on your extruder issue:
- when the motor is extruding and the filament isn't moving, can you help it along with your hand then?
- are you sure the 235 temp is reading correctly? I wonder if it's really just not hot enough?

And here's a random idea... what if you take off the nozzle and test it? Would that even work? I'm wondering if the extruder rollers are coming up against too much pressure somehow, so maybe you could test a low pressure situation.

Barnett

[Polygonhell]

A thought comes to mind is that the speed of printing the infill is much higher than the first 3 solid layers and this is where I see the problem. So I think you may be onto something. I'll do some tests.

I am still struggling with the extruder though. Driving me bonkers. I have 3 other Steve's extruders but all direct and not Bowden. I've pushed filament by hand and it moves easily up the Bowden tube into the hot end. It then takes a lot of pressure to push it to extrude (ABS at 235 deg C). When the extruder is pushing, the pinch rollers turn but the filament does not move. If I tighten the adjustment screws, I still don't get enough grip to push the filament and the filament gets badly squished into an oval. I suspect the roller grooves are not toothy enough. I haven't had a chance to check/change this yet though.

My current Hotend is the same as yours, seems to require excessive force to extrude, though I can extrude.

On my machine the Hotend reads cold, the coldest set temperature I can extrude ABS reliably is 235, and I've been running at 240 and 245 for the most part.

[mhackney]

Thanks guys. I've cranked the heat up to 245 but I actually have not measured it. I have a thermocouple so I can do that. I have tried to push by hand but am unable to do so, it just seems jammed. However, if I stop the print run and then extrude 10mm at 60mm/s from the host, it extrudes a nice bead and the filament moves 10 mm up the Bowden tube (I've marked the filament so I can see and measure).

I have thought about removing the nozzle and testing but on this new design, the Teflon tube would not be held in place, would push out and end up probably making a mess. I'll have to take a closer looks and see though.

[mhackney]

Well, at least the "unexpected X translation" problem is solved! Turned out to be loose set screws on the pulley on the X stepper. Careful observation revealed that the translation actually was towards the X tower.

Now I need to sort my extrusion problems. More work/research/exploration this morning but nothing discovered.d