Retraction Issues

[msimpson]

My machine is calibrated (mechanically), I have calculated the temperatures (check with extern thermocouple as well), I have calibrated my flow (volume of filament)

Now with retraction
I originally had a problem with the acceleration of the retraction and had to bring it down to 1000 to keep the motor from stalling. But even with that fix I can't seem to get a set of retraction settings that are acceptable.

I can make a cube as outlined in the instructions but all places where it stops and starts the filament leave blobs or holes. No setting seems to help.

I can print all day long perfect prints as long as it does not require any retraction. I am at a total stand still.

[mhackney]

How large of a retraction value did you try? If you haven't tried 10mm yet, try that. At some point the blobbing has to stop!

The other thing that can affect blobbing is the Z Lift. I am now using 1mm. That causes the Z to lift before moving. When coupled with retraction it pulls the excess hot filament out of the way. Although I am using Slic3r right now, KISSlicer has a feature called wipe that "wipes" the extruder back over the filament that it just laid down, thereby eliminating blobbing. I've heard it is the bees knees of deblobbing!

[msimpson]

I found your post where you were experimenting with z lift. I am going back and trying some controlled experiments. First is to experiment with temperature. I am using red abs for this on. It seems to extrude well between 210 and 240. I want to see how temperature affects retraction. I did notice that going from 230 to 220 reduces flow so my wall thicknesses are no longer perfect. IE I calibrated my E speed at the 230 temp.

[msimpson]

OK, I am definatly seeing the delamination issue as the extruder slides over a perimeter. This is what is causing complicated prints to self distruct. I am going to try raising the Z a little on each retraction.

[msimpson]

I can only retract so far before it is starved on the restart. I have raise the Z to 1.5 to keep it from rubbing, but I end up with little blobs on the top. All in all its a mess.

Im about ready to give up on this extruder combination and move to something else. These retraction setttings should have been fine tuned by the the folks at SeeMeeCNC.


Oh and I am still getting extruder motor stalling from time to time.

[aehM_Key]

Oh and I am still getting extruder motor stalling from time to time.

Adjust your current and acceleration-settings.

[msimpson]

I have the accelerarion down to 1000. Is there a place to adjust the current?

[cambo3d]

Oh and I am still getting extruder motor stalling from time to time.

Adjust your current and acceleration-settings.

im new to the setup of the rostock but shouldn't those settings already be configured for seemecnc version of marlin?

or are those settings part of the software you guys are using?

[aehM_Key]

I have the accelerarion down to 1000. Is there a place to adjust the current?

Hm, this is not very much - should work..
Have you tried without filament?

#define MOTOR_CURRENT {175,175,175,222,175}

I have 222 for the extruder

@cambo3d: I'm using Repetier firmware.

[Polygonhell]

Oh and I am still getting extruder motor stalling from time to time.

Adjust your current and acceleration-settings.

im new to the setup of the rostock but shouldn't those settings already be configured for seemecnc version of marlin?

or are those settings part of the software you guys are using?

Machines aren't identical, the firmware is usually close and some can use it as is, but it can require some messing with.
The extruder in particular seems to be very sensitive to the way it's assembled, some people run at 60mm/s retract with no issues, others have issues stalling even at much lower speeds.

[msimpson]

My extruder runs as smooth as silk by hand without the motor attached. I spent a great deal of time on the thing to get it assembled correctly. With the orriginal firmware settings it was stalling without any filament. So I have to say the firware was way off, not even close.

I just upped the current to a setting of 222. I will do some more tests to see if it helps.

[gabrielk]

i wouldn't try to start extruder without filament, because withouut it the component you put it inside (one with knurled roller) have to much play for my opinion, and can move sideways, up and down.

[theverant]

I changed my firmware over to Polygonhell's Repetier almost immediately, so I have little experience with the firmware which shipped on the RAMBo. Why not do the same and see if things improve? It would appear they couldn't get any worse at this point.

At least then you'll know if it is truly a firmware or mechanical issue and set about fixing it properly.

[msimpson]

I dont understand. If that firmware is better and fixes the problems I am having, then why does it not ship with the printer or at the very least, get included in the startup instructions?

[mhackney]

msimpson, you must realize that this is a hobby and exploring and experimenting are a big part of it. The Rostock (and all other) printers and electronics are evolving quickly. The software is evolving even quicker. What is best today is likely going to change in a couple of weeks.

The Rostock Max and many other kits on the market include parts and components sourced from other manufacturers. The RAMBo is a good example. In order to produce and sell it at the incredibly low price it sells for, customized software configurations are not economically feasible and the market for a value added service or higher end offering that does this is either not there yet or the market for the hobbyist machines is growing so quickly that it is not possible to divert resources. I experience this in my business on a daily basis. Everything is a tradeoff - quality, functionality and price. The Rostock Maxdoes an excellent job at all of these as it is. Could it be made more mainstream consumer oriented? Sure, but that isn't where the bulk of the market is right now.

We are all here to help. The extruder setup in ALL printers is in my opinion the weak link of the chain. It really is an art to get any of them setup properly, especially without experience. I have now setup 4 Steve's Extruders, a JHead with Micro Extruder and a QU-BD extruder and hot end. In the grand scheme of things, the Steve's is reasonable. If your extruder is stalling without filament and is not binding as you say, then most likely it is being over driven. Do you know about 8 vs 16 microsteps and setup the firmware properly? The RAMBo 1.0 were 8, the newer RAMBo 1.1 is 16. Next you want to check the acceleration. You can do these configs on whatever firmware you choose but Polygonhell has already created a config that is reasonable for 8 microstep version 1 RAMBos. There are several posts here on what to do to config for 16 micro steps.

[msimpson]

I moved to Kisslicer as others have reported better prints. I can report that the prints using Kisslicer are better. The reason for this is that it has better pathing than the slic3r software. There are still retraction issues on complicated parts.

The problem is in the extruder. Too many moving parts. Too much lag because of the bowden tube. Its just not a good match for the Rostock Max.

At this point I am giving up on the stievestruder and will be mounting a direct drve on the platform. The question is can it support the wieght.

Im going to be moutning a modified QU-BD extruder to the platform. Im just waiting for the springs used in the tension mod.

[cambo3d]

Im going to be moutning a modified QU-BD extruder to the platform. Im just waiting for the springs used in the tension mod.

i've been wanting to do this also but haven't gotten around to it. let us know how it works out.

[Flateric]

Has anyone else considered that the tube from the extruder to the hotend is also for sure part of the issue.

I know this from dealing with helping people on the cnczone forums and the sears brand router that uses a flex tube from motor to cutter. It sucks. It flexes causes lag and variable oddities.

The rostock tube is no different. I stiffened mine with an additional tube I slide over top of the stock one. Same material exact same just the ID fit the stock one perfectly. Not really stiffer to the point of causing carriage probs though. Just reduces the flex during retract and resumes.

I've been wondering if a different tube altogether would be even better. Perhaps a tube from a cycling shop, the kind that are used on the brakes with the wire down the middle? I already explored the possibility of using a mig welder liner but they are too small ID.

Also, the tube on the bowden should be as short as possible without causing other issues with being too short.

[cambo3d]

Has anyone else considered that the tube from the extruder to the hotend is also for sure part of the issue.

I know this from dealing with helping people on the cnczone forums and the sears brand router that uses a flex tube from motor to cutter. It sucks. It flexes causes lag and variable oddities.

The rostock tube is no different. I stiffened mine with an additional tube I slide over top of the stock one. Same material exact same just the ID fit the stock one perfectly. Not really stiffer to the point of causing carriage probs though. Just reduces the flex during retract and resumes.

I've been wondering if a different tube altogether would be even better. Perhaps a tube from a cycling shop, the kind that are used on the brakes with the wire down the middle? I already explored the possibility of using a mig welder liner but they are too small ID.

Also, the tube on the bowden should be as short as possible without causing other issues with being too short.

without the tube this wouldn't be a bowden extruder.. just thought i'd clarify so when you say "that the tube from the extruder to the hotend is also for sure part of the issue." your talking about the bowden design. let us know if the bike cable works. anything to improve the bowden design.

[Flateric]

I'm not sure what your point is really.

How would I have accurately described the pieces I was specifically discussing?

[cjdavis618]

The rostock tube is no different. I stiffened mine with an additional tube I slide over top of the stock one. Same material exact same just the ID fit the stock one perfectly. Not really stiffer to the point of causing carriage probs though. Just reduces the flex during retract and resumes.

Did adding the secondary tube seem to help with the system to a noticeable point in print quality?

[dbarrans]

I don't understand the point of adding outer tubing to the Bowden tube. I'd expect the end fittings might have some slop which would vary the overall length when extruding and retracting the filament, but lateral flex shouldn't significantly affect the length.

- dan

[Polygonhell]

I don't understand the point of adding outer tubing to the Bowden tube. I'd expect the end fittings might have some slop which would vary the overall length when extruding and retracting the filament, but lateral flex shouldn't significantly affect the length.

- dan

I guess the idea would be that if the tube itself is flexing, the outer tube would reduce that effect.
There are multiple things at play here, all adding to the additional hysteresis
Stretch in the outer tube.
Movement of the filament relative to the inside of the tube.
I suspect the second is more significan that the former.
At some level if you can retract fast enough the hysteresis is irrelevant as long as it's largely repeatable, but there are limits to how fast you can retract.

[msimpson]

Ok, it is obvious that the Marlin firmware has issues with printing on the RostockMAX. I have yet to see a decient print requiring retraction comeing from a machine with Marlin.

That said, I decided to try the Repetier Firmware. Where to start? The latest 82.2 will not compile if you set it to rambo. So I went to 81.

Does anyone have a list of all the firmware seetings that need to be changed?

[Polygonhell]

Ok, it is obvious that the Marlin firmware has issues with printing on the RostockMAX. I have yet to see a decient print requiring retraction comeing from a machine with Marlin.

That said, I decided to try the Repetier Firmware. Where to start? The latest 82.2 will not compile if you set it to rambo. So I went to 81.

Does anyone have a list of all the firmware seetings that need to be changed?

My Github has a configured 0.82.2 that works on the Max, depending on when you got your max, you'll have to make configuration changes.
John from SeeMeCNC also has a version configured for the Max, I would assume configured for the newer printers.
If you want to configure it yourself, there are a fair number of gotchas.