Bondtech upgrade is under extruding  

RE: Bondtech upgrade is under extruding

Posted by: @jimbo70

I added a Bondtech extruder to my e3d hotend and did the Bondtech firmware change as suggested but I have severe under extrusion - I estimated about 250%.   Everything else is working great.

I know the Bondtech has a lower gear ratio and would expect under extrusion, but I thought the Bondtech firmware would correct this problem.

Now I am stuck and do not know what to do!

You can either change the esteps for the extruder in the firmware, recompile and then flash:

#define DEFAULT_AXIS_STEPS_PER_UNIT {100,100,3200/8,415}

or you insert the following command into the slicer Start Gcode:

M92 E415
M500

After that, I would do some fine tuning: https://all3dp.com/2/extruder-calibration-6-easy-steps-2/ or https://www.matterhackers.com/articles/how-to-calibrate-your-extruder

With the command M503 (with Pronterface, Octoprint or another terminal) you can check if the E-value matches the new steps/mm value.

wbr,

Karl

RE: Bondtech upgrade is under extruding

Thank you very much, will try the start code first and get back to you. 

RE: Bondtech upgrade is under extruding

You were a great help. I have been trying for 2 days to get this to work. 

I tried the:

M92 E415

M500

 and it did not help, then I did the M503 and it was very interesting. It says my extrusion limit is 120!!!!

I am using a Repetier server and it has an interface for each printer. I started looking around because I did not understand that there was an extrusion limit. Buried in the Printer Settings/Tools there is an extruder configuration that has an extruder limit. I increased this to 500 and there was an additional setting for extruder steps and I set this to 415.

I did another test and my measurements now indicate I am within 1% of the expected extrusion.

I included much detail in my explanation to help anyone in the future with a similar problem.

RE: Bondtech upgrade is under extruding

@jimbo70

Thanks for the feedback. If I understood correctly, the repeater server has blocked or overwritten the slicer estep settings. Would be interesting to know how exactly this is going on.

"I included much detail in my explanation to help anyone in the future with a similar problem."

Where can we find these deatils?

Thanks!

wbr,

Karl

RE: Bondtech upgrade is under extruding

I have attached a part of the server setting under the printer extruder. The setting of extrude speed was 215 and I increased it to 415 and suddenly I was getting the proper extrusion.

the other setting you suggest would not force a change.

Unless I have made some other (unknown) change I can only conclude the server was limiting the extrusion. I am using the Bondtech MK2.5s firmware which does have the proper extrusion steps.

Interesting to me is: I have another machine on the same server (MK3 with a Hemera) and the extrude speed is set to 2 and there is no problem.

RE: Bondtech upgrade is under extruding

I want to update my finding so this post is as accurate as possible. At this point, I do not believe Repetier has any relationship to the firmware update.

When I flashed the new Bondtech firmware I did a reset as they advised but I did not do the reset properly. A proper reset will truly reset the printer and it will need recalibration just like a new printer.

The Prusa website says to reset you need to press the reset X them immediately press the selection knob. The word immediately is not clear enough. You need to press the reset X and within a very small fraction of a second press the selection knob. They can not be press simultaneously. When done properly the next screen to appear will as for a language preference. Then you can scroll through the reset options.