Marlin hack for Medusa feeder

[schafe 3]

I recently downgraded myself from a B+ Ulitmaker/Cura student to a C.  There is a lot I don't know.  Oh well.

 

I've been fighting under extrusion and the extruder motor skipping on my old UM2 for a long time and recently added the Medusa upgrade.  I read that I need to change the extrusion multiplier to double the motor speed.  20 teeth on the drive gear and 40 on the driven.  On the printer's control screen I set the flow rate to 200% which has worked so far, but loading filament is a pain.

 

I downloaded Marlin v2.0.5.3 and uncompressed it but cannot find anything in the folder that seems like it will install the program on my PC. 

 

I have never modified the firmware on my UM2, so I will need baby steps please.

[gr5 2,005]

You really want the TinkerMarlin version of Marlin - it's so much better.  It has so many more critical features (like being able to reverse motor direction and steps/mm and continue a failed print and dozens of other really nice features.

 

You can get it here:

https://github.com/TinkerGnome/Ultimaker2Marlin/releases/

 

You might have to do a "factory reset" but probably not if you currently have a valid Ultimaker version of marlin.  The issue is many settings are stored in eeprom and each version stores them in a different place.  But all newer versions of marlin know how to upgrade older versions.  It's when you go backwards in version that you get strange results and you have to do a factory reset.

 

[schafe 3]

Interesting news.  I started a new print.  25mm/sec, .4mm dia and .2mm height or 2mm3/sec.  The planets have aligned, and I obviously prayed to the right gods.  I was able to increase the speed to 600% with a feed rate of 190% and a temp of 210C.  That's 12mm3/sec!  No problems, perfect results, so far.  The next thing I print will totally fail and I will have no idea what changed.  The UM2 was going so fast that the small table it sits on was moving back and forth.

[gr5 2,005]

lol.  Yeah - I never print that fast but recently did a test with UM2+ feeder (about same as meduza feeder) and got I think 16mm^3/sec with < 5% underextrusion.  Insane.  Quality not so great but at least no underextrusion.

 

[schafe 3]

2 perfect prints now, and at a speed I am pleased with!!

 

Here is a page that describes what to do with the Tinkergnome firmware once you have found it. 

 

(There is supposed to be a link here.  Every time I paste it, it turns into a screen shot sort of thing.  In the Ultimaker forum go to Ultimaker software/firmware and search "Tinker firmware - introduction")

 

For those who have been keeping score, or care,  I've added:

-  New high temp teflon thermal isolator

-  Printed ABS spacer that replaces the steel spring for the teflon part

-  Medusa feeder upgrade

I am going to add the Alternative UM2 feeder - version two since the new firmware does not run the extruder motor at 2X speed when changing filament.

[gr5 2,005]

Did you print the iRoberti feeder to go on the medusa?  Or are you still using the black feeder.  If you use the iRoberti feeder on there then you just slide filament in and out of the printer - no need to use any menu items at all.

 

[schafe 3]

Yes, that is it.  On the youmagine screen it is called "Alternative UM2 feeder - version two."  I see now the author is iRoberti.