Are MK7 or MK8 drive gears a direct replacement?

[profepaco 0]

Are MK7 or MK8 drive gears a direct replacement?

Or do I need to make some adjustments to avoid under / over extrusion?

Thanks.

 

[takei-naodar 0]

They are a sort of Replacement.

This is for the MK8.

You will need to alter the Feeder Case to be usable with the filament path changed by 0.5mm, due to the new effective Diameter of 7mm. Also due to that you will need to change the new filament diameter to 2.68 to work with the new effective diameter aswell as set Retraction Speed and length bigger. Everything in a Ratio of 1.14:1

but for that "hard" work you will get a drive gear that cuts in the Fiolament so well that you can use 1.6A on the feeder motor without problems. Except that the drive gear may Start to slip on the rod because of the power.... but that is another topic

The biggest difference is that you have now a Set height where you have to put that drive gear.

I think i put the needed Parts for an MK8 Replacement in my Version of the feeder. Link in the Siq

Have fun

 

[selmo 0]

What did you use for the mm/step for the extruder?

 

[chuck-yanke 9]

"You will need to alter the Feeder Case to be usable with the filament path changed by 0.5mm, due to the new effective Diameter of 7mm. Also due to that you will need to change the new filament diameter to 2.68 to work with the new effective diameter aswell as set Retraction Speed and length bigger. Everything in a Ratio of 1.14:1"

I'm new to printing what do you mean ratio changes 1.14:1 for retraction speed and length

[takei-naodar 0]

Since i always easily want to use the newest firmware version without much editing i did not change the E-Steps. Also i want to be able to do the extrusion tests.

 

[selmo 0]

OK, I see -- you're using the filament diameter to compensate for the difference in diameter. I guess you could also do that with the flow rate. Did you calculate your ratio based on the fact that filament diameter changes the extrusion volume by the square, not linearly like the extruder diameter?

I use filament from a bunch of different mfgs, so I adjust my filament diameter for each spool (I've got spools ranging from 2.7 to 3.0 nominal). You'd have to recalculate your ratio every time you use a filament of a different diameter.

Changing the steps/mm is a hassle, but it only needs to be done once -- and it can be done in gcode with M92 E____ , and saved to the machine's EEPROM. It does not require you to edit the firmware. Use M501 to load settings, M500 to save settings, M502 to reset to firmware defaults, and M503 will print the settings to the serial port / log window. (note that in Marlin, M502 does not save the loaded default settings -- you need to do an M500 as well if you want those defaults loaded when you restart)