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Different diameter filaments

Posted: Tue Oct 20, 2015 5:49 am
by Nightram
This should be easy.

I have hotend #1 with 3mm filament, and hotend #2 with 1.75mm.

If #1 has a extrusion multiplier of 1.00, how do I determine the rate of #2?

Re: Different diameter filaments

Posted: Tue Oct 20, 2015 7:02 am
by CompoundCarl
Ok, so let's assume you set the filament diameter on the Other tab to 1.75mm. But one of your hotends uses a 3mm diameter filament instead. You just need to lower the extrusion multiplier for that 3mm extruder.

The value to use is:
((main filament diameter/2)^2) / ((alternate filament diameter/2)^2) = ((1.75/2)^2) / ((3/2)^2) = 0.340

So just enter 0.34 for the 3mm nozzle extrusion multiplier and it should be very close to ideal. You may still need to make tiny adjustments though as you watch it print.

Re: Different diameter filaments

Posted: Tue Oct 20, 2015 4:39 pm
by Nightram
Well it was a 50/50 guess.

My filament is set at 3mm!

So using the formula I get 293.87 for 1.75 as secondary.

Re: Different diameter filaments

Posted: Wed Oct 21, 2015 5:59 am
by CompoundCarl
I think you are off by a factor of 100...

((3/2)^2) / ((1.75/2)^2) = 2.939

So if you have 3mm set as the filament diameter in the Other tab, but one of your extruders is using 1.75 filament, then change the extrusion multiplier for the 1.75mm extruder to 2.939 (not 293.9!)

Re: Different diameter filaments

Posted: Wed Oct 21, 2015 6:14 am
by Nightram
CompoundCarl wrote:I think you are off by a factor of 100...

((3/2)^2) / ((1.75/2)^2) = 2.939

So if you have 3mm set as the filament diameter in the Other tab, but one of your extruders is using 1.75 filament, then change the extrusion multiplier for the 1.75mm extruder to 2.939 (not 293.9!)
yeah, you are correct. I couldn't edit it as I cant be trusted for a few posts. I was think of it in terms of "percent".

Re: Different diameter filaments

Posted: Mon Apr 18, 2016 5:53 pm
by hlavac
Here is a little table I made for using extrusion multiplier to compensate for different filament sizes in multiple extruders:

Code: Select all

     |	3,00	2,95	2,90	2,85	2,80	2,75	2,70	1,90	1,85	1,80	1,75	1,70	1,65	1,60
-----+--------------------------------------------------------------------------------------------------
3,00 |	1,00	0,97	0,93	0,90	0,87	0,84	0,81	0,40	0,38	0,36	0,34	0,32	0,30	0,28
2,95 |	1,03	1,00	0,97	0,93	0,90	0,87	0,84	0,41	0,39	0,37	0,35	0,33	0,31	0,29
2,90 |	1,07	1,03	1,00	0,97	0,93	0,90	0,87	0,43	0,41	0,39	0,36	0,34	0,32	0,30
2,85 |	1,11	1,07	1,04	1,00	0,97	0,93	0,90	0,44	0,42	0,40	0,38	0,36	0,34	0,32
2,80 |	1,15	1,11	1,07	1,04	1,00	0,96	0,93	0,46	0,44	0,41	0,39	0,37	0,35	0,33
2,75 |	1,19	1,15	1,11	1,07	1,04	1,00	0,96	0,48	0,45	0,43	0,40	0,38	0,36	0,34
2,70 |	1,23	1,19	1,15	1,11	1,08	1,04	1,00	0,50	0,47	0,44	0,42	0,40	0,37	0,35
1,90 |	2,49	2,41	2,33	2,25	2,17	2,09	2,02	1,00	0,95	0,90	0,85	0,80	0,75	0,71
1,85 |	2,63	2,54	2,46	2,37	2,29	2,21	2,13	1,05	1,00	0,95	0,89	0,84	0,80	0,75
1,80 |	2,78	2,69	2,60	2,51	2,42	2,33	2,25	1,11	1,06	1,00	0,95	0,89	0,84	0,79
1,75 |	2,94	2,84	2,75	2,65	2,56	2,47	2,38	1,18	1,12	1,06	1,00	0,94	0,89	0,84
1,70 |	3,11	3,01	2,91	2,81	2,71	2,62	2,52	1,25	1,18	1,12	1,06	1,00	0,94	0,89
1,65 |	3,31	3,20	3,09	2,98	2,88	2,78	2,68	1,33	1,26	1,19	1,12	1,06	1,00	0,94
1,60 |	3,52	3,40	3,29	3,17	3,06	2,95	2,85	1,41	1,34	1,27	1,20	1,13	1,06	1,00