Diamond hotend switching usage Hi! I'm thinking to buy a Diamond hotend and use it as a switching color hotend, not mixing (I read that passive mixing is not ideal, because of the toothpaste effect). In theory, switching only needs 1 motor, as only one filament is used at a time. But in the case of the Diamond, all filaments have to be engaged, to avoid back extruding in unused heads. My first question is: do unused filaments need to be maintained by their respective motors? My first idea was to use only one motor, and a servo to move a gear to choose which filament to drive... But this means that unused filament won't be maintained. My second question is about Bowden tubes: what is the maximum length I can use? What happens if using too long tubes? I would like to put the extruder on the (coreXY) frame, not above with a swinging stuff. Thanks for your help. https://reprap.org/forum/read.php?1,753085,753085#msg-753085 Fri, 12 Jun 2026 04:26:47 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,753085,753488#msg-753488 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753488#msg-753488
Quote
Origamib
Use a piezo sensor for each head to determine Z offset.

I was thinking this would be a very good use of the sensor.]]> DjDemonD General Sun, 05 Mar 2017 18:58:33 -0500 https://reprap.org/forum/read.php?1,753085,753232#msg-753232 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753232#msg-753232
Good to know about Bowden length.]]> fma General Sat, 04 Mar 2017 17:16:40 -0500 https://reprap.org/forum/read.php?1,753085,753228#msg-753228 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753228#msg-753228
Quote
fma
Hi!

I'm thinking to buy a Diamond hotend and use it as a switching color hotend, not mixing (I read that passive mixing is not ideal, because of the toothpaste effect).

In theory, switching only needs 1 motor, as only one filament is used at a time. But in the case of the Diamond, all filaments have to be engaged, to avoid back extruding in unused heads.

My first question is: do unused filaments need to be maintained by their respective motors? My first idea was to use only one motor, and a servo to move a gear to choose which filament to drive... But this means that unused filament won't be maintained.

My second question is about Bowden tubes: what is the maximum length I can use? What happens if using too long tubes? I would like to put the extruder on the (coreXY) frame, not above with a swinging stuff.

Thanks for your help.

Not only do you need to keep the unused filaments in place, it seems that you need to retract them at the same time as you retract the active filament. See section "Extruder retraction" at [blog.think3dprint3d.com].

My delta printer has a Bowden tube more than 600mm long, and although this is much longer than ideal, I get good prints from it. I had to tune the retraction very carefully. 7mm turned out to be optimum, enough to prevent blobs but not enough to cause the E3Dv6 to jam. Using pressure advance helps with print quality.]]> dc42 General Sat, 04 Mar 2017 17:02:36 -0500 https://reprap.org/forum/read.php?1,753085,753205#msg-753205 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753205#msg-753205
That's why I'm looking at a single nozzle head as the Diamond...]]> fma General Sat, 04 Mar 2017 15:40:46 -0500 https://reprap.org/forum/read.php?1,753085,753201#msg-753201 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753201#msg-753201
Quote
fma
Yes, but what about X/Y? If one could find an easy way to calibrate...

With a decent mechanism I don't see why XY should be a problem, as long as it's made to a tight tolerance. The example I gave isn't the best designed.]]> Origamib General Sat, 04 Mar 2017 15:22:02 -0500 https://reprap.org/forum/read.php?1,753085,753197#msg-753197 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753197#msg-753197 fma General Sat, 04 Mar 2017 15:06:30 -0500 https://reprap.org/forum/read.php?1,753085,753192#msg-753192 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753192#msg-753192 Origamib General Sat, 04 Mar 2017 14:46:55 -0500 https://reprap.org/forum/read.php?1,753085,753172#msg-753172 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753172#msg-753172 fma General Sat, 04 Mar 2017 13:19:59 -0500 https://reprap.org/forum/read.php?1,753085,753168#msg-753168 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753168#msg-753168 Tool changer

There have been plenty others posted. I've seen one for ultimakers as well. Basically use magnets to 'grab' an extruder and off you go! Has the advantage of multi-materials, multi temperatures, multi nozzle sizes and different heat blocks.]]> Origamib General Sat, 04 Mar 2017 13:10:59 -0500 https://reprap.org/forum/read.php?1,753085,753111#msg-753111 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753111#msg-753111
About servo, my idea is to use some sort of cam shaft to disengage the unused filament, by pushing back their respective springs. Using a cam can give string effort without much torque on the servo. Close to what it is done with the Dondolo.

I don't know about the tool changer your are mentioning; do you have links?]]> fma General Sat, 04 Mar 2017 08:09:21 -0500 https://reprap.org/forum/read.php?1,753085,753099#msg-753099 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753099#msg-753099
As for bowden tube, the shorter the better. The shorter you can get it, the more precise and short you can make retractions. Some people have massive bowden tubes, but I personally wouldn't want one much longer then say 400mm. Hence the flying extruder mod to get an almost direct drive extruder. If you are considering a servo to change gears, I don't see why a motor driven hanging extruder should be too much of a problem for you to design.

If you only want to change filaments, have you considered alternate methods? eg, IDEX or tool changers. The diamond is very limiting for material switching as they must have similar melting points so you can't experiment with removable support or complex multi materials.]]> Origamib General Sat, 04 Mar 2017 07:30:59 -0500 https://reprap.org/forum/read.php?1,753085,753098#msg-753098 Re: Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753098#msg-753098
But I thought, switching extruders work with two filaments ( not three) ?]]> o_lampe General Sat, 04 Mar 2017 07:30:23 -0500 https://reprap.org/forum/read.php?1,753085,753085#msg-753085 Diamond hotend switching usage https://reprap.org/forum/read.php?1,753085,753085#msg-753085
I'm thinking to buy a Diamond hotend and use it as a switching color hotend, not mixing (I read that passive mixing is not ideal, because of the toothpaste effect).

In theory, switching only needs 1 motor, as only one filament is used at a time. But in the case of the Diamond, all filaments have to be engaged, to avoid back extruding in unused heads.

My first question is: do unused filaments need to be maintained by their respective motors? My first idea was to use only one motor, and a servo to move a gear to choose which filament to drive... But this means that unused filament won't be maintained.

My second question is about Bowden tubes: what is the maximum length I can use? What happens if using too long tubes? I would like to put the extruder on the (coreXY) frame, not above with a swinging stuff.

Thanks for your help.]]> fma General Sat, 04 Mar 2017 06:17:16 -0500