Some Dual Extrusion improvements

[Zorgonaute84]

Hello,

I'm the owner of a BCN3D Sigma which is in my opinion the best dual extrusion printer on the market (The 2 head are independant). But I can't use all the potential of this printer and Simplify3D until somes dual extrusion functionalitie are not added or improved.

Dual Extrusion Startup script:
I manually (in the Script tab) add somme prime extrusion for each extruder before the print. The target is to be sure that the nozzle is prime enough before the printing. The problem concerned the first layer... During the print of the first head, the second continue too ooze and when it's the time for this 2nd extruder the nozzle is not perfectly prime. Using prime tower is not enough because the last movement of this 2nd extruder is an extrusion and the pressure into the nozzle is too high, so the oozing is very important. Usually the changing tool process is perform a retraction during the waiting time to reduce the oozing then extruding the same amount, then print the prime tower.
So the idea is to be able to perform a retraction in my startup script, but perform an extrusion with this same amount when it's time for the second extruder.

Dual Prime Tower :
When you use the dual extrusion process to print support, have the same prime tower for the both heads could be a problem. For example, if you use PolyMaker which is a easy removal support material, the adhesion with the PLA is not perfect. So the risk is too see your beautifull prime tower fall down. So the idea is to be able to print 2 separate prime tower for each head. And it could be very well to be able to set the place for this 2 prime towers. The Sigma 3D Printer have a left and right extruder which are waiting during the printing of the other. So we can imagine the left prime tower located at the west and the right prime tower located at the east.

Change dual extrusion settings automatically :
It could be very usefull to stop printing the prime tower and heating the support extruder when we don't need support anymore. It's a must have functionnality to print with PVA wich carbonize into the nozzle if it's not print during a too longer time.

Different fan settings for extruder :
In the case you are using a dedicated head to print support, it could be very usefull to use different cooling settings for each extruders.