Triple or quadro extruder printer

Hello everone, have not been here for a while and it is nice to be back

I am building a coreXY 3d printer that is going to be used for continous manufacturing of the same parts.
Design is based on Vulcanus V1 3d printer: [www.instructables.com]

This printer is going to have 3 or 4 nozzles that are attached to the same X carrier. This means that instead of making 1 part at the time it is going to be printing 3 or 4 identical parts on the same bed. The bed is not going to be heated.
I will be using 1.75mm filament (that requires 3 times less force to push than 3mm) and hope to be able to use 1 (or 2) Nema 17 motor to push plastic into all the nozzles. I might add wade type extruder with a ratio of 3.75:1 if the motor would appear to be lacking in torque.

My biggest concern is wiring of such configuration. I have very little knowledge on firmwares. There is an included configuration.h file for this printer on thingiverse for RAMPS 1.4: [www.thingiverse.com]
The configurations I have in mind:
1. RAMPS 1.4 with 3 nozzles connected D08, D09, D10 and three thermistors connected to T0, T1, T2. I am not using a heated bed so could connect D09 and T1 to a nozzle. Seems that I could google out all the information on how to make such the firmware changes. Any of you know why this would not work?
2. RAMPS 1.4 and extrudrboard. This would allow me to connect two extra heatends so I could make a quadro extruder printer. I would think that changing the firmware would not be easy but I should be able to find guides for diamond hotend.
3. Rumba board. Now this one seems to have place for up to 5 heatends and thermistors. But what about the firmware?

All the knowledge of the firmwares I have is loading the firmware to ramps 1.4 on my Prusa i3 a few years ago.
I am looking forward for your suggestion on the configurations I have in mind.

Four identical nozzles printing the same thing? You would only need one output and thermistor for that.
Wire two nozzle heater elements in parallel and then two paralleled sets in series. Then use the 11A output with a 24V PSU( ex bed connector ) and you´re done.
-Olaf

Edited 1 time(s). Last edit at 09/25/2015 11:10AM by o_lampe.

Thanks Olaf. Thats is a nice an simple solution. However I am a little concerned about using a single thermistor on a single nozzle to control the temperature on the rest of the 3 nozzles.

In Marlin you have the option to use a second thermistor as redundant probe. You don´t need to write firmware or buy expensive hardware.
-Olaf

What do you mean by a "redundant probe"? I still think that it would be a good idea to have a separate thermistor for every single nozzle.

Duet 0.6 + DueX4 electronics can control up to 5 hot ends. Duet 0.8.5 + DueX4 can control up to 6 hot ends. This is supported in the standard firmware.

IMO you will definitely need a geared extruder if you want to drive 3 filaments at once from it. 3:1 gearing is about right for extruding a single 1.75mm filament. For 3 filaments I would choose about 5:1 or 6:1 gearing. An alternative is to use 3 standard extruder designs, each with its own motor, and use 24V power; then you can connect the 3 extruder motors in series. This would make it easier to load filament, because when the motor current is off you would be able to turn the 3 extruders individually by hand.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I thought that people are using direct drive extruders with no gear ratios for 1.75mm. Is not that right?
I am currently running gregs wade on 3mm diameter filament on my Prusa i3. Considering that 1.75mm requires 3 times less force I should have no problem extruding through 3 nozzles using the same extruder. Yes it has a 5:1 ratio but I really do not like the backlash I have on fishbone gears and have ordered GT2 endless belt together with 16T and 60T pulleys to run the extruder on a new printer. Unfortunatelly 60T pulley is the biggest I can find. 80T would have been perfect.

So I checked a firmware video on Youtube by Thomas Sanladerer and it seems pretty easy to set it up and looks like I would have no problem configuring 3 nozzles and 3 thermistors on Ramps/Arduino board.

That DUET board sure is expensive. I have to think if it is worth it as for the same money I can get a Ramps/Arduino with all the motors, screen and many other electronic parts (and thats buying from the local shop not requiring shipping).

Quote
Edvardas
I thought that people are using direct drive extruders with no gear ratios for 1.75mm. Is not that right?

It can be made to work, depending on the type of filament. For the greatest chance of success, choose a long (= high torque) motor with a rated current low enough that your stepper motor driver can drive it at up to 85% or its rated current. However, extruding 3 filaments at the same time will need 3 times the torque, so direct drive is not viable for this IMO.

I use an extruder with approx. 3:1 herringbone gears on my Ormerod, and I have no problem with backlash. A small amount of backlash doesn't matter anyway, it just means you need 0,05mm or so extra retraction. If you don't want to use printed gears, you can buy stepper motors with integral 5:1 gearboxes.

Quote
Edvardas
That DUET board sure is expensive. I have to think if it is worth it as for the same money I can get a Ramps/Arduino with all the motors, screen and many other electronic parts (and thats buying from the local shop not requiring shipping).

The Duet 0.6 from Replikeo is only $50, although the quality doesn't appear to be as good as boards from T3P3 or RepRapPro. Unlike RAMPS etc. the Duet gives you software controlled stepper motor currents, a proper USB port with flow control, an Ethernet port supporting a web interface, 24V compatibility, and faster (32-bit) processing.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have a huge backlash on my herringbone gears. On both the set I printed and another I received with a printer. I can imagine that it is possible to print them so there is very little backlash but they just dont seem that reliable and I hate to do any work around extruder as gears are oiled. I hope belt driven extruder will be great.

Most of the features of Duet are insignificant to me as I keep printing speed comparably low.

I suggest you look for a better geared extruder design. If you really don't want to use printed gears, buy a stepper motor with an integral 5:1 gearbox..

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

As I said I am going to use endless GT2 belt and 16 tooth and 60 tooth pulleys to run a shaft that has MK7 or MK8 hobbed nut on it. Like this design: [www.thingiverse.com] All parts are already ordered.

I suppose this motor would be perfect for an extruder as it has a maximum torque of 52 N*cm and a current of 1.3A? [shop.germanreprap.com]

como cl Conectar mi Impresora 3D a la corriente automaticamente el extrusor comiensa un CALENTAR indiscrimidanamente , heno Alguna Posibilidad de switch to las Salidas de corrientes d 08 d 09 d 10 Entre si ( EJEMPLO Donde iria el refrigerador Poner el extrusor )

l connect my 3D printer to automatically power the heating indiscrimidanamente comiensa extruder , is there any possibility of changing the current outputs d 08 d 09 d 10 each ( eg where would go the cooler put the extruder )