Controller for my larg format 3D printer

bernardomattiucci

@dc42 said in Controller for my larg format 3D printer:

As @Veti says, the thermistors for the extruders should be connected to the expansion board. Support for filament monitors for extruders connected to expansion and tool boards is one of our highest priorities, and I expect to start work on that for the 3.3 release even before 3.2 stable is released.

we have time to do everything!

If your extruders are direct drive and have modest motor current requirement, you may wish to consider using three tool boards instead of one 3-channel expansion board, because it will simplify the wiring to the tool heads.

I am not an expert in this electronics (until now I have only made CNC with breackout board, driver and linuxCNC) and that is why I asked for information.
I am making this machine for myself, but I would like to put a larger version of it on the market. I am open to any suggestions and / or collaboration ... because I think the project is interesting!

For maximum fail-safeness, I suggest you connect the emergency stop button to the main board if possible.

Yes, No problem

You have only shown one fan per extruder. Do you not have print cooling fans as well as heatsink fans?

I forgot about it

dc42

To clarify the point about tool boards:

If the extruders will be direct drive, then for each extruder you are likely to have 4 motor wires, 4 fan wires, 2 heater wires, 2 thermistor wires. That's 12 wires going to the hot end assembly (with the possibility of reducing it to 10 if you share the V+ wires to the heater and fans). if you want to add a BTouch, that's 4 more wires. if you want to use fans with tachos, even more wires.
A direct drive extruder with a tool board mounted on the extruder assembly needs just power and ground, plus 4 CAN wires (which can be reduced to 2 if the wires are not too long). That's even if you use fans with tachos and a BLTouch. For the case of a single extruder, it also costs less, even if you include a tool distribution board to make future expansion easier.
If the extruders are not direct drive, then it's probably simpler to use the 3-channel expansion board instead.

Think of an tool board as a single-channel expansion board, small enough to be mounted on the tool head, and with lower maximum motor current than the 3-channel expansion board.

oliof

how long is "not too long"? 750mm? 500mm? "Depends"?

dc42

@oliof said in Controller for my larg format 3D printer:

how long is "not too long"? 750mm? 500mm? "Depends"?

I suspect that 1m would be OK. Ideally, ferrite beads would be added at one end of the cable, to reduce reflections.

bernardomattiucci

The "small" (this one) has a useful print volume of 600x600x600mm expandable up to 1200x1200x1200 with Nema17 motors. The moment of the X and Y axes is a toothed belt with recirculating ball guides. Z axis with recirculating ball screws and recirculating ball guides.

The "large" version uses Nema23 motors instead and will have useful dimensions of 1000x1000x1000 mm expandable up to 3000x3000x3000 mm. The movement of the X and Y axes is by rack with linear encoder. Z axis with recirculating ball screws and recirculating ball guides.@oliof
this project

My prototype (pictured) uses structural and mechanical parts recovered from old CNCs and 3D printers and has a useful volume of 600x600x600mm.

bernardomattiucci

@dc42

this Toolboard?

![alt text](

Veti

yes that is the one

dc42

More info on the tool board at https://duet3d.dozuki.com/Wiki/Duet_3_Tool_Board.

bernardomattiucci

@dc42

beautiful

MrDui

Hello to you, fellow large format printer maker

@bernardomattiucci said in Controller for my larg format 3D printer:

This plan should be calibrated every time the Z axis is zeroed, to do this I thought of controlling the 4 motors independently and using the (optical) limit switches, 1 for each motor, in order to have a fixed reference for each edge of the XY plane.

Instead of this, I'd suggest you to use only one limit switch at the top of one of your Z axis corner and install a BL touch or any other probe you like somewhere on your tool head.

The printer will first go to its home position, moving until it hits the endstop. Then it will go down until the Z probe hits the bed. Next step will be to probe each corner, near your leadscrews. After that, the printer will adjust the bed to make it leveled automatically.

I only have 2 Z axis on my printer but that's how I did it, same principle for you there with 4 axis. It's much easier to do it this way.

bernardomattiucci

@MrDui

Thanks for the suggestion, very interesting!

bernardomattiucci

Ok
If I am not mistaken, then, I should take the following:

1 Duet 3 Mainboard 6HC +
1 Duet Toolboard +
1 Duet PanelDue 7" +
1 BLTouch

Correct?

Veti

@bernardomattiucci said in Controller for my larg format 3D printer:

1 Duet Toolboard +

if you want 3 extruders, then you need 3 toolboards or 1 Duet_3_Expansion_board_3HC

bernardomattiucci

@Veti

at this moment i only need 1 extruder

Thank you
Bernardo

dc42

You might also want to buy a Tool Distribution board. You can manage without it, but it make wiring easier when you add more extruders. If you don't use one, you will need add a CAN termination resistor, and provide a fuse in the VIN feed to the tool board. See https://duet3d.dozuki.com/Wiki/Duet_3_Tool_Board#Section_Connecting_CAN_FD_Bus_and_Power.

bernardomattiucci

Good morning,

is there the possibility of having the 4 motors of the Z axis of the "closed loop" type with 4 linear encoders mounted on the recirculating ball guides placed at the 4 edges of the XY plane?

dc42

Not yet, but we have a closed loop expansion board for Duet 3 under development.

bernardomattiucci

Ok, then I have to wait ^ _ ^

Thank you

bernardomattiucci

Good evening. I hope everything goes well with you.

For my part I completed the zero prototype of the printer I was assembling and I started some tests using, as electronics, Arduino Mega, with a Ramps 1.4, external TB6600 drivers (in reality they are TB67S109AFTG) for Axis X, Axis Y and Axis Z , all powered at 24 volts; while for the extruder I'm using the original DRV8825 mounted on the Ramps.

As you well know, the complexity is given by the presence of 4 motors for the Z axis. Currently these motors are connected in parallel, the 2 on the right on one driver and the 2 on the left on another driver.

The adjustment is currently done manually ... acting directly on the ball screws SFU1204.
The ideal, however, is to have an "independent" control of the 4 motors, to which I intend to add linear encoders mounted on the guides.

In the current configuration, the zeroing of the Z axis occurs at the bottom, with a sensor positioned at X0 Y0.

The vertical movement of the XY plane (the printing table is fixed) occurs regularly and as long as the speed is not excessive, all 4 motors move simultaneously and with precision.

Not wanting to spend too much and wanting to use a Duet2 wifi, what configuration do you recommend the most?

First test: https://www.youtube.com/watch?v=N0FEGJcm668
Last test: https://www.youtube.com/watch?v=Xsnecz19VRQ

EDIT:

Duet2 Wi-Fi or Duet2 Maestro
Duex2_2
PanelDue 7i

Questions:

Is it possible to control Nema17 motors with Encoders (linear or angular) through this card?
Axis X, Y, Z and Extruder, how should they be distributed on the 2 boards?
the Duet2 Maestro, can it be enough to control my printer?

Thanks
Bernardo

Phaedrux

Encoders are not currently supported. Same situation as the last reply from DC42. So if encoders are a hard requirement you'd have to wait a bit longer yet.

The Maestro is no longer being produced and is being supplanted by the Duet 3 Mini 5+ which is coming in the new year.

Given your requirement of 4 Z drivers, X Y E I think your best bet is probably a Duet 2 + Duex 5. With all 4 Z drivers on the Duex.

Some would question whether encoders are really useful anyway given the fact when properly configured skipped steps are quite rare and stall detection for X Y is fairly reliable for when the print head gets caught up on the print causing it to skip.