Duet 3 6hc vs some others

deckingman

@SageAardvark The Duet 3 series uses CAN to connect expansion boards to a main board. You can have as many expansion boards as you are likely to need and they can be mounted almost anywhere on the machine - useful when you have a lot of motors in different locations. There is a clue in the naming of boards as to how many stepper motor drivers they have - e.g. a 6HC has 6 drivers, a 3HC has 3. There is no distinction between axes drivers and extruder drivers. Each board needs only power and data in addition to whatever periferals you connect to it. It's best to use a single power supply.
So a good place to start would be to count up how many stepper motors you will need in total, then peruse the available options to decide on which boards you need. E.g. if you need 8 for your extruders plus 3 for axis motion, that's a total of 11 so a 6HC main board with two 3HC expansion boards might be a good option (it gives you 12 drivers). Alternatively you could use two 6HC main boards with the second one configured as an expansion board.

dc42

@SageAardvark it's as @deckingman says. If your extruders are direct drive then using a tool board for each if them may save you a lot of wiring. That takes care of 4 motors, leaving 7 if your total is 11. If the motors are Nema 17 or smaller then a Duet 3 Mini with the 2+ addon can probably handle those, otherwise you could use a 6HC and one 3HC or perhaps another tool board. Can you tell us what motors you intend to use?

SageAardvark

@deckingman So to connect both duet 3 3hc daughterboards to the mainboard would I need to use a tool distribution board for it? And then as you mentioned I wouldn't need to have an extra power supply so I would have to connect a positive and a negative cord to the tool distribution board and it should power all of the daughterboards? I again am very sorry as I am very new to this. And then plug in a positive and negative cord to the Duet 3 6hc and it should completely power that board?

SageAardvark

@dc42 They are probably going to be nema 17 motors. Just so you know I haven't fully built it yet but I have been trying to do a lot of research so I know what to do when I get it, the extruders may be run by a direct drive or it might be a bowen setup. Ill have to so a little modeling if i wanted to try and see if it would work. Thank you all so much for your help with this and taking your time to respond.

I hope this information helps

SageAardvark

@SageAardvark in my response here I made a slight mistake. I meant that the board that I was thinking of using only has enough room for 3 extruder and 3 temperature sensors as I know of. The board wouldn't have enough slots for all of the extruders so is there any boards that I can use that would have 4 extruder slots or expansion boards I could use. And would the Duet 3 3hc have any slots for extruder heaters.

deckingman

@SageAardvark Tool boards (1LC) are a bit unique in that they only have CAN in. So if you want to use multiple tool boards, then you need the tool distribution board. As @dc42 suggested, tool boards are a good option if your extruders are direct drive. As the name implies, you can fit one to each tool. On the other hand, expansion boards such as the 3HC have both CAN in and CAN out. So they can be "daisy chained". That is to say you connect CAN out from the main board to CAN in on the 3HC. If you wanted to add another expansion board, then you connect the CAN in of that board to the CAN out of the first expansion board and so on.

With regard to you latest post, for 4 extruders you have a number of choices. Firstly, don't forget that a 6HC main board has 6 stepper drivers so you could use one or more of those to drive extruders. If you can't or don't want to use any of the mainboard drivers, then you could use a single 3HC plus a single tool board. Or you could use 4 tool boards plus a tool distribution board. Or you could use a second 6HC as an expansion board although that would give you 6 stepper drivers.

I think it would be best if you peruse the documentation here https://docs.duet3d.com/en/Duet3D_hardware/Duet_3_family

This will give you the capabilities of each board in the Duet 3 range and should answer all your questions about heaters and so forth.

jay_s_uk

@deckingman the 1LC has in and out (2 x CAN_H and 2 x CAN_L on the 4 pin connector) so you could chain them if required.

dc42

@SageAardvark said in Duet 3 6hc vs some others:

@SageAardvark in my response here I made a slight mistake. I meant that the board that I was thinking of using only has enough room for 3 extruder and 3 temperature sensors as I know of. The board wouldn't have enough slots for all of the extruders so is there any boards that I can use that would have 4 extruder slots or expansion boards I could use. And would the Duet 3 3hc have any slots for extruder heaters.

The 3HC provides 3 high current outputs (e.g. for extruder heaters), 3 thermistor or PT1000 inputs, 6 lower current outputs (e.g. for fans), and additional I/O.

The tool board provides one high current output for an extruder heater, two lower current outputs intended for fans, an accelerometer, two thermistor or PT1000 sensor inputs, and various I/O to handle Z probes, endstop switches etc.

You can use tool boards without the tool distribution board, but the tool distribution board makes wiring easier when you have multiple tool boards. In particular, it provides fused power output connectors for up to 4 tool boards.

deckingman

@jay_s_uk said in Duet 3 6hc vs some others:

@deckingman the 1LC has in and out (2 x CAN_H and 2 x CAN_L on the 4 pin connector) so you could chain them if required.

Having just wired one up a couple of weeks ago, you'd have thought that I'd remember that - thanks for correcting my senility driven error

ablack

i have a question. I have 2 6HC. Is it possible to use one as a main controller and the second as the expansion board? (connect it via CAN bus)

deckingman

@ablack said in Duet 3 6hc vs some others:

i have a question. I have 2 6HC. Is it possible to use one as a main controller and the second as the expansion board? (connect it via CAN bus)

Yes - it is now (I was the first person to use that configuration and helped the Duet guys iron out any issue so i know it works).

ablack

@deckingman super. maybe you can briefly explain how to do it properly? and what steps are important to do. thank you

jay_s_uk

@ablack You just need to put an SD card in the second and use M954 in your config.g. Then just connect the two boards together using CAN

deckingman

@ablack As @jay_s_uk has said and you use the "A" parameter in M954 to denote the CAN address you want to use. Plus you need to put a special IAP in the /firmware folder of the main board that you are going to use as an expansion board to facilitate firmware updates by the usual method. Fora 6HC, that file is Duet3_CANiap32_MB6HC.bin

Bear in mind that main boards only have a single CAN connector, so if you have other expansion boards, the 6HC must be the last one in the chain.

Here is a link to everything you need to know. https://docs.duet3d.com/en/User_manual/Machine_configuration/CAN_connection

You might need to scroll down to find the section "Mainboard as expansion board".