Upgrading melzi board to a duet board, help please

hi,

I have a reprappro mendal, the last generation to use the melzi board. Unfortunately i have found the chip on my melzi board to be bricked so after looking into repair methods i have decided just to upgrade the printer to a duet system.
What i am unsure about is what else i will have to alter to ensure the board is compatible with the hardware already in my printer.

Could anyone help on this matter?

thanks

Connor

in my mendel duet is controlling 1 Y axis switch 1 infrared sensor for X and Z homing . it also controls the bed and steppers and the hotend....! So most of them i imagine are the same ( steppers bed and hotend ) . just look the type of the belt and get ready for some hardware changes to fit the sensor and switch ( if they are differents ). The documentation at the RPP site is for the latest model so i think it would be easy to make the upgrade . Did you asked rpp for this upgrade?

it would be good if you could post a photo of ur mendel .

The best wishes Guys and Girls

I sourced a Duet from Think3DPrint3D after smoking the heated bed terminal on the Melzi for the second time. Their current production comes with headers for 2.54mm Dupont connectors. If you're sourcing one elsewhere, I'm not sure what they'll use, so I'll assume you're going through T3P3. Unless you can find pre-made looms, you'll need to get 2.54mm Dupont crimps and housings and make your own. Converting your existing wiring for the basic Duet should just involve 4-pin (motor drives) and 3-pin (endstops) housings. 2-pin housings and a 1-pin here and there come in handy if you're going to do a Duex4.

Then you need to decide how to mount it. If you're just doing a standard Duet, the mounting parts for the Melzi will probably work in something close to the Melzi's same location. For the Duet/Duex4 I designed and made some additional parts. It is likely you may need to extend or re-make some of your wiring to reach.

That should cover the mechanical modifications.

Some resistors will be needed for the ADC compensation procedure described at [forums.reprap.org]

Thanks for replying so quickly guys!!
I was going to contact reprappro but they have unfortunately closed their doors.

after studying some of the circuit diagrams i dont think it will be too much of a problem to upgrade to it. The only though i have now is what sensor can i use for the auto level part. Also do i need the external 5v converter or does the duet have an on board one capable?

unfortunately Reprappro dont seem to have given a part number list for their printers.

from my understanding the Duet Board has an internal 5V Converter, but that one is not entirely reliable hence the external Converter. Also it can draw the 5V from USB alternatively - not sure how much it may draw, but to be on the safe side either connect it to a USB 3.0 Port* or plug a powered USB Hub in between



* they increased the possible current there compared to USB 2.0, and altough USB 2.0 Devices should not use this additional Power according to specification the Converters/stabilizers on USB 3.0 Ports should be more reliable under load for this reason)

Edited 1 time(s). Last edit at 01/12/2016 12:56AM by UniTrader.

The built in regulator on the Duet is reliable. The reason RRP used the external regulator on some of their kits is that the on board one on the version 0.6 board generates too much EMI for the completed kit to achieve CE certification.

If you are looking for a sensor to do auto bed compensation, take a look at my mini differential IR sensor at [www.escher3d.com]. However, if your printer was working well without a Z-probe and you are happy to keep it that way, you can configure the Duet to use a Z homing switch instead.

Edited 1 time(s). Last edit at 01/15/2016 02:55AM by dc42.

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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].

champion!

my duet board just arrived hopefully i wont be out of commission for too long. Im happy with it on a Z axis however i feel that i would probably get a better print quality and bed adhesion with an auto-leveling system.

one more thing, my Z motors are currently daisy chained together so they work in unidson from 1 Z port. will i have to separate them or will it work fine as it is?

Leave your Z motors connected in series.

See [reprap.org] for firmware configuration info.

Edited 2 time(s). Last edit at 01/15/2016 06:44AM by dc42.

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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].

Quote
dc42
The built in regulator on the Duet is reliable. The reason RRP used the external regulator on some of their kits is that the on board one on the version 0.6 board generates too much EMI for the completed kit to achieve CE certification.

thanks for the correction - remembered that part wrong..