Instructions to upgrade to multiple extruders?

Hey all,

I have an older RepRap. I think it is the Mendel Tri-color (though I have never taken the extra steps to get more than one filament working). I looks something like this: TriColor

My controller board is a RepRap Melzi v2.0 that looks like this: Melzi

I recently got an additional 3D printer (a Taz 6), so thought I could now take some risks with my older one. I am interested in trying to upgrade it to a dual extruder. Apparently my printer model is set up for this.

I'm trying to decide in advance how much effort would be involved in the conversion.

Questions
1)Instructions: I found what looks to be the correct instructions here. It mentions getting a second controller board. Also I guess I would need to purchase the hot end etc.
Is there an online store for this?

2) Software: the Taz6 has a slicer that knows how to work with multiple extruders. It is a customized version of Cura. Does anyone know if that Cura would work with this printer? Or would I need to use the RepRapPro slicer mentioned in the instructions?

3) Has anyone done this before and would be willing to share there experience?

Thanks in advance
Kevin T

The Melzi is a very old controller. Rather than get a second Melzi controller and trying to get the two working together, I think you would be better off upgrading to a new controller that can drive more extruders. You would need a board with 5 stepper drivers for dual extrusion, or 6 stepper drivers for triple. Most electronics supports 5 stepper drivers these days, a few support 6, and some have expansion boards available for increasing the number of drivers. RepRapPro switched to Duet electronics for later versions of their Mendel, see [reprappro.com].

Other upgrades you might want to consider when choosing the controller electronics:

- Do you find that the two Z stepper motors get out of sync? If so, that can be avoided by driving them from separate drivers and using firmware that can adjust them automatically. You need a Z probe as well as another stepper driver to do this (perhaps you already have a Z probe).

- Getting the two nozzle heights exactly the same can be tricky, and even then the non-printing nozzle sometimes leaves marks on the print. A solution is IDEX (dual independent X carriages). Obviously this would be a major modification, but perhaps someone else has already done this conversion on a Mendel and published the details. You would need another stepper motor for the second X carriage.

HTH David

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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].

David,

Thanks for the reply. So are controller boards essentially swappable? There doesn't have to be any calibration to the thermister, or the particular stepper motors that my current printer uses? Do you have any recommendation for a particular controller board? I found this page that lists a variety of boards, with widely ranging prices. I also see this page giving repRap electronics and alternatives....

Thanks again

Kevin T

edit: I found this page giving details on the Duet. Looks like it is about 107 pounds (approx $140 US)

Edited 3 time(s). Last edit at 10/14/2017 08:11PM by kdtop.

@kdtop

DC42 is a sales person, his answer to everything includes purchase of Duet electronics....

The melzi board does not have enough stepper drivers to control any additional extruders, so additional hardware is required. Most simple is to just add an external stepper driver and plug it into your melzi. Also needs a heater and thermistor control for a full second extruder. so also needs a mosfet and a analog in pin.

The original design of the Mendel Tri-color does use a additional melzi as a slave to the primary controller... all firmware is already done.

Moving to a duet basically means you will have to re wire everything and start again with the configuration, yes it will work, but it is a huge investment, time and money wise.

Dust, you are being unfair. I recommend Duet for high end 3D printer projects, but not for people building a printer on a budget. There is little point in spending money on a high end controller if that means you can't afford decent mechanics.

Kdtop, yes controller boards are essentially swappable. Melzi has very limited expansion, and I haven't heard of anyone additional an external stepper driver, heater and thermistor to it. It also has only 128kb of flash memory, which is often too little to run current versions of firmware if LCD support is enabled.

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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 think everyone's more or less agreed that the Duet (Wifi) with Reprap Firmware running on it is the best controller currently available. But it does also come with a Rolls Royce pricetag.

If all you're after is dual extrusion, then there's a number of controller boards that can drive 5 steppers. Probably the cheapest option would be an Arduino 2560 plus RAMPS 1.4. Marlin should be straightforward to install on this. Depending on how well the connectors on your Melzi match up with those on the RAMPS, you may or may not need to rewire as well.

You might also want to think about a Diamond hotend, which has 3 extruders and only one nozzle, avoiding the issues with dual nozzles. (But of course it introduces other issues).

To handle 3 extruders, you could add another stepper controller to the RAMPS [www.aliexpress.com] Or you could get a Rumba board instead. Again, installing Marlin would be straightforward.

Quote

I found this page that lists a variety of boards,

I cant believe that red ramps made that list its a bonfire waiting to happen !!! there's an alternative to the RAMPS these days with the MKs Gen L series for the budget builder, thou as frank suggest the rumba its a belting 8 bit board with all the extra required for an advance user without stepping up to 32 bit.

Edited 1 time(s). Last edit at 10/15/2017 05:40AM by jinx.

The Smoothie Board is much better than anything else out there for the price!

Quote
cwaa
The Smoothie Board is much better than anything else out there for the price!

You've obviously never used a Duet WiFi or Duet Ethernet

Edited 1 time(s). Last edit at 10/15/2017 01:32PM 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].

How long have you been using a Smoothie?

According to this forum in a survey in 2017, the most popular controllers were in this order, Ramps, Smoothie, Gen 7, Rambo and Duet in at no. 5.

I appreciate everyone's replies. It sounds like people have strong loyalty to various controller boards. I think the Duet board is in my price range, but perhaps not right now, having recently gotten a Taz 6. I like the sound of it being WiFi enabled. Perhaps this can be an upcoming Winter project. Then again, my son might want to take this over, and would be looking for a cheaper solution, so I would want to look into the Smoothie board and even the Arduino board.

Thanks again everyone for the helpful replies!

kdtop

See also my other post.

I'm a little fuzzy on nomenclature. Is "RAMPS" a piece of hardware or software? And Marlin is a software version, correct?

Thanks
Kdtop

RAMPS is an electronics board... it plugs into an Arduino Mega2560 and has stepper drivers and MOSFETs and connectors for fans and heaters and all kinds of other groovy stuff to control the printer hardware.

Marlin is firmware (i.e. software designed for some particular piece of hardware). It's possibly the most widely used firmware (but lets not get into *that* flamewar!)

Quote
cwaa
According to this forum in a survey in 2017, the most popular controllers were in this order, Ramps, Smoothie, Gen 7, Rambo and Duet in at no. 5.

Gen 7 at #3 - really? I find that hard to believe. Maybe you are thinking of the survey of messages on the RepRap IRC channel that was done up to March 2016. All that proves is that the creators of Smoothieboard and Gen7 were active on RepRapIRC and people like me were not.

Btw I think Smoothieboard was a good board for its time, roughly comparable with the Duet 085. But Duet WiFi and Duet Ethernet have raised the bar, and Smoothieboard 2 isn't available yet.

Amongst 8-bit boards, the best design I have seen is the Rambo. Its designers have made a good effort to protect the board against mis-wiring. It even has an isolated USB interface, to avoid getting a ground loop. However, the price of an original Rambo from Ultimachine isn't much less than a Duet WiFi. I don't know how good the clones are.

Edited 2 time(s). Last edit at 10/16/2017 03:37AM 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].

@KDTOP,

I have a reprappro tricolour. It's slightly later than yours as it's fitted with the original Duet 0.6 electronics plus expansion shield rather than the Melzi boards that the really early ones used. I soon gave up on the three nozzle setup up and converted it to a Diamond 3 colour hot end but I still have all the original parts as well. Depending on where you live in the world, I could be tempted to part with it as a complete package for not much money. P.M me if you are interested. I'm in the UK.

Ian

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[somei3deas.wordpress.com]
[www.youtube.com]

Quote
Dust
@kdtop

DC42 is a sales person, his answer to everything includes purchase of Duet electronics....

The melzi board does not have enough stepper drivers to control any additional extruders, so additional hardware is required. Most simple is to just add an external stepper driver and plug it into your melzi. Also needs a heater and thermistor control for a full second extruder. so also needs a mosfet and a analog in pin.

The original design of the Mendel Tri-color does use a additional melzi as a slave to the primary controller... all firmware is already done.

Moving to a duet basically means you will have to re wire everything and start again with the configuration, yes it will work, but it is a huge investment, time and money wise.

DC42 is a partner of Duet3D so yes obviously he has a vested interest. However, he writes all the firmware which IMO is the most advanced that you will find anywhere. To describe him as "Salesman" is demeaning to say the least.

For info, the very early reprappro mendels used Melzi electronics but later changed to the Duet. In fact it was Adrian Bowyer (the founder of reprap) who wrote the original firmware for the Duet. This is how the Duet was spawned - as a control board for the original reprappro Omirod and later version of the mendel to replace the Melzi boards. So configuration isn't a huge investment - it's a piece of cake as all the original stuff is still out there.

Here is the survey....
You can weasel word the results if you feel the need!

[reprap.org]

love to read a shot out between the boards,,,
@ cwaa how do you equate popular too be better,, your way the RAMPS would be better than both boards which aint the case.

@frankvdh, thanks for the clarification. I found this lthis where an arduino + RAMPS + LCD for $25. That seems like a lot of electronics for not a lot of money.

@deckingman, I'm curious about why you gave up on the 3 printheads. I suspect that calibration -- getting them all equidistant to bed -- would be a big problem. I mostly would want a 2nd print head to print dissolvable support structures. Regarding the offer for selling your other printer, I don't think that would work well. I live in the US. And if your RepRap is like mine, it would be difficult/costly to ship across the seas without damage. But I appreciate the offer. :-)

KT

I've used ramps (both good quality ones and cheap ones), re-arm (smoothie) and Duet wifi.

Ramps is adequate for most low/modest budget 3D printers, my microdelta printer runs off ramps/Arduino at 1/32 micro stepping and produces nice prints. It's cheap but adequate. Cheap cloned Arduinos work fine, but the super cheap ramps boards can have the wrong choice of mosfets (which get hot if inadequately specc'd), poor power connectors, traces that shouldn't be there such as between the microstepping jumpers, etc.. these are worth avoiding. Pay £15-£20 for a ramps board and buy from a reputable supplier and avoid all of this trouble.

Re-arm is a clever 32-bit replacement for Arduino mega, to save you a lot of re-wiring, runs Smoothie and is a big step up from 8-bit boards, with text file configuration (no compiling/upload issues), faster processors which can handle higher micro stepping, reasonable documentation and active development. That being said re-arm is great to upgrade your older machine which has ramps/Arduino, but the cost of it, if you were starting out from scratch, is the same as a complete smoothie compatible board like the Azteeg series, so if you are going to rewire you machine it doesn't make much sense.

Duet is a premium product, its clever design and features make it the obvious choice for a high-quality machine, why spend a lot on linear motion, motors, sensors, sturdy expensive frame, and wire them all up with the cheapest electronics going? I bought one despite being fairly against the idea for quite a while, now I have 2 and would buy a third one in a heartbeat. The forum is polite and helpful, David actively helps users to get the most out of it, including writing new features into the frequent updates, even for some quite obscure schemes, like CoreXYU /dual IDEX coreXY, deltas with extra axes to support moving extruders, it's versatile enough to do a lot of these things. We have filament sensors, emergency power failure resume, optional analogue probing for highly tuneable z-probes. Also, the newer boards are very tolerant of miswiring and shorts, by design.

Prusa's new Einsy Rambo looks great, but even if Ultimachine starts selling them, they will be expensive, and it's still an 8-bit board, which might struggle to generate enough step pulses to run 5 extruders, and 5 axes simultaneously at high speed. Of course you might not need to.

Edited 1 time(s). Last edit at 10/16/2017 04:00PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
cwaa
Here is the survey....
You can weasel word the results if you feel the need!

[reprap.org]

Without wanting to fan the flame-war, this is "This first list of boards are the ones that were most talked about on the Reprap IRC channel up to some time (March?) in 2016". What people are talking about is the *quality* of the board, not popularity. They *may* be correlated, but I suspect that price and popularity are probably more closely linked.

For me personally, it's the support and speed of regular firmware updates that are as important as the electronics themselves.

I know I'm biased but only because I'm a huge fan of Duet - not because of any affiliation. Because dc42 gets a share of the profits, he is able to concentrate more or less full time on firmware development. So for example, when I first started using a mixing hot end, I needed to be able to retract all filaments at the same time. I mentioned it in the Duet section of these very forums and within a couple of days, the necessary changes to firmware had been implemented. I've seen numerous similar examples on the Duet WiFi forum in the last few months. e.g IDEX machines and Scara kinematics - the list just goes on. Then there are also the various add ons such as PT100 and Thermocouple Daughter boards, expansion for a further 2 or 5 steppers using the Duex 2 or 5 or external drivers, IR probe, Panel Due touch screen controller, filament monitor, smart effector, etc etc. I'll shut up now because I'm sounding like a fan boy.

Quote
kdtop
@deckingman, I'm curious about why you gave up on the 3 printheads. I suspect that calibration -- getting them all equidistant to bed -- would be a big problem. I mostly would want a 2nd print head to print dissolvable support structures. Regarding the offer for selling your other printer, I don't think that would work well. I live in the US. And if your RepRap is like mine, it would be difficult/costly to ship across the seas without damage. But I appreciate the offer. :-)

KT

Yes, getting them all exactly the same height in relation to the bed is a real pain. Then you also have to set the X (and Y) offsets really accurately which you can do in firmware but it takes of lot or measuring and trial and error prints to get it spot on. You also lose a lot of X travel - especially with 3 heads and the RepRapPro Mendle didn't have a huge amount to start with. The other problem is fighting ooze from the unused nozzle. The standard way to do that is to use a lowish standby temperature but then every time you change tool, you have to wait for the new one to come up from standby to active which slows the print time down a lot. Even with wipe and prime towers and setting the inactive tool to a lower standby temperature, I never could prevent the unused tool from scraping across the surface and leaving marks. A mixing hot end negates all of the above but brings a whole load of other issues which I won't go into here. On balance, having tried both approaches, I prefer the multiple inputs/one output approach but it's by no means easy.

Also, if you are in the US, then I agree that shipping it across the pond would add too much to your costs.

Ian

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[somei3deas.wordpress.com]
[www.youtube.com]

Quote
frankvdh
What people are talking about is the *quality* of the board, not popularity. They *may* be correlated, but I suspect that price and popularity are probably more closely linked.

Most likely true. Also, as others outlined already, most of the boards are no competition to each other. RAMPS is for the cheap, Smoothie/Duet for feature richness and Gen7 for DIYers. Somebody looking for a $30 controller unlikely considers a $150 alternative and somebody considering plugging in a readily made board to be do-it-yourself unlikely watches out for a Gen7 thing. Still all of them have their customer segments. Some like to be proud of their soldering, some have fun wiring up the most fancy combination of sensors and actors, some are enthusiastic to keep the entire printer build below the $200 mark.

I'm a bit surprised this aggressive pushing of one board or another still happens, we all lost to the cheapo-chinese. People like @dc42 and @arthur convinced me that RepRap has no collaborative future. That's why I got pretty quiet over the last few years. Next development will be much more like a traditional business. Teacup Configtool as a Firefox-AddOn, Gen7 even simpler and more robust ... a granule extruder ... there's no shortage of ideas :-)

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Quote
Traumflug
........................... People like @dc42 and @arthur convinced me that RepRap has no collaborative future.

Really? I'm a bit surprised by that comment. The Duet is fully open source and based on the original RepRap firmware. All the designs are done using Open Source software and are available for anyone to build their own versions. Likewise the firmware which is published on GitHib and anyone can fork it and "do their own thing".

I think it's more that the spirit of early RepRap is fading away (which I missed as I got into it too late) but you can still feel the echoes of it here. A time when it was all about collaboration, and very little about selling stuff. Like the early internet.

Now I know I recently joined the selling stuff brigade, (though its pretty small scale I'm not going to be quitting the day job anytime soon, I still do 3D printing more for fun than profit), but with Precision Piezo we're trying to make it so that you can either buy it, buy a kit and make it, or make it entirely yourself with open-source printed parts and a breadboard. Our product is still simple enough that you can do this. I wouldn't fancy trying to lay out a Duetwifi on a breadboard with through-hole components, though I'm sure its possible.

I have tried very carefully to keep the commercial side to my one thread, which is also for support. (there is a development thread but that's not for selling stuff, it's for sharing ideas/information).

I am also trying hard on this forum, not to jump in with "did you know our sensor is very accurate and here's the shop link" unless the topic is directly about z-probes and it is appropriate to mention it, or I am asked.

Edited 1 time(s). Last edit at 10/17/2017 09:15AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
deckingman
The Duet is fully open source and based on the original RepRap firmware.

That's certainly nice, but no help for collaboration at all. Yes, people do fork their own thing. And that's it. Zero efforts to get such forks back into mainline for the advantage of everybody. Collaboration is a lot more than just forking.

If you want to see collaboration, look at projects like Linux kernel, Git, Gcc, Clang, etc. People fork there as well, but after doing so they make sure their work gets back into the main repo and aligns with the needs of everybody ... or they get forgotten.

I don't want to point fingers or insult anybody. This is just how things work here.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Quote
Traumflug

Quote
deckingman
The Duet is fully open source and based on the original RepRap firmware.

That's certainly nice, but no help for collaboration at all. Yes, people do fork their own thing. And that's it. Zero efforts to get such forks back into mainline for the advantage of everybody. Collaboration is a lot more than just forking.

If you want to see collaboration, look at projects like Linux kernel, Git, Gcc, Clang, etc. People fork there as well, but after doing so they make sure their work gets back into the main repo and aligns with the needs of everybody ... or they get forgotten.

I don't want to point fingers or insult anybody. This is just how things work here.

Actually there is collaboration in the development of RepRapFirmware. I've helped others to port RepRapFirmware to other boards (Due/RADDS and Alligator) and merged their changes back into my github master. Likewise when somebody wanted to add support for IDEX on CoreXY machines, I did some restructuring of RepRapFirmware to make it easier for him to add, and I merged his changes back into the master when he had completed them. I did the initial support for SCARA printers in collaboration with a user who had one and could explain the requirements to me, and I am now doing the same for polar printers. So collaboration is not dead, at least in firmware development.

When it comes to hardware design, I don't think RepRap has ever seen the same degree of collaboration as with firmware, at least since I entered the field in late 2013. This is probably down to the large choice of 3D printer controllers now available, the expertise needed to produce a good design, and the costs of prototyping a complex controller board. However, the original Duet was a collaboration between two companies (Adrian Bowyer's RepRapPro and Think3DPrint3D), and the Duet WiFi and Duet Ethernet is too (Think3DPrint3D and Escher Technologies).

So IMO, collaboration in RepRap is not dead. But I can quite understand that there may have been even more collaboration in earlier years, when the field was less mature and there was a greater need for new stuff.

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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].