Marlin for delta printer on UNO

Hi everyone,

I am working on a delta printer and trying to fit the electronics on an UNO board. My idea is not using any pre-assembled board like RAMPS would be for Mega, but develope a keep-it-simple board. Since UNO has a lack of pins compared to Mega I know I will have to set apart some utilities, so the idea is using:

14 Digital OUTPUTS: 4 for motors STEP, 4 for motors ENABLE, 4 for motors STEP, 1 for bed and 1 for hot end cartridge

3 digital INPUTS for MIN endstops

2 Analog INPUTS for extruder thermistor and bed thermistor

So the idea is using modified Marlin with the Duemilanove w/328 pin configuration and attach them to the UNO board, do you think it would work?

I have seen that modified Marlin for delta printers makes modifications on the pin assignement for RAMPS, but not for other boards: would I need to make changes, or is it ok like that?

Thanks in advance

Hi Toalla,

Did you make something since you wrote this quite interesting proposal? I am also interested, because i wana change all the ramps headache to a much simpler solution. I have once realized a delta printer with uno and grbl on it. But without any extruder. Just the movements. Since then I went to ramps, not the best choice if you have no to little money in case if anything goes wrong. You know?
The marlin firmware however is to big for duemilanove or my uno. I'm looking for any understandable advice about the issue of shortening the code, because for a noob like i am, its almost impossible to do. Another problem is, that in the other case all the gcodes generated with grbl gui must converted to delta movements. I know only one python script what is capable to do that.
So what is your status right now regarding this issue?
Best regards,
Z.

I just gave up on that and kept the typical RAMPS-Mega configuration.
Sorry I cannot help you, but if you achieve something interesting post it, I guess quite a lot of people is interested in something like that

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Toalla
So the idea is using modified Marlin with the Duemilanove w/328 pin configuration and attach them to the UNO board, do you think it would work?

Yes. I see two possible ways:

1. Tweak Marlin until it fits into these 32 kB Flash the '328 comes with.

2. Use Teacup firmware (which currently compiles to some 20 kB with all features enabled) and add delta geometry. Should be possible to take algorithms from Marlin. Teacup's "scara" branch showns how it was done for polar printers, it's only about 100 lines of code. And Teacup developers would be very happy to see a contributor owning a delta configuration; currently they can't implement it, because they have no such device.

Regarding pins: it's tight, but if it matches, it matches. An ATmega328 just as fast as an '2560 and there's nothing more useless than unused pins. With normally-closed mechanical switches one can chain all three endstops to one CPU pin.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

The Uno is quite a bit less powerful than the Mega. You might be able to pull it off but you'd take major performance hits. Given how cheap Mega clones are, it would make more sense to use one of those.

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epicepee
The Uno is quite a bit less powerful than the Mega. You might be able to pull it off but you'd take major performance hits. Given how cheap Mega clones are, it would make more sense to use one of those.

I agree, and in fact I ended up using one of those cheap mega, but anyway it would be a nice work trying to make it fit in there. I'm not currently working on that, but that may be a future project for me or for someone else.

Please be aware of Chinese Mega clones. They're not just cheap but also weak in performance and quality. Without any reasonable explanation burned out two boards until yet.