Best RepRap Firmware for Delta's

Hello,

I built a classice Rostock over a year ago. I had issues getting it to print correctly, I eventually grew frustrated with it and set the project aside to work on other things. Now I want to get it printing again and try to fix all the problems I had before. For the longest time I have been using the Marlin firmware with the delta kinematics enabled. before I get back to messing around with Marlin's config again I want to know if there is a better choice of RepRap firmware for Delta style printers.


TL/DR
What is the best RepRap firmware that provides optimal performance for delta 3D printers?

I don't have the answer to your question, but I can tell you that there will soon be another electronics and firmware combo for Delta printers. I am extending my fork of RepRapFirmware for the Duet electronics to support Delta printers, and I expect to complete this in January. One big advantage of this combination is that it provides an Ethernet interface and a web app for controlling the printer. The SD card socket is built in to the electronics.

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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 tried Marlin and Repetier. They are about the same but Repetier has two small advantages:
1) it is slightly quicker
2) it uses constant maximum speed for effector (marlin uses constant maximum speed for carriages)

Repetier has other theoretical advantages which do not matter at all because they do not really work (e.g. it has advance algorithm to control nozzle pressure ... but it does not work well). Repetier has bed levelling but it is completely different from Marlin bed levelling. Repetier measures only 3 points and rotates/moves the coordinate system appropriately. Marlin has point based matrix (e.g. 4x4) and does interpolation ... so your part will be as distorted as your bed is. If you cannot calibrate your printer properly (either manually or using e.g. this: [github.com]) then you may prefer Rich Cattell's Marlin branch which has some (often working) heuristic to calibrate automatically.

Quote
dc42
I don't have the answer to your question, but I can tell you that there will soon be another electronics and firmware combo for Delta printers. I am extending my fork of RepRapFirmware for the Duet electronics to support Delta printers, and I expect to complete this in January. One big advantage of this combination is that it provides an Ethernet interface and a web app for controlling the printer. The SD card socket is built in to the electronics.

Will your extensions added to your fork of RepRapFirmware rely on a dynamics model of the delta mechanism ? Like such found in this paper:
[dro.deakin.edu.au]

From the rest of the responses I'm thinking I'm going to either stick with Marlin or give Repetier a shot.

Quote
stratmaster458
Will your extensions added to your fork of RepRapFirmware rely on a dynamics model of the delta mechanism ? Like such found in this paper:
[dro.deakin.edu.au]

That's an interesting paper, however I don't think the dynamic calculations in it are applicable to a delta robot driven by stepper motors. They appear to be designed for constant-force motors (e.g typical permanent magnet DC motors driven with constant current). With that type of motor, I can see that the feedforward approach proposed would be better than simple PID.

One difference between my firmware and Marlin is that I don't plan to split long linear moves up into a sequence of shorter moves and then generate the motor steps needed as if the stepper motors move linearly. Instead, I intend to schedule the steps as required in real time. This will also make it easier to change the step scheduling algorithm to pre-compensate for Bowden elasticity and other effects.

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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].