Donut shaped polar printer?
January 11, 2019 02:58AM
Hello!

I'm working on I guess a polar printer. But the build area is a donut. The z axis is in the center of the circle. And the X arm rotates 360 degrees. I see most Polar printers have the Z axis outside of the circle.

But I'm thinking the same commands would apply. You still have a radius and distance.

Is there any firmware for my style Polar printer?

Thanks

Max
Re: Donut shaped polar printer?
January 11, 2019 03:03AM
RepRapFirmware supports SCARA printers with a similar shaped build area, so I think it would support your polar printer. However, the polar support in RRF has been very little used so it might need some improvement. I can provide firmware support if you decide to use RRF on a genuine Duet for your project.

Edited 2 time(s). Last edit at 01/11/2019 03:04AM by dc42.



Large delta printer [miscsolutions.wordpress.com], Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
Re: Donut shaped polar printer?
January 11, 2019 12:00PM
Hello dc42!

I can buy a Duet. This is a very large scale clay printer. The center Z axis in the middle and a straight arm (gantry giving a max radius of 36") The inner "Donut hole" occupies a 12" radius (non build able area).

I've read the mathematics of going from Cartesian G-code to Polar Radius + distance. Doesn't sound to complex for the firmware to calculate. I think Scara is more complicated since it has 2 Radius to calculate?

Do you have a link I can purchase your duet?

Thanks

Max
Re: Donut shaped polar printer?
January 11, 2019 12:48PM
That's right, Polar kinematics is simpler than SCARA, except that there is a singularity at the axis of rotation. Bur your design avoids that singularity, so it removes that problem!

To buy a genuine Duet, go to [www.duet3d.com] and scroll down to products. You can buy either directly or through one of the local distributors listed. The Duet WiFi and Ethernet both support a wide range of stepper motors and they have floating point hardware on the CPU, so the polar calculations will be very fast. The Duet 2 Maestro has lower current stepper drivers, so (like the Einsy board) it is best suited to 24V power and lower current motors. It doesn't have the floating point hardware on the processor, but it's still 32-bit and should be fast enough to run a polar printer.

The standard firmware binary includes polar support. See [duet3d.dozuki.com] for how to configure the firmware for a polar printer.

It's unlikely that the polar support is perfect, so please report any problems on the forum at [forum.duet3d.com].

Good luck with your project!



Large delta printer [miscsolutions.wordpress.com], Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
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