RepRapFirmware Polar 3D support

frafa

Hello David,

it's François (Scara with DuetWifi)
At fabLab we have a member who works on a polar 3D printer similar to R-360
http://reprap.org/wiki/R_360
he works with an old version of Marlin …

Is it possible that you add the support of the polar printers in RepRapFirmware ?

dc42

It's possible, but it may be a little while before I have time to do it. Please supply some details:

Is the X=0 Y=0 point at the centre of the turntable, or somewhere else?
Does the print head move linearly along the diameter of the turntable, or does it pivot about the Z axis and move in an arc across the turntable?
What is the expected behaviour if you print a line running through the centre of the turntable?
How do you home it?
Please provide photos of the printer.

frafa

Cool
we have time on this project, nothing urgent

the member of the association is prosthetist
it works on a polar printer to print circular shapes quickly

its current prototype:
round tray without end-stop
x is linear
x = 0 end of travel at the center of the plate

I contact him to tell him to come on the forum
photos to come

because it is I who rule Marlin is it is far too old …
I contact him to tell him to come on the forum

pir2z

Hello David
I'm Pierre, Montpellier Fablab member. I contact you following the previous talk with François.
I ordered today a duetwifi on your website.
As François said I develop a 3d printer based on the project R-360 and I'm now on hardware programmation.
My 3d printer is, I think, very simple.
Z = Z
turntable is based on :
x= R cos Theta
y = R sin Theta

I have only 2 endstops z0 and r0. When z=0 and r=0 : Theta =0
Rmax = 150 mm
Zmax = 1000mm (not a joke… I will send you later a picture of the printer)

The print head is on R and slides horinzontaly.
The bed is heaten during the printing and turnes in the same time. In my mind it turns mainly in clockwise.

The target is to print prosthetic sockets and covers
You will see typical results on this website : https://www.createoandp.com/
My project is not new, you can get a look on this link http://prostheticdesign.com/index.php?route=product/category&path=75
I wish to do something similar but vertical and more "3D printer look like"

If you think you can help me on this project it will be very kind of you.

Thank for your help

Best regards

Pierre Zanetti

dc42

Hi Pierre,

Thanks for the information.

As I understand it, you don't have a homing switch for the turntable, you just use the position it is in at power up as the reference. This would prevent the use of power down and resume functionality; but depending on other details of the printer, that might not be possible anyway, because you may be unable to home Z with a print on the bed.

With your current electronics, do you use the X motor output to control the radius motor and the Y motor output to control the turntable motor, or the other way round?

pir2z

Hi David
Thanks for your quick answer. I see you have well understood my project.
About steeper
Xsteeper = R
Ysteeper = Turntable (Theta)

I would like to send pictures but I have some difficulties to join something with this forum.
Please send me an email to zanetti_pierre@hotmail.fr and I will forward some schemas and pictures.

Best regards

Pierre Zanetti

frafa

if need be we will add a hall effect end-stop on Turntable (Theta) …

dc42

Thanks. Initial support for Polar printers will be in the next 1.20beta. See https://duet3d.com/wiki/Configuring_RepRapFirmware_for_a_Polar_printer for the initial documentation.

To include images in posts, store them on a file sharing site and put the link between img tags in your post. If you use Dropbox to host your images, replace ?dl=0 at the end of the link by ?raw=1.

pir2z

Hi David
Thank for your support. I'm waiting for the duet and asap I will plug in on my 3d printer I will do some tests.

For pictures I will do that this evening if I all is ok.

Best regards

Pierre

pir2z

Dear David,
Long time I didn't give you any news.
The duet is not set on my Polar 3D printer.
I connected all and I did first test, the manual control works more or less ok but nothing go to print.
I would like to know what's wrong with my programation.
What do you need to see where is the trouble ?

Thank for all

Best regards

Pierre Zanetti

dc42

Are you able to home the printer?

What happens when you try to print something?

pir2z

Hi thank to take time for me.
Last version seemed worked but during the priting the 3D printer during long minutes untill to start again.
We tryed with François to understand what wrong without success. Now I installed my printer at home and I intented an upload with last information on forum, actually the printer made the homing and nothing else. I don't understand what's wrong with it.

Thank for your help

Best regards

Pierre Zanetti

dc42

I'll need more detail than that.

I suggest you start by testing the motors individual by sending G91 to select relative mode followed by G1 S2 X... and G1 S2 Y... commands. Use these moves to check that the steps/mm and steps/degree are correct.

When you are satisfied with that, send G90 to switch back to absolute coordinates, and test homing.

If homing is working, test straight line G1 XY moves at low speeds. Check that the moves look as though they are straight relative to a fixed point on the bed.

If that looks OK, try a very simple test print such as a cube, printed at low speed so that you can better see what is happening if something goes wrong.