XY movements are scaled by 4.5?

Hi,

Im finally seeing a bit of light with my non standard delta. Due to some miscalculation I have 400mm arms for a base triangle of 630mm and a radius of 382mm. I managed to manually calibrate it to a rather small print size of 150mm diameter. Endstops and radius are calibrated up to one paper thickness.

The one thing that prevents me from printing is actually that when I command 10mm in any XY direction it actually travels 45mm. The z height moves normally and I checked that the carriages actually move the right z distance.
Any ideas what causes this scaling factor?

Edited 1 time(s). Last edit at 04/13/2015 07:22PM by sungod3k.

That's odd.

What command do you run to move the nozzle?
Have you tried G29 auto level probe?

Manual calibration requires precise movement of X, Y, and Z axis.

Four points of manual calibration
- Center (0, 0)
- X / Y / Z tower point

The coordinate (x,y) of each tower point is derived by
x = Build_radius * cos(theta)
y = Build_radius * sin(theta)

Angle of X tower = 210 degree
Angle of Y tower = 330 degree
Angle of Z tower = 90 degree

If the build diameter is 150 mm, Build_radius is 75 mm.
(x,y) coordinate of X tower is
x = 75.00 * cos(210) = -64.95
y = 75.00 * sin(210) = -37.50

Y tower is (64.95, -37.50)
Z tower is (0.00, 75.00)

The calibration step is iterations of
[Center -> X tower -> Y tower -> Z tower] -> check the nozzle height and adjust Delta Radius -> [Four point check]

Edited 1 time(s). Last edit at 04/13/2015 09:52PM by janpenguin.

Thanks for the extensive answer, thats exactly how I did it exept the raduis the machine though it was using was 4.5 times smaller.

But I just figured out that the marlin mainbranch has correct scaling contrary to rich cattels marlin. I had a weird error with dimensions before, so Im not sure if I messed up a setting. Im calibration the normal marlin version now. That should work.