Delta Printer setup help

Hi
I have been trying to get my Reprap Rostock printer going and I ran into an issue and I was wondering what I need to do to fix it.
When I use the commands to move the printer in the horizontal directions it does not move level, it rises as it moves farther in the x and y axis. I was wondering what I need to adjust to fix this issue?
Another question I had was the setting for the distance for the z home position with the calculated steps per millimeter is smaller than I measured,it takes a setting of 51.15 when the actual hight is 81.5cm, will this cause problems in the scale of the prints? Should the z home position setting be in mm because that is what the rest of the program seems to use for units?
I have 20 teeth pulleys, GT2 belts, 200 step nema 17 steppers, and 1/16 step pololu drivers. The setting I have for the xyz steps is 80.0
Thanks
Tanner

Hi Tanner

Your steps per mm is correct. I suspect you don't have the jumpers under the drivers set correctly. You need all three on there for 1/16 microstepping (unless you are using DRV8825 drivers in which case all three will give you 1/32). As far as the head raising as it moves issue you need to alter your Delta Radius. Most people do this by changing the delta_smooth_rod_offset value in Marlin. If the print head moves concave i.e it gets further away from the bed as you get further away from the centre then you need to decrease the value. If it's closer at the edges than in the middle you need to increase the value. I normally measure the difference between centre and edge and add or subtract that value from my original value for delta_smooth_rod_offset. You can then fine tune it with .05 steps until you get it spot on. If you have Rich Cattell's version of Marlin it's easy as you can adjust it with M666 Rxxx.xx. Don't forget to issue an M500 after each change.

Andy

Ok
I am not sure how to setup the jumpers, do you have a little bit more information about what I have to do?
Do I just have to put jumpers on the three sets of pins on the RAMPS under the stepper drivers?
Thanks
Tanner

Quote
tanner331
Ok
I am not sure how to setup the jumpers, do you have a little bit more information about what I have to do?
Do I just have to put jumpers on the three sets of pins on the RAMPS under the stepper drivers?
Thanks
Tanner

Yes. Exactly. If you check the Pololu web site they show which combination gives which micro step mode. For 4988 type drivers all 3 populated gives 1/16