Simplify3D User Forum

Sorry to ask this here, but i am building a large kossel and i have it all up and running calibrations. But i have a problem.

Ramps 1.4, DRV8825 stepper drivers (with cooling) set at 0.85v (2.4A 0.9dregree steppers) set at 1/32 microstepping. Extruder stepper is PG35L geared stepper.

When the reprap full graphic display is configured in marlin, then the steppers runs with pauses in every move. For example when homing, starting a print and in the print it pauses all steppers for a 1/10th of a second
every 2 seconds . Even the extruder stepper.
I have tried Vref voltages from 0.5 to 1.0v (lower than 0.5 and they won't move).

If i disable the display in marlin, they all work as they should.
Powersupply is 12v 18Amps.

Very strange..Perhaps i have missed something?

I know that driving a delta printer is already pushing it really close to the max processing power provided by the mega at 1/16 microstepping with and a standard 20x4 lcd character display, it's possible that doing the delta arm function calcs + 1/32 microstepping + a full graphics display, you're pushing the mega beyond what it can handle and that's why you're seeing the pauses. A good indication is when you disable the display there are no pauses.

Ahhh.. i had my suspisions.. I'll try 1/16 instead or just leave the display out.. And perhaps invest in a another board if i get everyhing up and running.

After more investigating it is correct that ramps/mega2560 is to slow for a delta. One thing to do to get better speed is to lower "segmenting" from originally 200 lines to 180 or less. That will free up some cpu.
And get down to 1/16 or even 1/8 stepping.
But it is still not enough to also drive the display.

I still have some work to do. I must get stronger magnets for the rods. The ones i have only have a holding weight of 0.7kg (10x4mm) so the rods pop off all the time.