RAMPS 1.4 & Marlin

[scalci]

Hi Everyone

I need some input.

I build my printer with a RAMPS 1.4, DRV8825 drivers, Latest Marlin, Nema24 steppers and threaded rods.

I had a huge wobble on the X&Y, so I replaced the threaded robs with ballscrews, made all the necessary step changes in the firmware.

As part of the wobble I had, my printers X&Y movement was very slow. I thought as I did he "upgrade" the speed would also improve but it did not.

Can anyone maybe assist with ideas what to check?

[Roxy]

If you want to run the printer faster... You change the max feed rates and the acceleration and jerk. But don't go crazy. Do it a little at a time and verify everything is still working. If you push it too hard, it might look like it is working, but you will lose steps and print will start to shift.

[scalci]

Roxy that is what I am doing.... Is there a sweet spot?

When I went to the latest RC code I left everything at defaults except the steps... If I change one setting at a time, will It work or do they together make the difference?

I think maybe I should go back to basics and read the manual again...

[Roxy]

There are a couple of different sweet spots. Not only is there a Max Feed Rate, there is a Max Acceleration and Jerk. You want the printer to move quickly but you also care about what the print looks like. If you only print round vases and flower holders and candlestick holders, you might be able to really crank up your feed rate because the acceleration is smooth the whole time. But if you print things with lots of sharp edges, it is possible you have to slow things down to make the print look good even if the machine doesn't lose position.

I would bump up (and down) the X & Y together. The Z doesn't really matter other than if you are printing on an unlevel bed with Auto Bed Leveling that can end up limiting the speed you go at if it isn't high enough. (The planner won't exceed the speed needed to do a move on any of the affected axis. If the Z can't move fast enough for what is being asked for in the X & Y, it can limit the speed. But the Z usually can tolerate speeds much higher than default.)

[scalci]

Hi Roxy

thank you, I will start with this and work up.