z-axis is not moving enough

so i finally got my lowrider 2 up and running! started with a first cut today, and noticed, that when i say go up or down 10mm, the motor moves for about 450 degree thats 2 a 3 mm! so how do i change this? is this normally?

 

i have 1.8 degree motors.

ramps 1.4

firmware freshly updated from the site and made no changes, ( dont know how)

thanks!

Are you using drv8825s and do you have all the jumpers underneath the drivers? If so, you’re stepping with 1/32 microstepping and the Z steps/mm should be 800, not 400.

Is it skipping steps, or just not moving as far? If you tell it to go back down 10mm, does it go to the original start?

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Jumpers are all in, I have those drivers, and the LCD said 800! And it ends where it started when it goes back down 10mm The pitch of the screws are 2mm. And 200 steps is like 1 round with 1.8 degree if I’m correct, so 800 would be about 8mm right?

200 steps/turn * 32 microsteps/step * 0.125turn/mm = 800 microsteps/mm. So that should be right.

0.125turn/mm or 8mm/turn, because it’s 2mm pitch and 4 starts.

Someone the other day had a leadscrew that wasn’t 4 starts. It should have 4 threads if you look at the end.

The other common problem is moving way too fast on Z. If you send a command like G1 Z10 F300 it should move slower. I don’t think that would end where it started though.

Ahw yeah, i see… Now I know why my lowrider doesn’t crash down…

https://s.click.aliexpress.com/e/p1HU6jg99

I have this one. Is has just one! But is it possible? Except for it being slower…

Or should I order another one :o

 

You should probably make sure you order two, so they are both the same :).

No, actually, it will work as is, to an extent.

First off, you can quadruple the steps/mm to 3200. That will leave you with a new limit though. When the processor is moving one mm, it needs to be able to step 3200 times to get that axis to move. If you try to move 1mm too fast, then it will swamp the CPU and there will be errors (Marlin used to reset, but I think now it will just not do it).

One thing you can do to help is to change the jumpers under the driver to 1/16th. That should reduce the steps/mm to 1600. You can even go to 1/8th, which will be back to 800.

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Heffe you are a troubleshooting power house. I just have to step in and say thank you for all that you do around here. I have been trying to clear my inbox and more often than not you have already answered it. Thank you, Do we to set up a crew member of the year program?!

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i will order the parts, thank for the amizing quick reply!

can’t wait to see how the machine will create stuff for me!

you guys are amazing, is speak for the noobs that dive in and don;t know what they are doing! haha

thanks!!

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