Hi everyone! Recently I made an i3 style printer from scratch. I used the usual prusa style design for the Z-axis, with M8 threaded rods(2mm pitch) and T8 leadscrews. I run the motors(1.8 degree per step) at 1/32 microstepping with DRV8825 drivers. From prusa calculator I found the steps per mm value to be 3200. But when I operate the printer the scaling is 10 times that… I mean a 1mm height in a stl file turns to 10mm in the print and so on. Does anybody have ideas…what I might be doing wrong, and what I should look for? Thanks!
have you got the jumpers right on the ramps board?
Yes, I used all the three jumpers (although not required for the DRV) for 1/32 microstepping
m8 pitch is 1.25mm not 2mm unless you are using tr8
Is this a Tr8? I don’t know much about the names…but I measured this one’s pitch as 2mm.missing/deleted image from Google+
Okay, I got it from google, its a TR8 threaded rod
I’d guess your rod has a 2 mm pitch and 8 mm lead. The latter is what to use in your calculation.
Turn the screw 360 degrees by hand and check home much your Z axis has moved.
Okay, I’ll check that out. Thanks!
this is not a 2mm pitch it is around 4 or 6mm . the place where u ordered will give you the spec
@ekaggrat_singh_kalsi Could very well be 2mm pitch but it’s not a 2mm lead for sure.
“Lead is the axial advance of a helix or screw during one complete turn (360°) The lead for a screw thread is the axial travel for a single revolution. Pitch is defined as the axial distance between adjacent threads on a helix or screw.”
@Johan_Jakobsson ok sorry for the wrong term… that is what i meant… i have made the same mistake before because of the looks of the screw… but luckily the seller gave me the true lead when he sold me the screw
Hi guys! I measured the lead to be 8mm. This results in 800 steps/mm.
Thanks @Johan_Jakobsson for your help. 800 steps/mm fixed it!