August 11, 2016 at 8:25 am #15969
Thinking about using a real lead screw. Wondering what a good equivalent would be that I could get for around $20?August 11, 2016 at 8:28 am #15971
Nothing for under $20 is going to be an improvement.
What is the goal of the “upgrade”, that will help in the selection? The right thing is a ball screw, but the prices reflect that.August 11, 2016 at 8:47 am #15975
I saw this guy saying he made an upgrade to a lead screw. Would be willing to spend up to $40 if it’s worth it.August 11, 2016 at 9:19 am #15976
What problem are you trying to solve? Why change?
Backlash can be brutal on these things, it is different on a 3D printer where gravity is providing the anti backlash and the forces are only acting with gravity. On this CNC you are pushing down and your material is pushing back, making backlash a huge factor. Your cutting bit can actually vibrate up and down if you aren’t careful. If I though these where a good idea I would have used them. A ball screw has backlash compensation, a leadscrew needs added hardware for backlash compensation (we used to use a second nut and spring but too many people didn’t understand how to set it so I had to take it off).August 11, 2016 at 9:44 am #15977
I don’t know enough about these things to even know what I’m trying to accomplish. Just saw it mentioned a few places, and thought that a real lead screw might be better somehow. Straighter? Smoother? Higher precision? I don’t know. Probably just go with the one in the kit for now.September 17, 2016 at 1:14 pm #17884
Hi vicious I had purchased this items at amazon
described as follows 400mm Lead Screw 3D Printer Z Axis Lead Screw ACME Lead Screw 8mm Screw Pitch
Material: Stainless steel lead screw, copper nut
Screw diameter: 8mm
Screw spacing: 2mm
Lead of thread:8mm
Range: Reprap makerbot 3d printer accessories
3D engraving machine lead screw 400mm length with nut.
Nut turn an around move 8mm
1x 400mm lead screw
1x Brass Nut
The rod for my z axis I could I have used the prusa calculator to determine the correct micro step settings to replace the current settings on the marlin set up you have provided on the site I have not successfully determine the correct rotational amount with the information given on amazon thru trial and error I have approximated that 1600 as a better number than the 8mm 5120 the calculator provides could you illustrate the math followerd to calculthe steps for any given angular pitchSeptember 17, 2016 at 1:17 pm #17885
It should be 800, once and a while 788.
That leadscrew is not recommended for your z axis. Reasons are 2 posts up.September 17, 2016 at 4:34 pm #17899
Thank you I am certainly learning a lot I have taken the scenic route in getting my machine up and running I have fallen in just about every pot hole there could be in this road. But the adventure continues to be exiting?January 5, 2017 at 5:00 pm #24396
I understand the backslash problems(try to resolve it with antibackslash nut) but if I want to try lead screw which one will be better for MPCNC
The one start two millimetres lead per turn or four start eighth millimetres lead per turn.
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