Prusa M5 Leadscrew upgrade / M8 to M5 Adapter
by Dbach_MetalWorks, published
M5 nut adapter for M8 Receptacle. I made this to use with M5 Z leadscrews.
instead of remix the X-Ends with M5 receptacles just use this simple adapter
Before trying this mod please read this instructions completely.
I made this mod on my Prusa because I couldn't easily couple a 8mm leadscrew to a 5mm shaft without wobble.
Coupling 5mm to 5mm is way easier! Just use a 6,35mm tubing and voila! looks nice too!
M5 Leadscrews also reduce the torque needed on the Z axis stepper, so you can turn the driver amps down a little and have cooler motors.
- At least 6cm of 6.35mm x 1mm ( 1/4" ) Polyurethane Tubing
(Most used on Compressed Air Instalations and devices)
- 1m M5 threaded rod (OPTION: get 3 pcs of it)
- At least 2 M5 nuts
- Bench Grinder
- X-acto knive
1) Print: I used 100% infill, 0.1mm layer and 60mm/s feed
2) Check dimensions: outside should be between 12.73mm-13mm as per DIN specs. inside just test fit a M5 nut
If you want you can tweak the dimensions to better fit your X-end receptacle / M5 nut you can as I uploaded the soliworks source file.
3) Cut the M5 threaded bar to your actual leadscrew sizes: I used 330mm this way the Lead screw is long enough for a bearing on the bottom if needed
4) Carefully grind the hacksawed tips of the leadscrews and clean all metal shavings in them
OPTION: Cut as many leadscrews as you can and check them for straightness on a lathe or a flat surface, choose the best two of them
5) Test fit the nuts in the leadscrew to remove any stray metal left
6) Remove your wobbly M8 Z leadscrews and motors
7) Cut a 30mm piece of PU tubing and put on the leadscrew (Dont try to push the screw on the tubing it is too hard, instead rotate the screw into the tubing as the threads will push the screw in
8) Trim the tubing to be shorter than the stepper shaft, when installed the leadscrew should be almost touching the shaft inside the tube and not far away from it
9) Push the leadscrew/tube into the stepper shaft. as the tubing ID is near 4,2mm and the shaft is 5mm will create a strong and snug fit.
10) Install the printed Nut adapters into the X-ends repectacles
11) Install the motor-leadscrew assembly
12) Align the X-axis
13) Recalibrate the Z steps/mm using your DTI (1/16 microstepping + 200ppr stepper + M8x1.25mm = 2560 pulses per mm, with the M5x0.8mm should be near 4000 pulses per mm)
Done! Now enjoy the Z axis wobble reduction and the sexy look of your Prusa!