Nema 17 belt drive roller blind by Junkmail90210

Last crawled date: 2 years, 11 months ago

I have remixed my previous design. https://www.thingiverse.com/thing:4784786
What this is:
This is an interim release of the design. It's working very nice, I have it currently running on 4 roller blinds. I have since the last design been iteratively improving the design. Currently the design is broken into parts. If you do make this, you will need modify it to adapt to your wall bracket or to change the frame to a direct to wall interface.
Since the last round of changes, I have thickened the frame structure which lessens the twist that did occur (twisted the old frame, which then bent metal wall bracket). I have improved how the clutch works so there is less slop in the action (less creep up or down from day to day)
The motor on the inner side of the rollerblind. I am installing them back to back. You could save some filament by installing the motor outside the rolllerblind (frame-motor riser bit).
The tollerances of my printer aren't great. But the design is intended to spin freely, so if you assemble it all together without the belt and the springs the 100tooth gear should spin nicely on the spindle. The cap should not be chaffing the clutch parts, and the 'clutch on rod' should rotate in place.
Once the design is complete I will print an enclosure for the motor. Currently working on the heavier of the blinds. I think I am reaching the shear limit for printed plastic :-(
Components:
I use a lolin v3 nodemcu as my microcontroller ch340https://tttapa.github.io/ESP8266/Chap04%20-%20Microcontroller.html
I have included in my hardware selection the TCM 2209 stepper motor driver from Trinamic, you can learn more about it here. https://www.trinamic.com/products/integrated-circuits/details/tmc2209-la/
I can't recommend purchasing one enough. It is absolutely silent, you can hear the bearings turn. Here's good youtube comparing them.https://www.youtube.com/watch?v=Lx40lJkk9NQ
I used a simple stepper motor 1.5a. I also implemented the accelstepper library, which supports acceleration (gradual start and stop). I'm not sharing my arduino sketch at this time. If there is interest, perhaps at a later date.https://www.makerguides.com/drv8825-stepper-motor-driver-arduino-tutorial/
The VREF on the 2209 stepper driver is different than the drv2855 or a4988.
Here's a calculator for the vref for my 1.5a I'm putting 1.66vref (keeps silent step active)https://wiki.fysetc.com/Silent2209/#calculator
The 2209 uses a stallguard technology which you can learn about here.https://www.youtube.com/watch?v=Prw7wNa20Gk&t=2s
Stall guard is a new feature, getting it working in arduino is still pretty new, and way outside the scope of what I'm doing now... Here's some usefull information.https://electronics.stackexchange.com/questions/384522/how-do-i-wire-a-tmc2130-stepper-motor-driver-to-an-arduino-uno-in-order-to-contr/518984#518984
Included:
I've uploaded my fusion working files (it's a mess!!!)
I've also included an excel file that you can calculate your life requirements for your motor
parts:
1.5 amp stepper motor.
4 m3 30mm to hold on your motor
1 8-32 2 1/2" bolt and nut for the spindle (double nut or some threadlock)
1 gt2 300 belt (you can adjust how far the motor is from the roller in one of the sketches(should make this a parameter))