I want to try to automate my standing desk so that getting it into the exact position when standing is easier.
The NEMA17 steppers I have lying around are a bit hard to identify but I think they’re going to give me ~3.5 ft/lb.
My desk is a MultiTable. I bought a digital torque wrench from Harbor Freight but it is not sensitive enough to give me the amount of force required to raise the desk. I do know that it must be somewhere under 20 ft/lb. I’ll just print out some prototypes and see if I can’t figure anything else out.
I’m using the parametric herringbone script for now. Here’s the settings from my first attempt:
// OPTIONS COMMON TO BOTH GEARS: distance_between_axels = 35; gear_h = 10; gear_shaft_h = 7 ; // GEAR1 (SMALLER GEAR, STEPPER GEAR) OPTIONS: // It's helpful to choose prime numbers for the gear teeth. gear1_teeth = 13; gear1_shaft_d = 5.25; // diameter of motor shaft gear1_shaft_r = gear1_shaft_d/2; // gear1 shaft assumed to fill entire gear. // gear1 attaches by means of a captive nut and bolt (or actual setscrew) gear1_setscrew_offset = 3.5; // Distance from motor on motor shaft. gear1_setscrew_d = 3.5; gear1_setscrew_r = gear1_setscrew_d/2; gear1_captive_nut_d = 6.2; gear1_captive_nut_r = gear1_captive_nut_d/2; gear1_captive_nut_h = 3; // GEAR2 (LARGER GEAR, DRIVE SHAFT GEAR) OPTIONS: gear2_teeth = 31; gear2_shaft_d = 0; gear2_shaft_r = gear2_shaft_d/2; // gear2 has settable outer shaft diameter. gear2_shaft_outer_d = 18; gear2_shaft_outer_r = gear2_shaft_outer_d/2; // gear2 has a hex bolt set in it, is either a hobbed bolt or has the nifty hobbed gear from MBI on it. gear2_bolt_hex_d = 9; gear2_bolt_hex_r = gear2_bolt_hex_d/2; // gear2_bolt_sink: How far down the gear shaft the bolt head sits; measured as distance from drive end of gear. gear2_bolt_sink = 0; // gear2's shaft is a bridge above the hex bolt shaft; this creates 1/3bridge_helper_h sized steps at top of shaft to help bridging. (so bridge_helper_h/3 should be > layer height to have any effect) bridge_helper_h=-1; gear2_rim_margin = 2; gear2_cut_circles = 5;
This should give me a ratio of about 2.38.