After going on a two day 520 mile tour on my motorcycle, I decided I needed to make myself a wrist rest to remove some of the strain on my throttle hand. And why buy one when I have a 3d printer, and could make my own!LICENSE: I'm releasing this as non-commercial. If you'd like to print and sell these commercially I'm open to individual/one-off licenses allowing that.Print and install on the throttle twist grip. This is sized for a 2000 ninja 250, which has grips that are approx. 1.3 inches in diameter. It is a tight fit on these grips.MATERIAL: I printed this in ABS. I'm not sure this will work in PLA since it needs to be fairly springy in order to be installed. The springiness of the material is also what makes it stay in position.PRINT SETTINGS: I strongly recommend using >2 perimeters and >50% infill on this part, since it is under constant load, and the more spring force the part generates the better it will stay in place. No retention features other than friction are needed to keep it in place - the downward pressure from your palm tightens the band/clamp portion against the grip.INSTALLATION: The rest should be snapped onto the outer end of the twist grip, with the palm rest sitting very gently against the palm of your hand when the throttle is in the idle position. Make sure it does not interfere with your ability to close the throttle and find the front brakes. The important thing is that it not be so high that it causes the throttle to be held open when your palm is in your neutral position.I've attached a few pictures showing the installation on my bike relative to my neutral hand position. The angle of the picture is a bit weird but it should give you a starting point.FIELD RESULTS: This works satisfactorily. I ended up adjusting it slightly lower than I had it initially. It provides adequate support that I can maintain/adjust throttle position without holding onto the throttle with my fingers at all. It also does not interfere with more "spirited" riding, which is good. All-in-all I'm pretty satisfied with the results.