150g Antweight Axe Mechanism

This is a weapon module designed for use in an 150g antweight robot. This lets a cheap 9g servo power a visually effective axe that has greater speed and travel and can also better be used for self righting.

This is designed as something for newcomers or people building easy demo bots for your kids. You are able to bolt this to any flat plate, either printed or using traditional building methods (Polycarbonate, aluminum, hdpe sheet etc)

It is all held together with m3 bolts, save the servo which is two m2 or alternatively you could use the screws that come with them.
This has two types of gear, one with a plain bore you can press a metal servo output spline into or one , more for use with plastic gear servos that has a servo horn indent in it, you will need to cut the horn down by about 3mm but it should just press in and be securable with some superglue. This also works perfectly well for the metal geared servos too. Most 9g or micro servos will fit. MG90 is what it was first designed and tested around but SG90's will fit too.

The main shaft is just a bolt into a plain bore as it is designed to be simple and functional. the addition of ball bearings or a plain nylon bearing on a 3mm plain shaft would be an upgrade if you have problems.

The axe is just a blank! You can mount anything there with the hole pattern, lasercut steel, hand cut titanium or spoons and other household objects. Go nuts.

You will have to spend some time adjusting your setup to get the desired swing and making sure that the travel of the larger gear isn't too great so it stops contacting the axe gear. I set it up by having the gear just touching the base of the unit and then adjusting the travel with end points on my transmitter and trims until it was repeatable and enough swing.

Inspired by the mechanism used in https://www.thingiverse.com/thing:3811105 which is a much better design and it's a full robot!