Since watching slam plan on nhrl last year I really wanted to try and build a big wheel since they seemed a very fun challenge and I was kinda getting sick of dolos so wanted a “competitive” weapon focused robot
this originaly started out as a hub motor huge which ive talked about in my cads that time forgot post,
i liked the idea but designing the hub motor to work well was proving tricky and swapping the bars out would of been a royal pain in the butt so pivoted to a gear driven weapon using some badass 2820 910kv which i had bought for a rebuild of yam i never went through with so with a roughly 3:1 reduction i could get a 210mm bar right up to the tip speed limit
due to how expensive these motors are to get into the uk (i bullied sion into bringing me 2 back) i wanted to ensure it woudlnt die, so its got a custom printed tool steel shaft to remove the need to set-screws for the gear, it also lets me add rear support to help keep the motor happy
jumping forward a bit but ive got some 6mm carbon fibre right angle with some light weighting milled sections to reduce the weight (which was very tight) this should give a nice stiff frame
the main machining fun was all the bits in the middle, i had china make me the frames either side of the weapon and i made the 18mm titanium shaft that connect the whole machine, its got an m12 tapped hole which a pair of titanium bolts hold it together. the main reason for the hollow shaft was that its running 6s and i dont have the weight for separate battery’s
i also made some magnesium wheel hubs that grip onto the shaft. im using repeat pros with a 139:1 gearbox for 10mph top speeds. the wheels themselves are 4mm laser cut hdpe with some self amalgamating silicone tape on them for grip
finally for me the most interesting bit of the machine is the weapon bars, 6mm hardox with machined edges with 45, 30 and half round designed to slice through opposing robots. with a few test hits it was cutting 25mm into hdpe with a really bit hit which was pretty crazy
this also helps with the tip speed due to being slightly better with aerodynamics which would be important since i only had weight for a 380mah 6shv battery which is cutting it very close haha
due to its hight the top armour is 0.9mm tegris, basically paper but im hopeful i wont get hit there
and thats him all done, looking forward this weekend to try it out!
), it did still work despite all the damage!