Hobbyweight JackHammer : O
(sorry if you thought it was a feather - it said I had to add a weightclass)
Hi Guys me again.
Some of you may remember JackHammer my beetle from a few years ago:
This was my first proper beetle and I iterated on it for a few years until early 2025. Safe to say I’ve always had a soft spot for this robot.
The main reason I shelved this robot was not because it was a bad robot (because I actually think it was a fairly ok robot) but because I was a bad driver - Hammersaw not usually the go to for first robots and whatnot. This led me to instead develop some less driving-heavy robots where I could just throw a kilo of spinning mass on something and call it a day. Why am I making a hobbyweight version of this then?
It’s simple:
There is currently no evidence proving I am bad at driving hobbyweights.
On to the cad then with that out the way. I have seen robots of this weight class precisely once ever - last year at Gareth’s test event, so if anything and everything looks completely terrible then please do tell.
Main Objectives:
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Look epic - duh
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Work ok - ideally should be able to win fights yk
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make as much in house as reasonably possible and worthwhile - always like setting myself this constraint since for me that’s part of the fun and it helps me see how far I’ve come in terms of the parts I produce and the way I design around my manufacturing capability
Ok so here’s some cad wow
Looks kinda like this at the moment. fairly bare bones I know but I’m fairly happy with the shape. There will be some cool flowy tpu top armour on top of that structural plate stuff. also a Hammersaw arm lol. This has a much wider aspect ratio than the OG jackhammer (long boi) and I’m trying to go about it in a way where it makes it more competitive and gooder whilst also trying to squeeze some visual interest in there.
Frame:
heres the frame look wow. it’s going to be 15mm HDPE and use the square nut pocket thing that I do for my beetles. I also found these screw in threaded thingies but idk if I trust them. HDPE frame will sit on a 4mm carbon base and then have all these angled 2mm carbon bits acting as like top and back support and then some tpu on top. I managed to procure an absolute ton of 2mm carbon from a skip at uni so basically if it can be made of 2mm carbon it will be. (yes there are massive holes in those side rails they will be explained I promise)
Screw in threaded thingy Vs square nut in printed thing
Drive:
I think the drive setup is kinda interesting here but that doesn’t necessarily mean good. Here’s a top down of the left drive rail though it might need some explaining.
so Motor is top right. It’s one of weatherlys new low kv things and I think in the only person with them as of yet so basically I’m about to be either a advert for him or stocks in weatherly enterprises are about to tank depending on how this robot does lol.
wheels are top left (front wheel) and bottom right (back wheel) I had fun cadding the treads lol.
It’s an Alex drive configuration that runs a 4.something: 1 to the pulley then the pulley is ratioed out to the wheels too. Interesting thing here is that the wheels are on opposite sides of the rail and the gearbox is integrated into the inside of the rail. This is the thing I’m worried about lol. I’m worried that any decent hit will seize the gears and snap the frame rail since it’s quite thin. lots of tpu around it and it’ll be rait?
I made this test thing look
It’s got all bearings and stuff in there and preload and whatever. idk I think it’s kinda novel. 2mm carbon plates encapsulate it obviously. You may also notice there’s 3 gears in there instead of 2. I had to add the intermediary gear to space the motor a bit further away from the sprocket. I don’t love it but I guess it’s fine? if it gets hit I think it’ll seize either way.
Weapon:
Idk not done it yet.
current mockup with an arm is just block cad. Arm will be driven by a repeat magnum with another one if weatherly’s motors on. Think it looks funny next to the max since thats what ran JackHammer3’s arm.
“Don’t talk to me or my son ever again” shot
Arm will be clutched. I have some ideas but not done any real work on it so will reveal at a later stage.
blade will run on some hubmotor I will have to make. I think I’ll use the same donor motors I use on rotavator and the shell spinner because they come in lots of kv options (and I’ll eventually have to make diff versions for different tipspeed limits yay)
This’ll effectively be a fairly beefy beetle specced hubmotor if all goes to plan.
Arm itself will be 20mm HDPE
Still to do:
Loads
make all the parts
design arm assembly and clutch
redesign all the bits I don’t like
add cool embellishments and vents and stripes and stuff (v high importance)
Will keep posting updates as I make them but trying to get as much done as I can since I will be away for a month or so quite soon so want to get the ball rolling. currently waiting on lots of material then I fear it’s lots of lathe and cnc time for me
