I haven’t written a build log on here before and thought for my own interests I’d document my journey into bigger weight classes. If you are looking for something that hasn’t been done before then you will need to look elsewhere. Here you will find many ideas borrowed from other people.
I have been lucky enough to have the RoboDojo on my door step, that run a few ant, beetle,hobby and featherweight competitions a year. Here I have ran many ant and beetle weight bots with a complete mix of successes and failures. Of which the latter has driven my addiction of building robots even deeper to better myself at each competition.
Using my beetle experience I am going to build a bigger version of my Targ-It vertical spinner.
My usual way of building is buy all the components I need first and then build around them. Maybe not the conventional way but each to their own.
The only major changes other than size would be to run a double pulley system for drive instead of direct drive and pulley, 5s LIHV and a 179mm weapon.
Got the layout pretty much sorted and going to print a test chassis to check all the belts drive distances work.
Decided to also have a good at making my own connector blocks.
I bought a 10x10mm extrude of aluminium. Designed and printed 2 jigs. 1 to cut 35mm lengths which could be slotted into the other jig with pilot holes. I drilled 4.2mm holes which I then tapped for m5 bolts.
These will be used in the 4 corners and 2 on the bulk head to hold the chassis together. This means I can CNC the hdpe with the bores I need and not worry about screwing in and out of hdpe when I need to change out parts. Or drilling inaccurate holes.
Wheels have 2 bearings in to mount onto shoulder bolts. A flanged small bear at one side to help keep it aligned and a larger 22mm “skateboard” bearing on the other. Eventually I will cast rubber wheels so the wheels could end up being quiet heavy but I’ll tackle weight issues later on!
Will run 2x 5s LIHV in parallel (kindly donated by Morgan) they seem to fit so far but will need to print something to protect the motors catching on loose wires. The battery choice is purely based on getting 2 free batteries. If it turns out to be overkill ill get a different ones.
Sadly I’ll have a pause in progress for a few weeks. Prep for Robodojo and an over due Holiday!
Been working on the drive chain and altered some brass hubs to have an 8mm through shaft and 2 extra grub screw holes.
Brass I know, it’s heavy… have I had fun altering them? Yes and are there plenty of alternatives? lots but it’s a tried and tested method at beetle weight using the Aluminium just cuz hubs.
Batteries are a squeeze so I am going to invert the cavities on the bulk heads to give more space inside the chassis. This will allow me to run the wires behind the drive motors.
Next plan is to solder up the ESC’s and give it a test spin. Unfortunately it doesn’t fit in my beetle weight test box more work required for a safe spin up.
Drive chain almost complete, could do with tensions a little tighter on the smaller wheel. Going to recess a 3mm aluminium mounting plate for the motor into the 10mm hdpe wall.
The front wheel shoulder bolt will eventually be screwed into the side armour and the motor shaft cut down so a bolt can be screwed into the end for extra security.
Drive pulleys up and running with two different ecs to test. Tekko32 and Vortex, not sure why an 80amp ecs is recommend other then for sales. They were only pulling max 10amps each on testing. Maybe when they stall? Tekko32 seems the way forward as they are cheaper and I can stick a heat sink on if needed.
Also started to prototype some sort of “can protector”. Going to use m3x65mm bolts through to an end plate then clip on some sort of panel on each side to stop cables rubbing.
Unfortunately run out of fun colours and now it’s just whatever’s cheapest on Amozen and doesn’t have awful reviews .
Time to focus on some wiring and cable management while I wait for some Hardox. Then I can size up what battery capacity I will need and hope the ones I have already will be sufficient.
unfortunately I can’t work out how to change the posts name.
more work required for a safe spin up.
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