Getting Uplift ready for the first event of 2025

22nd March 2025

The first event of 2025 for us, Bristol Bot Builders’ North Down Havoc, is now just under a month away and Uplift needs some love before it will be ready to fight again.

New drive motors

Internally it survived the previous event in Bristol last August almost unscathed, with the exception of a burnt out front-left drive motor which suffered some mechanical distress after taking a direct hit from Easy Over’s frying pan.

Over winter I had purchased some new 775 drive motors from Gimson Robotics. These new motors were broadly the same as the old ones, the biggest difference being they are rated for 24v instead of 18v. This should mean they run cooler at the expense of a bit of top speed. More importantly I was able to source enough to ensure I had plenty of spares.

The old motors were also 775s so swapping them out was time consuming but quite simple. I did take the opportunity to move some of the main wiring harness from XT90 connectors to ring terminals while I had everything apart. The ring terminals give me more flexibility when it comes to interchanging spare parts and are quite a bit smaller and easier to route inside the robot than a block of several XT90s.

I also swapped out the power light for a much brighter LED. We found at the last event that the old one wasn’t really bright enough to be easily visible if it was a sunny day (and the fact it was yellow didn’t really help either). The new one is brighter and red, which fits better with the theme of the robot.

New body panels

With the internal updates sorted it was time to spruce up the outside. Over the winter I’d made new CAD models of the top lid and side armour panels. The original top lid was half CAD and half hand made, and the side panels were 100% hand made. These are parts I’m likely going to need to replace regularly and being able to cut out replacements on my CNC router in just a few minutes would be very helpful, so getting them into CAD was somewhat a priority.

I also wanted to make Uplift’s “look” a bit more uniform. The first time around there was a mix of black, red, white and silver parts. I’d bought some PLA+ filament in a nice red colour from which I printed some sleeves for the threaded steel standoffs that hold the side armour on. I also replaced the silver bolts with black ones, which gave the sides a more consistent look.

The lifting arm got pretty mangled by Captain Kathryn Chainway at the Bristol event and there were some things I wanted to change about it anyway, so I decided to make a completely new arm.

Dimension wise it’s pretty much identical to the original one. I took off some material from the underside so the armour panel under the arm could go to 10mm thick instead of 5mm. The old arm didn’t have enough clearance to allow for 10mm.

I also added some “horns” to the top, the first set of which should help when self-righting as it means the robot reaches the tipping back over point before the arm gets to its maximum reach. The new arm also got the same 3D printed red accent treatment as the side armour.

The 3D printed lifter gear block that transfers the torque from the big spur gear to the lifting arm itself also got a re-print in the PLA+. I changed the design slightly so the bolts that hold it to the arm are accessible without taking the arm off. On the old design they were partly obscured by the lifter supports.

Here’s the new 10mm thick top armour panel that sits under the lifting arm. The hexagonal pockets are for weight saving so most of it is actually still only about 5mm thick, but there’s enough 10mm material left that it’s much stiffer than the old one.

I made up some new front “eye” panels – these have less material removed compared to the old ones (which bent in combat) so they make the front of the robot more rigid.

One of the nice things about going to an event is you can confirm your scales are accurate – Uplift came in a few hundred grams underweight at Bristol so I know I can safely add some material back onto things like this without worrying about going over the limit.

With that in mind, the front forks also got a small redesign. I added a bump to the back which should stop them flicking up into the air as much. They can still go up a little as they need to be able to ride over bumps in the floor, but in Bristol they spent more time flipped upside-down than they did on the floor.

Old fork at the top, new underneath:

At this point Uplift was looking like a complete robot again, just needing a fresh set of vinyls to be applied:

And as if by magic, the vinyls were applied!

North Down Havoc is April 26th 2025, so check back after then to see how Uplift gets on!