Building a Big, Dual Weaponed Combat Robot - Derive Part 1

Since I first got involved with combat robotics i've wanted to compete with featherweights. Despite the name they are the largest class fought in australia at 13.6kg. This series will follow me building a battlebot for this weight class with two distinct weapons to control and damage opponents.
The machine is based on Derive, my smaller antweight prototype. The event is in january so I better get moving.
Get the CAD for Derive and all my other machines here, no cost: grabcad.com/library/combat-ro...
Music: Pinna Park rendition by Tom Brier

[@gtdgabriste1]

Love this style of video! And, thank you so much for making your cads available. I love downloading them and seeing just how inadequate my own cad skills are 😂. I don't know about other viewers, but I would love to see an in-depth "It was broke, here's how I fixed it" style video where you spend ~30 minutes talking about how you fixed an issue like the chain skip issue you had at 16:00. Algorithm?

[@BrokenLinkRobotics]

I'll integrate something like that when I can. I'm sure there will be many failures to talk about as the machine is tested more...

[@michaellesliegmail]

Some of the best combat robotics videos on youtube, love it.

[@user-qo3sw3kh2q]

So true!!!

[@JamieReilly-DarkBots]

Let's go Lifter/Spinner gang! Best of luck with this design!

[@evancookaudio]

loved the shot of you taking a ride. world class

[@TheInvertedFollicle507]

Reminds me of big dill or Terrortops from battlebots. You can have redundancy of the weapons and maybe cause more unpredictability for the opponent as well. Good design and great video.

[@larryslobster7881]

masterclass in ME and robot design, keep it coming

[@patrickcollins5752]

10 mins in, what is that musical madness ?!?!

[@AmericanKilljoy]

8:10 Great. Now I want to play Super Mario Sunshine again. Thanks. 😅 Love your design videos, man. Keep 'em coming!

[@teamleanmean4542]

Great video and Bot, also love your approach putting your CAD out there to help others 🤟🏻

[@Hilshoist50]

Keep 'em coming James!!

[@Think666_]

Might be worth noting that under significant enough shock the resistive force between fastener joints can fail catastrophically, best to dowel or key if possible.

[@pratikchougule5931]

You have got best engineering skills, your cad as well as manufacturing knowledge is awesome!!

[@hilaryhinde2884]

Excellent explanation. Great work, very interesting 🎉

[@TherapyWithWind]

Ah, thought it was going through your garage door when you got it rolling 😉! Awesome documentary, thanks for sharing!

[@scheffield]

Great video as always. Keep up the good work. 🎉

[@Spiethstar]

I like

[@mw4222]

6:50 How did you structure your CAD file so that you can do such a drastic change? I usually try to do a top down approach as well but any change like that would mean a complete redesign for me.

[@BrokenLinkRobotics]

Two methods: 1) fully parametric parts, each brought in separately. Therefore all changes can be undone and references updated. 2) my method, just brute force the updates to the part using push-pull and direct modelling. Not ideal but it isn't an actual engineering model for production so fine by me.

[@hazza2247]

great video, such a cool build

[@zachary3777]

When bending uhmw I found that if you run in under cold water while bent into position, it will hold its shape permanently. Hardox is hardened all the way through, not just case hard. It's hard but still tough.

[@joashparker8271]

Awesome work

[@nickdobrikov]

Really nice content!

[@Roboticlay]

Beautiful!

[@razer259]

I like where this is going. 👍

[@oliverwilliams296]

Damn, good video

[@katiemmm347]

Hi thanks for this, brilliant build and video skills you are a very tallented guy 👍

[@overmatchrobotics]

i love this!!!

[@roboman2444]

I'm not 100% convinced about the serpentine belt drive. With your previous design (one driven wheel, one by belt), at least if the belt-only wheel/sprocket was damaged, the belt was damaged, or things got shifted and the belt lost tension, you would still have the driven wheel working. In this setup, if the belt, idler pulley, drive pulley, front wheel sprocket, rear wheel sprocket gets damaged, you lose that entire side. Even if the robot just gets bent a little, the belt may lose tension and slip. The wheels and pulleys are also only mounted on one side, so potential for a bolt backing out just slightly could cause the entire system to lose tension, even if otherwise it was still operational. It will be interesting to see how it performs, especially against undercutter style horizontals.

[@roboman2444]

I've seen this technique done elsewhere in other 4wd verticals... Have 2 belts from the motor shaft, one to the front wheels, and one to the rear wheels. Long motor shaft, with one sprocket on the inside and one on the outside. Flip one set (either the front or the back wheels, whichever drives better) so the wheel dimensions stay the same, and you don't require any extra space. Now there are less moving parts, less likely to get tension issues due to simpler belt paths, and redundancy in the belts/belt paths while making no significant changes to the layout of the parts. I don't think this would work 100% on your design, since the armor mounting may get in the way of the outer belt path.

[@BrokenLinkRobotics]

The current drivetrain has a ridiculously loose belt tension and works fine due to having heaps of wrap on each pulley. If the belt is lost it loses drive yes, but I considered it worth the weight gain.

[@user-zh2lh4iz8j]

you got this win melbon (spelt wrong idk the right spelling)

[@trainboyplus2652]

Please PLEASE do a video on your grabcad 150 gram derive

[@andrecook4268]

Noice

[@mw4222]

2:50 hmmm not sure about the weight comparison... My feather drive (a shameless copy of Glen's drive) is 450g per side including motor, gearbox and a wheel. Edit: sorry I misheard, thought you said the gearbox was 450g my bad

[@mw4222]

Also can't believe the last full combat feather event was already four years ago. Time sure flies.

[@BrokenLinkRobotics]

Pretty sure I pulled the numbers out of nowhere, just an example to get the point across. Good to know I was close!

[@duconlajoie9680]

this just my own opinion but i prefer the sound of the machining thant the music you put over it.

[@vincentlewis93]

Are you going to make an omni wheel drive robot with an egg beater like Riptide and linx?

[@BrokenLinkRobotics]

Yes, check two videos ago