Catalyst - My beetleweight Build

With the Kinematics UK Beetleweight championship in mind I've started to upgrade my first bot attempt.

(first version is here: http://www.fightingrobots.co.uk/thre...a-beetleweight )

However a dimension changed here and there......one thing led to another and I've basically ended up rebuilding it again :mrgreen:. As the champs now has gotten a little further away, it will probably change again before then (but hopefully not). Its a 4 bar lifting robot, still using 8mm HDPE and it will be 3mm Polycarbonate and Aluminium on the outside. This version will have bigger ebay motors rather than servo drive, but only 2wd this time, plus botbitz controllers and a LiPo battery.

As I've mentioned before, I'm not an engineer or anything, and this is still my first bot, so I still don't know what I'm doing, and welcome any comments :lol:

Providing this isn't a name already being used (which I can't find anything yet after searching) it will be called "Catalyst".

This time I tried to be a little more precise with the marking out, as I know how it should go together. After drawing everything to exact size, I copied the parts onto clear adhesive vinyl using a normal, run of the mill printer (after checking it actually came out the original size)
Attachment 6285Attachment 6286
A whip round with the jigsaw and voila.
Attachment 6287

The main parts of the chassis I've built to slot into each other, hopefully for extra strength. Then it will be self tapping screws to hold it properly. Here it is slotted together.
Attachment 6288Attachment 6289
Motors and baseplate
Attachment 6290

More to come soon!

I like this 'slot together' chassis design. I hope it holds up well. :)

God that's neat. My parts look like they lost a fight with a lawn mower.

that is beautiful!

Thanks for the positive comments guys. Had time to do a bit more in the last few days, so now we have wheels, a battery, servo for the lifter and wiring.
Attachment 6309
I'm using an xt60 plug for the link, although I'm not sure if i like it being near the front, but thats where it has ended up at the moment, maybe see if I can shield it some way.
Attachment 6310
Also realised that i also had to squeeze a stand alone BEC in somewhere, as it turns out the servo I'm using draws just under 4A at stall, so more than the one on the botbitz ESC could supply.

i like the look of it man but one piece of advice find different tire material i had similar ones on bone-crusher at last years champs and although they worked really well on the lino at home on the steel floor of the arena they get next to no traction and just spin alot of people are finding success with either finger tech foam wheels or the bane bots wheels

Quote:

---

Originally Posted by suvv

i like the look of it man but one piece of advice find different tire material i had similar ones on bone-crusher at last years champs and although they worked really well on the lino at home on the steel floor of the arena they get next to no traction and just spin alot of people are finding success with either finger tech foam wheels or the bane bots wheels

---

Thanks for the heads up, I had heard people having traction problems. I was going to persevere with the rc one for now, mainly because there are loads of different compounds and constructions that fit them. I used to race model cars years ago, so im hoping I can find something no one has thought of. ;)

I'm sure I'll be wrong and end up with the foam wheels haha

i was running tires similar to these... http://www.hobbyking.com/hobbyking/s..._Compound.html
and they did fantastic wheel spins but nothing else i think a really aggressive tread will be your only hope though one person is experimenting with liquid latex(not like that) to see if that improves traction so you might want to look into that aswell

What sort of thing do you think would come close to replicating the slippy floor for testing this out? A Smooth dusty, painted piece of metal maybe?

a sheet of unpolished unpainted metal i think thats what the bw champs arena floor is made off the paint would provide traction

The floor is dusty metal.

Time for some panels on the outside I think. The scoop on the front is actually a cut down kitchen dough cutter, and the corners are recycled off the front of an old boiler.
Attachment 6311
Also, I got a bit carried away, and made some fancy stickers for the sides. I'm finding this whole thing really quite fun :roll:
Attachment 6312
I also tried the new drive out on the kitchen floor. I got myself tied in knots trying to set up the mixing on the DX6i. Ended up having it "2 stick style". Here it is having a little fight with some bathroom scales that were lying around. Think I'll be adding some little wheels or something at the front, because it seems to dig itself into the floor when it lifts something :talker:
https://www.youtube.com/watch?featur...&v=skFsgMuvapU

I might be able to help you out with the mixing. I had a little trouble with it at first too, but I figured it out on one stick :)

I think the problem is also related to the escs. I've got the elevon mixing on, and then gone in the "mix 1" and "mix 2" and set the ail-ele / ele-ail to 100% so full forward gives full power. However when turning, itseems to want to give more than 100% to either of the channels, which causes one of the escs to cut out. This only happens when turning full right (left motor is cutting out so it just stops). Turning left it behaves just how i want.

Turn off elevon mixing. You want one mixing method or the other not both.

Ok thanks. Just tried again with elevon mixing off, but no success. I've tried playing about with the settings, but the best have managed to get is:
Mix 1
Elev - Aile
Rate L +100% R +100%

Mix 2
Aile - Elev
Rate D -100%. U -100%

Does that look right?

Again, the problem is when I start pushing the stick diagonally up/right and down/right. It works fine with small inputs, but then cuts out when I get to about 50% or so travel

It's been quite a while since I updated this, so I thought it was about time I show you more of what I have been doing experimenting / evolving / attempting to generally improve Catalyst. I was thinking of doing an update after I'd actually been to some event with it, but lord knows when that may be, so I may as well go for it now. :talker:

One of the large problems that I had was getting it within the weight limit, and then having enough weight to put some meaningful armor on it. I had already gone down the road of drilling holes, which looked promising until I realised how much this had weakened the chassis. This prompted a bit of a redesign where I switched the lifter design from 4 bar, to a more standard setup, and shortened the whole thing by around 30mm:
Attachment 6437
This shortening meant that the servo for the lifter had to go on the underside of the "lid", but after putting it all back together, and treating myself to a small sheet of Grade 5 titanium for the scoop, it looked like this:
Attachment 6438Attachment 6439
Adding the rear panel (also made from my old boiler) plus the lower weight at the front really helped the maneuverability, and it seemed much more nimble to drive. However having this design of lifter meant that it would not self right with a wedge shaped back, so I decided to move the battery to the front and make the rear flat HDPE, which significantly helped the weight situation:
Attachment 6440
Also neatened up the front:
Attachment 6441
Now with ample weight to spare I was actually able to add some top panels, and after an excellent suggestion on the wheels:D, changed to some orange Banebots ones:
Attachment 6442Attachment 6443
Paint and stickers and it sort of feels like its done:roll:.........for now anyway:
Attachment 6444Attachment 6445Attachment 6446

Looks fantastic - can't wait to see this at an event sometime.

looks like a propper little tank at the rate beetles are popping up the champs will be a long day

Really love this robot, nice work!

Thanks for the love guys. It is my firm intention to actually make it some sort of live event this year, if I actually made New Years resolutions, it would be that :roll:. (yes I know we are already in February, haha)

One other, and the most recent addition has been a new speed controller courtesy of Rapidrory. I got myself one of the Beetletwo escs, and swapped out the pair of botbitz ones I was using to use as spares in the future (the spare parts pile is growing!)
Attachment 6447Attachment 6448

I realised my mistake after taking the photo, almost forgot to disconnect the BEC!
I have to say I'm quite impressed with the esc, it has on board mixing already set up which works really well and I'm really happy with how it drives now. Plus I can possibly run a larger battery in the future as it can take up to a 6 cell (!) LiPo. Think I'll just stick to 3 cell for now.....

Live Event Update

So the big news is that I made it my first live event this weekend! I made the trip down to Burgess Hill with Catalyst to finally find out what this roboteering lark is all about. Overall it was a fantastic weekend, great fun, and it was awesome to meet so many friendly new faces that form part of this community. I also got the chance to check out many lovely machines (of all sizes!).
As far as the beetle competition goes, I arrived full of optimism about how Catalyst would perform, and to a certain extent it actually really exceeded my expectations, (ignoring the actual outcomes of the battles, but we'll get to that!). The only real change to my last post was I had a few grams of weight left, so I swapped up to a 4s LiPo before the day, because....you know more......is better ;). As it happens, I was lucky (or should that be unlucky) to go up against some seriously well made and expertly driven bots.....

(Credit to Gareth for these videos)

Fight 1 - Catalyst Vs Tempus
https://youtu.be/82oGXjz8QaI
So my first fight ever turned out to be to the eventual winner to the tournament! Tweedy's vertical spinner really was something else, and this was over pretty quickly. 3 hits and a sheared servo motor shaft left me KO'd, but luckily nothing else major! This was when I realised how serious the wedge war is in this class, and despite the front being dead flat on the floor, it wasn't enough. So after swapping the servo, and being kindly lent a sharpening stone (cheers Tweedy!) I quickly attempted to put a better edge on it.

Fight 2 - Catalyst Vs Inertia B2
https://youtu.be/v_EpjISU0Vg
Another nasty vertical spinner, and this fight didnt go a lot better. I feel like I spent most of the fight flailing around trying to avoid Will's weapon after what had happened with Tempus. This time there was one moment where I was briefly on top, and pushed Inertia towards the pit, but it was not to be as the next hit sent me cart-wheeling over the arena wall having parted company with my carefully sharpened wedge blade!

Fight 3 - Catalyst Vs Incomplete Control
https://youtu.be/CbylZtrF0AQ
Day 2, and after discovering I had ruined another servo, I had another generously forced into my hand for my last fight by Craig (Snappy). I screwed my blade on again, and was ready to take on Rory's brilliant Super-nippy-hooky-bot! This was easily my best fight, and everything was working surprisingly well, even after the hits it has taken the previous day. It even managed to get a couple of lifts in, but really I.C. was too strong an opponent. I got pushed to and fro, really it was only a matter of time before I was plopped in the pit!

Fight 4 - Annihilator
Ok, so there was one more fight, but I cant seem to find a video for it. In summary, 6 (I think) robots and carnage. I was eliminated first and then almost died laughing watching an RC toilet almost take the win!:rofl::rofl::rofl:

So that was my first robot fighting experience, and I'll definitely be back at another soon. Big thanks to Dave Weston and Gareth Anstee for organising everything beetleweight, Tweedy and Craig for their help, suggestions, spares, cheery banter, and general entertainment, and everyone else for being generally friendly and welcoming.

Jimmy

Man, well played indeed! Definitely a tough little machine you've made. Have you got any ideas about stopping that servo getting broken so easily?

was fantastic meeting you Jimmy, hope to see you and the robot again soon! :)

IC is a git, great pusher, and yes, spinners are murderous.

Quote:

---

Originally Posted by R9000

Man, well played indeed! Definitely a tough little machine you've made. Have you got any ideas about stopping that servo getting broken so easily?

---

Cheers! I was a bit daft and made the linkage direct, I wasn't expecting to have it so violently forced open! it needs a servo saver or something. I think I'm going to experiment with some gear motors next, and make it so an arm pushes the lifter up without being actually connected to it , and a torsion spring holds it closed otherwise.