Ion (Beetle Weight Drum Spinner)

Hey all, decided to make a build diary to log updates on my beetle, even though it’s been around for a while now. The robot body is CNC milled out of a billet of 6082 aluminium, with an aluminium drum using M12 high tensile cap head bolts as teeth.

Been working on a few things, mainly making the transition to brushless drive to save weight and improving the weapon a bit. The brushless drive motors are just the generic SK3 ones, was looking at some other motors to try but they just seemed the best for the job out of the hobby king selection. I flashed some 12a blue series ESC’s to use with them and they seem to work alright (thanks R9000 for the great guide on flashing!), just need to fix the pinions onto the shafts and mount them to the 1000rpm gear motor gearboxes, I’m slightly afraid the pinions will keep coming loose and make the drive really unreliable but I’ll have to see if the Loctite I have is strong enough to keep them in place.

As for the weapon, it worked fairly reliably at the beetle champs in November so changing it was probably a bad idea, but I’ve upped the voltage from 3S to 4S for more power and speed, as well as upping the motor pulley size. Also got bored and decided to make and fit my own 4mm silver steel shaft to the motor to add a bit of strength, and drilled a hole in the outside of the robot to have bearing support on both sides of the pulley.
Attachment 5831

Bearing hole came out slightly bodged but just about fits, when I first span the weapon up the bearing flew out and there was some friction in the system somewhere so it needs sorting out a bit. Pressed the bearing further into the side bulkhead and added a circlip and some Loctite since the test, so the bearing should be more secure now.

Changed a few other small things since the beetle champs, angling the HDPE outside armour to stop the robot getting stuck on its side, which it did a lot at the champs lol, also adding nuts to the bolt feet rather than nylon spacers, which shouldn’t shatter like one of the nylon ones did.

That’s all for now! Cheers, Andy.

With regards to keeping the pinions on, I used to use loctite and they were forever coming off. I switched to 2 part Araldite and haven't had a problem since... best to rough up the shaft a bit first; I used some wire cutters to basically knurl it.

I found that the weight benefit of brushless only really works if the drive runs off the same battery as the weapon... otherwise fitting a second battery wastes most of the weight gain.

It's all off one battery, ill just turn down the power going to the drive on my transmitter. Also thanks for the tip with the Aaraldite i'll give that a try

If you do mixing on the TX, be aware that the channel are turned down before the mixing happens, so if both sticks are down at 50%, it can mix back up to 100% depending on where the sticks are. I've seen plenty of motors blown based on the assumption that 50% travel adjust limits to half the voltage. If you're using SimonK you can probably adjust the settings to limit it to what you need, that way regardless of what your mixing is doing you can't go over the max.

Ive not done the maths, but won't the RPM of the brushless motors be considerably higher than the brushed, so you'll need a different GB (one with lower final rpm) to compensate?

I use the SK3s on 2S with the standard gearboxes for drive in FL... it's a bit faster, but that's a good thing :P

Yeah it'll definitely be on the fast side since the wheels are 60mm too, the speed should be helpful for bite since the drums geared fairly high now, if its too fast, I'll tweak the transmitter settings again :)

Also tah for the heads up Rory, I'll keep that in mind.

Do you draw the stuff in the computer and then send off to get it made or machine it yourself? I really want to learn cad and cnc but not sure where to start tbh. I know there's the usual free versions I suppose I just need some patience to sit and learn it.

Hey David, I use Autodesk Inventor, you can get a three year trial if you say youre a student on the website so might be worth looking into that. I design it and get it made elsewhere yeah, I don't have the equipment or skills to do the machining myself haha

Lol that's really cool. I've asked loads of questions to different people in the past gonna get summat n have a go. You going to any beetle events this year? Gonna start giving my beetle a refurb tonight.

Goodluck with it :) I'm going burgess hill and any other ones I can make it to really

I wanna go to Burgess Hill but it's a trek from Blackpool.

Hey all,

Had lots of fun at Burgess Hill even though Ion didn’t work quite as well as I would have liked, first fight the drum worked pretty well but the belt heated up and loosened, disabling the weapon for the rest of the competition since I didn't have any spares.

Here’s a link to the first fight where the drum worked, I was pretty satisfied, even though we lost haha. Won the next fight even though my tag-team partner and I both had dead drums then lost to Gonzales/Wodge again in the third fight.

https://www.youtube.com/watch?v=5AAmTH8G6rU

Didn’t bother with the brushless stuff in the end as the pinions came off the motor shafts when I tested it, so just resorted to the safe brushed option which always works well.

Will probably go to Reading in a few weeks so I’ll start thinking about upgrades and such.

Cheers, Andy

So, did a bit of work for Reading on the beetle..

Brutally attacked the lovely milled aluminium with a hacksaw and cut it into two pieces, drilled and tapped it to bolt it together..mainly because it was so unpractical with changing belts etc. Three bolts are endtapped at the back and two go into some M4 threaded bar at the front behind the drum. I also changed to HTD belts so hopefully they won't stretch like the old ones did.

Heres a picture of the robot in its fairly bodgey state!

Attachment 5957

Cheers, Andy

Great event at Reading, cheers to Dave and Robots Live for making it happen!

Pleased with how the robot performed overall, got to the semi final and lost to Incomplete Control, then lost to Ash 2, resulting in fourth place.

Got my first three fights on video, thanks to people filming for me :)

First round fight, fairly uneventful

https://www.youtube.com/watch?v=g0KjQQkZ1-o


This one was definitely my favourite, but resulted in a bit of damage. The impact from the last hit killed the brushless motor for the weapon, also got a few nasty chunks out of the aluminium

https://www.youtube.com/watch?v=etZF_pRycwQ

Was definitely losing this one until Limpets link came out

https://www.youtube.com/watch?v=-1-lFxTWAsQ

Probably won't do much to the robot for whatever event I go to next, just minor fixes and its ready to go again.

Cheers, Andy

Very cool. I never saw Limpet's link fly out, was it on impact or somewhere in the middle of him pushing you against the wall? Did it just get shaken loose?

i actually have no idea, could be any of those haha

Been working on Ion a bit for Cannock and the champs later in the year

optional wedge for fighting wedges and things..

Attachment 6202

Also new foamy wheels as the banebots lacked grip and were probably the reason I had to replace 2 motors in the robot after the impacts against First Left because they don't absorb as much shock.

Also ordered a new motor for the weapon to spin the drum a lot faster than before, also got some more power behind it. Going to use the new motor with a 40a Blue Series ESC reprogrammed to use BLheli for better response times and better spin up. This upgrade is probably not that needed but should be fun and interesting

Attachment 6203

Big motor is big

cheers!

Hi Andy.
Ion looks really cool, is the new motor a lot heavier than the old one? If so, do you think you will you have to find some weight to lose elsewhere in the bot? I guess that depends if it is close to the weight limit already. Just curious about the process really.

It was very close as it was but the wheels are lighter now and ive done away with the side armour since it won't fit around the wider wheels and I've never needed it until now so just hoping for the best really lol

Hey all, been a while, mainly due to not doing much work on the beetle and a lack of events lol.

Had a fantastic time at Burgess, thanks to the Robots Live team, dave for setting up his arena and gareth for running the beetleweight competition!

Upgraded Ion with a new drum that was lighter, had better KE and accounted for countersunk bolt teeth to increase bite quite a bit..it worked pretty well, the weapon being great and the drive letting it down due to some settings in the transmitter somewhere I think?

One hit in testing on tin metal did this, I was pleasantly surprised at the time

Attachment 6581

Got third place overall after losing a brutal fight against Tempus in the semi final.

Vids of my four competition fights:

https://www.youtube.com/watch?v=tq7J_DZuzM0

The wedge worked as planned, giving me an advantage against pushy bots, can tell the drive is really dodgey in all of these fights.

https://www.youtube.com/watch?v=GXHmXzAd1rU

https://www.youtube.com/watch?v=X5crHeP2n28

https://www.youtube.com/watch?v=NaWMZhQKsZI

Got some big chunks out of the armour and weapon in this one, was close to OOTAing him twice sadly, brilliant fight.

Attachment 6582Attachment 6583Attachment 6584

First pic shows self inflicted damage in my fight against fat lip, I can only assume the teeth weren't big enough and the opponents wedge dug into the alu behind. The second pic shows the MASSIVE gash from the Tempus fight which put the drum significantly off balance, impressive stuff!

May or may not have had a fun fight against the RC toilet after the competition and set fire to myself and burnt at least 2 electrical components..well pass over that for now ;)

Cheers, Andy

Looking good Andy! The power of beetles has ramped up since the last events I was at (2015 Champs), gonna need to get back in the game soon :)

That's awesome. Do you know when the next beetle event is?

I think Dave is taking it to Manchester if there is enough demand, I will try and get Ion ready for that just in case but got a whole feather to build so not sure yet lol

Hey all, quick report from Grantham beetle comp.

There were only 5 competing beetleweights at the event, including 4 spinners and 1 lifter, making for a pretty brutal round robin competition! Congratulations to Sam with Swag Demon taking the overall win.

Videos of Ion's fights in no particular order..Lost two of the four fights by being beached on my own link when upside down which was a bit annoying, but the fights were fun either way.

https://www.youtube.com/watch?v=4PHc2pkX0Cc

All four of the fights were pretty short and explosive, I guess whats what happens when its spinner vs spinner over and over :D

https://www.youtube.com/watch?v=glc-a9d5ipY

https://www.youtube.com/watch?v=alMcnLnvw1I

https://www.youtube.com/watch?v=2GY_GEbIz-I

Got a lot of chassis damage from this fight, but the internals are mostly intact. Time for a few upgrades including a new chassis for the BW champs in September! More progress on that when it happens!

Cheers, Andy

I was genuinely quite shocked when I saw how much damage Ion took against BFS, looking forward to seeing the new one.

SD isn't in great shape either despite the win, It's been running for almost 2 years now so hardly surprising, I'll be building a new chassis for the champs too, hopefully we get another drum off.

Yeah, work has started on new Ion, if we don't draw each other we'll have to organise a proper BW drum off ourselves, and hopefully this one will last more than one hit haha