RogueTwo Robots

[RogueTwoRobots]

Event Report

So another championship has come and gone and this year's wasn't quite as successful as the previous one. But despite that I had an absolute belter of a weekend, thoroughly enjoyed every minute of it (with the slight exception of a rubbish tent and sub-zero temperatures when camping).

As for the robots:

Drumroll 2 got off to a good start, winning its first fight by knockout. But when doing a victory spin, the gyro effects put the robot on its side for a few seconds before landing upside down close to the arena wall. I then forgot to activate the Scorpion XL flip function and moved the stick backward to pull away from the wall but ended up driving into it. The collision caused the bolts that were holding on one of the teeth to shear and the tooth flew off. Upon inspection in the pits, the shaft of the brushless motor was also bent as was the mount.

Some frantic repairs were effected and the robot went into its next battle with 4 4 Toon and Asgard but not at 100%. To make matters worse, when I armed up I discovered one wheel wasn't working so things weren't looking good. Asgard was suffering ground clearance issues and the battle turned out to be a rather damp squib, with 4 4 Toon winning by knockout after roughly ten seconds and very little movement.

Third match was against Tiny Toon and Asgard and the wheel was fixed (smoking drill motor was the problem) but the weapon was poor and gave up the ghost early on which left me in a pushing match with Tiny Toon (Asgard had earlier been pitted). The Toony one then pitted me and claimed a knockout.

With eight points from the league, Drumroll 2 fell short of a guaranteed place in the top ten and had to go into a five-way melee with other robots tied on eight points to claim one of the three remaining places. But that was a bit of a fail as Drumroll was in the pit within 30 seconds and out of the main competition.

It then went into the Annihilator with Captain Scarlet, Seraphim, Aftershock (dressed as Whirlwind), DB5 and Nasty Spinny Thing and made it all the way to the final. It was a close match with Seraphim driving in and out of the open pit several times and Drumroll losing its weapon halfway through. Eventually it was awarded 2-1 in favour of Seraphim, mainly due to the failure of the drum on my part. Having rewatched the match on video though, I feel Drumroll had the stronger case for winning, even with the weapon failure, but the loss will be a good motivator for when it comes to improving the machine and eliminating reliability issues.

So that was that for Drumroll 2's first outing. It went in a whiteboard at the end and promptly got humped by Boner and OOTA-ed by Beauty 4. But despite coming (I think) 12th in the main competition, I'm overall pretty happy with the robot. The drive is lovely, fast and controllable and while it seemed to be lacking a bit of pushing power, that might improve when it has got more weight pressing down (currently got almost 4kg spare).
The main area for improvement is the drum. The M5 bolts securing the teeth just weren't strong enough for the impacts involved. If I'm to keep that drum, it'll need to have channels milled in the ali so the teeth can be recessed and supported, and the bolts will have to be enlarged to - probably - high tensile M8s. With no competition lined up, and therefore no rush, the most likely scenario is a return to the welded ring-teeth setup on the original drum. That gave and took a bashing in a lot of Boner's fights but it's still holding up well from what I saw. The ring-teeth are also more deadly than the bars so would be a definite improvement. After that, some hardox armour and a rear wedge (although I did like its shape without the wedge) and some lithium batteries. I've also been fortunate enough to have been given the old gearbox and a motor from 360s disc setup as well as a reversible speed controller so that will be getting incorporated into the robot as the Align model is a bit damaged and sounding a bit rough. Many thanks to Dave Moulds for that.

On to Carcinus. It was just signed up for whiteboard fights but entered most fights that had spinners :P
In one fight it got flipped out the arena. In another fight, it got humped by Boner and some of its innards fell out into the arena. And in the subsequent fight, after having the claws removed and being patched up, it got completely ripped open by NST and spilled its guts everywhere. Chassis was a write-off (thankfully, disliked it for a while) but all the internal components have survived minus the receiver which needs a little bit of soldering, or just substituted for a £10 replacement if my soldering skills aren't up to it.
So for that, there is a complete rebuild on the way. I'm going to change to the same RG1000 material I used on Drumroll 2 and make it a little more compact. The linear actuator is going out (and probably for sale shortly) and incoming will be a homemade threaded rod/motor setup. The claws will also have a little length taken out of them as the current fully-open position is unnecessarily large and they don't fully close so they'll be made a little shorter. All in all it should become a slightly more effective robot.

With regards to other robot developments, I would ideally like to get Drumroll 2 and Carcinus up to full running spec and then take a break from featherweight building to move onto the lighter weight classes (mainly kilobots and possibly an ant) but I've still got a Bosch 400 kicking about that I would love to try and put into an electric axe featherweight so there may be one more feather to come. We shall see.

[RogueTwoRobots]

[jonny]

wow nice! and merry christmas to you to

[calumco]

fixed it all then jamie?

[Mouldy]

I've also been fortunate enough to have been given the old gearbox and a motor from 360s disc setup as well as a reversible speed controller so that will be getting incorporated into the robot as the Align model is a bit damaged and sounding a bit rough. Many thanks to Dave Moulds for that.

Note;

The titanium output shaft will need securing at the back for your application- Easiest way is to drill and tap an M4 bolt with a washer in to keep it captive onto the rear bearing- you should then be able to slide your small pulley over the output shaft thread and butt it up against the flat, If you file a recess into the rear of the pulley boss it would make a real secure connection. then you can just bolt it down with an M8 nylock...That should make sense to you if your looking at it.

I think it was a 1.2:1 reduction.

also if you choose to use a different motor- there are other holes drilled on the correct PCD to accept most brushless motors.

[RogueTwoRobots]

fixed it all then jamie?

Lol, nope. That pic was taken back in March. Plans are under way for the rebuild but I can't really do any robot work until I start earning some dosh :P

Note;

The titanium output shaft will need securing at the back for your application- Easiest way is to drill and tap an M4 bolt with a washer in to keep it captive onto the rear bearing- you should then be able to slide your small pulley over the output shaft thread and butt it up against the flat, If you file a recess into the rear of the pulley boss it would make a real secure connection. then you can just bolt it down with an M8 nylock...That should make sense to you if your looking at it.

I think it was a 1.2:1 reduction.

also if you choose to use a different motor- there are other holes drilled on the correct PCD to accept most brushless motors.

I've not got round to dismantling Drumroll from the champs and haven't yet tried the motor to see the spin-up but I have had a good look at the unit and can follow what you said, with exception of the M4 bolt/washer part.

I know the titanium shaft is currently capable of just being pulled out of the gearbox, but I can't visualise the area that you're referring to for drilling and tapping a hole, or how it will hold the shaft in. When it's pressed in all the way, the rear of the ti shaft rests and rotates in the rear bearing so I was just planning on having something (small bit of plastic attached to the chassis) at the front of the gearbox/output of the shaft pressing against it just to restrict any movement and prevent the shaft from coming out. Or is that pretty much the same as what you were meaning?

[Mouldy]

If you look at the gearbox from the back- the plate the motor bolts to, you can see the rear end of the titanium shaft in the bearing? Just drill and tap what you can see... so the bolt goes into the shaft with a little washer (you might need to make your own) sitting on the rear of the bearing... pulling it against it. (so the washer needs to be just over the size of the diameter of the shaft).. i cant remember of the top of my head what the size of that hole is... if its only 8.2mm or something, take the gearbox apart, tap the bearing out and drill it out to 10.5mm and replace the bearing. you could then use a washer thats got a 4mm ID and a 10mm OD.

If you do what you were planning the pulley or whatever's next to the plastic will probably melt the plastic due to friction eventually... remember it will be spinning at a peak of 28,000rpm (@24v) ...thats alot of frictional heat.

If its easier get a picture of the gearbox from the back (showing the motor) and ill draw what i mean on paint and post it on here for you.

[calumco]

lol u mean you can't start your rebuild untill i've made pinsor 2 for u to make a similar design :P aha

i actually started it about 2 months ago but havn't had time to do anything else to it, its just a base with 4 drill motors so far but going for a vertical claw this time

[RogueTwoRobots]

Dave, I get what you mean now. That's something I'll probably need to get done for me as I've not got a decent enough tool setup at home for drilling/tapping titanium, but there's a lot of machine work I'm going to need to get done on it anyway (I'm leaning towards getting an ali chassis made) so I'll add that to the list. Definitely a much better option as I hadn't taken the frictional heat into consideration.

Calum, for once I'm not copying your design
I've explored the vertical grabber/lifter route in the past, and got a basic CAD started but never progressed much from there as I turned my attention to making the old Drumroll not suck. But the design for Carcinus 2.0 is already close to being locked in, so shouldn't be any risk of me plagiarising your design.
Should be interesting though, this version will actually move more like a crab

[calumco]

cool, look forward to seeing it (Y) FYI thou not like i was ever bothered about u making a robot styled on my design, i sorta stole the design off kan opener first lol

with mine im just deciding whether to go down the route of having serous crushing power or down the route of grab and lift will see i spose