Tormenta 2 - Build Diary

[Ellis]

Re: Tormenta 2 - Build Diary

Ours have never come with two plates... that's odd. We once put two in accidentally (don't ask) and it didn't like it at all, but I'll look into that tomorrow. Thanks.

I think it's simply the mechanical limit of a pin pushed into a hole, then loads of lateral force being put on it. If over the past 3 years it has been used and used and used, every time the drill changes direction hard the pins come under stress. So if we're lucky this is simply fatigue and we won't see a repeat with the newer gearboxes.

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Also, oddly, one of the pinions on the 18v motors has come loose. Ewan has very kindly sent out a replacement, and we'll try to get the current one back together. I don't really have an explanation as to why it came loose, Ewan said he has never had a report of one loosening before, so I can only assume it was a dodgy one from purchase. Bit of a shame, as if we can't fix it we can't have any more test drives until we get to the UK and put in the new one, but it could be worse.

[RogueTwoRobots]

Re: Tormenta 2 - Build Diary

I have a replacement gearbox to put in. Don't know what we'll do if they continue to break...

Stock up on GR02 drill shafts and replace them instead of the gearboxes.

If you take the shaft circlip off and remove the ball bearings, you can stick a screwdriver in the end of the shaft (careful not to damage the reverse thread) and hammer it out through the gearbox housing with relative ease. Hammer a new one in its place, then refit the bearings and circlip.

Done this many times over the years and not had a problem. A much easier solution now that Ewan stocks the shafts. Managed to 'make' six 12V drill motors the other week from old empty gearboxes just by stocking up on the shafts and motors

[Mouldy]

Re: Tormenta 2 - Build Diary

This sounds like a problem that could be fixed with a tig welder... You got 4 sets of plates with pins that have fallen apart? If so bring them along to the champs, I'm sure if you ask grant nicely he'll weld them up on one of the nights.

[Ellis]

Re: Tormenta 2 - Build Diary

Feels like we've got more than 4 sets! I'll bring them along. Might as well weld any good ones too, and just avoid the issue.

Also Jamie, I've replaced shafts in these a few times, I just avoid doing it if possible as it feels quite invasive, especially if I have an alternate complete gearbox available. For the future we're going to try and ditch the reverse thread screw locking method and go for some form of grubscrew setup, the GR02 shafts will be perfect for that, with their flats. Had already crossed my mind to do that ahead of the champs but I don't see why the pins on those shafts would be any stronger, I believe they're identical. One day we'll run out of old drill shafts, I'll go Gimson shafts then!

Crossing my fingers that the failure we had was because it was an abused gearbox, and not because we're still putting too much stress on the pins. Don't see how we can be, to be honest, we're no longer overvolting...

[PJ-27]

Re: Tormenta 2 - Build Diary

Reading this thread is not giving me any confidence in my Argos 12v drills....

[Ellis]

Re: Tormenta 2 - Build Diary

If they haven't been used in a silly overvolted setup for a year then they should last perfectly well. Replace the plastic gears with metal ones, run them at their nominal voltage, and they should last years. We're just pushing their limits way beyond reason.

[mattsdragons]

Re: Tormenta 2 - Build Diary

I seconds Ellis on that, as long as they are on all metal gears you can run them all day and not have a problem

[PJ-27]

Re: Tormenta 2 - Build Diary

Erm, yeh they're not

[mattsdragons]

Re: Tormenta 2 - Build Diary

Can buy some metal gears from ewan, about 4 quid for a set of 3

[Ellis]

Re: Tormenta 2 - Build Diary

Well even the plastic gears should last some time if you're not overvolting and running them hard (big wheels, powerful batteries, harsh driving, etc) but they will fail eventually. The resulting plastic mess will go all around your gearbox and get stuck in the grease, and the only way to ensure they run smoothly from then is to strip them completely (toothbrush + warm soapy water, in our experience). Any plastic bits left inside and it'll never run smoothly.

I'd save yourself the whole hassle of that and just buy some metal gears from Gimson. It's worth the money in time spent having to mess with the gearboxes once the nylon gears fail. Plus there's a chance that them failing will cause the gearbox to lock up, and you could burn a motor out... point is it starts costing money quickly!

[PJ-27]

Re: Tormenta 2 - Build Diary

The issue is that BitzaWood was never intended to be a long term machine, so changing parts is a pain.
I'm just hoping it'll last the weekend then I'll make a proper version after.

[Ellis]

Thought you guys might be interested in this! Not long now!

http://www.youtube.com/watch?v=tWdrL43vF3k

[RogueTwoRobots]

Looking great Ellis, can't wait to see it at the weekend. And your journey, though longer, looks far more awesome

[Ellis]

Been a while since I posted here.

Tormenta 2 is kind of in limbo. It's not quite dead enough to justify moving on completely, but it will take quite a lot of work to bring it back up to 100%.

We were killing gearboxes as regularly as ever up until the last day of Yeovil. There, after discussions at the pub the previous night, James/Grant/Nick donated some of their modified drill shafts that they made up to run in their kitbots. We did three fights after swapping them in at Yeovil and another four at Colchester without a failure. Looks like Tormenta 2's drive is finally getting there in reliability.

However after that happy note we got a direct hit from Major Damage at Colchester. The hammer hit the top bars square, and in doing so it has completely marmaladed (that's a word now) the threads that hold the sprocket adapter Mario made for us last year onto the weapon motor shaft. That will need to be completely rethought, as the threads on the drill are literally no longer there, and retapping makes no sense as it'll fail in the same way eventually.

Moving on to the inherent flaws of our design, the robot needs to be a lot tougher at the front. To make it tougher, we need to claw back some weight. I don't completely know how we'll do that yet, but by changing a few things I think we can get about a kg extra to play with. That shall go into a nice hardox plate on the front, and anything else that can be reinforced.

Another flaw is trying to use chain for ratio reduction as well as simple transmission. If it were 1:1 we could just up size the chain (it broke constantly at the champs and Yeovil, constantly...) but that isn't possible. So we're going to try a belt and pulleys. That ties in to what we do about the weapon motor shaft being mangled. I'm confident there's a way, though.

Otherwise it's basically alright. The pros and cons of the robot are more or less balanced, so our plan is to give it one last burst of life and let it run from there until it can't. We'll be taking it to Germany in September (to try and win this time!) and if it lives through that, we'll put it in for next year's champs.

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Tldr; Tormenta 2 is in a state but we're going to give it one more lease of life, despite it being in a bad way after the latest trip.

[Ellis]

Well, that September trip never happened. Instead we went to the UK (just dad and I), more for family reasons, but as those who's hands we shook and who's bits of robot I used to make my beetle work will know, we got to the Deeside event with Gonzales. That's a different thread, though.
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I thought I had lost the fight footage of Tormenta 2 from Yeovil. It disappeared without trace for months, until a few weeks ago, when it was discovered on mum's PC... for... some reason. Either way, I just got around to uploading the fights.

You can see them near the top, here: http://www.youtube.com/user/TeamExpat/videos

Or, if preferred, the individual links, not necessarily in chronological order (can't make them links as it automatically makes them videos):
http://www.youtube.com/watch?v=f6CY-Fy2XA8
http://www.youtube.com/watch?v=Nro5Ii2J4SY
http://www.youtube.com/watch?v=PtIVjlbKWI0
http://www.youtube.com/watch?v=tDM6jMoEJyQ
http://www.youtube.com/watch?v=TcZCvt7BcNo
http://www.youtube.com/watch?v=g5oIwyhUqhU
http://www.youtube.com/watch?v=6Bor7DXCEB8
http://www.youtube.com/watch?v=Lu6Zdv4sv3Y

In robot terms this event was actually quite hard. Essentially every fight resulted in either a gearbox failing, or the chain breaking. Overall of course it was very relaxed, more people should go to the events held in Yeovil!

Anyway, I am very happy with some of the performances of the machine in the above fights. I think they're some of its strongest, which is odd, considering the robot got mauled just 3 days earlier at the champs. That scoop is some springsteel cement flattening whatsit from Wickes, properly bodged on. Yes, the enemies weren't super high end spinners, but still, this event showed us that the weapon concept works. Just thought I'd pop them up here as this is meant to be a diary for the thing. :P

These videos have refueled the want to get on and build Tormenta 3!