Ratatoskr Build Diary. (Featherweight)

[Outlaw]

I may have to look into that as an alternative, though I was never any good at systems and control. But if it's as simple as you say it is, then I might give it a shot. But do I need a BEC to go with it though? And if so, what'd be a good BEC to go with... 3 of them? (One for left, one for right and one for weapon.)

As for the ESC, I have it in my little box of electrical stuff, but it's never been used, which is a good thing. All the information about it is on here. The only time I opened it was to check if everything was in it, so it's pretty much near mint condition, haha. Once again, I'll have to confer with my mother so she knows what I'm doing.

[Roboteernat]

https://www.dimensionengineering.com...bertooth2x12rc is the specs for a sabertooth - Outlaw is this the one?

The TZ85s are good, will have a go at programming one in a bit, but if you wanted to go down this route im sure someone could program them for you if you pay the cost for them from hobbyking.

the BEC would only be needed IF the esc do not have it, so depending on what you do with the esc you may not need to buy a BEC.

The BEC would fit after the jumper and fuse. May have its own fuse depending?

[Outlaw]

"Built with imported N-Channel mosFET's and an ultra fast Atmel MCU & heartbeat make this a high performance ESC with excellent sync capabilities. This ESC has a 5A SBEC for solid reliable servo power." - From the Hobbyking website.

So it has a SBEC, is that the BEC we're talking about?

Also yes that would be the one, thank you for pulling through again Nat.

[Roboteernat]

SBEC is a 'Switching BEC' meaning the electronics are capable of running from higher voltages, supply more amps (ie run more stuff from them - servos electronics etc), generally do not heat up as much as a linear BEC or UBEC and have a clean reliable output.

[Outlaw]

Oh nice. Then that's more than likely going to be my go to then. I'll either have to contact Ellis and see if I can get two more from him. Failing that, I'll have to give it a shot myself. But I'll have to wait til Monday for that.

[daveimi]

The sabertooths have a bad rep but they were ok ish whilst i used them. Literally just plug and play. No soldering, programming, messing about. If you don't order one, can heavily recommend other dual controllers. Tz85's are fashionable, but such a faff.

[Outlaw]

So me and my friend Sid has made more progress on Ratatoskr today. Had to cut out a couple of holes in the spines of the robot, so some of the wiring is going to be underneath the robot's axe mechanisms. Which isn't too bad as it's more than likely going to be covered up with some more HDPE, weight allowing.

The other two ESCs came from Gary Cairns, who really pulled through with them, super speedy delivery too, would recommend him for deliveries and such, as well as quality products. Yet to test them out, but as soon as I get the drive motors wired up to them, I will definitely give them a trial run and such.
On that topic, I also bought a futaba y-lead for the R/C wiring so that one signal can be split up into two... just a question of if I need to do a mix job on the day of testing, but that'll come around when it comes around.

But now I have even MORE questions... GAAAAH...

So first on the agenda... Battery wires. So one of the batteries have to power the drive motor ESCs. Would creating a Y-lead set be the best way to do so? Or is there a better way?

Also the wheels... What's the best way of making them? Or are there any better alternatives? I need wheels that're 12.5 cm in diameter. And are able to be secured onto the axle of the motors without any wobbling at all. They're just typical 18v drill motors from eBay, haha.

I also have doubts about using aluminium cans as a skid plate. If I cut them out, made them safe to handle then used them as the skid plate, would that work? Or would I have to spend some more money on buying some nylon? Not that that's a problem, I can always nip down to directplastics haha.

Any help in those few areas would be much appreciated.

[Ocracoke]

So first on the agenda... Battery wires. So one of the batteries have to power the drive motor ESCs. Would creating a Y-lead set be the best way to do so? Or is there a better way?

Yeah, I'd use a Y-Lead in this instance as it creates a independent part that you can add in the wiring for the drive system removable link. I'd use something like a XT60 Y-Lead as the connectors are super tight (not something you want to come undone during battle).

I also have doubts about using aluminium cans as a skid plate. If I cut them out, made them safe to handle then used them as the skid plate, would that work? Or would I have to spend some more money on buying some nylon?

I'd probably go with the Nylon here. You could add in several layers of cans to strengthen it but I fear it would buckle when suitably hit. A single block of Nylon (or HDPE, although that does scratch fairly easily) would be more resistant.

[Outlaw]

I figured as much. Thank you Michael, much appreciated. I wouldn't mind using the aluminium because A) it gives me a chance to try and do some metalworking, even if it's just aluminium, B) it gives me a reason to use the cans of diet cola and energy drinks I have lying around, and C) if everything goes well, I can just remove, hammer out the kinks and put it back on whilst the batteries charge and the typical damage checks haha.

Well, as of right now, I'm really sketching out about the wheels. I'm not sure if they're even on properly, like how cockeyed it is when it's mounted, how to keep it on the axle itself, how to add the rubber to the wheel itself, and such. The wheels you see on the bot right now is what I cut out of that sheet, as explained a couple of posts/videos, and honestly, the quality of my cutting is absolutely friggin' shocking.

My questions are... what's the best way of mounting wheels to the drill axle? Is there a better way of cutting out the wheels? Because they need to be at least 12.5 cm to 13 cm in diameter. Or are there wheels that size that I can slip onto the drill without problem?

[typhoon_driver]

Tony Smith was machining up sets of wheels for featherweights I believe. Check out either the commercial or for sale section.

[Ocracoke]

I figured as much. Thank you Michael, much appreciated. I wouldn't mind using the aluminium because A) it gives me a chance to try and do some metalworking, even if it's just aluminium, B) it gives me a reason to use the cans of diet cola and energy drinks I have lying around, and C) if everything goes well, I can just remove, hammer out the kinks and put it back on whilst the batteries charge and the typical damage checks haha.

I mean, you could use the cans in a layered fashion (though it would have to be well layered). However, it is less work to maintain something like Nylon as a skid plate. The Honey Badger has just had a door plate put on the front of it which is made out of Aluminium and it is fairly soft, my metalworking hammer can easily bend it with a single hit but it is supported by the HDPE wedge underneath it so if you wanted to go down that road, that could work.

My questions are... what's the best way of mounting wheels to the drill axle? Is there a better way of cutting out the wheels? Because they need to be at least 12.5 cm to 13 cm in diameter. Or are there wheels that size that I can slip onto the drill without problem?

I'd check out the commercial section as Gary suggested but I took a look at fleabay and maybe something like this if you were going to use a chuck? http://www.ebay.co.uk/itm/M8-Thread-...-/362027342339

The wheels you see on the bot right now is what I cut out of that sheet, as explained a couple of posts/videos, and honestly, the quality of my cutting is absolutely friggin' shocking.

Can't be as bad as mine, one side looks absolutely hacked to ribbons just to get a kinda/sorta reasonable shape on it.

[Outlaw]

I mean, you could use the cans in a layered fashion (though it would have to be well layered). However, it is less work to maintain something like Nylon as a skid plate. The Honey Badger has just had a door plate put on the front of it which is made out of Aluminium and it is fairly soft, my metalworking hammer can easily bend it with a single hit but it is supported by the HDPE wedge underneath it so if you wanted to go down that road, that could work.



I'd check out the commercial section as Gary suggested but I took a look at fleabay and maybe something like this if you were going to use a chuck? http://www.ebay.co.uk/itm/M8-Thread-...-/362027342339



Can't be as bad as mine, one side looks absolutely hacked to ribbons just to get a kinda/sorta reasonable shape on it.

Well, that's kind of the point I was going to go with, just have a small ridge on the front of it to act like the kind of thing ol' Firestorm had, so that nothing got under it, and have a home hammered aluminium plate under it as well to act as the skid plating. I know it's a little confusing, that's more to my poor sentencing but it sounds good in my head.

As for the wheels, if I cut them any more, they'd look like sliced hardboiled Ostrich eggs. XD

ANYWAY, as a little bit of an update without a video, I managed to get some soldering done without burning the hell out of myself. Got the drive motors soldered up to them and working on the Y-lead. Though one of the links I think I may have to redo, and I don't think my soldering is exactly up to scratch either. Last time I did soldering was when I was... 14? 15? I can't remember. Wish I didn't flunk my systems and control, haha.

[Ocracoke]

Got the drive motors soldered up to them and working on the Y-lead. Though one of the links I think I may have to redo, and I don't think my soldering is exactly up to scratch either.

I can tell you from bitter experience that if you don't think your soldering is up to scratch, go over it again until you are happy with it. You do not want dodgy soldering/electrical connections to hold you back.

Whilst at Robots Live! at Grantham, I decided before the Featherweight Melee on the Saturday to charge both of the drive batteries. When I put the batteries back into The Honey Badger and checked to make sure it was still running properly, one side wasn't playing ball at all. After a sleep, I realised the soldering I did to get the removable link installed just didn't work and the crimp connection to the battery hadn't been done properly.

Behold (apologies for the blurriness):

oh_dear.jpg

I can't imagine why I thought this was OK. Re-soldered + re-crimped it on the Sunday and it was fine... until after the event :P Point is, if you don't think it is OK, work on it again until you are OK with it.

[Outlaw]

Well, needless to day... I fudged my soldering all to s*%t... So that means I have to redo every single solder... Ah well, I'll have to do that tomorrow if anything. Just need to learn how to tin things properly.

[Outlaw]

So, no pictures or videos this time again, but I managed to get most of the soldering done for the drive motors, with a lot of use of the files to get rid of solder overflow, and a watch/glasses sized screwdriver to push the little buggers into the bloody housing of the links. Not only that, I've managed to make a decent safety link on top of it all, everything is fairly secure too.

Now for the battery... unfortunately, it didn't come with EC5 connectors so I'm going to have to solder that up myself, and then after that, I'm going to have to make my own charging lead, as the ones that came with the charger were xt-60's. So that's a job for tomorrow. And as soon as I have a charged battery, I can do a dry test of all of my wiring, and make sure that when I spin the wheels, the bloody motors won't unscrew and let the wheels off. If that does happen, I'm gonna have to figure out what I'd have to do to make sure they stay on...