Team Health & Safety - First Time Builder

[daveimi]

"7.4V is waaaay too high for a yellow LED"

First world problems lol

[R9000]

Ofcourse there's a resistor in series. That's Page 1 in the Great Western-European Almanac of LED Soldering!

I am probably going to add other LEDs in the actual robot, just for redundancy.

Ah, phew. Sorry, it's just I've had LEDs explode at lower voltages than that. :P

[Zenith]

I might actually be coming to the point where it's starting to look like something.

You see, I seem to have picked up this rather frustrating habit of continuously improving the design during, or after, construction. This saw me do the usual Design > Cut > Assemble routine, but with an added "Gee that looks good... but it would be even better if - " which would lead to a repeat of said cycle.

So here's a timeline for you guys - I started off with this, the chassis from the last update:

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"Oh Gee, those front prongs just seem a bit flimsy. Why not beef those up?

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"That's better. Now the mounts for the wedge have twice as much plastic and twice as many screws. Approved."

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The beauty of interlocking construction occurred to me again - this H profile isn't held together by any screws (the nutstrips are bolted to single pieces of plastic but do not to protrude into others), but just by slotting the plastic together in such a way that it's snug. Once again I threw this through the room, and it didn't budge.

But then there was the matter of the back-end. That was going to be simply screwed on, but now I had the hang of interlocking stuff, why not go all the way?

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*sigh* allright then.

I made the side rails a bit longer, and cut out a slot big enough to accommodate both the back end and the wheel guards. This way, also the wheel guards would be locked in place.

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And wouldn't you know it, it worked. Not a single bit of glue or metal, and yet room-throw proof. Solid as a rock.

With all this going on, I also got delivery of some of the innards, which led to some weighing. First, the chassis, bolted up and everything.

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Oh ain't life grand. With wheels, motors, servo, ESCs, receiver and the like added the tally is 726g, which gives me about half of the weight limit left for, titanium top- and baseplate, wedge and lifter mechanism. Things are well and truly getting interesting now.

When it comes to the lifter though I'm still very much in doubt as to how it'll go about. I like being able to drive upside down, and if I were to join the Front Hinge Master Race that would be a more likely possibility than as a Rear-Hinged Peasant. Given the notorious amount of spinner evilness lurking around these lands I'd rather not open up my juicy innards to one of them every time I open it up.

Anyway, after some further deliberation I finally did a proper mock-up. using some paper cut outs as Titanium stand-ins.

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Don't be mistaken though - the end result will not be as much as a blanc canvas (or tabula rasa if you're posh) as this. When it comes to the theme, I'm very much sticking to the one discussed at the start of this thread. I've sketched a bit over the past week, and the retarded cackling spawned by my maniacalities disturbed my SO and sibling to such an extend I hope you Brits are going to enjoy the end result in two and half months.

Crikey it's just two and a half months. Best get going then!

[Zenith]

Hi everybody! Glad you joined us to celebrate in my radiant mediocrity! Yay!

Construction is slowly pacing along. First, I got the dimensions in for what is to become the primary line of defense: the 2mm grade 5 Titanium façades, here mocked up in cardboard.

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To me it seems a good idea to alternate wedges - this would be more of a design to face other lifters or rambots...

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...whereas this one has a more "WOMEN AND CHILDREN FIRST"-tone to it, inspired by Ziggy/Lucky. I'm aiming to have both setups available during the Euros, plus probably another 'ZOMG ZOMBIES'-wedge for a laugh.

Anyways, I seem to be fast approaching the point where I'm happy with the chassis, and the job is now to get the insides in proper shape. I mean, it's nice if I build a brick, but it'd be grand if it would move as well (and keep moving whilst we're at it).

This led to more soldering. The Euros require three main things when it comes to electronics - a power light (check!), a removable link (check!) and a fuse.

Now, I'll be squeezing in a 1300mAh 40C LiPo in there, so if my math is correct the fuse should be somewhere below 52A (f my math is not correct, feel free to comment, point, and laugh). I have two kinds at my disposal, but decided in the end to go with a 40A fuse.

Having a fuse is all fine and groovy, but it needs to get in there properly as well. I'm soldering novice at best, so cue my gallery of embarassment!

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Fuse marries wire. Such novice, much noob. Wow.

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After changing out the solder gun for a proper iron, I set out to work on those mythical XT60 plugs. I reckoned that if I were to learn soldering properly, wiring these up is going to improve my skills a lot better.

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But every learning curve starts at zero. You can almost hear a faint 'Killl..... mee" coming from this shambolic attempt at a removable link (I'll have you know though that the wires were in there solid as a rock, but as Quasimodo will tell you that doesn't matter if you look disfigured)

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The socket went a bit better. Redid the removable link, and there we are.

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Did a socket for the battery, and added a fuse. Just like in a motorbike (or car) the fuse should be the first halt after the battery I reckon.

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From right to left: power socket, fuse, removable link, and somewhere in the future I'll be adding an LED light to that.

If anything though I'm regarding this as a practice setup of sorts - apart from the fuse and the battery plug, everything is subject to change. Once I can finally mount a baseplate in the chassis I'll be mocking up the insides, and measuring up the wiring just so there won't be any waste of space. This is quite important as, even though the bot itself is quite wide, the inside is a tad cramped.

If anyone has a suggestion for placement of the removable link (as in, where to best put it on the bot) I'm all ears. I'm probably not going to use the XT60 as a link as the small BEC plugs are just more suitable to work with - the bulky XT60s just take up too much space.

If you've got anything else to share, suggest or ask I'm all ears too by the way, unless it's in defense of the Hunchback of the Notre Dame. Proper men watched The Lion King and Jungle Book as kids.

And Thunderbirds. Virgil was the man.

[daveimi]

Choc blocs ftw

[Zenith]

I finally got round to fiddling around with the lifter system.

You see, there was a bit of an issue. As is the case with every roboteer stalking the badlands these days I like my insides to be thoroughly protected. You know, just in case there's some evil robot pulling a rabbit out of a hat and you're left with a smoldering heap of what once was delicate, costly electronic circuitry.

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First, there was the matter of harnessing the power of the servo. I fabricated a bracket out of HDPE, and moved right along.

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I chose the first emulate the two-bar system that the Viper lifter uses, and this is how far I got. Now, the big piece at the top is merely taking the role of surrogate here as opposed to being an actual representative model (as it is, it has no lip to get underneath other bots - the actual lifter would have a bend at the end), and there were a number of issues.

To start off: fully extended it didn't really seem to have much reach. I mean, it had enough for my control-type of lifting, but for something like selfrighting this certainly left to be desired.


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It certainly looked cool though, especially when folded down.

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However, the biggest issue was with the lifter mechanism itself. When all is said and done I like my stuff beefy and simple and whereas the lifter itself was quite chunky...

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...it's only as strong as its weakest link. I mean, if your lifter is held on with the tiniest screw imaginable then you shouldn't expect favorable results in the jungle that is robotic combat.

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I therefore reckoned it best to flip the servo, put on a bigger arm and operate the lifter by letting the servo push the arm upwards with rubber bands pulling the lifter down, instead of connecting the arm directly to the servo. This is simpler approach, which not only makes the servo less prone to feel the hits, but also enables me to make the 'lifter slot' in the top armor less than half the size, meaning more protection for the juicy innards!

As far as the juicy innards are concerned, you can probably tell it's going to be a bit of a squeeze, but I reckon I can get everything to fit just fine.

The coming week will see titanium enter the construction phase, and hopefully I'll be able to do some first driving soon as well.

Plenty of fun to come then!

[Zenith]

NO BRAKES ON THIS TRAIN!

What a day.

Today I paid a visit to the lovely home and workshop of Mario and Babeth in Belgium, for the first time in 15 (!) years. I reckoned my need to make some sparks fly was as good an excuse as any to revisit the place where the foundation was laid for my robotics bug all those years ago.

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First, Mario showed me the ropes, and then we set to work as a team. I did the grinding, and Mario drilled the holes.

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I must say that doing all of this, time flew by at an alarmingly fast rate...

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...but the result was great. We tried bending the top lips of the small wedgelets upwards as well, but found that the titanium just sheared off. One of the sides also sheared as we bent it, but Mario welded that up in a jiffy.

Anyways, the result looked better than I'd have hoped.

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Especially the big wedge. After seeing the titanium shear with the small wedgelets, we chose to leave the top lips on the big wedge as they were.

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Coupled with the lifter this will give you an idea of what the end result will look like. All titanium will be painted, but I'm waiting with that until all electronics are in place. I'm doing that deliberately because I tend to be quite... aesthetically inclined, so I want to save that as a reward for when the bot is actually finished.

I weighed the entire thing with all the nuts and bolts required, and without the electronics it weights around 950g. It seems to me that I will have some wiggle room for extras once everything is in place.

Speaking of which, now that I FINALLY have a base plate I can put the rest of it where it belongs, and start doing the insides.

More on that in the coming week. Whooo!

[Jimmy]

Looking good Greg. Can't wait to see it in action

[Zenith]

Looking good Greg. Can't wait to see it in action

Thanks, me too! I mean, we have to do something against all them spinners this September, right?

Any big changes to Catalyst?

[Zenith]

Dear god how are you still following this thread?

Like an elephant charging towards nosy Americans that are getting too close, I seem to have hit my stride. Must be that the summer holidays have started - lots of spare time, yay!

With all of this free room to maneuver there's plenty of time....

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...to make an absolute mess of the dining room table. Now, we're not going to have dinner. I'm not finished.

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First thing on the agenda was testing the servo - I basically took the ready-made circuitry (including old battery) I used in the test chassis and hooked it up to the servo to see what was what. I could then also get a feel for how this new chassis handled.

So naturally, time for a lap through the living room:

That seemed fine! Now, it was time to get busy with the actual circuitry to be used. Right on cue I took delivery of my XT30 plugs, so right away there was more soldering to be done!

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I credit Rory from the Nuts team with putting the fuse atop the link like this - I adore how the two parts seem to be made for each other and everything. Whoever said romance was dead?

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Then, time to fit it all inside, and see how the wiring would go. The two holes in the center of the baseplate are not a poor excuse for weight saving or anything - they're for the servo mounts.

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Anyways, more soldering! Most of the circuitry is done here, save for the connection between the negative leads.

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After some more cocking about (I first wired one of the ESCs to the LED pictured above, so one motor was lagging behind) this was the eventual result. XT60 plug for the battery, XT30 for the link with a 30A minifuse, then the ESCs and parallel there's the Power LED. Everything should fit, but it's going to be rather snug in places.

Upon completing all the wiring (and fixing my LED screw up) I took it out for another drive, new battery and all. The first drive will all of the actual insides in place.

Seemed quite nippy, although the real heavy stuff (like uh... the titanium wedge and top plate) is still missing from the chassis. The prognosis is that I'll be quite underweight though, so my devious brain is already concocting evil right on par with Black Adder's weasel fetish.

Question for you though: I'm a bit puzzled as to how to solidly connect the ESC wires to the motors. Up until now I just hooked them in since that's more than enough for a test drive, but I've read that soldering the lugs of the motor is risky (the heat can screw up the insides). I reckon that I could just hook the wires in, squeeze the wires to 'fold' them after which I shrink wrap the lead so it can't go anywhere. Does that sound sensible or am I distilling a Baldrick-esque vibe upon this thread?

Leave your message after the beep.

[Al_]

I have used the 4mm bullet connectors to attach the drive motors to the ESCs on Pressure Point. They were liberally wrapped in heat shrink and had a bit of strain relief on either side of the cables (cable ties!). Despite been thrown around, and out of, the arena they have never given me any trouble.

https://hobbyking.com/en_us/4mm-gold...airs-20pc.html

[Zenith]

I have used the 4mm bullet connectors to attach the drive motors to the ESCs on Pressure Point. They were liberally wrapped in heat shrink and had a bit of strain relief on either side of the cables (cable ties!).

I imagine these connect two wires together? I'm at the point where the motor does not have any wires at all, but only the lugs visible at the back of this motor (these are in fact the very same motors I'm using).

Soldering these lugs seems risky to me, so it seems more sensible to hook the wires through, fold them backwards and then shrinkwrapping the folded wire around the lug.

Let me know what you think.

[overkill]

Soldering wires to those motors is fine as long as you use appropriately sized wire - NOT soldering them and just wrapping bare wires around the lugs will be far less reliable.

[maddox10]

Soldering is better.

[TechAUmNu]

Solder the wires on and put heat shrink over to stop them bending too much. They will come off if you don't solder them and the resistance will be higher (probably doesn't matter much for these tiny motors though).