Team Riptide Birmingham Chronicles

[mrsam]

Seeing as Matt decided to put all of his robot builds into one thread i figured i'd do the same, bit of a weird team scenario we have going on here with two different build diaries but it would be way too complicated with the umpteen amount of robots we have between us.

So on to the robots, i never really bothered with a post champs report and it seems a little late now, having said that i'm eager to get on with some updates instead of taking a break like i said i would.

Hatchet performed so much better at the World champs than i thought and i think it surprised quite a few of you as well, despite taking on 8 different spinners over the weekend it took no significant damage, took a few huge hits from NST but even that was easily repairable. So as it stands i can still use the current machine at some live events until i rebuild it, sticking with all of the same internal components as i was really happy with the weapon and drive but changing the chassis design slightly.

I was much happier with the chassis this time around, the thicker hdpe and the addition of barrel buts really helped with strength. Having said that the top panel was pitiful due to weight reasons and the body was so tall that there was a huge amount weight tied up in empty space. A few changes are definitely in order then, i'm actually going to look at Hatchet 1 for inspiration here, the old machine had the side panels bolted to the baseplate and the front and rear panels overhanging so they were flush with the base of the machine.

I like this design better, it gives me a little more space inside, means i can make the machine sorter and also makes the baseplate and lid flush with the front and real panels. I had a few times at the champs where the lid was caught and peeled back so hopefully that doesn't happen again. I'm also going to make the chassis from a mix of 15 and 20mm hdpe, the rear and side panels took no damage at all this year so they will be made from 15, the front panel, wheel guards and axe bulkheads will stay 20mm thick although i will be drilling a few holes in the axe bulkheads to remove a bit of weight. All of this means that i can afford to have a thicker lid and hopefully fit the Aluminium bracing to the rear corners.

My final update will please some of you in particular (Dave Weston), as happy as i was with the axe this year i wasn't all that pleased with the damage (or lack of) that it caused, especially to hdpe. Seeing as i have a double sided axe with a nice pointy end i'm going to be fitting a second 8mm sprocket to the other side of the axe shaft. This means that i can alternate between pointy and broad heads depending on the opponent, it also means that any of you with suspect top panels had better hope you don't meet Hatchet next year .

If you managed to sit through all of that well done, I'll be keeping this thread updated regularly with progress on Hatchet and the rebuild of my beetleweight spinner Lynx.

[mrsam]

and the rebuild of my beetleweight spinner Lynx.

It's been a while since i last updated with, well, anything. Finally got around to building a new version of my Beetleweight undercutter Lynx, some of you may remember Lynx as the spinner that always promised so much but then cacked it's shiny robot underpants every time another robot looked at it funny.

Well, hopefully that is now a thing of the past, i decided this time that i needed to do Lynx properly, it needed a properly designed chassis, a good drive system and a weapon that is more clever than "ZOMG Lets make it as big and fast as we can and it'll beat all of the everything!!".

So, on to the actual build, first up was designing a proper chassis, for this i grabbed a copy of Emachineshop (not the best for chassis stuff i know but it did the trick just fine) and got to work CADing something based around the old chassis only sort of.....good.

As you can see, much better than it was before. It's the same grade Aluminium ( 3mm 6082 T6) but it has 1.5mm deep pockets to keep the weight down whilst keeping the structural strength in the frame, it also has thicker drive motor mounts and it's all been welded into one single piece which means a) it's stronger and b) i can save weight by not having bolts.

Next up were the internals, now Lynx has always been unmistakably a big weapon and i wanted to keep that but build in some reliability. For as long as Lynx has been around it was using an NTM 3536 1800kv 875w brushless motor....which is great if you like that sort of thing. the problem is, it had too much speed and not enough torque for my liking. So time for a change, the weapon motor is now a Turnigy 3548 1100kv 910w motor, i'm also running this on 4s instead of 3, so more torque from the motor, a higher voltage and a more sensible speed of 6000rpm.

I didn't take many pictures throughout the build so we've skipped to a nearly finished robot, you can see the new brushless set up and frame and how everything kind of...fits? Wait wait....things fit in Lynx? what kind of sorcery is this?

Glad you asked, Lynx has always had an internal space problem, i've always just crammed everything in and kind of hoped for the best. I could hardly spend all this time and effort on making it better and then shoehorn all of the bits in like some sort of cretin could i? So i decided to make use of the gaping amount of space in the rear spar and mount all of the drive electrics in there. The drive this time is a bit of an experiment as i'm using small brushless outrunners, i've done my research don't worry. It uses 25a Turnigy Trackstar esc's and tiny 1800kv outrunners mated to the very chinese ebay gearboxes. The whole set up runs at 2s which seems to give around the same speed as the normal brushed motors but more torque. This coupled with Lynx's snazzy new foam wheels and the extra weight over them by putting the electrics in the rear means that Lynx actually sort of drives...quite well in fact.
So, that's the new Lynx, well done if you managed to sit through and read all of that. It'll be Debuting at the Kinematic event in Scotland on the 6th of August where i'm hoping the upgrades will mean it does well.

Cheers! See you all soon

[harry hills]

The drive this time is a bit of an experiment as i'm using small brushless outrunners, i've done my research don't worry

*Harry did his research don't worry

Good to see my drive system working out. Need video of it driving asap. NIce improvement over the last version. Wish it luck in combat.

[mrsam]

Haha, I did my research through harry (copied him)

Drive works real nice actually, i'll get a video up here some point today.

[daveimi]

That's a very pretty robot. I can only dream of this sort of stuff with my hammer n kitchen step. Do you draw it in CaD and then send the file to someone to get milled? If I learnt cad could I do this?

[mattsdragons]

You don't need to learn to CAD at all, there are plenty of people if you ask nicely will lend a hand in that department. *cough* Jarvis, Ellis, Haz *cough*

[mrsam]

Yepp all drawn up in CAD and then sent to someone else, I'm pretty rubbish at CAD tbh but Emachineshop is simple if a little clunky at times.

There's no reason why you couldn't do stuff like this if you learnt to CAD, heck i've managed it and i'm more than useless at that sort of thing.

[mrsam]

You don't need to learn to CAD at all, there are plenty of people if you ask nicely will lend a hand in that department. *cough* Jarvis, Ellis, Haz *cough*

*Cough* Botwright, Matt Smith also *Cough*

Completely agree with Matt there though, if you don't feel all that confident there's people who are usually more than willing to CAD stuff up for you.

[harry hills]

Always learn CAD if you can. It's a fantastic skill. However, being able to design is way more important. Any schmuck can CAD, not everyone can design properly. Not saying I can ofc I build boxes with exposed wheels but it's still a fairly valid point.

[mrsam]

^^

What he said

As cool as Lynx looks, it's still untested so it could turn out to be a piece of complete poodoo