Another New Antweight..

[Rapidrory]

Hi guys, Rory here..

I'm just joining the Antweight scene, (having been talked into it by Alex (Haywire)) and as such have started work on a robot to play with

The robot I'm building is an Alu/Polycarbonate flipper.. I've ordered all the relevant parts (most are from the US branch of Hobbyking though so could be waiting a while..) and have started work on the chassis.

At the moment I only have the aluminium part built, which holds the motors and all the other electronics..



The servo I plan to use for the flipper is a Turnigy XGD-11HMB. The specs on it seem to good to be true at 3.5kg/cm torque, 0.09 sec/60deg, 11g, all for £3.35. It does have a nylon/metal gear train, which may be a bit weak, but I'm still a little sceptical about it. At least its hardly a huge waste of money if it's not suitable...

Having more or less finished the alu part and fitted the wheels, I wanted to try it out to check the motor speed was right/ because it's fun However all my parts are still on their way from the US... Sooo, in an attempt to redefine the meaning of 'lash-up', I had a rummage around in the attic and found an old dual channel 40MHz RC kit.
Took apart the two servos and had a bit of a resolder to make a dual ESC, then taped the rest of the receiver in with some AA batteries...



Works surprisingly well all things considered, however some how don't think it's a competitive setup just yet

Also have plans for another little flipper, but that's for another day :L

[haz]

That's pretty cool man, well done.

I like the folded alu.

Harry

[Remote-Controlled Dave]

The thrown together version looks like mine do when they're finished.

It's a great start though. Is the aluminium chassis all hand made? Tin snips and a tape measure type job? The motor mounting is cool.

[earthwormjim]

Nicely done Rory! Looks really good, well done on the metal work so far. I am suprised the 2x 360 degree folds didn't crack! Looks like you are making good progress!
I get most of my ingredients from hobyking. Sometimes they are quick. , sometimes they are sloooooooooooooooooooooooow.
You never can tell!

[Rapidrory]

Yeah, the chassis is all hand cut and folded... by folded I mean beaten with a hammer a lot in an attempt to get it looking roughly like it was supposed too..

No CAD used in the design either; spent many hours sat on my floor with a geometry set, a calculator, and lots of paper

Fitted the polycarbonate bits now... Came in only 0.6g over what I thought it would weigh, so that should be easy enough to deal with.



Need to give it a bit of a polish up first, but otherwise it's almost done.

This is the other little robot I'm working on:



It's a little flipper called Tinny Not meant to be competitive; more just an interesting mint tin project!

[Remote-Controlled Dave]

Starting to look great! Both of them. Never say that about "not meant to be competitive" though, cos it means almost certainly that it'll progress further than your "proper" robot through an AWS

[razerdave]

Dave's got a point, I built Bulletproof as a drive all day robot, it has a better AWS record than Stewir or Baby Hell do!

[Rapidrory]

Haha, that's quite possible

Btw, has anyone got any ideas about wheels I could use for Tinny? Need to be about 20mm in diameter and fit a 3mm D shaft... The motors I'm using are from RS and so only have a 5mm long shaft, but otherwise they're much the same as the ones from Polou.

I've looked at using Lego wheels or making some from scratch, but mounting them on a D shaft properly has so far been unsuccessful...

[Remote-Controlled Dave]

I have the same issue with the d-shaft. Getting wheels to fit that aren't already purpose made or printed is a pain. The best solution I had was Rhys gave me some d-shaped 3D printed inserts that you glue inside the hole on a Lego wheel. There are a few people on here who have their own 3D printer so maybe you could strike a deal with someone? Mind you, if you can do that, you could just get the whole wheel made...
Or ask someone who knows how to do it, haha.

BTW, I think you should rename Tinny 'Curiously Strong Peppermints'!

[Rapidrory]

Hehe, would save me writing the name on it at least

Had a thought on wheel mountings; gonna try drilling a 3mm hole in a slightly larger steel bolt, then slide it onto a 3mm D bar and hammer it to get the D shape and tight fit... might work, just have to make sure I can get it off again

[teamocean]

I've got some 20mm wheels which will fit the D shafts. How many are you after?

[Rapidrory]

That'd be great, i only need 2.. What sort are they?

[Rapidrory]

Well, most of my parts have arrived now, so can get on with building a bit more..

However, turns out you can't use a 3 channel ground Rx with a standard aircraft transmitter... suppose it makes sense, but none the less irritating as now I need to find another receiver...

[EpicentrE]

Rory, what frequency is your transmitter? If it's for aircraft it's most likely 40mhz - if that's the case, I have quite a few old 40mhz receivers which I'll probably never use again which I don't mind donating, as long as you have the appropriate crystals.

[Rapidrory]

No no, my 2.4 GHz Orange Rx/ Tx just arrived today... Seems there's a difference within DSM2 between ground and air protocols though... Fortunately i did get a 6 channel air receiver as well, it's just i have 2 robots and i'd rather not have to share receivers between the two, specially since i'm going to be soldering it in! :L Appreciate the offer though

Also, shouldn't we strictly speaking be using ground protocol systems anyway? I know no one does, i just always remember being told about not being allowed to use 40MHz on an aircraft, and i'm assuming the rule applies for 2.4GHz? (albeit the other way round in this case)