Skipdiving Robotics

[daveimi]

I've come up with a Beetle shape. It's half built but I need to take a picture yet. It's as simple as I can make it with the bare minimum of parts. It'll be the usual beetle motors, hopefully Banebots wheels and hub adapters and then a cheap speedo and battery pack. If the shape works ok I am planning on making a new feather in the same vein.

[daveimi]

Ok well, cue the next surplus special as per the CAD Department aboves specs. Beetleweight, rammy pusher bot, two 25mm 12V 30:1 motors that everyone's using and so on, Banebots wheels, hub adapters bla bla. Can't dream up a name yet. The motors and stuff are on the way, dunno whether to get another sabertooth. I also wanna stay away from lipo batteries as I don't understand them lol. Any suggestions/thoughts etc welcome as ever.

[daveimi]

Going to start building feather number 2 "Rollcage" so thought I would put my sketch up. 90% of the time it was Rag N Bones internal frames n shields etc. that stopped big damage. To that end I'm gonna have a go with just a baseplate with a roll cage type frame with bits of plating over the dear bits. Sketch has spikes but scoop is possible, just having a think. Will more than likely have a big nimh pack and two 18V drill motors. Anyway, picture as mentioned.

[Danny B]

I think that frame design's a very good call, because the only weapon that could go through the cage is an overhead spike, which I don't think any feathers have. Use steel chunky enough and it might even become Tiny Hurtz-proof!
As for a scoop, maybe you should make it detachable so you can change the configuration between fights if you want.

[daveimi]

Haha Rag N Bone was mangled after that clout from Tiny Hurtz!

Was thinking last night after posting and I'm gonna make a detachable scoop. I'll make the side spikes interchangeable with a blade type thing with its own frame that attaches to to the same bolt holes.

[Danny B]

It's probably also a good idea to do as I did, and make a scoop that works either way up.

[daveimi]

Worried about making a pusher without having some massive drive behind it.

Gradually thinking about making something really fast and maneuverable instead. I'm supposed to be building a beetle and a heavy as well but dunno which to focus on first, they get more expensive the bigger you go lol.

[daveimi]

I've built a new robot! And it's SHINY!!!

[Mega Masher]

Shiny indeed!
Is this a FW or BW?

[daveimi]

It's a featherweight My beetleweight is nearly finished, my motors arrived from Santa I need to put some pictures up.

[Danny B]

Very impressive! What's it made from this time?

[daveimi]

I'm really sorry I didn't see your post till just now for some reason.

It's 2x2 and plywood! I have drill motors this time round that I sorted out myself. I stripped them out two drills, locked the clutches up and have made my own mountings for them. They run at 14.4v so it's hugely faster than Rag n Bone. I've got two fresh 100mm Robochallenge wheels but I've learned there not making anymore. I've recently had a huge jump in confidence and bought some really nice tools. It's meant I'm having a go at making my own wheels, gearboxes and metal bodywork.

Pretty much everything I make is hand made so it all feels almost sculpted. No cnc, workshop tools etc. just really simple hand tools lol.

I took a picture with the lid off to show you, also bought some Beetleweight motors.

[Danny B]

You made a good choice putting the wheels far apart, it'll make the steering a lot less twitchy. Do you think any new weapons might be in the pipeline?

Also, I forgot to ask. I'm wanting to replace my SLA battery with a NiMH. What are the specs on yours, and where did you get it from?

[daveimi]

Hiya, am really sorry I didn't see your reply the email notifications are definitely hit and miss. To answer your question I have been using 2x 7.2V NiMH 1.6amp/h packs wired in series to give 14.4V. In practise this has been a mare as you have to first make your own loom to cable everything up and then in between fights you'll be constantly panicking about getting both packs charged up. Just this morning I've started building a new robot that's not invertible after getting fed up with it so am moving to this single 12V pack.

http://www.componentshop.co.uk/12v-3...tery-pack.html

This way you can bolt it in, and after each match just put the charger back on it. We were finding with a pair of drills and lightweight robot that 1.6a/h was starting to go flat at the end of a couple of fights. So my logic is that a 3a/h + pack would do us for at least three fights before having to stick the charger back on to put some juice in. So from my junkyard maths, I would say with four drills you'll probably have a good couple of fights at least with 3500a/h or above like the one I've linked.

We're building a new robot called Rammatron and just using a roll over hoop. I've had a mare with ground clearance on invertible stuff so moving over to a propper body with some decent drives in. Sticking with the Sabertooth 2x12 for now although have been looking to get a bigger controller to cope with some Banebots 775's we have planned for 2015. I wanna try this shape out although it's a rip off of several robots. I'm thinking about a lifting arm and a hammer, although in practise they don't seem all that effective and a waste of time. Robots like Little Hitter seem to gain most of their effectiveness from the Speed 600 drive at twenty-something volts and four wheel drive and hinged front plates etc.

Edit: Sorry I should mention though that we’ve sussed a load of stuff we couldn’t do before. I’ve been hacking my own drill motors with grub screws and then hose clamping them to baseplates after finding you can quite easily file a flat on drill gearboxes. One problem is that the supply of Robo Challenge 100mm wheels has dried up. I'm having a go at making a wheel that goes in the chuck of a drill to make life easier lol. That's the cool thing about just building for the fun of it really, if it doesn't work you've not really lost anything in having a go.

Picture of new robot:

[razerdave]

Can your charger not handle a 12-cell NiMH battery? If it can, why split them?