Skipdiving Robotics

[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?

[daveimi]

The charger I have was a fiver online and is an extremely basic trickle charger that will only charge up to 12V. The 10-cell NiMH packs are a lot cheaper that the other stuff and all the motors I have are 12V so thought well I'll stick with 12V for now.

Edit: Razerdave just re-read your post. Originally I had 7.2V packs lay around as I race a lot of 1/10th RC stuff. The first robot ran 7.2V and was awful, so to speed up I simply cabled a couple of packs together to give 14.4V even though the running gear has always been 12V

[daveimi]

Found some pictures from Doncaster '13

[daveimi]

Also...made robot progress!!

[daveimi]

Am desperate to update this, I have no pictures to put up but will by the end of the weekend. We've all been hammering and sawing for 6 months only to realise that our original Rag N Bone was the best we could come up with. We all think that the reason some robots are so successful is because they come back year on year as a development of the same design, rather than keep trying to come up with something new. To this end we've started building Rag N Bone 2 and in fact I spent £100 today on new parts. These have included some new drill motors and mountings, a fresh 12v pack from component shop, and also a propper bonafide fail safe.

We're going to start building this weekend, sort of the same design as the original but a bit faster (12V as opposed to 7.2V) and heavier, thicker armour, some new wheels, better wiring, fresh link, new super bright LED, huge 3700mah pack, fresh shock mounts, the list goes on and on. We're going to spray it black the same as last time, and again use found parts to put it together. I was desperate to update this as a sanity check and am going to be signing up Monday for everywhere that will have us. Not gonna do the Champs as we'll get ripped to bits, but going to get back in action for 2014.

Thanks for reading, will come back with pictures in a day or two.

Dave

[daveimi]

Rag N Bone 2 chassis done! Took about half an hour haha that's really bad! Am going to chuck the running gear in this week with the new battery. Need to make a fresh top cover and bolt that on and we're ready to fight!