Keeler Carrot, Big Orange and Wet!
|Created and maintained since September 2000 by Rob Englebright|
After the fun of Robot wars, and in an attempt to bring family harmony, we decided to have a go at Techno Games.
Alison's interest in swimming was the mediocre excuse to build a swimming robot, the idea being to create something as simple and light as possible to prevent the back strain suffered during Robot Wars.
Build diary last updated: 24/3/01
24/03/01 So now you know, or you probably didn't even notice, but poor old keeler carrot had a massive system failure, the whole limb articulation thing went terribly wrong and tore the plywood base apart. Still, Adam finally got to be on TV after waiting around all week watching Jane Middlemass tease out the swimming events. I still think we looked the best, the biggest brightest angiest looking carrot out there. Next year we'll be running a calypso style "outboard", with the aim of creating a huge wake and ramming the end of the pool! Watch out.
12/12/2000 Well, it's all over, we finished the carrot, got it going and it did look the business, but you'll have to wait till March to see how we fared! I can say it was a good day out, I didn't have to go to work, and Adam got to meet his friends Jo and Alex from MBC. I had a chat with Adam Clark about robotic fish and got indigestion from a little chef all day breakfast. Excellent.
Here's a couple of pix of the big orange monster. The first one is the nearly completed robot in my basement, the other is a relatively deserted looking pits at Park street studios. MBC weren't being so tight about photographs but sadly the batteries on the digital camera let me down.
On the day we had to saw off a foot from the keel as the tank at the studio was not as deep as we'd hoped. We had a phone call from Kelly at FBX magazine asking for some details about the robot so we should be in the mag as well as the telly.
23/10/2000 Ok we've got a rush on now, MBC have finalised the date for filming, it's Dec 8th, and were up against 60 other teams!! This is a bit more than we were expecting. Build continues slowly with carrot, Most of the control systems are up and running but we need a bigger steering servo and we've yet to finish the drive line:
Disgusting orange paintwork is sort of in place and the rudder is now fitted
28/10/2000 Disappointment for Dom as Jo from MBC phoned to say the age limit is 6. It looks like another day spent at Park Street studios with Adam. Apparently they are going to construct a pool there for the event! Sounds like a very ambitious project when there are so many swimming pools available. Keeler carrot has taken a back seat while we've been preparing for AWS3 but now I have no excuses and will be nagged mercilessly by Jo if I hint that it isn't ready.
16/9/2000 Gluey mess has been and gone and I'm impressed with the results. Dom (aged 4) was a star at paper mache, and the whole lot has set reasonably hard even if some of the bits are a bit wonky.
The drive motor has been changed to a more torquey unit running a reduction worm drive gear box, then a 4:1 chain reduction and finally using KC1's motorcycle chain and sprockets on the final drive. This should allow us to link on offset connecting rod to the "hand" giving the limb the articulation required in the rules.
The photos give an indication of the shape though they aren't the clearest due to all the clutter in the background. Squint and use some imagination:
23/9/2000 Carving the polystyrene has proved more difficult than anticipated, in the end I resorted to heating up a pointing trowel with a blowtorch and melting lumps off.
The next step is to bond a plywood base onto the lower half of the foam, install the keel and cover the whole shooting match in strips of PVA soaked paper, this will later be varnished and painted.
It's a job for the kids, and I anticipate a huge amount of very gluey mess.
The basic design is a 4ft long, foam carrot with a large UPVC keel for stability, and swimming arms powered by an 18v cordless drill through a reduction gearbox. A Carrot tail rudder will be steered via a single servo and a great deal of cable.
At last some pictures, one looks like a pile of ice cream and the other the QE2 but they are in fact the polystyrene shell of Keeler Carrot
The power is coming from an 18v Power Devil cordless drill I originally bought for Robot wars, the funny grey lump is a reduction drive my Dad has treasured for about 30 years.
Hopefully the reduction in gearing should bring the speed of the arms down to a manageble rate, but it's still looks a bit too quick to me.
The arms are on cranked hollow shafts. The fixed insert allowing the hand to alter it's pitch when entering and leaving the water. I've checked in Ali's swimming book and this should simulate the action of a real swimmer pretty well.