New Robots

EpicentrE · Post by **EpicentrE** » Sat Jul 01, 2006 11:39 pm

The problem I can see with a sharpened disk without teeth is that, while it might be very good at cutting an object which is held in place, it would likely not do anything to something as light as an ant, simply scratching the surface and pushing it out of the way. You're welcome to experiment and prove me wrong though

Nemesis · Post by **Nemesis** » Sun Jul 02, 2006 7:37 am

Thank you EpicentrE,
your theory sounds sound, the disc should probably have teeth.

Also I'm wondering whether or not the disc should be horizontal, seeing as a lot of robots I see look very very vulnerable to vertical attack, ones with exposed components etc. Basically, if we can make the motor/servo spin both ways I'd be tempted to make it vertical, as it isn't going to be a particularly big saw and may not cause regular flipping.

Nick

Adam Hargreaves · Post by **Adam Hargreaves** » Sun Jul 02, 2006 10:31 am

for my A-level, i did a test of disc profiles. I had one with loads of teeth, but it tended to just jam in things. The most successful one was one where i attached the teeth separately, and they were made out of a heavier metal than the rest of the disc. avoid spinning bars-they're complete rubbish (from my results anyway)

Slitting saws: http://www.rdgtools.co.uk/acatalog/HSS_ ... _SAWS.html

Oh, and if you're using a servo-take the gearbox off. Also, you may find you have problems fitting a disc to a servo motor-the shafts are usually quite weird, or have gears fixed onto them.

And regards the horizontal/vertical issue, that's purely a design choice. Horizontal would be good for attacking wheels, wheras vertical, as you correctly say is good for flipping.

olivers · Post by **olivers** » Sun Jul 02, 2006 10:42 am

With horizontal spinners they tend to want to rotate the ant round. The spining disk acts like a gyro.

With vertical spinners if they spin downwards they lift you when you hit the opponent so they need to spin upwards (ground towards opponent) so they lift the opponent up.

For a starting and I would build a basic pusher or lifter and get to grips with the basics of driving and control. Adding spinning weapons complicates matters a whole lot more. And the fact that it becomes a lot more dangerous.

Nemesis · Post by **Nemesis** » Sun Jul 02, 2006 12:00 pm

Thanks everyone, I think I have all the pros and cons of various discs registered. Did an A-level on testing discs? There's a thought.....

Peter Waller, ready or not, here come the NAC Robotic Team!

Nick

Adam Hargreaves · Post by **Adam Hargreaves** » Sun Jul 02, 2006 2:49 pm

yeah, Oliver has a very good point-iirc, product safety is a section of the GCSE paperwork, and having a spinning disc does compromise this somewhat. The disc never made the final project with my A-level, due to technical issues (everything went wrong, lol)

Nemesis · Post by **Nemesis** » Sun Jul 02, 2006 5:08 pm

Ah yes. "Product safety". With a cardboard/cotton wool composite cover and clever wording I'll dodge that, for example by saying stuff about the completely-safe cover covering the not-quite-completely-safe saw whenever out of the comlpletely safe arena.

Many thanls Peter Waller, for your help and advice and enough polycarbonate to keep us going into the holidays, to do experimental work with until we get school-provided stuff.

Also I found out about slit saws, very neat, don't know how on Earth I'll make one but I'll be sure not to give up until I have a good saw.

Nick

Chris · Post by **Chris** » Mon Jul 03, 2006 3:43 pm

Where do i get decent batteries Ni-cad/NiMh? Pete pointed me to Overlander I had to look at Mr. Windisch's site to remind me what the adress was, But they don't do 1/3AAA battery packs. and is this servo ok for drive?
With this R/X & T/X?

Flippt · Post by **Flippt** » Mon Jul 03, 2006 3:51 pm

I doubt that you'll need all 6 channels, ever.

And the receiver seems to have 6 channels aswell, which is very heavy/big for an antweight.
Go for a 4 channel, like the Futaba Skyport 4, easy to use, and cheap (at some places). They are tons of micro receivers, some are cheaper then others and such.

The servo may be good for drive, depends really if your going for small or big wheels.

Chris · Post by **Chris** » Mon Jul 03, 2006 4:14 pm

we use small wheels, and if the receiver is a bit big why does it use a Mini R/X crytal? that is another place Pete pointed us to during our visit. But i ask you , when you give us advice on what to buy post a link to where you can get it!