New Featherweights

Team Orr · Post by **Team Orr** » Wed Aug 13, 2008 12:20 pm

yeah dave i know, looking for alternatives now but as i have a lipo going spare i thought i would use it

joacim, the reason i'm trying to make it light is to get all the speed the motors can give ,e.g a 1.5kg feather with 4mph motors is more likely to go faster than a 8kg feather with the same motors.

also, wombat uses the same stuff you just posted, i think to many feathers are just boxes with drill motors, sometimes they are good but i like to go against the trend, as said it's a fun bot just to get a few laughs and stand out a bit.

but i really appreciate the help guys

any other comments are welcome

jack

Team Orr · Post by **Team Orr** » Wed Aug 13, 2008 1:44 pm

ok guys i have had a few more comments which have all been negative so i have decided to go for drills again

does anyone know of a site for modifying drills (i dont know how cos i bought my last drills pre moded)

however i will be looking at this setup for my sumo bot!

jack

Team Orr · Post by **Team Orr** » Mon Aug 18, 2008 9:21 am

ok update!

i have decided to merge wombat and fodder to make... da bomb

it will use wombats armor with some motors from xbots.com ad a ni-cad battery. the motors are better than drills and only ?5.50 each!

for speedos i will use 3 electroise speedos

it will have a motor powered flipper/lifter

jack

bitternboy · Post by **bitternboy** » Thu Jun 17, 2010 7:47 am

What is a good feather weight size? You see I don't want to turn up with a huge or miniscule robot at a competition and feeling like an idiot.

leo-rcc · Post by **leo-rcc** » Thu Jun 17, 2010 10:08 am

bitternboy wrote:What is a good feather weight size? You see I don't want to turn up with a huge or miniscule robot at a competition and feeling like an idiot.

I've seen good feathers as small as 20 x 15 x 5cm. And as large as 40 x 30 x 20cm. There is no "good size", it all depends on the build and it's weapon (if there is one).

terminaldamage · Post by **terminaldamage** » Thu Jun 17, 2010 12:12 pm

The best thing to do is to make your robot as compact as possible, but not so much that it's difficult to wire up or maintain. The basic principle I use is to get as much power as possible into as small a space as possible.

The smaller your robot, the less surface area there is to attack. A smaller robot also generally means you can have thicker armour as you are not needing to cover as much area in armour panels, which should stand you in good stead when under attack from your opponents.

bitternboy · Post by **bitternboy** » Thu Jun 17, 2010 1:04 pm

So, In the light of that knowledge, plans for a featherweight are so:

Motors: 2 x B&Q own brand 12v hand drill motors
Reciever and transmitter: Need to buy a 2GHZ system as 40MHZ will be excluded from featherweight combat soon. Unsure what is sutible so suggestions appreciated.
Speed controller: Sabertooth 10A Dual Motor Drive.
Battery: Probably 2 x 7.2v power pack batteries.
( http://www.sussex-model-centre.co.uk/shopexd.asp?id=923 )
Weapon motor (claw): RE 540/1 24V Metal Gearbox 3000:1
( http://www.technobots.co.uk/acatalog/Sh ... r_230.html at the bottom )
I also need a brushed motor controller for the weapon motor so I can plug it straight into the reciever; any suggestions?

Build is not certain but will likely start after exams in july and get a saturday job

Edit: The 2.4GHz transmitter discussed in the question and answer section from Giantcod sounds fine. It comes with a reciever aswell so that's good.

terminaldamage · Post by **terminaldamage** » Thu Jun 17, 2010 4:57 pm

You say you're using the motor to power a claw? What is going to be the transmission method i.e. how are you going to get the movement of the motor to move the claw. Are you going to have the claw connected directly to the motor output shaft or are you using a threaded rod setup? Or something different?

bitternboy · Post by **bitternboy** » Thu Jun 17, 2010 5:59 pm

I think either direct or though maybe a pair of sprockets. Both have their problem; direct linkage has a whole heap of pitfalls to do with leverage and the chain could easily slip of a sprocket. The setup with a chain could also be quite complicated with each joint needing to be very secure. On the other hand, using sprockets of different size could mean I could change the ratio and direct linkage would be very simple. I wan't make it clear I'm not hoping for incredible crushing power, a simple gripper was the original plan and a speed of 6rpm for the arm sounds fine to me.

daliad100 · Post by **daliad100** » Thu Jun 17, 2010 7:32 pm

You could always try hooking your claw up to the motor using a four bar linkage to allow the motor to be somewhere else and you can use the geometry of the linkage to give more speed or force.