Servo size

[MrFrothy]

I did a search and found nothing. I'm a student making a robot for class, and I want to buy some wheels and hubs but I need to know how big the axle is on the servo (this one). Can anyone help me? Thanks!

 

[BeanieBots]

I've moved your thread from the finished projects area to the main area where you are likely to get more replies.

All servo manufactureres have their own shaft standard which are either splined or square in cross section. If you want to fix a wheel, it is best to get one from the manufacturer or make your wheel fit the horn which comes with the servo.

 

[nfk]

Normally servos come with a selection of wheels/horns. If you get really stuck I've found that ServoCity (http://www.servocity.com) has an excellent selection of servo accessories.

Cheers,
Nigel

 

[Wrenow]

Note that that servo is 180 degree rotation. If you are using it for wheels, you will not be going far. If you are looking for running wheels, you want either a hacked servo, or, better yet, a Vex Robotics motor (which has an electronic speed controller in place of the standard servo board). Are you in the States, the UK, or elsewhere?

Cheers,

Wreno

 

[MrFrothy]

I'm in the US. Apparently the servo can be opened up and have the thing that gives precise control disabled (can't remember what it's called). Anyways, I already ordered the parts so if the hub doesn't work oh well, there goes 8 dollars. Sorry I posted in the wrong forum.

The question was what standard/size is the axle on the servo. It's what the picaxe site sells, but I couldn't seem to find the datasheet.

At any rate, I can always resort to hot glue, but I want the wheels to be nice and straight to reduce friction.

 

[sjremington]

Servo modifications and matching wheels

Instructions for continuous rotation modification (google servo modifications or continuous rotation servo ):

http://www.seattlerobotics.org/guide/servohack.html
http://members.tripod.com/robomaniac_2001/id154.htm
http://www.acroname.com/robotics/info/ideas/continuous/continuous.html

Solarbotics, Parallax and Pololu sell inexpensive modified servos (you need an H-bridge chip with some of these) as well as wheels that fit many servos

http://www.solarbotics.com/products/sw/
http://www.solarbotics.com/motors_accessories/2/
http://www.acroname.com/robotics/parts/R174-CONT-RO-SERVO.html
http://www.pololu.com/catalog/product/695

 

[Wrenow]

OK, 1st there are "pre-hacked" servos readily available from many sources as noted in the previous post, so you do not have to modify them. However, you would be FAR better off with a Vex Robotics motor http://www.vexlabs.com/vex-robotics-motor-kit.shtml (looks like a servo, but has an actual ESC [electronic speed controller] in place of the regular servo electronics). It uses a square shaft, but I understand the final gear can be replaced with a Cirrus or Futaba gear of the right size to get a regular splined hub. Have not tried this, myself.



The electronics in regular servos (and hacked servos) is not really designed for a wide range of speed control.

In addition, http://servocity.coml
and http://www.lynxmotion.com/Category.aspx?CategoryID=74
among others, have tons of methods for attaching shafts, sprockets, gears, wheels, etc. to your servo.
You also might ant to check out http://www.robotmarketplace.com/store.html

Good luck.

Wreno