Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: stopgo on October 26, 2007, 04:18:11 PM

Title: Mounting Wheels onto a Servo
Post by: stopgo on October 26, 2007, 04:18:11 PM
Hi,

So I've run through this forum, and read this:

http://www.societyofrobots.com/mechanics_chassisconstruction.shtml#wheels

But I'm having trouble mounting my wheels.  Specifically, I understand the idea of attaching the servo horn to the wheel, but then I'm supposed to screw that servo-horned wheel onto the motor shaft:

Quote
Then I just attached the servo horn to my servo output shaft with a 3rd screw.

But I don't have a screw that's long enough.  The original screw which mounted the plastic circle thing (what's that for, anyway?) to the output shaft is certainly far too short, and I went to my local hardware store but they couldn't find any appropriately sized screws.  Where'd you get the screw?
Title: Re: Mounting Wheels onto a Servo
Post by: stopgo on October 26, 2007, 04:23:39 PM
Also, I realize I could super-glue my wheels onto the motors, but I'd like to be able to remove / reuse them should my motors die.
Title: Re: Mounting Wheels onto a Servo
Post by: ed1380 on October 26, 2007, 05:13:22 PM
this is what I did
(http://i43.photobucket.com/albums/e398/RussianCommy/untitled-47.jpg)

black- servo
blue- servo horn
yellow- wheel
pink- screws
Title: Re: Mounting Wheels onto a Servo
Post by: garriwilson on October 26, 2007, 06:50:39 PM
If you're using the cardboard wheels then the small screw is FINE.

If you're using a different wheel, here ya go (http://servocity.com/html/long_servo_screws.html).

If I was you, I wouldn't buy that because the shipping is like 10 times the price of the screw. You could check though, maybe since it's small they won't charge at all or very little. Should've bought them with your servos.

Don't use super glue because you'll need your servos in the future, trust me.

DO NOT use any other screws because that will mess up the spiral where you put in the screw. Then I will crack and good bye servo.

Also, could you post a pic of the wheels you're using? And the diameter. That way we'll be able to help you more.

I recently made the 50$ robot so that's how I know this stuff.
Title: Re: Mounting Wheels onto a Servo
Post by: stopgo on October 26, 2007, 08:56:17 PM
Ohhhhh - I feel a bit silly now.  Thanks for the feedback guys.  ed1380, your approach works fine :)  I was trying to attach the servo horn to the other side and press-fit the wheel onto the motor stem (it actually happens to fit very snugly - just as well as the servo horn).

However, the wheel is such that screws would be a bit awkward - do you think superglueing the servo horn to the wheel will be sturdy enough?
Title: Re: Mounting Wheels onto a Servo
Post by: Admin on October 27, 2007, 07:54:40 AM
Quote
do you think superglueing the servo horn to the wheel will be sturdy enough?
definitely not!

Although I did have some success with JB Weld, I think the screw method is by far superior.
Title: Re: Mounting Wheels onto a Servo
Post by: stopgo on October 27, 2007, 03:06:02 PM
OK then, thanks admin!