www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

attaching ball screw to drill gearmotor


Post new topic   Reply to topic
  Author    Thread
Phyrexian Robotics



Joined: 31 Aug 2012
Posts: 7
Location: Athens, Georgia USA


 Reply with quote  
attaching ball screw to drill gearmotor

I've seen a fair number of robots with actuators made from attaching a 16mm ball screw to the shaft of a hacked drill motor. I would like to try this out, but I don't know how to securely attach the ball screw to the gearbox shaft. I *think* I have heard of these being made by boring out the ball screw, and tapping the bore so it "screws on" to the drill gearbox shaft. In this sort of set-up, what prevents the attachment between the gearbox shaft and ball screw from unscrewing itself? Is high-strength loctite used?

Post Fri Aug 31, 2012 12:38 pm 
 View user's profile Send private message
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

I was rather more technical than that. AKA, drill/bore out the threaded rod/ballscrew then bash it onto the shaft with a hammer. It never moved EVER. Smile

But yes being more elegant about it just tapping the ballscrew for the same thread then pinning it to the shaft would work just as well.
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Fri Aug 31, 2012 12:44 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Phyrexian Robotics



Joined: 31 Aug 2012
Posts: 7
Location: Athens, Georgia USA


 Reply with quote  

Also, the reduction on an actuator like this is (gearbox gear ratio x threads/inch), right?

Post Fri Aug 31, 2012 12:57 pm 
 View user's profile Send private message
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

You need pitch which will tell you how much travel you will get from one turn on the ball screw, not threads per inch. Another ass-backwards facet of the imperial system because most every calculation is done from pitch. (okay ill ease up with the imperial bashing haha, but hey this is a metric forum Razz)

Thankfully pitch is the reciprocal of TPI so you can convert them easily enough.

Once you know that you can work out what speed your lifter or whatever you are making will move at, taking into account the output rpm of a drill which will be either 550rpm or 900rpm.

If you start dealing with acme threads with more than one start then it all gets a bit more tricky but that's the basics of it anyway. Welcome to the forum also ^^;
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Fri Aug 31, 2012 1:14 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 1 of 1


Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.