Go to Post If this thread isn't a sign that CD is going through some serious withdrawals, I don't know what is. - Ty Tremblay [more]
Home
Go Back   Chief Delphi > Technical > Motors
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 12-03-2007, 17:48
simeon1770 simeon1770 is offline
Registered User
FRC #1770
 
Join Date: Feb 2007
Location: chicago
Posts: 9
simeon1770 is an unknown quantity at this point
How to Lock a motor

How do you lock a motor?
  #2   Spotlight this post!  
Unread 12-03-2007, 17:53
Jeff 801's Avatar
Jeff 801 Jeff 801 is offline
Registered User
no team
Team Role: Alumni
 
Join Date: Jun 2006
Rookie Year: 2004
Location: Florida
Posts: 346
Jeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond reputeJeff 801 has a reputation beyond repute
Re: How to Lock a motor

what do you mean by lock a motor do you mean dynamic braking or something else
  #3   Spotlight this post!  
Unread 12-03-2007, 18:21
simeon1770 simeon1770 is offline
Registered User
FRC #1770
 
Join Date: Feb 2007
Location: chicago
Posts: 9
simeon1770 is an unknown quantity at this point
Re: How to Lock a motor

i mean to make the motor stop moving, when my arm it reaches a certain height it falls pretty fast and i want to know how to lock it at my leisure, so when it starts falling i can lock it and stop it from falling
  #4   Spotlight this post!  
Unread 12-03-2007, 18:27
meatmanek meatmanek is offline
Programmer/physicist/mathematician
FRC #0868 (TechHounds)
Team Role: Programmer
 
Join Date: Mar 2004
Rookie Year: 2004
Location: Carmel, Indiana
Posts: 142
meatmanek is a splendid one to beholdmeatmanek is a splendid one to beholdmeatmanek is a splendid one to beholdmeatmanek is a splendid one to beholdmeatmanek is a splendid one to beholdmeatmanek is a splendid one to beholdmeatmanek is a splendid one to behold
Re: How to Lock a motor

There are a few solutions.

My preferred solution is to use a positional feedback sensor of some sort (potentiometer, encoder, etc) mounted to the arm, so the controller knows where the arm is, and then use a PID loop. This is the most complex in terms of programming, but if there's an easy way to mount your sensor it can be the easiest mechanically.

The next solution would be to use a worm drive, or a motor that has worm drive built in. The Denso and Keyang window motors are all worm drive, and cannot be back-driven.

The third solution, if you don't want to mess with tricky PID tuning or replacing a motor entirely in an arm, is a brake system.
Here is a picture of another team's brake mechanism:
http://www.chiefdelphi.com/forums/at...9&d=1172112278

You may want to read this thread:
http://www.chiefdelphi.com/forums/sh...ighlight=brake
EDIT: Never mind, you've already posted on that thread.
__________________
Real programmers use vim.

Last edited by meatmanek : 12-03-2007 at 18:29.
  #5   Spotlight this post!  
Unread 12-03-2007, 19:51
WaterFreak WaterFreak is offline
Registered User
FRC #0708 (Hardwired Fusion)
Team Role: Mentor
 
Join Date: Feb 2007
Rookie Year: 2002
Location: Warrington, PA
Posts: 29
WaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to behold
Re: How to Lock a motor

we used a clutch plate mechanism with a servo to release the clutch when we want the elevator to go down.

if you need some pics, let me know.
__________________
Thanks, Jim Orr
Senior Software Engineer - Motorola, Connected Home
Supporting Team 708 - Hardwired Fusion
  #6   Spotlight this post!  
Unread 25-03-2007, 19:19
bear24rw's Avatar
bear24rw bear24rw is offline
Team 11 Programming Captain
AKA: Max T
FRC #0011 (MORT)
Team Role: Programmer
 
Join Date: Sep 2005
Rookie Year: 2005
Location: Flanders, NJ
Posts: 385
bear24rw is a splendid one to beholdbear24rw is a splendid one to beholdbear24rw is a splendid one to beholdbear24rw is a splendid one to beholdbear24rw is a splendid one to beholdbear24rw is a splendid one to beholdbear24rw is a splendid one to behold
Send a message via AIM to bear24rw
Re: How to Lock a motor

Turning the brake on, on the speed controller will help too
  #7   Spotlight this post!  
Unread 25-03-2007, 20:38
Daniel_LaFleur's Avatar
Daniel_LaFleur Daniel_LaFleur is offline
Mad Scientist
AKA: Me
FRC #2040 (DERT)
Team Role: Engineer
 
Join Date: Apr 2005
Rookie Year: 2003
Location: Peoria, IL
Posts: 1,980
Daniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond reputeDaniel_LaFleur has a reputation beyond repute
Send a message via MSN to Daniel_LaFleur
Re: How to Lock a motor

Each of these solutions has things that you need to consider.

Quote:
Originally Posted by meatmanek View Post
There are a few solutions.

My preferred solution is to use a positional feedback sensor of some sort (potentiometer, encoder, etc) mounted to the arm, so the controller knows where the arm is, and then use a PID loop. This is the most complex in terms of programming, but if there's an easy way to mount your sensor it can be the easiest mechanically.
Some motors do not like to be run this way (specifically the banebots) as their cooling is attached to their drive shaft. Choose your motors wisely when doing this.

Quote:
Originally Posted by meatmanek View Post
The next solution would be to use a worm drive, or a motor that has worm drive built in. The Denso and Keyang window motors are all worm drive, and cannot be back-driven.
This is probably the best solution, however these motors tend to be less efficient and less powerful, so you may need to 'assist' them (depending on your application)

Quote:
Originally Posted by meatmanek View Post
The third solution, if you don't want to mess with tricky PID tuning or replacing a motor entirely in an arm, is a brake system.
Here is a picture of another team's brake mechanism:
http://www.chiefdelphi.com/forums/at...9&d=1172112278
This is a great way of doing things, but you must make sure that the brake can be released with weight on it and that the brake is released when you want to move the motor again (or else it will quickly stall)

Quote:
Originally Posted by meatmanek View Post
You may want to read this thread:
http://www.chiefdelphi.com/forums/sh...ighlight=brake
EDIT: Never mind, you've already posted on that thread.

Each of the above will work as long as you take the proper considerations into the design.
__________________
___________________
"We are not now that strength which in old days moved earth and heaven; that which we are, we are;
One equal temper of heroic hearts, Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield. "
- Tennyson, Ulysses
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Drill motor gearbox lock mechanism golf_cart_john Motors 2 28-04-2004 02:22
Rotating the motor cage to lock in LOW sanddrag Motors 3 10-03-2004 07:23
How to get Nippon-Denso Motor walterj Motors 2 05-02-2004 07:20
How fast is the torque motor? archiver 2001 3 23-06-2002 22:55
How fast could a torque motor turn if a torque motor could.. archiver 2001 0 23-06-2002 22:54


All times are GMT -5. The time now is 15:41.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi