OCCRA
Go to Post Use checklists. If it's good enough for NASA, it's good enough for FIRST. - Rick TYler [more]
Home
Go Back   Chief Delphi > Technical > Motors
CD-Events   CD-Media   CD-Spy   FRC-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 05-05-2012, 02:52 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Optical Encoders

Before our team goes to the CORI event on June 23, we are trying to improve our robot. One of our goals is to connect optical encoders to our shooter, and attach a camera to track the hoops. Our shooter uses two Banebot RS-775 motors with P60 16:1 gearboxes. Will the optical encoders given in the KOP work with these, or do we have to buy different encoders?
  #2   Spotlight this post!  
Unread 05-05-2012, 03:02 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
Before our team goes to the CORI event on June 23, we are trying to improve our robot. One of our goals is to connect optical encoders to our shooter, and attach a camera to track the hoops. Our shooter uses two Banebot RS-775 motors with P60 16:1 gearboxes. Will the optical encoders given in the KOP work with these, or do we have to buy different encoders?
It depends.

How do you intend to mount the encoder, e.g. are using a live or dead axle, what is the axle diameter, direct drive or belt/chain/gear driven etc.

How fast will you be driving the encoder. Do you plan to attach it to FPGA or Jag. Do you plan to use 1x, 2x, or 4x decoding.

How do you intend to use the signal. PID, Take-back-half, Bang-Bang, something else? Some are more immune to noise than others.


  #3   Spotlight this post!  
Unread 05-05-2012, 03:24 PM
DonRotolo's Avatar
DonRotolo DonRotolo is offline
Back to earth once again
FRC #1676 (Pascack PI Oneers)
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2005
Location: Montvale NJ
Posts: 6,397
DonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond repute
Re: Optical Encoders

The short answer is yes, they can be made to work.

For more details, consider the questions posed by Ether and let us know, so we can offer some suggestions. And, if you don't know what something means, say so, we'll be happy to explain.
__________________

I am N2IRZ - What's your callsign?
Also visit TARPN to see what's up!
  #4   Spotlight this post!  
Unread 05-05-2012, 03:41 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Re: Optical Encoders

I only know a few of the answers, so I sent an email to two of my programmers/electrical to try and answer the rest. What I know is: the shaft of the gear box is .5in, it is run belt/chain/gear driven etc., and at full speed (but we only go about 35%) it can go up to 3,408 rpm.
  #5   Spotlight this post!  
Unread 05-05-2012, 03:43 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Re: Optical Encoders

I do not understand the question of dead or live axle. And the other questions I think my programmers should be able to answer.
  #6   Spotlight this post!  
Unread 05-05-2012, 03:44 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
I do not understand the question of dead or live axle. And the other questions I think my programmers should be able to answer.
Live axle => axle turns with wheel

Dead axle => axle does not turn


  #7   Spotlight this post!  
Unread 05-05-2012, 03:52 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
I only know a few of the answers, so I sent an email to two of my programmers/electrical to try and answer the rest. What I know is: the shaft of the gear box is .5in, it is run belt/chain/gear driven etc., and at full speed (but we only go about 35%) it can go up to 3,408 rpm.
Here's what I think you said, but I can't tell for sure:

1) Your 775 motor is connected to a gear box.

2) The output shaft of that gearbox is 1/2" diameter

3) There's a sprocket on the output shaft of the gearbox

4) There's a chain on that sprocket

5) That chain goes to a sprocket connected to the wheel

6) The wheel rides on a dead axle.


How and where do you plan to physically mount the encoder?

What is the gear ratio of the gearbox?

What is the tooth count on the two sprockets?


  #8   Spotlight this post!  
Unread 05-05-2012, 04:00 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Re: Optical Encoders

All of that sounds right, but Im going to post a picture just to make sure.

I do not know how or where we will mount the encoder, what is the best way?

The gear ratio of the gear box is a 16:1. http://banebots.com/pc/P60K-S7/P60K-44-0007

The tooth count I believe a 32 tooth on the big one, and a 10 tooth on the other.

Last edited by Jengles : 05-05-2012 at 04:08 PM.
  #9   Spotlight this post!  
Unread 05-05-2012, 04:13 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Re: Optical Encoders

Im having trouble uploading the picture..
If you go to our website www.stcharlesrobotics.com , I just put the picture as the first one.

Last edited by Jengles : 05-05-2012 at 04:15 PM.
  #10   Spotlight this post!  
Unread 05-05-2012, 04:15 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
The tooth count I believe a 32 tooth on the big one, and a 10 tooth on the other.
Which one is which.


  #11   Spotlight this post!  
Unread 05-05-2012, 04:20 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Re: Optical Encoders

Quote:
Originally Posted by Ether View Post
Which one is which.


Were you able to find it? I also posted the back view of the sprocket.
  #12   Spotlight this post!  
Unread 05-05-2012, 04:21 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
Im having trouble uploading the picture..
see attachments


Attached Thumbnails
Click image for larger version

Name:	step1.png
Views:	39
Size:	50.3 KB
ID:	12730  Click image for larger version

Name:	steps2&3.png
Views:	41
Size:	27.2 KB
ID:	12731  
  #13   Spotlight this post!  
Unread 05-05-2012, 04:28 PM
Jengles's Avatar
Jengles Jengles is offline
Registered User
FRC #4753 (Bexley Lions)
Team Role: Leadership
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Bexley, Ohio
Posts: 45
Jengles will become famous soon enough
Re: Optical Encoders

I followed the steps, its not uploading them properly. But the ones one the website work.
  #14   Spotlight this post!  
Unread 05-05-2012, 04:31 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
Im having trouble uploading the picture..
If you go to our website www.stcharlesrobotics.com , I just put the picture as the first one.
You said it was a dead axle, but that's a live axle. You are driving the axle with the chain.

You are gearing the motor speed down with the gearbox, and then gearing it back up with the sprockets. Generally speaking, you want to avoid doing that if possible.

I don't see a good place to mount the encoder without making changes/additions to the design.

Perhaps you could drill a hole and tap threads into the end of each wheel axle and make an adaptor for the encoder disk.

EDIT: See attached pic

Attached Thumbnails
Click image for larger version

Name:	shooter.jpg
Views:	87
Size:	136.5 KB
ID:	12732  

Last edited by Ether : 05-05-2012 at 04:41 PM. Reason: added pic
  #15   Spotlight this post!  
Unread 05-05-2012, 04:32 PM
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 6,025
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Optical Encoders

Quote:
Originally Posted by Jengles View Post
I followed the steps, its not uploading them properly. But the ones one the website work.
When you say "it's not uploading them properly", what do you mean by that? Can you describe what is happening?


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


All times are GMT -5. The time now is 08:06 AM.

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


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi