Go to Post But their robot puts its wheels on one at a time just like ours, so we can be a HOF winner too! - Foster [more]
Home
Go Back   Chief Delphi > Technical > Kit & Additional Hardware
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 26-01-2005, 14:50
Peter Matteson's Avatar
Peter Matteson Peter Matteson is offline
Ambitious but rubbish!
FRC #0177 (Bobcat Robotics)
Team Role: Engineer
 
Join Date: Sep 2003
Rookie Year: 2003
Location: South Windsor, CT
Posts: 1,653
Peter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond repute
Re: Titanium chain & sprokets

Just a little more info on titanium sprockets.

Shimano Dura-Ace ten speed cassettes have 4 Ti sprockets, the four largest sizes vary depending on the cassette. They cost ~$150 (for 11-23) to ~$170 (12-27). This is cost prohibitive very quickly.

Also the 7075 Al sprockets are hard-coat anodized (class III) for durability while the Ti is nickle coated for the same reason.

However you may be able to get Ti, and definitely Al bike chainrings on sale from some of these places. Think prelightened sprockets. Just don't bogart the Dura-Ace on me Also any one who builds a robot with Campy should win the form over function competition immeadiatly.

You can get these from any number of bike cataloges:
www.worldcycling.com
www.coloradocyclist.com
www.supergo.com
www.nashbar.com
www.performancebike.com

Last edited by Cory : 26-01-2005 at 15:08. Reason: fixed your link :)
  #2   Spotlight this post!  
Unread 26-01-2005, 15:50
roboticscom13's Avatar
roboticscom13 roboticscom13 is offline
Registered User
no team
Team Role: Alumni
 
Join Date: Jan 2002
Rookie Year: 2000
Location: USA
Posts: 46
roboticscom13 is an unknown quantity at this point
Re: Titanium chain & sprokets

We used nylon sprockets for our robot's drivetrain last year. We got into pushing matches and we ran at high speeds and they were perfectly fine. If you are concerened that much about wieght i would say use the nylon sprockets. We used steel sprockets in the '02 competition and they were exceedingly heavy even machined out. We also had a couple of them fail. We incorporated nylon sprockets in the same drive train but for last year and they worked perfectly. I would use nylon sprockets for the drivetrain, and then like alreadly said if there are high ammounts of torque needed then you should do calculations to see if it would be beneficial to go for steel sprockets.
  #3   Spotlight this post!  
Unread 26-01-2005, 22:38
Holtzman's Avatar
Holtzman Holtzman is offline
Sometimes...
AKA: Tyler Holtzman
FRC #2056 (OP Robotics)
Team Role: Engineer
 
Join Date: Apr 2003
Rookie Year: 2003
Location: St. Catharines
Posts: 179
Holtzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond repute
Send a message via MSN to Holtzman
Re: Titanium chain & sprokets

Quote:
Originally Posted by Dzdconfusd
Just a little more info on titanium sprockets.

Shimano Dura-Ace ten speed cassettes have 4 Ti sprockets, the four largest sizes vary depending on the cassette. They cost ~$150 (for 11-23) to ~$170 (12-27). This is cost prohibitive very quickly.
You should also note, that these bicycle sprockets are designed to take torque in one direction only. Ex, you don't ride a bike back wards. If you look closely, the tooth profile is optimized for load in the pedaling direction. It is much more obvious on the front chain rings.

These sprockets would also be very hard to work with. All the major bicycle component manufactures have there rear sprockets fitted on a non-standard spline, that would be VERY difficult to machine yourself. Theres also not very much material left over do drill your own mounting holes either.

The front chain-rings would be much more easily adapted. Most road chain rings fit on a standard 130mm bolt circle, and the higher quality ones are very light. Mountain bike chain rings are smaller in size, and also have a smaller bolt diameter.(which i don't know off the top of my head) On the other hand you still limited to bicycle chain, which although is 1/2", is much narrower than standard ANSI chain. You also need special connecting pins, to change the chain length, and a different chain tool. Also, you cannot get half-links for it.

In summary, it is my opinion that, although very light, high-performance bicycle sprockets are more hassle than their worth. You can get standard aluminum sprockets, and just lighten them yourselves, and they will be just as light as bicycle sprockets, and a whole lot easier to work with.
__________________
"making the simple complicated is commonplace; making the complicated simple, awesomely simple, that's creativity." - Charles Mingus

Last edited by Holtzman : 27-01-2005 at 09:17.
  #4   Spotlight this post!  
Unread 27-01-2005, 07:53
Peter Matteson's Avatar
Peter Matteson Peter Matteson is offline
Ambitious but rubbish!
FRC #0177 (Bobcat Robotics)
Team Role: Engineer
 
Join Date: Sep 2003
Rookie Year: 2003
Location: South Windsor, CT
Posts: 1,653
Peter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond repute
Re: Titanium chain & sprokets

Quote:
Originally Posted by Holtzman
You should also note, that these bicycle sprockets are designed to take torque in one direction only. Ex, you don't ride a bike back wards. If you look closely, the tooth profile is optimized for load in the pedaling direction. It is much more obvious on the front chain rings.
Not true. They only see it in one direction. The teeth however are ground to help shifting in the normal direction of operation. See the below link to see what I mean.
http://www.dura-ace.com/publish/cont...ive_train.html


Quote:
Originally Posted by Holtzman
These sprockets would also be very hard to work with. All the major bicycle component manufactures have there rear sprockets fitted on a non-standard spline, that would be VERY difficult to machine yourself. Theres also not very much material left over do drill your own mounting holes either.
This is true and I purposely didn't mention it before. It's also a PITA to take apart a cassette. Which is why I pointed to front chainrings.

Quote:
Originally Posted by Holtzman
The front chain-rings would be much more easily adapted. Most road chain rings fit on a standard 130mm bold circle, and the higher quality ones are very light. Mountain bike chain rings are smaller in size, and also have a smaller bold diameter.(which i don't know off the top of my head) On the other hand you still limited to bicycle chain, which although is 1/2", is much narrower than standard ANSI chain. You also need special connecting pins, to change the chain length, and a different chain tool. Also, you cannot get half-links for it.
Shimano Std Chainring BOLT circle = 130mm
Campagnolo Std Chainring BOLT circle = 135mm

Yes they use a 1/2" pitch chain. No the chaintools aren't that special just smaller. No special parts are required you just add or remove links. Bike chains don't use master links. Yeah they make really narrow chain for the 10-speed cassettes that doesn't even work with the 9-speed cassettes. The advantage is you can get it at any bike shop.
  #5   Spotlight this post!  
Unread 27-01-2005, 12:58
Holtzman's Avatar
Holtzman Holtzman is offline
Sometimes...
AKA: Tyler Holtzman
FRC #2056 (OP Robotics)
Team Role: Engineer
 
Join Date: Apr 2003
Rookie Year: 2003
Location: St. Catharines
Posts: 179
Holtzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond reputeHoltzman has a reputation beyond repute
Send a message via MSN to Holtzman
Re: Titanium chain & sprokets

Pete;
You are correct on the first point. The teeth are ground to help shifting. As a result of that, you end up with an asymmetric tooth profile, which takes torque better in one direction than the other. I think were both right on that one. We seem to be in agreement regarding rest of my points. I think we've gotten a little off topic anyway.
__________________
"making the simple complicated is commonplace; making the complicated simple, awesomely simple, that's creativity." - Charles Mingus
  #6   Spotlight this post!  
Unread 27-01-2005, 13:00
Peter Matteson's Avatar
Peter Matteson Peter Matteson is offline
Ambitious but rubbish!
FRC #0177 (Bobcat Robotics)
Team Role: Engineer
 
Join Date: Sep 2003
Rookie Year: 2003
Location: South Windsor, CT
Posts: 1,653
Peter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond reputePeter Matteson has a reputation beyond repute
Re: Titanium chain & sprokets

Quote:
Originally Posted by Holtzman
Pete;
We seem to be in agreement regarding rest of my points. I think we've gotten a little off topic anyway.
Agreed.
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
Chain Drive Question Matt_Kaplan1902 Technical Discussion 34 12-04-2004 14:21
Aluminum chain? Brawler006 Technical Discussion 11 24-02-2004 15:52
25 or 35 chain? Alan Ing Technical Discussion 24 02-03-2003 13:56
1/4" chain and links from small parts archiver 2001 2 24-06-2002 00:18
Chain and chain breaker source? kmcclary Off-Season Events 4 22-10-2001 22:51


All times are GMT -5. The time now is 17:53.

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