View Single Post
  #7   Spotlight this post!  
Unread 26-04-2010, 17:48
Tom Line's Avatar
Tom Line Tom Line is offline
Raptors can't turn doorknobs.
FRC #1718 (The Fighting Pi)
Team Role: Mentor
 
Join Date: Jan 2007
Rookie Year: 1999
Location: Armada, Michigan
Posts: 2,524
Tom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond repute
Re: Drivetrain experimenting

Quote:
Originally Posted by Ether View Post
You mentioned these three combinations:

1) CIM motor/Toughbox transmission
2) CIM motor/Dewalt transmission
3) Dewalt Motor/ Dewalt transmission

For the first one, the torque vs speed motor curve for the CIM motor is available at the andymark.biz website. And the gear ratio for the toughbox is specified there too. So with just a tiny bit of physics and math, you have a good estimate (neglecting friction) of what the torque vs speed curve at the wheels would be.

For the second one, just look up the gear ratio for the Dewalt transmission and compare it the the toughbox spec. This will tell you if you will get more torque and less speed, or less torque and more speed, compared to #1.

For the third one, look up the motor specs for the Dewalt motor and compare it to the CIM. This will tell you how #3 stacks up against #2.


~

As an additional note, if you choose to do the math remember to include basic efficiency losses. 1% per spur-style gear is usually adequate. Which means that a planetary tranny is going to be far less efficient than one with only 2 or 3 gear interactions like a toughbox.

I suggest, before you do any testing, you start reading a bit about different styles of transmissions and their strengths and weaknesses.