OCCRA
Go to Post (middle school age) One time I had a truly awful day at school and came home crying. My mother's response? "Do you want to go to the build session tonight? It will make you feel better.." And it did. It always does. - rachelholladay [more]
Home
Go Back   Chief Delphi > FIRST > General Forum
CD-Media  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Reply
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 07-08-2018, 02:20 PM
Stuart's Avatar
Stuart Stuart is offline
#include coffee.h
AKA: Stuart Rampy
FRC #1745 (The P-51 Mustangs)
Team Role: Mentor
 
Join Date: Jan 2006
Rookie Year: 2004
Location: Dallas, TX
Posts: 431
Stuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond reputeStuart has a reputation beyond repute
Most useful basic equations/reference for FRC/FTC?

So Im making a 1 page quick reference for my team.

If you had a 1 page basic Equation/Reference sheet for FRC/FTC what would you want on it?

Things I'm thinking of
  • Some Pythagorean triplets.
  • An example of force and speed in some basic gear configurations
  • Arm force equations & diagrams
  • projectile motion equations & diagram
__________________
Proud mentor of Team #1745 the P-51 Mustangs

If at first it doesn't work, use a hammer.
If that doesn't work, use a bigger hammer.
Reply With Quote
  #2   Spotlight this post!  
Unread 07-08-2018, 02:37 PM
ClayTownR's Avatar
ClayTownR ClayTownR is offline
Registered User
AKA: Clayton
FRC #0100 (The WildHats)
Team Role: CAD
 
Join Date: Dec 2016
Rookie Year: 2015
Location: California
Posts: 195
ClayTownR has much to be proud ofClayTownR has much to be proud ofClayTownR has much to be proud ofClayTownR has much to be proud ofClayTownR has much to be proud ofClayTownR has much to be proud ofClayTownR has much to be proud ofClayTownR has much to be proud of
Re: Most useful basic equations/reference for FRC/FTC?

Here's a short list of equations that I have used in FRC and FTC:

Code:
Geometry
sin^2(x)+cos^2(x)=1
C=2*pi*r

Mechanics
F=ma (and its angular complement T=I*alpha)
at^2+vt+k=x
W=Fd (the calculus definition W=integral F ds is also useful)
w=mg

Electricity
V=IR
P=VI

Gears
Ratio = Driving teeth / driven teeth (also true for belts)
Center distance = (Pitch Diameter 1 + Pitch Diameter 2) / 2 + Center Add
__________________
FTC 4800, 2015-2017
FRC 100, 2016-
Reply With Quote
  #3   Spotlight this post!  
Unread 07-08-2018, 04:42 PM
deslusionary's Avatar
deslusionary deslusionary is offline
kult of the kotlin
AKA: Christopher Tinker
FRC #7093 (Veritas Valiants)
Team Role: Programmer
 
Join Date: Mar 2018
Rookie Year: 2018
Location: Austin TX
Posts: 135
deslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant future
Re: Most useful basic equations/reference for FRC/FTC?

Not mechanically oriented so here's a PID equation:

Click image for larger version

Name:	PIDController_Equaton.png
Views:	297
Size:	21.2 KB
ID:	23479
Reply With Quote
  #4   Spotlight this post!  
Unread 07-08-2018, 06:05 PM
Michael Hill's Avatar
Michael Hill Michael Hill is offline
Registered User
FRC #3138 (Innovators Robotics)
Team Role: Mentor
 
Join Date: Jul 2004
Rookie Year: 2003
Location: Dayton, OH
Posts: 1,892
Michael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

DC motor equations
__________________
'12-'xx: Mentor FRC 3138 - Innovators Robotics
'07-'07: Mentor FRC 1646 - Precision Guessworks
'04-'06: Student FRC 45 - TechnoKats
Reply With Quote
  #5   Spotlight this post!  
Unread 07-08-2018, 06:11 PM
Tomithy's Avatar
Tomithy Tomithy is offline
RIP Bag
FRC #5727 (REaCH Omegabytes)
Team Role: Mechanical
 
Join Date: Mar 2018
Rookie Year: 2016
Location: North Carolina
Posts: 192
Tomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud ofTomithy has much to be proud of
Re: Most useful basic equations/reference for FRC/FTC?

Quote:
Originally Posted by Michael Hill View Post
DC motor equations
^this
__________________
Cookie cutters: still not made on anvils.
The best letter will always be 9.
Reply With Quote
  #6   Spotlight this post!  
Unread 07-08-2018, 06:21 PM
deslusionary's Avatar
deslusionary deslusionary is offline
kult of the kotlin
AKA: Christopher Tinker
FRC #7093 (Veritas Valiants)
Team Role: Programmer
 
Join Date: Mar 2018
Rookie Year: 2018
Location: Austin TX
Posts: 135
deslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant futuredeslusionary has a brilliant future
Re: Most useful basic equations/reference for FRC/FTC?

DC motor equations, with explanations:

http://motors.vex.com/introduction
Reply With Quote
  #7   Spotlight this post!  
Unread 07-08-2018, 08:32 PM
marshall's Avatar
marshall marshall is online now
"Who's Marshall?"
FRC #0900 (The Zebracorns)
Team Role: Mentor
 
Join Date: Jan 2012
Rookie Year: 2003
Location: North Carolina
Posts: 3,062
marshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

V=I*R

And all of its various derivatives.
__________________
"La mejor salsa del mundo es la hambre" - Miguel de Cervantes
"The future is unwritten" - Joe Strummer
"Simplify, then add lightness" - Colin Chapman
Clarke's Laws
Reply With Quote
  #8   Spotlight this post!  
Unread 07-08-2018, 09:32 PM
NerdRage's Avatar
NerdRage NerdRage is offline
Student Captain
AKA: Aaron Fang
FRC #3863 (Pantherbotics)
Team Role: Student
 
Join Date: Apr 2016
Rookie Year: 2016
Location: Newbury Park, CA
Posts: 103
NerdRage is a glorious beacon of lightNerdRage is a glorious beacon of lightNerdRage is a glorious beacon of lightNerdRage is a glorious beacon of lightNerdRage is a glorious beacon of light
Re: Most useful basic equations/reference for FRC/FTC?

for gears: pitch diameter = # teeth / diametrical pitch
for pullies: pitch diameter = (# teeth * pitch) / pi
__________________
FIRST Stronghold - LA Regional Judge's Award & Semifinalists, Ventura Regional Semifinalists
FIRST Steamworks - Orange County Quarterfinalists
FIRST Power Up - LA Regional Quarterfinalists, Ventura Regional Semifinalists



Reply With Quote
  #9   Spotlight this post!  
Unread 07-08-2018, 10:26 PM
nickbrickmaster nickbrickmaster is offline
Registered User
AKA: Nick Schatz
no team ('Snow Problem, 3184 Alum)
Team Role: Programmer
 
Join Date: Jan 2015
Rookie Year: 2014
Location: Eagan MN
Posts: 476
nickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond reputenickbrickmaster has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

All you need is F = m*a and you can derive the rest.
__________________
This is a postmodern signature.
Reply With Quote
  #10   Spotlight this post!  
Unread 07-08-2018, 11:06 PM
GeeTwo GeeTwo is offline
Somebody Else
AKA: Gus Michel II
no team
Team Role: Mentor
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Slidell, LA
Posts: 6,032
GeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

It appears you're talking about for design time.

Along this line:

Quote:
Originally Posted by Stuart View Post
  • Some Pythagorean triplets.
I'd add some near-pythagorean triplets that are "close enough" to 30 and 45 degree angles to build Versaframe triangles without drilling holes in either gussets or tubes:

30/60/90 triangle: 152 + 262 ~ 302
45/45/90 triangle: 122 + 122 ~ 172

We used 15/26/30 (actually 7.5", 13", 15") on our 2017 robot and 12/12/17 on our 2018 competition robot; the errors were small enough in both cases that we had no problem fitting the rivets. I have also used 30x26 and 15x13 tiling patterns to make honeycomb wallpaper. Also, as it turns out, the 5/12/13 pythagorean triple is close enough to a 22 1/2 degree angle for many practical purposes.


Nickbrickmaster: This really should be ΣF = ma, and you also need Freaction = -Faction. All the F's and a's should be annotated as vector quantities. Then you can derive the rest. The derivations get shorter if you add ΣΓ = Iα with Γ and α being pseudo-vectors.

I might also add the equation for effective gear ratio of a planetary gearbox with a fixed ring: Rp = Rring/Rsun + 1.

Pneumatic cylinder equation: F=pA [also works for hydraulics, but not useful for FRC).

Some energy/work equations! Likely some I'm missing, here are a few:
  • Ekinetic = mv2/2 or Iω2/2
  • Egravitational = mgh
  • Espring = kx2/2
  • Epneumatic (slow) = pV

Edit: even on a one-pager, there should be some room for the key numbers of the legal motors (stall and free current, stall torque, free speed, peak power). Also, some conversion factors. Top of the list: 1 rpm ~ 0.1047 radians/sec.
__________________

If you can't find time to do it right, how are you going to find time to do it over?
If you don't pass it on, it never happened.
Robots are great, but inspiration is the reason we're here.
Friends don't let friends use master links.
[Quoting brennonbrimhall]: We design a new robot every year, but we can't forget that we also design a new team every year as folks come and go.

Last edited by GeeTwo : 07-08-2018 at 11:30 PM.
Reply With Quote
  #11   Spotlight this post!  
Unread 07-09-2018, 09:37 AM
ratdude747's Avatar
ratdude747 ratdude747 is offline
Official Scorekeeper
AKA: Larry Bolan
no team
 
Join Date: Feb 2009
Rookie Year: 2008
Location: Madison, IN
Posts: 1,193
ratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

This, if you're a district team
Attached Thumbnails
Click image for larger version

Name:	District qual points.PNG
Views:	205
Size:	143.2 KB
ID:	23480  
__________________
Dean's List Semi-finalist 2010
1747 Harrison Boiler Robotics 2008-2010, 2783 Engineers of Tomorrow 2011, Event Volunteer 2012-current

DISCLAIMER: Any opinions/comments posted are solely my personal opinion and does not reflect the views/opinions of FIRST, IndianaFIRST, or any other organization.
Reply With Quote
  #12   Spotlight this post!  
Unread 07-09-2018, 10:44 PM
jhill42 jhill42 is offline
Registered User
FRC #1747
 
Join Date: Apr 2018
Rookie Year: 2015
Location: IN
Posts: 8
jhill42 is an unknown quantity at this point
Re: Most useful basic equations/reference for FRC/FTC?

Quote:
Originally Posted by deslusionary View Post
Not mechanically oriented so here's a PID equation:

Attachment 23479
Donít most people write for their constants to all be positive? If so, shouldnít the derivative term have the opposite sign?
Reply With Quote
  #13   Spotlight this post!  
Unread 07-09-2018, 11:14 PM
Jared Russell's Avatar
Jared Russell Jared Russell is offline
4933T15
FRC #0254 (The Cheesy Poofs), FRC #0341 (Miss Daisy)
Team Role: Engineer
 
Join Date: Nov 2002
Rookie Year: 2001
Location: San Francisco, CA
Posts: 3,561
Jared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

Quote:
Originally Posted by jhill42 View Post
Donít most people write for their constants to all be positive? If so, shouldnít the derivative term have the opposite sign?
There are a bajillion forms of the PID equation people use.
Reply With Quote
  #14   Spotlight this post!  
Unread 07-09-2018, 11:49 PM
Ginger Power's Avatar
Ginger Power Ginger Power is offline
Founder of COR Robotics
AKA: Ryan Swanson
no team
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Minnesota
Posts: 1,541
Ginger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond reputeGinger Power has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

From one of my favorite professors and I'm sure a bunch of other places, here are the fundamental equations for a few different engineering disciplines:

Electrical Engineers: V = I*R (Ohm's Law)

Mechanical Engineers: F = M*a (Newton's 2nd Law)

Civil Engineers: "if it goes uphill you gotta pump it" (... most civil engineers)
Reply With Quote
  #15   Spotlight this post!  
Unread 07-10-2018, 08:45 AM
marshall's Avatar
marshall marshall is online now
"Who's Marshall?"
FRC #0900 (The Zebracorns)
Team Role: Mentor
 
Join Date: Jan 2012
Rookie Year: 2003
Location: North Carolina
Posts: 3,062
marshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond reputemarshall has a reputation beyond repute
Re: Most useful basic equations/reference for FRC/FTC?

Quote:
Originally Posted by Ginger Power View Post
From one of my favorite professors and I'm sure a bunch of other places, here are the fundamental equations for a few different engineering disciplines:

Electrical Engineers: V = I*R (Ohm's Law)

Mechanical Engineers: F = M*a (Newton's 2nd Law)

Civil Engineers: "if it goes uphill you gotta pump it" (... most civil engineers)
TIL will.i.am is a civil engineer.
__________________
"La mejor salsa del mundo es la hambre" - Miguel de Cervantes
"The future is unwritten" - Joe Strummer
"Simplify, then add lightness" - Colin Chapman
Clarke's Laws
Reply With Quote
Reply


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 02:01 AM.

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


Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi