paper: JVN's Mechanical Design Calculator 2016
 

Thread created automatically to discuss a document in CD-Media.

JVN's Mechanical Design Calculator 2016 by JVN

This new version published for 2016 includes some small improvements.
Older versions still available:
http://www.chiefdelphi.com/media/papers/2755
http://www.chiefdelphi.com/media/papers/2059
http://www.chiefdelphi.com/media/papers/1469

Everything is iterative. Email me if you have questions or find issues!

Re: paper: JVN's Mechanical Design Calculator 2016
 

Awesome to see a new version! Can't wait to play with it.

Re: paper: JVN's Mechanical Design Calculator 2016
 

The unique sheets for each WCP/VEXPRO gearbox should make things a lot more straightforward

Re: paper: JVN's Mechanical Design Calculator 2016
 

Thanks for keeping this up to date! I've learned a lot just from puzzling out your earlier versions. I'll definitely have to dig in this year on the calculations for the heteromotored gearboxes.

Re: paper: JVN's Mechanical Design Calculator 2016
 

Very nice and clear update. I like the changes, Thanks very much.

Re: paper: JVN's Mechanical Design Calculator 2016
 

I'm not sure I understand the Articulating Drive. What is it for exactly?

This is another awesome resource.

Re: paper: JVN's Mechanical Design Calculator 2016
 

Thanks! It's a great resource

Re: paper: JVN's Mechanical Design Calculator 2016
 

I would assume for butterfly, grasshopper, octocanum etc. Drivetrains with articulating wheels.

Re: paper: JVN's Mechanical Design Calculator 2016
 

My favoritest release this season so far!

Re: paper: JVN's Mechanical Design Calculator 2016
 

This is the key to having more success.

Re: paper: JVN's Mechanical Design Calculator 2016
 

Just posted an updated version:

• Added RS-550 Motor Data which will be up on motors.vex.com
• Changed the Motor selection lookup formula on the "non VEXpro" sheets to better allow for multiple iterations on the same sheet
• Added additional "All MiniCIM" motor selection options on VEXpro sheets
• Fixed some formatting that no one else would notice but was driving me nuts

Thanks to everyone who provided feedback. Enjoy and Good luck!

Re: paper: JVN's Mechanical Design Calculator 2016
 

Wow @ the 550 power. I now get why we had issues with our elevator last year. Thanks for testing the 550.

Re: paper: JVN's Mechanical Design Calculator 2016
 

Thanks for the effort you put into - and for sharing - this universally valueable tool

Re: paper: JVN's Mechanical Design Calculator 2016
 

This is the first time I have worked on a drive base, and so I wanted to make sure that I was doing everything correctly.

1. For the "Weight on Driven Wheels", that weight is distributed evenly among wheels, right? (say 25% if there are 4 wheels)
2. What is the "Speed Loss Constant"?

Thanks in advance!

Re: paper: JVN's Mechanical Design Calculator 2016
 

Speed loss constant accounts for the difference between actual speed and free speed of the motor. You can pretty much leave it at 81% for most FRC applications.

For "weight on driven wheels" if you have a 4WD robot with all wheels being driven then you would set that at 100%. If 2 of the wheels where non driven casters that would be 50% assuming a perfect weight distribution. Also for the purposes of this calculator omni and mecanum wheels are the same as traction wheels and wheel drop is ignored.

Re: paper: JVN's Mechanical Design Calculator 2016
 

Can a brother get more stages in the Rotary Mechanism tab for the 2017 version? I need more than 4 stages please. :P

Re: paper: JVN's Mechanical Design Calculator 2016
 

It's an empirically-determined value, and will "vary from robot to robot".

The 81% value is "about right" for the robots that team 148 builds.

"This is all very inexact. The calculations end up being "about right."
"About right" is totally okay for a FIRST Robot."

Stuff in quotes are excerpts from an old JVN post.

Your team can measure this speed loss constant for robots that your team builds, and eventually to get an idea if a different number would be more suitable for your team's robots. The number depends not only on type of drivetrain and the design details, but also on craftsmanship.