We are introducing our Spectrum Robot Design Sheet (SRDS). This was inspired by several design calculators and references that have been posted by other members of the FRC Community. A huge thank you to the people that have produced these documents in the past.
Inspiration for This Sheet and other designs sheets
The Spectrum Robot Design Sheet is designed to be a centralized resource to use while designing FRC robots. Each page includes part specifications and calculations that you can use to help in the design process. Many of the COTS parts common to FRC robots have their size and other design parameters included here so you don’t have to open up the part in CAD to measure or find and download the drawings every time you need to quickly add something to a sketch or prototype.We keep a copy of this sheet for each robot that we build and then add new pages for each module/subsystem on our robot. That way we can keep track of our design decisions, variables, part numbers, etc in one centralized place.
You can add new pages for part references or inventory for your team. Timelines or simple gantt charts could be made to help keep everyone on schedule. Please make a copy of this sheet and add your own team’s conventions, materials, resources, and references and share it with your team if you think it is useful. If you make a cool page and want to suggest we add it to our public template just send us an email [email protected] and we’ll look at it.
Features
Belt, Chain, and Gear C-C calculators.
Simple drive train, and mechanism calculators.
Pneumatic cylinder base lengths, clevis, lengths and more.
Gas spring retracted and extended lengths.
Sample Module page to document your robot design variables, and decisions.
Drill sizes, & bolt sizes
Electronics status light reference
Spectrum
"Designing a product is keeping five thousand things in your brain and fitting them all together in new and different ways to get what you want. And every day you discover something new that is a new problem or a new opportunity to fit these things together a little differently.
And it’s that process that is the magic." - Steve Jobs
One thing I would add though. IMO the most valuable part of my spreadsheet calculator is the mechanism gear ratio calculator. Basically you give the calculator the motors and load going into the mechanism and excepted output of the mechanism, and it tells you the required gear ratio to get that output (or if that output isn’t possible given the inputs). I’ve found that this saves a lot of time guessing and checking gear ratios, and also helps see approximately how much power you need for your mechanism. My team used it for basically every mechanism last year and for our offseason projects.
One correction: L13 on the Mechanical sheet says AndyMark compliant wheels are 0.5" thickness. That’s true on the 2" wheels, but the 4" wheels are 1" thick like the Stealth Wheels.
Just shared this with my team, thanks for taking the time and effort to put together this awesome resource! Allen & Spectrum once again showing why they’re the best
Here’s my humble contribution. Instead of the pulley center distance calculator, the link below leads to table of all center distances worked out for commonly-available HTD belts and pulleys. It helps to know at a glance what lengths you can work with.
(edit: for 1:1 pulley runs only, both pulleys the same size)
Brendan,
The row you have labeled perimeter is actually pitch diameter.
Several of the configurations in the top left corner shown require the pulleys to pass through each other; I suggest blanking those out.
It really is amazing! Thank you for not only creating it --which I imagine took weeks, if not months to make-- but for sharing the document for the rest of us!
