Firstly, everyone please check this thread out. Any advice that you can give would be appreciated.
Now my actual question…
Our team this year wants to try and create a multiple geared robot. We want to try and essentially make our own shifting mechanism as supershifters are effective, but expensive. Does anyone have a CAD drawing or white paper or really anything to help us? I know that plenty of people have one somewhere, and since most of our team is extremely young this year, any help that we could get would be fantastic.
Thank you all and again, please read the above posted thread.
973 has posted CADs of many of their recent robots. All their bots(except maybe 2009, don’t remember) have shifters based off of supershifter parts. This is the best way of doing them because you can get most of the parts without having to machine much. To get aluminum gears check out WCP: http://wcproducts.net/gears-20-dp/
On the topic of gearboxes, I highly reccommend you go COTs your first year of shifters. You don’t want to run custom during the season if you haven’t prototyped during the season. WCP is releasing some new shifting and nonshifting gearboxes that you might want to check out(WCD and Regular), but the supershifters are definitely a great, reliable option too.
I’ll echo this. I believe for most FIRST games, single speeds will keep you competitive. Develop them in the off season if you can and then work to implement them next year if at all possible.
You might not necessarily even have to buy a pair of supershifters if you’re seriously interested in designing your own. I must preface this with this suggestion only working if you have some previous designs of your own and are looking for some advice. If you’ve made some solid progress and research, you can “accelerate” your design process by buying one supershifter, taking it apart, putting it back together, taking it apart again, cadding each piece (yes this includes making CAD of gears), assembling it in your CAD package, then transferring what you’ve learned to your own design. It will probably end up looking somewhat similar to a supershifter, but you can make design changes along the way. This is what a lot of teams, us included, do for developing Swerve drive, but it transfers across to anything that can be bought COTs.
In short, don’t reinvent the wheel when you can buy it and give it a paint job and some new rims.
AM publishes CADs of the supershifter, so using those cads is probably a more ecenomical solution. Also if you have to use custom, using supershifter design isn’t the best. It has an extra reduction that isn’t needed as long as you use smaller wheels(which you should do anyways). For completely custom the 973 CAD is probably your best bet. Again, at this point in time, you really should either bite the bullet and buy supershifters or settle for single speed. Unless you work VERY, VERY hard to get a drivetrain prototyped before season, you run the very high risk of not moving. There are a lot of things that you will not learn unless you go through prototyping a custom drivetrain. Currently, I think the time could be better spent to prepare for the build season in other ways(training members, stocking up, etc.).
Fair enough but there’s something about understanding a design that you can get from handling it yourself. Perhaps I’m just a hands on rather than visual person. I’ve downloaded the supershifter design myself and taken a look. It’s just not the same.
I agree with other’s comments that SSers are the way to go.
If you have to ask the general question of , “how do we do this”, you won’t be able to make your own for season reliably. And you’ll certainly dump more money into that than just buying shifters.
SSers are awesome guys, after running them for a while you can analyze them and work on making your own.
The white papers here on CD have several shifting transmissions. Fairly simple designs by Andy Baker, Dave Lavery and myself were posted before the time when AM shifters were sold. All of these were competiton tested.
Search by tag “gearbox” . If you add the tag “frc716” you will find my 2005 dual motor, dual speed. It costs about $200 in parts and can be made with non cnc equipment.