[Behind the Lines] Ep. 5 Mechanism Design with 118, 3847, and 973!

[IKE]

Originally Posted by Greg Needel

It is really simple. Get a 12 volt drill with variable speed(old ones with burnt out motors are fine). Remove the motor, gearbox, chuck, etc. All you are left with is a handle with a switch and battery contacts. Wire your connector of choice to the output of the trigger (Where the motor used to be). That's it.


The advantage of this is you get the right voltage (assuming a 12 volt battery), variability in speed that is easy to control, and reversibility (without removing the wires.

Be warned, the really cheap ones can "burn up". did this with some $10 specials. It worked really well for a while then fried itself.

Thanks for the reminder that I need to make a couple new ones.

[jkelleyrtp]

I'm interested in learning a bit more about shooters as our team hasn't had to do anything with flywheels just yet. The wheel selection was well presented, but I just don't understand 254's robot in 2014 could fire the balls with a shooter! Considering the speeds and torques the 2012 motors ran out, it boggles me that the yoga balls could be fired with significant speed. Allen, do you have any resources pertaining to the deeper physics involved with shooters?

[AllenGregoryIV]

Originally Posted by IKE

Be warned, the really cheap ones can "burn up". did this with some $10 specials. It worked really well for a while then fried itself.

Thanks for the reminder that I need to make a couple new ones.

Also like Lucian mentioned in the video adding fuses will help your prototyping and increase the safety of using these devices.

A cheap fuse holder can hold a snap action breaker too. We purchased a few of these to add to ours.

[AllenGregoryIV]

Originally Posted by jkelleyrtp

I'm interested in learning a bit more about shooters as our team hasn't had to do anything with flywheels just yet. The wheel selection was well presented, but I just don't understand 254's robot in 2014 could fire the balls with a shooter! Considering the speeds and torques the 2012 motors ran out, it boggles me that the yoga balls could be fired with significant speed. Allen, do you have any resources pertaining to the deeper physics involved with shooters?

The Poofs do a great job of explaining their development process each year. Their build blog and technical binder are available on their website.

One suggestion is to go back and read some of the early season threads from previous shooter games. Each year we as a community learn a bit more.
2013 small wheel linear shooter design for example.

Another suggestion is the behind the design series. The 2006 book is getting hard to find but it's a great read.

The Fighting Pi posted some great Behind the Design articles for a variety of awesome 2012 robots.

[Mike Marandola]

Originally Posted by AllenGregoryIV

Lot of teams use them, they are very easy to build. Just open up a 12v drill (118 uses 18volt drills sometimes but that's a bit risky with some motors) and remove the motor. Connect the wiries to Anderson connectors or some other quick dissconnects. This allows you to change the speed and direction of whatever motor connects to it.

We use a small makita 12 volt drill that we broke the chuck off of and a cheap 12 volt model from Walmart that we bought specifically to use for that purpose.

Awesome, thanks. I wish we didn't throw out the rest of the drill that we took the gearbox out of last year.

[arc25565]

Does anyone know where I can get the power point that they used in the video as it had some great info. It was a great episode and I learned a lot, thanks!

[Mike Marandola]

Originally Posted by arc25565

Does anyone know where I can get the power point that they used in the video as it had some great info. It was a great episode and I learned a lot, thanks!

Here

Originally Posted by AllenGregoryIV

The Poofs do a great job of explaining their development process each year. Their build blog and technical binder are available on their website.

One suggestion is to go back and read some of the early season threads from previous shooter games. Each year we as a community learn a bit more.
2013 small wheel linear shooter design for example.

Another suggestion is the behind the design series. The 2006 book is getting hard to find but it's a great read.

The Fighting Pi posted some great Behind the Design articles for a variety of awesome 2012 robots.

Here are a few more.

[z_beeblebrox]

Originally Posted by Mike Marandola

Here are a few more.

Our engineering journal for the 2015 season can be found here.

[Ty Tremblay]

Originally Posted by arc25565

Does anyone know where I can get the power point that they used in the video as it had some great info. It was a great episode and I learned a lot, thanks!

Here's FIRST's archive:
http://www.firstinspires.org/resourc...hind-the-lines

[topgun]

I just reviewed the video again. Lucien mentioned a "magic rubber strip tape". What is that and what is it used for? Any links to where to buy it?

Thanks.

[AllenGregoryIV]

Originally Posted by topgun

I just reviewed the video again. Lucien mentioned a "magic rubber strip tape". What is that and what is it used for? Any links to where to buy it?

Thanks.

This is from memory from a few years ago but I believe it's 3M self sealing tape. Something like this but someone from 118 can confirm it.

[ahartnet]

Not from 118, but can confirm that it's linerless electrical rubber tape. I took a picture of it to remember what it was when I was talking to them once, because I knew magic tape wasn't going to help me find it later.

[AdamHeard]

Originally Posted by ahartnet

Not from 118, but can confirm that it's linerless electrical rubber tape. I took a picture of it to remember what it was when I was talking to them once, because I knew magic tape wasn't going to help me find it later.

Rescue Tape?
http://www.rescuetape.com/

[ahartnet]

Originally Posted by AdamHeard

Rescue Tape?
http://www.rescuetape.com/

The picture I took specifically says it's rubber tape and not silicone. I can't imagine you'd need the high temp resistance (or the cost) that would go with the silicone tape.

[AdamHeard]

Originally Posted by ahartnet

The picture I took specifically says it's rubber tape and not silicone. I can't imagine you'd need the high temp resistance (or the cost) that would go with the silicone tape.

OH! that comes in various permutations from 3M, and googling "rubber splicing tape" brings up a lot of options.