Purchasable Tricks and Easy Fixes

[nnfuller]

So I have been helping budget for our next season, and I was thinking that maybe the CD community could help. I wanted to create a list of things that can help a team during the build season. My favorite example of this would be the plastic air tanks that arrived mid season last year. I was wondering if there were other links that solve common problems.

These problems might include but are not limited to:

• Weight Savings
• Chain Tensioning
• Non-Traditional Gearboxes
• Wheel Sources (Not Andymark or IFI)
• Sensors
• Tools

Thanks for the help!
Nathan

[JesseK]

I have to warn you that there are many red herrings in any sort of list you'd get. There ain't no such thing as a free lunch -- but there are cheap lunches. For example, I'm willing to bet my BBQ pulled turkey lunch today that many, many hours were spent searching for an air tank that would fit the needs of a team within our rules before the white fiberglass ones were actually found. Many other 'tricks' (such as the Dark Soul Chain Breaker) have caveats like "#25 chain is the ficklest $#*! chain you'll ever use -- 1 degree out of alignment or 1/4" too much slop and it's guaranteed to come off!".

That being said, the Dark Soul tool worked great until we lost it, heh. We're going to get a new one soon. The caveats: #25 chain is the ficklest $#*! chain you'll ever use. The sprocket teeth are so shallow that even the slightest imperfections in your robot production process will show up at the most inconvenient times.

If you need thin, strong boards that can hold the weight of a robot (like ramps for 2007), then honeycombed fiberglass may be a good fit. We've also use it for our electronics boards since 2007. This year we might use something different. The caveats: it shears very easily, so use wide washers at every mount point; it is not meant to be a structural member that can withstand impacts, so the weight it carries should be light during all interactive times of play.

[Jon Stratis]

I'll also caution you that any list you come up with may not be valid next year - rules always change. Last year was the first time those plastic air tanks are a prime example - last year was the first time they were legal. I know (from personal experience as an inspector) that they were a huge pain during inspections. Speaking personally (I have NO insight into the GDC or what they're thinking on the rule book), I wouldn't be surprised if that specific rule changes again this year to help make things run a little easier... It's just a nightmare for both inspectors and teams to trace those plastic air tanks back to specifications and show that they are rated for the appropriate air pressure.

[Andrew Schreiber]

[*]Weight Savings - Freshmen with a hole saw? But there is no easy way of doing this, a lot of it requires you to do the math to figure out exactly what material you need and how much of it. Be very careful here.

[*]Chain Tensioning - AM sells a chain tensioner that works reasonably well. You could also just design for an integer number of links between the wheels and be done with it. According to some discussion on last night's cast #35 chain will just deal with it.

[*]Non-Traditional Gearboxes - Dewalts were pretty popular for quite a few years. However, in my experience, the majority of top tier teams use the AM guts with a custom housing. A few build completely custom ones nowadays but the need to do that is diminishing. As far as other sources. Banebots is TECHNICALLY a source but there are a lot of people on these forums that have some very creative words for BB transmissions.

[*]Wheel Sources (Not Andymark or IFI) - Colson wheels. Literally worst kept secret in the NE region. Avoid BB wheels, they tend to shred. Probably would work ok for grippers though. Some teams have been going back to the old school pneumatic tires but they are by no means easy as interfacing with them has, traditionally, been a pain.
[*]Sensors - Sparkfun Electronics. Incredibly support, reasonable prices, and probably the coolest shipping boxes in the industry. Most of their stuff is of decent quality, I've never had any problems with them. Just don't order resistors or leds from them, their prices are a little steep.
[*]Tools - Can't help ya here.


Not really a list of easy fixes or quick purchases that will turn you into the next 254 but it should point you to some alternate options you can utilize in the future.

[EricH]

Originally Posted by JesseK

If you need thin, strong boards that can hold the weight of a robot (like ramps for 2007), then honeycombed fiberglass may be a good fit. We've also use it for our electronics boards since 2007. This year we might use something different. The caveats: it shears very easily, so use wide washers at every mount point; it is not meant to be a structural member that can withstand impacts, so the weight it carries should be light during all interactive times of play.

Corrugated plastic, properly supported by frame, is similar, but maybe a bit tougher. You still need the washers (the plastic crushes a bit), but it can take a pretty tough impact. 330 used it for ramps in '07.

[Peter Matteson]

Originally Posted by Andrew Schreiber

[*]Weight Savings - Freshmen with a hole saw? But there is no easy way of doing this, a lot of it requires you to do the math to figure out exactly what material you need and how much of it. Be very careful here.

We prefer the Unibit (aka stepdrill):
http://www.irwin.com/tools/browse/dr...it-step-drills

These are safer and easier to use than hole saws when your holes are in the correct size range.

Tensioning is easy to do with various size delrin idelers. Just swap in different ODs to in crease or decrease tension.

[sanddrag]

Originally Posted by EricH

Corrugated plastic, properly supported by frame, is similar, but maybe a bit tougher. You still need the washers (the plastic crushes a bit), but it can take a pretty tough impact. 330 used it for ramps in '07.

As did 696 with great success. Good stuff.

[Chris is me]

A neat little known product: IFI sells pre-punched C-channel and gusset plate that basically looks like Vex on steroids. If I was on a team with a bit of cash and no mill, I'd certainly strongly consider it as a general frame material.

[George C]

We had great success with some new (to us) products last year:

Garolite sheet available from McMaster Carr. We used it for paddles on our gripper. Easy to work with, very strong and a lot cheaper than carbon fibre

Constant force springs available from McMaster Carr. Helped counterbalance our 3-stage elevator

Igus linear slides available from Igus. Used in our 3 stage elevator and our mini-bot deployment system.

I echo the comment on step drills, plastic air tanks and UHMW plastic spool and cam-type chain tensioners.

Surgical tube is wonderful stuff. Many strengths at McMaster Carr and elsewhere

[BJC]

Some great things we always use:

- echo the Dark Soul chain tensioner: We have 2 or 3. We always use seemless chain and hardly ever lose chains. (Not one all last season.)

-Surgical tubing: Used for counterforce, passively springing something, and battery straps(<-this works really well) among other things. We always have this on our robot usually serving multible functions.

-Polyurthane belting: this is the choice material for convayer belts such as 2009. However, it is also great for powering rollers in other applications and can act as a mechanical clutch if desired. In 2011 this powered our claw as well as provided the grippy surface for the tubes. It also allows for figure 8 belts which can make it better then chain in some applications. We also always have some of this on our robot every year.

-lexan: This has a variety of uses not the least of which is an electronics cover. We always use this for decorative body panels however, do to its flexable nature it is also VERY durable in the 1/8 - 1/4 size range. We also used 1/8 as the entire bottom half of our claw in 2011 and It never broke once. It is also quite light which makes it a pretty great building material in the correct applications. We definatly use this every year on the robot.

-velcro: its great for things that are often taken on and off the robot. We use it especially for bodypanels.

-Zipties: Especially the high strength ones. In 2008 we held togeather our elevator with zipties for the remainder of competion after it was sheared off by the overpass in elims.

-1"x1"x1/16" L brackets: You can't buy them, however its great to have a bunch pre-made. Every year we usually have a couple of these on the robot. They are also great for prototyping. The first thing freshmen make in the shop is always these, and they always seem to get used up.

Good Luck, Bryan

[AlecMataloni]

If you don't already use them, the Anderson Powerpole Connectors are a MUST HAVE for any team's wiring! They make replacing motors, speed controllers, and other important electrical components parts much easier, faster, and safer.


Here's a guide from the FIRST website related to them. At the end, it tells you where you can purchase the connectors and the related crimping tool. http://www.usfirst.org/sites/default...pole-Guide.pdf

[Chris is me]

Originally Posted by AlecMataloni

If you don't already use them, the Anderson Powerpole Connectors are a MUST HAVE for any team's wiring! They make replacing motors, speed controllers, and other important electrical components parts much easier, faster, and safer.

We successfully received sponsorship from Anderson Power Products last season and got our connectors all for free. This has been more useful than I could have imagined. We have a single, asymmetrical electric "plug" on our robot with connectors attached to each other that allows us to remove our electronics board from the robot with one click. I would recommend it especially to teams without a practice set of electronics.

[JamesCH95]

Originally Posted by JesseK

If you need thin, strong boards that can hold the weight of a robot (like ramps for 2007), then honeycombed fiberglass may be a good fit. We've also use it for our electronics boards since 2007. This year we might use something different. The caveats: it shears very easily, so use wide washers at every mount point; it is not meant to be a structural member that can withstand impacts, so the weight it carries should be light during all interactive times of play.

The fiberglass laminate is awesome. It can be custom made too, with various skins and cores if one is so inclined.

To solve the bearing stress issues (fiberglass sheets are actually very strong in shear if laid up anisotropically) using a big washer clearly works, but a stronger solution is to epoxy the washer in place. Or better yet epoxy a bushing in place to prevent crushing the board. Smaller washers/bushings could probably be used if they are glued, to save weight.

[Peter Matteson]

Originally Posted by Chris is me

A neat little known product: IFI sells pre-punched C-channel and gusset plate that basically looks like Vex on steroids. If I was on a team with a bit of cash and no mill, I'd certainly strongly consider it as a general frame material.

We have a mill and welding capability yet we use this on many of our robots to save time. FYI IFI calls it SuperVEX in house.

[remulasce]

Double stick tape was influential in keeping sensors, motor controllers, and joysticks attached where they should be, while also serving as a structural component in minibots and our "borrowed" minibot deployer.