Low cost components

FIRST General Forum
#1

High Guys,

I’m on a pre-rookie team and me and my teacher advisor are looking to get training underway. We plan to break students into groups of 5 and guide them in producing a rolling chassis. This will result in us building 6 chassis’s and a single drag and drop control system. This will however get very expensive. We are looking for ways to decrease the costs. We live in Canada and unfortunately the closest thing we have to McMaster is Princess Auto. So I’m wondering if you people know of good places to get bearings for plaction wheels and cheaper steel versions of AM sprockets (mounting holes and all).

Also, many teams have accumulate extra KOP parts over the years and if they would be willling to sell them to us on the cheap we would be very greatful. We are looking for:

  • Toughboxes
  • CIMs
  • Plaction-ey Wheels (for example IFI wheels are good too).
  • Contol system parts, especially victors (but also the old cRIO or any othe parts))

PS do plaction wheels only take flanged bearings or can we put the bearings that come in the kit for the sky way wheels in?

#2

All the andy-mark wheels can use normal bearings except the mechanum and aluminum omnis. We keep costs down by prototyping in wood, 2 by 4 lumber is more than strong enough for a frame.

#3

http://www.atomicrobotics.com/resources/parts-suppliers/

You can also make wheels out of wood. 188 and several others used to all the time (still might?).

Whatever you buy, just make sure its things you might also use for the actual build season so you don’t end up buying useless stuff.

I recommend a VEX controller for the brain.

#4

Congratulations on joining FRC. It is great to see another team in Western Canada.

You are probably already aware of the veteran FRC 1482 team at Bishop Grandin high school in Calgary, but did you know that there was also a team from Red Deer’s (Team 1870) Hunting Hills High School for several years? Queen Elizabeth also ran a team many years ago.

<edit> Just realized you listed team affiliation as 1482… so you’re definitely aware of them! I figure there must be close to 14 CIMs and a couple dozen speed controllers kicking around Bishop Grandin school by now. I was going by your “pre-rookie” team description, but if you’re affiliated with 1482 then you’re already off to a great start. </edit>

You may find local veteran support (and spare parts) from those organizations.

You will also be pleased to know that McMaster is quite happy to ship to Canada, as are AndyMark, IFI robotics (or VEXPro, as they call their product line now), Banebots, robotshop.ca and pretty much everyone else. You’ll pay a brokerage fee at the border, and a premium on shipping, but you are still miles ahead of where we had a sixty-cent dollar! (And many kilometers ahead of our friends, overseas, who have a significant issue with regards to shipping parts and robots, or even getting permission for team members to come to competitions. In most of the world you can’t find a 1/4-20 bolt, or #8-32 screw for instance!)

Princess Auto is great for a lot of things… chain, sprockets and such, but rarely did I find great stuff for the robots there other than that. Even their sprockets tend to be a bit heavy and we’ve either ordered aluminum ones on-line or machined our own. (Your local university or technical institute may very well have a water jet cutter ideal for such a purpose.)

You are right that six chassis will get very expensive, even with a modular control system. It took our team six or seven years before we finally started to build good, cheap, light, robust drivetrains that really made me happy.

There is more information on it here http://www.chiefdelphi.com/media/photos/35536

There is no reason that you can’t use wood for wheels… I’d go with plywood, but if you want to get fancy… http://www.chiefdelphi.com/media/photos/22924 (like those Maple bearing blocks, too, eh?)

Perhaps rather than building six chassis, what you might want to consider is building just two or three robots and diverting some of the time and energy into building a few virtual chassis using Autodesk Inventor (or similar modelling software). The ability to rapidly model a robot in Inventor has saved our team a lot of nightmares. It took us a few years to clue in to just how valuable that ability is… there is a reason Boeing and GM and all those industry people do it, you know!

Good luck and have fun.

Jason

#5

On our team, not everyone builds the chassis. Some of them wire the chassis, some of them program the controller, build bumpers, build game pieces, and still others work on the manipulator. And so on.

Rather than try to teach everyone one of the skills needed to be successful, perhaps you should teach smaller groups specific skills, to fill a particular need.

Let’s just say that’s not going to work for your team. OK, then:

Use less expensive materials. Wooden chassis, wooden wheels, and so on, can be pretty inexpensive. Expanded Polystyrene (Styrofoam) is a light, rigid, low-cost material great for prototypes. Or, like dtengineering wrote, build them virtually.

#6

@Don,

I am well acquainted with the concept of subteams, and fully intend to implement them, but we wanted to start off by giving everyone a basic understanding of all the skills and engage them by letting them see a robot that they built drive around.

I like the ideas of low cost alternatives like wood, but at the same time I want to practice the actual skills we will be using during build season. The current construction method shouldn’t be too expensive, we will just be using tube aluminum and gussets.

-Lemiant

#7

I’d recommend 2008 KOP wheels instead of plaction wheels if you are making 6 drivebases. $7 a wheel beats $29 when buying in bulk for an off-season project. They aren’t shabby either, team 111 has used KOP wheels on their robots for years and still have one of the strongest drivebases.

#8

So you’ve already decided that you won’t be using wood during build season? Nothing wrong with that, of course… aluminum tubing works great, too and if that is where your skill sets and tool availability leads you then go for it.

But don’t assume that you have to build a chassis from Aluminum if you have other options available to you. Wood and composites have been very good to our team.

Jason

#9

http://frcsupplierscanada.wikispaces.com/

These are either Canadian, or at least “Canadian-friendly” suppliers for FRC parts.

We may have some components on your list. Let me check our lab, and I can take a quick inventory.

In the meantime, can you PM me your contact info?

#10