2002 Build.....

[Clark Gilbert]

With the 2002 build season coming up quickly, i thought i would pull this thread out of the archives

http://www.chiefdelphi.com/forums/sh...s=&postid=1602

It may be a very helpful thread (may be being the key word) when it comes to building your robot...

[Clark Gilbert]

Here is something else

[ahecht]

80:20 looks like good stuff, especially for a rookie team, but none of our mentors have any idea how to use it or what parts, connectors, etc. we'd need to order. Anyone have any suggestions?

[gniticxe]

This is the first I've heard about the 80:20 / IPS material. But, if you're having trouble with that stuff, my team used BOSCH / Airline Hydraulics materail last year to make our cart and this year for our pit. It looks remarkably similar to 80:20 - it carries a 30x30mm line, a 45, 90 and bigger - and it comes in rectangular (eg 45x90) pieces too.
I almost gave up on searching for a link, but I found it almost by accident Here it is. It seems that online ordering is available there and it looks like they have CAD diagrams up for everything - oh and their "FAST" delivery means overnight

[Jordan A.]

Clark, I cant begin to thank you enough. You just saved our team hours upon hours of unessesary work.

I (before now) had never heard of this stuff. But wow. Very excellent.

I will probably be calling IPS Canada friday to place our order.

Thanks again.

-Jordan

[Elgin Clock]

80-20 IS A GOD-SEND.

That stuff is awesome, I remember trying to draw the shape of it on CAD, that part was a little tricky, but the 80-20 Extruded aluminum is awesome. Those little things you connect it with is a little tricky but nonetheless it still is awesome.

Remember the thread about the FIRST 2001 robots at the Boston Museum of Science???? The display case for one of the robots was made from 80-20 Extruded aluminum and lexan. The stuff is so cool!!!!

[ahecht]

I was talking to our mentors, and they suggested instead that we use thin wall copper pipe and fill it with foam to make it rigid. When this is done, it's supposed to be as strong as the aluminum. The advantage is that welding is really easy, and can be done with something as small as a pen-torch, and it's pretty light. Has anyone done this (or seen another team that has done this)? Anyone know of any disadvantages?

[Andy Baker]

Sure, there are many ways to skin a cat... or build a robot.

Welding foam-filled copper pipes would work, but keep in mind these things:

a. you are about to design, build, and debug a robot in 6 WEEKS!
b. you will get to the 3rd or 4th week and want to alter the design slightly.
c. you will need to lose weight right before the ship date
d. you will get to your Regional competition and want to change your design some more to make it more competitive

If your team had 4-5 months to design the robot, do a FEA study on the structure, and analyze the strategy of this year's game by watching hours and hours of other team's matches... then you could weld up a copper frame that would be much lighter than using this aluminum extrusion stuff.

This type of aluminum extrusion lends itself to be easily put together (students can assemble it), and easily altered.

The reason why the we put together these two kits which Clark posted above is to give teams a resource of parts to use on a FIRST robot. The "small kit" is about enough to do one robot, and the "large kit" is enough to do some prototyping along with a FIRST robot, and possibly a practice drive base.

Whether you use IPS, Bosch, 80/20, Palletti, Item MB Kit, ParFrame... it's good stuff.

Our team has been in FIRST for 11 years... and we will be using this stuff this coming year. Do what you want, but I suggest that you give this stuff a try.

Also... I work as a machine designer for automated equipment at Delphi Automotive Systems, and our robotics design shop uses this stuff all of the time.

I suggest that you find a salesperson in your area who sells this type of extrusion and have them show you how to use it.

Good luck,
Andy B.

[Ed Sparks]

I'm assumming your talking about expandable foam (the stuff in a can that is used as an insulator.

However,

I've never seen this material on any additional materials list. The only foam I ever remember that was legal was the rhocell (spelling) we were given years ago.

I don't think you could legally fill copper tube with foam besides, we usually don't have that much copper tube (10' max) to work with.

Go with extruded aluminum. You'll never look back and regret it.

[Wayne Doenges]

The only problem I can see with 80/20 is that is heavier than what we used last year. We used 1" aluminum tubing.
We drew up the robot using AutoCAD, than cut the tubing to length. We than had it professionally welded. We got the finished frame back in 2 days. We had the back-up frame 3 days later.
The only draw back is that we couldn't make any adjustments to the frame. We did think ahead and made the frame 1" shorter and skinnier than the max. limits. This gave us room for adding sides.

Wayne Doenges

[ahecht]

Well, it sounds like copper is out, but has anyone had any experience with aluminum struts that aren't extruded (like an aluminum version of UniStrut)?

[Ed Sparks]

Ahecht,

I hate being the one that picks on your words but ..........

I'm trying to help, honest. The key word for using the additional materials list as a source of framing materials IS the word "Extruded". FIRST has allowed us over the last couple years to use "Extruded Aluminum" in any length up to a 2" x 3" cross section. They have also allowed "Extruded Fiberglass" in any length up to a 3" x 3" cross section. If you use a material outside of what's specified in the Kit or additional materials list, let's say steel unistrut, you technically violate the rules. An aluminum version of unistrut may indeed be extruded and if so, probably qualifies if it's cross section is <= 2" x 3".

I've seen some verrrrry loose interpretations of the additional materials list go unchallenged in the past. One that still gets me is "Timing Belt". I saw everytimg from knotched v-belt to creative laminations used last year that I think should have been called to the mat by the inspection teams.

But it's all about the competition at that point and FIRST isn't in the business of turning any team away. I't a matter of gracious professionalism.


Man, I gotta get packed. I'm leaving tomorrow morning for Kokomo. Cooool.

[ahecht]

Go ahead and pick. As a rookie teams, we haven't yet seen the rules. Thanks for your patience.

[Tom Fairchild]

Originally posted by Ed Sparks
Ahecht,
One that still gets me is "Timing Belt". I saw everytimg from knotched v-belt to creative laminations used last year that I think should have been called to the mat by the inspection teams.

This is something that our team faced. Before, I believe the part was listed as "belt." We used a conveyor belt material. This year, with the change to timing belt, we had to find a new tread material for our wheels. Many other teams had the same old material we used to use and FIRST allowed it, so we felt kinda bummed out by not being able to use the tread we liked most.

~Tom Fairchild~, who thinks his teams wheels did alright regardless.

[ahecht]

The way I heard it, there was a lot of resentment since high traction materials can be bought cheaply as conveyor belt material, but in order to buy the same stuff as a timing belf costs around $80 a belt, so only well funded teams could legally use it. There have been petitions to change that rule this year. This, of course, is all second hand.