Re: Types of Metal
 

its not my job to buy it so i dont know just ask someone on 842 (im sorry) but i do know its worth its mass in gold

Re: Types of Metal
 

I did some googling to no avail, since I haven't heard of it before: What is starbar?

Re: Types of Metal
 

We've bought fiberglass pultrusion from Creative Pultrusions. shipping is a bit expensive....

http://www.creativepultrusions.com/

Re: Types of Metal
 

Starbar may be a local nickname, It is a t-slot style aluminum extrusion bar that has special slot nuts and brackets. It is very versatile and many team use it for their frames because it is strong and easy to fabricate with. IMO it is crazy heavy though. Weight/ft is significantly higher than most other materials, but it is strong and if it saves you 1 week in the build season the weight penalty can be worth it.

Here is a link showing the cross section
http://www.aline1.com/products/?categoryID=16
When you see the cross section you get the nickname.

I know 494 used this through 2006. When I asked them why they sighted 2 weeks of practice with the robot. Hard to argue with that. We will likely stick to a sheet metal chassis, or a welded stickframe.

Re: Types of Metal
 

Our team used "Alumicore" for the plate where out arm was held. Alumicore is usually used to make outdoor signs. Its plastic sandwiched in between two 1/32 aluminum. Its REALLY light! the frame of our bot is made out of aluminum sheet and 80/20.

Re: Types of Metal
 

A couple materials from this post are interesting to me and I would like to know where our team could buy them.
The 1X1X1/6" square tubing with the hole pattern as used by 1216 appears to be very useful and easy to work with. Does anyone have a source for this?
How about the Alumicore? When I google it, I find many sign companies. Does anyone have a source for this where we can get it before the sign companies mark it up?

For panels on our robot, we have been using 8mm Twin-Wall Polycarbonate Sheet material from Farmtek.com. It weighs 1.5 KG/m2 or about about 0.3 lb/sq ft.

Re: Types of Metal
 

Yep, using acetylene and oxygen. A nice warm job in the middle of winter. Took a while to get used to doing it, the thin walls made it hard not to make holes in the tubes. All part of the learning experience.

Re: Types of Metal
 

Team 104 used 8020 quick frame material this year. We used the EZ tube connectors. The quick frame tube is a good alloy and the anodizing gives a nice appearance. Cuts nice with a miter saw. It allows a frame to be made very quickly. No bolting or drilling for pop rivets. We bought the material from the 8020 ebay store and saved allot. We had no problems with the plastic fiber reinforced connectors. It's a viable option for low budget low skill teams.
This is a link for the connectors.
http://www.eztube.com/connectors/connectors.html

Re: Types of Metal
 

Gas welding thinwall steel tubing is challenging...fortunately once you learn how, you never forget (just like falling off a unicycle!)

I took a couple welding classes at the local community college back when, and patiently learned the techniques to weld thin steel with a torch. Then I got a MIG welder and never did it again...until last week when I had to fix the steer tube (top of the fork) on an old bike, and I decided to gas weld it, and it worked just fine.

Re: Types of Metal
 

After several class sessions welding thin little plates with oxy-acetylene it was a revelation the day we tried the MIG welder for the first time. I remember thinking two things: 1. This is all? That's it? All you have to do is keep the wire moving?, and 2. Who wants to go back to gas welding?

Re: Types of Metal
 

[quote=Bruce Newendorp;751402]A couple materials from this post are interesting to me and I would like to know where our team could buy them.
The 1X1X1/6" square tubing with the hole pattern as used by 1216 appears to be very useful and easy to work with. Does anyone have a source for this?
QUOTE]

When I talked to 1216 they bought 1x1x1/16 wall and then drilled it to a usefule size on a cnc mill. (you can email them to get more details). I know most of us don't have cnc mills so in the off season we will be making a drill guide out of 1/4 steel or aluminum. We made a couple of them for sheet metal stuff and it worked really well. If you use 1/4 architectural angle, you can make a nice drill guide by taking your time or on a conventional mill. do 1/8" holes and then clamp it to your box tube and any newbie can make a nice piece. Unclamp, slide, pin repeat. For some unkown reason this seems to go under the lightening hole mystery where kids love to drill lots of holes. File an edge, never! Drill lots of holes, yeah. A bit of caution: only drill through 1 side at a time otherwise you will get bit-walk with a thin drill. If you do this when the stock come in you will have a nice straight starting edge to work with.

Re: Types of Metal
 

Using hole patterns is what 1501 does best. We have found that the best way to make a hole pattern that lasts for half the build season is to have a nice piece of steel laser cut to make the hole patterns. The laser cutting hardens the metal around the hole, making it harder for the drill to distort (which leads to a lot of awkward holes).

They lasted us a while, and we drill thousands of holes a build season.

Re: Types of Metal
 

[quote=IKE;751674]Another solution would be to press a drill bushing into each hole.

Re: Types of Metal
 

drill guides work great, but can get a bit expensive ($10/guide). Aluminum patterns can wear out quickly. A cheap way to fix them is as they start to wear out drill them out and press in small piece of steel tubing. Significantly cheaper but not as nice as drill guides.

Re: Types of Metal
 

team 270 uses the kitbot frame and secures another frame about 5 inches up from the main one out of 1x2 hollow box aluminum
its very strong
for most of our bot, we use box aluminum and plate aluminum and the occasional piece of plexi-glass or plastic lexan.