Types of Metal

[Billfred]

Originally Posted by IKE

I was mistaking 80/20 for starbar.

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

[MrForbes]

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

http://www.creativepultrusions.com/

[IKE]

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.

[Skifanatic]

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.

[Bruce Newendorp]

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.

[IKE]

[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.

[cooker52]

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.

[Cory]

[quote=IKE;751674]

Originally Posted by Bruce Newendorp

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.

Another solution would be to press a drill bushing into each hole.

[IKE]

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.