Re: 80/20 chassis
 

Team 980 has used 80/20 for our robot chassis for years (1010 extrusion). Our six-wheel drive with Andy Mark SuperShifters goes together quickly. Getting proper tension on the chains is very easy. We use simply-machined phenolic bar stock as pillow blocks for the axles with fastener through-holes spaced at 2". Instead of the more expensive drop-in T-nuts, we use economy triple T-nuts. We haven't had problems with fasteners loosening: just put a bit of Lock-tite on the threads and torque them down.

Oh yeah, you can save some $$ if you buy from 8020 Inc Garage Sale on eBay.

We've already received 6 pieces of 1010 (36" length) for $50 (plus $16 shipping).

Re: 80/20 chassis
 

My team used 1 inch by 1 inch 80-20 last year. It worked very well and we had almost no problems with it. If you have a square frame make sure you put in supprts to keep it twisting, If you take a hit, some of the fasteners aren't strong enough to prevent it from twisting a little. I still think 80-20 is wonderful and my team loves it. We made a frame for a six wheel skid in the off-season with 168 inches of 80-20. It's always good to have some extra. We used a little less than 350 inches on our robots frame in the '08 season, but it was a swerve drive and required a little more aluminum extrusion.

Re: 80/20 chassis
 

Never heard of phenolic. At first glance it looks like a great material for an impact-resistant non-conductive electronics board. How easy was it to machine?

Re: 80/20 chassis
 

Team 2228 has used 8020 from the start. We almost always stick with 1010. (We did go to 1020 for our 2008 lift). As for fastners, we have standardized on 1/4-20 wherever possible to reduce the need for more tap sizes and tools (DFM). With respect to fastners we mostly use the economy nuts. They are far cheaper than other 8020 alternatives and weigh less. You would be surprised how fast nuts can add up on weight. For the bolts stock up mostly on the shortest two sizes. While it is nice to have a few of the longer lengths in most cases you find these too long and the bolt bottoms in the 1010 extrusion prior to the head pulling whatever tight. We carefully tighten and have had very little problems with loosening. Be sure to properly clamp prior to drilling or sawing for safety.

We have no welding capability at this point and with 8020 I am not sure we will pursue that for some time.

Re: 80/20 chassis
 

Very old-school material, used as an insulator before there was plastic (like, aaround 80 years ago). Also known as Paper Phenolic, it machines like wood. Not terribly strong in tnesion (as with wood) but super in compression and shear, with some lubricating properties for low-speed rotational bushings. Not terribly heat resistant, and has a distinctive odor when burning.

Re: 80/20 chassis
 

I discovered something interesting today...

1/4-20 carriage bolts fit perfectly into 80/20 extrusion. Sure beats those dumb fasteners...

Re: 80/20 chassis
 

I must be getting old....

I think phenolic was the only material used for printed circuit boards in the old days, 1940s-50s. It was everywhere on the old surplus electronic stuff we played with as kids.

Back to the 8020 chassis stuff....I bought the material for our prototype chassis at one of the local hardware/lumber stores yesterday, $20 for enough material the whole structure, it came in flat, laminated sheets, and was grown naturally. Still looking for a good use for 80/20.

Re: 80/20 chassis
 

I really prefer to use the word "experienced" over "old"...;)

Phenolic is a class of materials: modern examples are Micarta and G-10 (Garolite at McMaster-Carr). Phenolic materials are durable, easily machined, have great mechanical properties, and cheap.

There's a lot to be said about materials selection in mechanical design. Using the right material can simply the design, making fabrication/assembly easy and repair almost unnecessary.

Re: 80/20 chassis
 

We use 80/20 for all of our fall warm-up projects and the BunnyBot competition. Depending on the competition, we build our FRC robots out of 80/20 1010 extrusion or 80/20 Quickframe, or some combination as well. Quickframe is about half the weight of 1010 extrusion but more of a pain to work with.

At the beginning of this thread there was a question about what to buy to get started. Here's my take. I’d say you could build 80% of a robot with just these 80/20 parts:

1010 Aluminum extrusion. I’d get at least eight 8’ pieces. More if budget allows.
3375 Drop in Nuts (100+)
3376 Drop in Nuts (100+)
3382 Econo nuts (200+)
3395 Anchor fasteners (100+) Drill press required.
4119 2 hole corner bracket (10+)
4101 4 hole corner bracket (10+)
4136 4 hole inside gusset bracket (10+)
4080 5 hole T plate (10) drop this if your budget gets tight.
6110 5/32” T handle wrench (5+)
6000 3/16” T handle wrench (5+)
6160 10 series counterbore cutter (cuts holes for 3395 fasteners.) Drill press required. You might get two in case you break one in the middle of the build season.

A nice assortment of 1/4 -20 socket head cap screws. Especially ½”-1”. You’ll also want some ¼-20 Button head cap screws especially around ½” and 5/8”. Obviously you can get these locally from a good hardware store or from 80/20. Which you use depends on your discounts. Some 80/20 distributors give nice discounts because 80/20 offers deep discounts for FIRST teams.

If you run into weight problems you can get 80/20’s Quickframe pieces for parts of your robot. Keep in mind that 80/20 1010 extrusion weights about .5 lbs a foot so it adds up fast. Quickframe is about half that.

As was mentioned before, you really do need to put Loctite on your bolts or use Nylock nuts when possible. The frame will shake itself to pieces after a match or two without it.

Team 1540 was the #1 alliance captain and won the Oregon Regional last season with a Quickframe robot. The previous year we were also on the #1 alliance and ended up as a finalist with an 80/20 based robot. The point is that you can be very competitive with this material and let students have the satisfaction of building the robot entirely themselves without knowing how to weld.

Re: 80/20 chassis
 

Team 1539 has used 80/20 for a few seasons, i think its about 3 so far, and have decided to work our way away from using it as much as possible. I will say that it is good metal, and easy to work with, but the only problem that we ran into was how heavy it is, because the (1"x1") weighs about a pound a foot. Otherwise, it works great for manipulators, and etc. (personally I would suggest using it sparingly)

note: small scrap pieces work as great pendants on necklaces (not that I made one for myself or anything :D )

Re: 80/20 chassis
 

I do not mean to be rude and correct you guys, but I know from many years of working with these materials that 1"x1" 80/20 Alum is 24.6" per lb. Where as 1"x1"x.0625 wall Alum extrusion is 48" per lb.

I also want to warn anyone who is machining phenolic that the dust created by machining it is very toxic to your lungs if you breath it in.

Re: 80/20 chassis
 

If you are not sure exactly what size/length of 80/20 to purchase I recommend going to a Pennsylvania company called Kodyn (www.kodyn.com) who makes a version of aluminum extrusion EXACTLY like 80/20 but it is a much smaller operation. They also make fasteners that I believe are much better than the 80/20 counterparts. Dave, the owner, is willing to take drawings and even hand sketches and will let you know how much material you will need and will even precision cut it to length for you. Tell him Matt from Quasics sent you...

Re: 80/20 chassis
 

Drawing up the whole whole robot in advance is good advice for teams on a extreme budget. However, what we like about 80/20 is it's flexibility to change your mind. You can bolt things together, get a better idea, and change it quickly without cutting out and splicing welded pieces. It's fabulous for prototyping.

To do that you need enough material on hand to play around. 80/20 1" extrusion costs only $.23 an inch list price. The FIRST team price, if you can find a distributor who will do that for you, can be 35% or more off of that. The expense generally comes from all the special inserts, bolts, brackets, etc.

I'm not sure the exact numbers but I think the cost to 80/20 distributors for material destined for a FIRST team is 45% off of list. They then may add a bit for their handling of your order.

Re: 80/20 chassis
 

I think what JesseK meant by in his first post was 1"x1"x.125" wall tube is roughly the same weight as 1010 80/20 extrusion. We came to this conclusion after taking two equal length pieces of both stocks and weighed them both. The difference was roughly .250-.5 lbs per 8'.

Re: 80/20 chassis
 

I once had a job assembling 8020 structures for a distributor and have used it since then on many other projects. We also built a robot out of it back in 2002 so i feel i speak from experience.

8020 Pros:
You can very quickly prototype things and move them around. It doesn't need welding which is a huge plus if you don't have good access to a TIG welder. This and the fact that we got it for free were the reasons we used ut. If you want to be able to move things around then use brackets or anchor fastners. Keep in mind the weight of brackets. If you want something thats strong and don't plan on moving it use end fasteners. Even if your not making a frame out of 8020 they make some very nice parts that come in handy. For a FIRST robot frame i would reccomend 10 series if you are designing in inches or 25 series if you are metric. 15 series or 40 series is overkill. 8020 is a great material and certianly makes for flexibility. In a fast paced design challenge like FIRST this is useful.

8020 Cons:
An 8020 Structure will be both heavier and more expensive than an equivilant welded structure from square or round. You have less freedom with wall thicknesses and there is a lot of mass concentrated in the center of the profile which does little for stiffness. It is particularly week in torsion. Keep in mind the weight the fasteners add.

Drop in T-nuts are your friend. get plenty of these. If you plan on using end fastners , get the jig so that you can drill the clearance holes painlessly. Thre is a fixture for milling the holes for anchor fasners but you don't really need it. Make sure you have a few ball allen wrenches in the appropriate size.

Also there are some older threads about this topic if you dig em up with the search