How Do You Make Your Robot?

[1086VEX]

the past 4 years team 1086 has used a bent sheet metal frame, this year using our sponsors new CNC laser cutter to cut the hole pattern. in years before we hand punched the holes.

[Jon Stratis]

We start with the kitbot frame (it may be heavier that some other solutions, but it's the quickest thing we can get going, and it have everything you want in a frame). From there, it's pretty much all sheet metal and angle stock. We usually end up having the machine shop at our primary sponsor do a few small things for us (lightening holes or complicated patterns), but 99% of the work is done in house, by the kids.

[Andrew Schreiber]

This year 397's robot was quite literally 2 KOP frames stacked on top of each other. We used 80/20 in between them. This made our frame quite heavy but incredibly rigid. It also gave us the benefit of letting us play with the mounting height of our kicker until we liked it by sliding it up and down.

In the past we have used the KOP frame and 1" square tube to build the robot. We bend the tube in house using a standard pipe bender. This can then be bolted together (or welded). The only time this method was a problem was in 2008 when the force of the launcher changed the shape of our frame as we fired. I'm sure someone has a picture of 397 hitting their frame with a hammer to make it go back square. I personally like the bent tube construction method. But as always, you work with the resources you have.

http://www.chiefdelphi.com/media/photos/27139 2007
http://www.chiefdelphi.com/media/photos/23321 2006
http://www.chiefdelphi.com/media/photos/30277 2008
http://farm4.static.flickr.com/3348/...cd2aa38f_b.jpg The fun bent parts in 2009. That PVC ring was a prototype, the final one was made of aluminum round tubing and bent by hand.

[BrendanB]

In years 2005-2009 we used the kit frame and aluminum angle and box for the other assemblies. In 2008 we used a smaller version of 80-20 on the speed racer robot and had some 1x1 80-20 in the upper frame work for our 2009 robot. This year we decided to use 80-20 for our robot frame as it was great for prototyping, moving stuff around, and very, very strong. However like many teams it ate up weight, parts shifted (a lot), and was a hassle when we ran out of sliders and brackets. Team 234 said in their swerve drive implementation conference that 80-20 is a great prototype, but aluminum box is better for the final as it is lighter and parts don't slide around.

I hope our team uses more aluminum box in our construction to help save on weight and parts moving, but a strong rigid frame was desired in our first meetings of the season which 80-20 accomplishes until parts move around.

[Chris is me]

Originally Posted by BrendanB

In years 2005-2009 we used the kit frame and aluminum angle and box for the other assemblies. In 2008 we used a smaller version of 80-20 on the speed racer robot and had some 1x1 80-20 in the upper frame work for our 2009 robot. This year we decided to use 80-20 for our robot frame as it was great for prototyping, moving stuff around, and very, very strong. However like many teams it ate up weight, parts shifted (a lot), and was a hassle when we ran out of sliders and brackets. Team 234 said in their swerve drive implementation conference that 80-20 is a great prototype, but aluminum box is better for the final as it is lighter and parts don't slide around.

Did you guys drill through the extrusion when you finalized part locations? That basically keeps all the advantages of 80-20 and takes away the sliding problem.

[BrendanB]

Originally Posted by Chris is me

Did you guys drill through the extrusion when you finalized part locations? That basically keeps all the advantages of 80-20 and takes away the sliding problem.

Yes, that was one of the solutions we had. Specifically with the wheels we took angle supports and bolted them to the frame to keep the wheels from sliding if they came loose. Loctite was another useful tool, but we also had problems with vertical frame members moving horizontally which we fixed by placing bolts vertically from one frame member to another. But adding more bolts just increases one of its disadvantages: weight.

[JamesCH95]

95 has used plywood frames with angle aluminum brackets frequently, and with great success. Recently we've started welded the kit chassis together which makes it both lighter and stiffer than using the bolted connections. Every year we've used the kit frame we've always dropped a sheet of something in the middle of the kit frame to strengthen it up.

If you have easy access to welding, a welded frame could work out very well for you because it is such a flexible fabrication technique. Be careful with welded aluminum frames because if you weld 6061 it loses its temper, 50xx series (that the kit frame is made out of) has no temper and so does not lose strength with welding.

[Peter Matteson]

We have a mixture of square tubing sub frames, machined plates and small parts, sheetmetal/sheet plastic fabricated brackets made using our shear and brakes, round tube, COTS, purchased sheetmetal shapes from IFI (now called VEXPro), welding, and whatever else we can think off. We pretty much do whatever we can to make what we need.

[hallk]

Most of the teams I work use a press fit Aluminium tube system like this one http://www.mcmaster.com/#press-fit-f...ystems/=5bymjz
Systems like this are light-weight, fast to assemble, easy to modify, strong, and relatively cheap. I wish all my teams would use something like this.
I think welding is a great and fun skill for kids to use but it can be prohibitive to use during the build season if the welders don't have much experience.

[gorrilla]

We have used the kit frame and 1' square tube or 1/2'-1.5' angle for nearly everything on our robots, from 05'-10'.

We have been very successful with this method.

Each year we have built the fram in two pieces(a drivebase and an upper structure for everything on top) then either welded, bolted, or welded and bolted(07') the two pieces together.
It's easy, cheap, reliable, quick, light, and very strong, plus we dont really need any machine other than a saw and drill to build everything*





*welding was done by a parent or mentor

[Durza16]

Team 2062 uses item normally, its a strong, lightweight, and durable aluminum. This last year though we used kit of parts for our frame.

[Chris is me]

Originally Posted by Durza16

Team 2062 uses item normally, its a strong, lightweight, and durable aluminum. This last year though we used kit of parts for our frame.

Did you guys use ITEM for the rest of your frame, or 80-20 extrusion? It seemed very strong in preship videos when you guys had mentors doing pullups on the sides; I didn't think 80-20 could do that.

[Tom Bishop]

We have used water-jetted aluminum plate for our frames, with other assorted aluminum and polycarbonate machined pieces for mountings and other parts.

Before that we used 1" welded aluminum box. We stopped using that system because it tended to be heavy and it's hard to modify if you need to change something.

The water-jetted parts are perfect and light but do put a lot of pressure on the CAD operator not to screw things up.

[lil'est lavery]

The structure of the robot varies every year depending on how we decide to approach the game. We generally have an aluminum frame made from square stock that can be drilled through so additions can be attached. Team 116 also uses sheet metal, plexiglass, carbon fiber and other materials all depending on the purpose. This past season we made a rectangular bot with a kicker, vacuum, and hook attached (frame made from square stock). Last year we used a rectangular frame from aluminum square stock with a large cylinder on top made from plexiglass and aluminum that was used to guide orbit balls up to our shooter.

[jamie_1930]

Originally Posted by Durza16

Team 2062 uses item normally, its a strong, lightweight, and durable aluminum. This last year though we used kit of parts for our frame.

You mentioned some of the pros of this material can you list, if any, it's cons? Also what version do you typically use? For instance with 8020, 1010 is the most commonly used, to my knowledge.