Cool Frame Ideas?

[IndySam]

We have used welded 1" aluminum for our frame 3 out of the last four years with great success. The other year we used the kit box frame welded together.

We have also used 1" thin wall for the superstructure but connected together with gussets and rivets. No need for fancy connectors or welding. Only tools needed are a hacksaw, tin snips, a drill and pop rivet gun.

[Madison]

Originally Posted by DeepWater

Madison et al.

As far as using the connectors with standard 1" thin walled square tubing I really don't think it will work. The 1" square 80/20 QuickFrame tubing is specially fitted for the connectors. It has longitudinal ribbing inside that forms a friction lock with the plastic connectors. This is sort of the secret to the whole system. The internal dimensions of the QuickFrame tubing is slightly smaller (thicker walled than standard 1" thin wall box tubing) so if you try to insert a QuickFrame connector into standard 1" thin walled box tubing the connector will just fall out (too loose). The tubing isn't really that expensive though. IIRC the standard 1" QuickFrame box tubing was about $10-$11 per 12 foot (145") piece after the discount. They also have tubing with flanges on the side in different arrangements for putting panels in, etc. We purchased some but didn't really use the flanges much and often just cut them off to save weight.

One trick we found was to drill a hole in the end of the tube through into the connector and put a pop rivet in on any connectors you REALLY don't want to back out. This trick is rarely needed but is cheap (and light) insurance.

Ah, thanks. I was pretty well assuming we'd need to drill through the connector and bolt it since I don't trust anything that's meant to be a press fit, so maybe that would be enough to hold even a loose nylon connector in place. I'll order a handful and see how it goes, I guess, but I can't see going through the time or expense of ordering new metal stock; especially if it's already anodized and harder to work. Even with a bolt through each, it seems like this will be as light or lighter than our existing methods of joining tubes -- lots of rivets and joining plates. The really nice thing about these is that they'll save lots and lots of manufacturing time, we hope.

[Protronie]

If a team had the money and time...

I'd love to see a demo robot built with polished brass or copper tubing.
Or one with some nice stained polished hard wood.

I know it would never work in competition hence the demo but it would look awesome and be a cool way to show off robotics in general.
Maybe in a off season there could be a American Robot build off

[Rapt0r9]

Our team has just started to weld the KOP frame just last year. We were amazed at how much weight was saved when not using the steel bolts. Additionally, the frame was stiffer and we never had to sweep magnets across the floor to pick up the dropped hardware. (In previous years, we would lose at least 4 to 5 bolts each time we drove the robot. That was before we started using nylock nuts.) So for something that is cheap, quick and strong, just welding the aluminum frame if a great option. Also, you might want to considers using the U rails which have the extended bar (the one used for mounting the wheels) sideways and cutting off the excess aluminum which isn't giving any structural support. Here is a crude example of this.


Rotate this
*__
l__
**l
**l

To look like this

_ _
l **l___

(The asteriks are just there to space the lines out. My formatting is stripped each time I've tried to submit it.)

This has saved us a lot of weight over the past year.

We have considered using carbon fiber or fiber glass, but the big drawback to us is that repairing broken components is difficult. These materials can't just be welded or braced with another bar, we'd need to bring replacement parts and swap out the broken for the working. We've also found that pound for pound fiberglass is about as strong as aluminum, so we have never found a reason to switch.

[joeweber]

2004 and 2005 we built our robot out of HDPE. We found a local company that could weld the plastic. pictures http://team1322.org/pictures.htm

[Qbranch]

Originally Posted by joeweber

2004 and 2005 we built our robot out of HDPE. We found a local company that could weld the plastic. pictures http://team1322.org/pictures.htm

Wow, thats a cool idea! Did you have much of an improvement in weight reduction? Any problems with warping? Unexpected benefits? Detriments? Why did you stop using HDPE in your machines?

I remember making our 2006 robot's auto-retracking guides (in case the robot tried to throw a track) out of UHMW and had a heck of a time doing it... i think i spent more time whittling with an exacto knife than actually machining the parts.

Very interesting...

-q

[joeweber]

No savings in weight, but this was before bumpers, was very srong but did flex, I think thats what made it strong. The big benifits was that the students could work on the material with out hurting themselves. It was like working with wood with out the splinters. When you run a wood screw into it it held very well. The weld are just as strong as the material. We have not useded it because of the design of the robots would not make it feasable.