Cool Frame Ideas?

[Billfred]

In a word: rivets.
In two words: quarter-inch rivets.
In more words than that: Quarter-inch rivets in a kit frame, now that we've found an affordable rivet tool for the job. (Blame it on Don Rotolo at BE.)

[Schnabel]

I don't have a frame idea that I want to specifically say, but I have some key concepts that you should follow with any frame.

-Simplicity is Key
-Rivets
-Keep it as simple as Possible
-Rivets
-Make sure it is not complicated to fix
-And last but not least, rivets.

No really, about the only thing I can say without repeating what has been said is to Keep It Simple Stupid! (KISS)

[Binome]

Bosch Extrusion
Its really nice, and reusable between years.

[techtiger1]

I've always wanted to make a circular frame out of alumnium tubing maybe like 1/2in or 3/4 in diameter. The shape would make for an easy drivetrain setup and would make it hard for people to push you. Done right it would also have pretty solid stability. We never have the time to protoype something like this and the resources aren't there to bend the tube that specific. We'd have to find someone or someplace who can. Another cool design is a octagon check out 180 Spam 2004. Finally I liked 67's 2005 chasis a horseshoe it was definitely a great concept. Just some thoughts.

Good luck,
Drew

[=Martin=Taylor=]

Get a piece of foam, carve it into the right shape. Add some spruce spars for extra structural suport. Cover it with fiber-glass or carbon-fiber, resin the whole thing and cover it with seran wrap to get it nice and smooth.

Then peil off the seran wrap an you'll have a nice smooth, strong, and earodynamic frame. And depending how well you squeeze out the excess resin - light too.

I've always wanted to build a robot that way. I <3 Fiber Glass

[geeknerd99]

Aluminium outer frame, lugged to carbon fiber superstructure. Light, strong, blingiful black and polished silver. Because on 401, we're addicted to mirror polishing aluminum.

[Dan Petrovic]

We're working on a frame that goes together easily and* comes apart easily. It will require a lot more machining, but we think it will totally be worth it.

* You can sometimes have one, but not the other.

[dtengineering]

If you weld the KOP frame together and pull out the bolts, you would be amazed how much weight you save. All those little bits of steel add up! Not only that, but the frame comes out stiffer, and you never have to worry about a bolt coming loose.

If you have someone who can TIG weld, or even have access to a MIG with a spool gun and appropriate wire and gas for aluminum, frames become much less daunting, and a lot of things that seem like problems suddenly disappear. 3/4" thin walled square tubing makes great superstructures!

If you can't TIG or MIG in-house, then keep in mind that somewhere in your community there is someone who wants to weld your robot for you. People who like welding tend to like welding cool things, and competitive robots are generally regarded as a pretty cool thing. Perhaps a local community college or trade school can help you out.

Of course there are many other examples of cool frame ideas... pultruded fibreglass comes highly recommended in some posts. But don't try welding it.

Jason

P.S. It just ocurred to me today that if you covered your robot in competition carpet that from certain angles you would appear to have a very "stealthy" machine. From other angles, of course, it would just be ugly.

[EricH]

Originally Posted by dtengineering

3/4" thin walled square tubing makes great superstructures!

I agree! See team 330's 2006 robot (shooter frame) and 2007 robot (ramp frame). You can't put a lot of holes in, though; it has to be welded.

[quote=dtengineering;650586]If you can't TIG or MIG in-house, then keep in mind that somewhere in your community there is someone who wants to weld your robot for you. People who like welding tend to like welding cool things, and competitive robots are generally regarded as a pretty cool thing. Perhaps a local community college or trade school can help you out./quote] Some machinists are also like that... In the case of some SoCal teams, one such is also an instructor at the local community college. Shop use and he could make parts for teams--not a bad deal.

[Molten]

Originally Posted by dtengineering

3/4" thin walled square tubing makes great superstructures!

I disagree. We use the 1 1/2" Aluminum tubing and it makes it much stronger. Last year, our robot got tipped over 3 times and did not show the slightest hint of damage. When making a frame, keep in mind that the best robot is lousy once it falls apart. The main point of the frame is to keep everything from falling apart. It does not necessarily have to be fancy, it just has to be functional. Remember, function over form.

[dtengineering]

Originally Posted by Molten

I disagree. We use the 1 1/2" Aluminum tubing and it makes it much stronger. Last year, our robot got tipped over 3 times and did not show the slightest hint of damage. When making a frame, keep in mind that the best robot is lousy once it falls apart. The main point of the frame is to keep everything from falling apart. It does not necessarily have to be fancy, it just has to be functional. Remember, function over form.

Obviously 1 1/2" tubing is stronger than 3/4" tubing. It is also heavier and takes up more space. We have had no damage to our welded 3/4" thin-wall tubing superstructures for the past two years (despite "vigorous" interaction with other machines), but we do design our superstructures for using the finer tubing, with some good gusseting at the corners.

There is nothing wrong with making your robot stronger and stiffer, for as you say a broken robot is no fun. Teams need to make a trade off between strength and weight that only they can decide. We have found success building very durable, lightweight superstructures (which we weld to the KOP frame) with 3/4" square thin-wall Al tubing.

Jason

[Molten]

Originally Posted by dtengineering

We do design our superstructures for using the finer tubing, with some good gusseting at the corners.

Maybe with gusseting, it would be fine. And I will admit some of the older teams make some great bases with the 3/4" tubing. However, to all of the new teams out there, you probably do not want to try this on your first bot. It works but you need to be well versed with stress analysis. Also, I suggest you have plenty of welders as I believe that you will have many more joints to cover. If, after reading this, you new teams are still confident on using this for your frame, Good Luck.

[EricH]

Originally Posted by Molten

I disagree. We use the 1 1/2" Aluminum tubing and it makes it much stronger. Last year, our robot got tipped over 3 times and did not show the slightest hint of damage. When making a frame, keep in mind that the best robot is lousy once it falls apart. The main point of the frame is to keep everything from falling apart. It does not necessarily have to be fancy, it just has to be functional. Remember, function over form.

I didn't say a thing about using it in the drivebase. Superstructure is the part of the robot above the drviebase. On our robot, we use 1 1/2" x 1" x 3/4" tubing for the drive frame and key superstructre (masts for arms, for example). 3/4" thinwall is used for stuff where we either need it to weigh nothing or we don't really care. It is pretty strong though. 330 used it for ramp framing last year. It supported about 140 lbs, often charging onto it, and we were more worried about the corrugated plastic being gouged than we were about the frame. I just wouldn't recommend using it for a drivebase.

[M. Mellott]

Here's a product I found...I haven't invested any funds to buy pieces for testing, but it looks great for making quick prototype frames:

http://www.eztube.com/

[Qbranch]

Originally Posted by M. Mellott

Here's a product I found...I haven't invested any funds to buy pieces for testing, but it looks great for making quick prototype frames: http://www.eztube.com/

Watch out!

We tried this stuff and it does look fantastic on paper, but they have a huge issue with being out of square. Well, not the connectors themselves, but what you put together with them. When we tapped our connectors in everything was nice and strong... but horribly out of square.

The robot frame we put together couldn't even hold an axle straight, let alone sit level. Maybe if you used force gauges or something when pressing the connectors in, or had really close tolerancs on the ID of the tube you use it would work... but just a heads up, with your ajax square tube it doesn't look too pretty...

-q