Cool Frame Ideas?
 

Does anyone have a cool or neat frame ideas?

Re: Cool Frame Ideas?
 

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.)

Re: Cool Frame Ideas?
 

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. :D

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

Re: Cool Frame Ideas?
 

Bosch Extrusion :)
Its really nice, and reusable between years.

Re: Cool Frame Ideas?
 

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

Re: Cool Frame Ideas?
 

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 :D

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

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. :rolleyes:

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

You probably don't want to hear this, but I'll bring it up anyway....

Based upon past years' rules, and the ways that they've typically been interpreted, only the most trivially modified extrusions are actually reusable under the rules. Basically, for a part to be reusable from year to year, it needs to be COTS and unmodified. In the case of extrusions, while the different kinds of custom cuts that are possible make interpretation of the rule a little fuzzy, things like milled slots or bolt patterns are almost certainly going to be ruled as non-COTS, and therefore not legal for next year's robot. So be careful what you reuse!

That's exactly what 188 tried one year (2006). We ended up with a very unconventional welded sheet metal frame. We also had a few too many crazy robot issues happening simultaneously, and nothing on that robot really got fine-tuned very well. Despite that, I'd like to see more of that sort of semi-monocoque aluminum frame—not because it's necessarily the most effective, but because it's an interesting engineering challenge. In the case of the 2006 robot, 188 recruited the services of a local engineering and fabrication company, but the community college suggestion is an excellent one. (As a matter of fact, for teams in Southwestern Ontario, there's a nice welding lab at Conestoga College in Guelph that might be worth talking to—I can supply contact details if anyone's interested.)

One last thing about welding aluminum: by virtue of the way aluminum heat-treatment works, fusion welding (i.e. when metal melts) almost invariably results in a weld that is weaker than the base metal. So even though you might be welding 6061-T6 extrusions, you might have to use a welding rod that deposits 4043-O filler metal* (which is far weaker). There's one thing that would be even more impressive than trying the fully-welded chassis: building a frame jig which would hold the entire frame rigidly while you heat-treated it in a large oven, back to a high-strength T6 condition.

*More precisely, it's actually -F with properties equivalent to -O, because it wasn't deliberately annealed, rather it just came out that way.

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

1024 has used fiberglass in numerous applications for guarding fragile components...

Maybe the best and most visible use was to guard our camera in our 2006 robot. One of our members was also on the football team that year and brough his helmet in... which he sat on the top of the robot over the camera. I looked at it... yes it worked but... then i picked up the helmet... well lets say we could have had an extra frame rail in the robot. :ahh:

But I digress. Yes, I agree with fiberglass being a spectacular robot material. It's easy to work with and requires a tiny amount of equipment to do well, none of which is costly. It's also easily repairable (west systems makes a great repair kit which can be bought in bulk if you plan on using fiberglass a lot, a hefty investment at first but well worth it + lasts you through a lot of holes/cracks).

1024 will eventually try experimenting with carbon fiber... as soon as we get someone to donate/get cheaply a large industrial oven. :o

Our 2006 robot was probably one of my favorite frames ever... it was simple but it worked. The cool thing was the frame rails (machined out of 1/2" thick 6061-T6 post-consumer aluminum) also had the bearing nests in them for the tracks, and the end of the frame had a tongue-and-groove section to allow for track tensioning (the last part of the frame was a seperate part that slid into it). The two frame rails were joined by a 1/16th inch thick aluminum sheet metal box that was riveted to both sides. Held together great through a season of slamming into the ramps at the last second... man I loved the 2006 game. :o

-q

Re: Cool Frame Ideas?
 

Anything from 1501 is pretty much a sweet frame design whether it be monocoque like previous years or their sweet chromoly design this year.

Re: Cool Frame Ideas?
 

2007 was the first time 342 didn't use a extruded aluminum (FMS) frame and we won the Palmetto regional for the first time after competing for 7 years (couldn't have done it without 1319). FMS is useful, but a major pain in the butt. Our whole pit and transporter are made from FMS and we constantly have to tighten stubborn bolts.

Re: Cool Frame Ideas?
 

222 has a prototype bot to play the 07 game built from 80/20 quick frame and 1/16" lexan. The quick frame is basically 1" aluminum square stock with .060" wall. The connectors used to assemble the frame are made out of nylon. The prototype bot is going to its second competition this weekend(we won BE 6 last weekend thanks to our partners 1626,25 and 1923 for picking us) . It's been through one competition and so far so good. I will be writing up some more detailed information on this frame when we disassemble and check for stress on the nylon joints. So far we're convinced the 80/20 quick frame makes a good, strong, light, and easy to assemble frame. I will post more information as soon as I can.

Re: Cool Frame Ideas?
 

Would you mind sharing from where you're getting the nylon connectors? I've been investigating using something like those recently and haven't found very many sources for them. I'm trying to get an idea for what's available, at what cost, and what the lead times are like for getting them delivered.

Thanks if you can help :)

Re: Cool Frame Ideas?
 

Your local 80/20 distributor should have them. The tube is $0.13 an inch (it is a special square extrusion with ridges on the inside of the tube, which I assume increase the strength of the connection) and the connector price varies depending on which one you get (straight through, t connection, 6-way, etc), but they all are between $2 and $3 each. My copy of the 80/20 price list is from last March so prices may have changed a tad, but these numbers should be pretty close.

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

I didn't even think that it would be produced by the same folks that market the T-slot extrusion. Thanks.

Has anyone used these connectors with more conventional 1x1x.0625" tubing? I'd rather not need special tubing when I've got a local supplier for metal stock and a few dozen feet sitting in the workshop already.

Re: Cool Frame Ideas?
 

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

Re: Cool Frame Ideas?
 

You might want to check with someone on 1089 I know they use the connectors, but I think they are using standard aluminum. I will caution you though, the 80/20 tubing is ribbed on the inside to grip the nylon connectors better. Also I've been using http://stores.ebay.com/8020-Inc-Gara...Q3amesstQQtZkm

this store on Ebay. They have a pretty decent turn around time most parts ship in a day or two and you can generally find parts cheaper through them.

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

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/

Re: Cool Frame Ideas?
 

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. :D

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 :cool:

Re: Cool Frame Ideas?
 

Watch out! :ahh:

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

Re: Cool Frame Ideas?
 

The EZ Tube was exactally what I was looking for someone to say. Did you use your own extrusions or the Eztube extrusions made for the connetors, did you use the composite or the steel core?

Re: Cool Frame Ideas?
 

Last year with 1493 we built a custom frame, the sides contained the transmission (a custom 2 speed based off the AndyMark shifter) and the wheels, the two sides were connected by 1 inch square tubing with 1 inch solid aluminum cubes welded on the ends. We threaded the cubes and connected the sides with counter sunk bolts. this allowed us to quickly remove one entire drive module and replace it with a spare. Allowing us to make repairs without having to miss matches of work directly around the robot.

I am going to attach a picture of the chassis, if you have any questions feel free to ask.

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

Madison et al.

We have used 80/20 QuickFrame extensively for the last two years. We haven't used it for the chassis but for most all of the other structural components. It is really great stuff and easy to work with. All you need is a miter saw and a rubber mallet. If you want to take it apart heat the aluminum near the connector with a propane torch to expand the aluminun just a little and then the connector will usually slide right out to be reused. The only downside is the plastic connectors aren't exactly light and can start to add up if you are trying to squeze out that extra pound or two of weight budget. We bought a bunch of stock and connectors in 2006 and will probably need to restock some this year. I don't know where everyone else buys their 80/20 material but we went through our regional distributor and they gave us quite a nice educational discount. IIRC it was something like 40% and I was under the impression this was the standard 80/20 discount for all FIRST teams.

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.

There are also 80/20 "transition" connectors available to use QuickFrame in combination with 1010 series where needed.

Search CD media photos for our team number "456" and there are 4 photos, 2 of our 06 and 2 of our 07 (1 lifting our 06) robot showing lots of use of 80/20 QuickFrame.

Oh yeah, we have used the KitBot frame for the last two years but the QuickFrame matches perfectly to the 1/4" 1" spaced hole pattern of the KitBot frame if you use the little base connector (part number 9140(gray) or 9240 (black)).

Hope this helps. Any more questions just ask.

Edit: I forgot the mention that 80/20 QuickFrame isn't really made by 80/20 but rather by Esto.

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

Just curious.... Why were the center wheels located more towards the centerline of the robot than the outer wheels?

Re: Cool Frame Ideas?
 

Thank you for the info--I too was hoping that by mentioning EZ Tube, somebody had to have seen it and tried it. Yes, I would imagine that in order to get a box frame that was square, you would have to have the opposite tubing pieces cut with 90 degree squared ends and be very accurate on the lengths since the lengths are controlled by the connectors bottoming out against the ends of the tubing. Keeping it squared up could probably be helped with some thin aluminum gusset strips and rivets, but now it's not so EZ.

Now that I've had time to look, the 80/20 system and the EZ Tube system look very similar, at least in concept, even with the availability of extruded tubing with panel-mounting flanges. EZ Tube connectors seem longer and have the option of the steel-core reinforcement (probably adds too much weight for a robot frame...probably).

Of course, if you're not worried about reusing the connectors, you could always use standard thin-wall 1" tubing and some two-part epoxy like JB Weld.

Re: Cool Frame Ideas?
 

We may try some more composite work this year. Last year we learned how to do some basic layups and such, but it would be really cool to build an arm or more interesting mechanism out of carbon fiber rather than a square ramp, which rarely got used. Unlike what someone said, you don't need a large oven, you can build a simple one with just heat lamps. You just need to get the temp up to around 100 or so. Last year we turned a tool closet into a "hot box" to cure our ramps.

Re: Cool Frame Ideas?
 

In past three years, our team has welded together an aluminum frame (hot metal, flying sparks, random passerby blinded over the shield at 8:30pm, what's not to love?:D). Last year, we had it professionally done when we realized something was wrong with our MIG, and our team spent more time fixing it than actually welding. Usually the students weld... This type of frame is sturdy, bottom-heavy and we can always include our traditional 10-degree wedge, but can cause difficulties in adjusting or repairing the drive train. This year, we're going to try to design a frame that is just as sturdy but doesn't require extreme flexibility in the hands or a robot tipping to fix the drive train.

Re: Cool Frame Ideas?
 

I don't know about these ovens you speak of.

Team 100 has used carbon fiber many times in the past. Usually we've just connected the pieces with resin and fiberglass.

-1995 We built our drivetrain out of a single piece of laminated carbon fiber with holes cut for wheels.

-2005 Our entire arm was made from honeycomb laminated carbon fiber that was resined together at the joints.

-2006 Our electronics board was made from honeycomb carbon fiber.

-2007 The v.2 "Head" (our manipulator) was made from a combination of wood and fiberglass with reinforced carbon fiber edges.

I'm personally not a big fan of the stuff. It takes special drill bits and saws to cut. And the edges are razor sharp, and can easily cut through wires and flesh :ahh:!

But if you're still interested in using it check out your local Tap Plastics, or The Robot Market Place. I know in the past it has always been donated to us by Battlebots builders.

I tried to get a local bike shop to sponsor us last year and build our frame out of carbon fiber (using the same techniques they use to make custom bikes). But they were neither enthusiastic nor happy about spending thousands of dollars on us :D So it fell through...

Re: Cool Frame Ideas?
 

I was referring to what Qbranch mentioned...

While in industry, autoclaves and ovens are often used, you can still get a good cure from building your own hot box.

That's the kinda thing that would be interesting to make. Do you have any pictures?

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

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

Re: Cool Frame Ideas?
 

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

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

If I Recall it was just an ease of mounting decision. We wanted wide wheels in the center to push but didn't want to have to make the whole drive module wider.

Re: Cool Frame Ideas?
 

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.

Re: Cool Frame Ideas?
 

Search before you post :p I got this picture off of your own team's website!

Re: Cool Frame Ideas?
 

side panels:
1" thick lightweight aluminum honeycomb, laminated to high density carbon fiber composite sheets on either side of the honeycomb.

internal frame: some 1x1x1/16" box beams to keep the side panels from crushing inwards.

analysis on such honeycomb and carbon fiber side panels show that the central layers of honeycomb take next to no force, and all the force is taken by the outside edge. so make it out of carbon fiber. superlightweight, and its strength increases exponentially the thicker the honeycomb layer is. then just make up a simple frame to keep the side panels in place, and cover the carbon fiber with like 1/2" foam to keep it from cracking under high pressure impacts. and then you have a really strong, lightweight frame.

my research group is using stuff like this... its lots of fun. the stuff weighs as much as foam and is as rigid as a steel plate.