Bosch Aluminum Structural Framing
 

We are interested in using Bosch Aluminum Structural Framing for the robot frame and would appreciate any suggestions. If you use proprietary extruded framing for your robot, who is the manufacturer? We are considering Bosch 30x30. Is this too light for the frame? Did you use Aluminum Structural Framing in the past and change to something else? What are you using now?

Carl Owenby
Maclay Robotics
Team 654

Too light?
 

I stood on a piece of Bosch Extrusion that was making a 30in long bridge.

I weigh 270 lbs.

The bosch beam flexed but did not plastically deform.

your robot weighs at most 130 lbs.

30x30 is very beefy.

20x20?
 

Is 30x30 is too beefy? Is 20x20 sufficiently strong enough?

My team used nothing but 30x30 last year when we used the extrusion.

We relised that in many areas of the bot it was stronger than we needed.

This year, in the main frame, we are still using 30x30...But for lots of connectors, and other misc parts we are using the 20x20.

I would think that you probably make an entire bot out of 20x20, but, well, call us paranoid of it breaking :P

Our team used the 30x30 the last two years for the frame and all other structural members. I think it's pretty good. Nice and beefy. You could probably get by with the 20x20 stuff for the less stressed structure and save some weight.

We used 30x30 last year, and it was ok i guess. It was great for moving stuff last minute and replacing parts... but it we really went thorought a lot of it.
we had a robust frame with the extrusion, but when we reamed the goal full speed (which we did religiously) the bosch would bend, deform and shear a lot. It might just be because we beat it pretty bad, otherwords it was great. the reason why i think it was just because we beat on it is becasue instead of the peices breaking, the bolt sheared first! so therefore the extrusion had to of been pretty tough!

bolts are for sissys
 

We are using thick wall 6063 aluminum thick wall tubing that is 2" square for the frame and chassis. We have about 100 feet of this stuff and about 100 feet of 1.5" square and 100 feet of 1.25" square that we got for free. We plan on welding the frame and chassis and we might as well go for the stronger stuff. (plus it was free)
-Andy

I have never seen the Bosch bend on a robot.

We have have problems at the corners tho. Sometimes the gussets don't hold all that well.

Make sure you double them up in high-stress areas.

This year is the first that we're going to use the Bosch extrusion. In the past, we've used .5" square Al tubing, and it has held up fairly well. We only ever got dented once, but even then, the tubing survived much better than the .25" plate that got hit.

Therefore, we decided to stick with the 20x20 (approx .75") since we figured 30x30 (approx 1 1/8") is overkill. We have no idea how it's going to turn out, but we're hoping for the best.

it wasn't exactly that the aluminium would bend, but the bolt would rip thorought the gussets and the peice would rip off...
also don't forget to use some lock-tight on the bolts! they really get vibrated around and will unscrew if u don't (and sumetimes even if u do).
also, where there is going to be a lot of impact or stress in any way, sometimes it is best just to bolt straight thorought the extrusion. It is much stronger than any hardware you can use.

i'll tell you now, if you use extrusion, make sure to have plenty of extra extrusion, nuts, bolts, and loctite on hand. you will most definitly need it. that being said, if i remember to, i'll take a picture of our robot from last year, and show you how the extrusion currently is (and this is with several parts completely removed cause they were too far gone to fix).

Yeah.....Its Good
 

Bosch tubing is more expensive, but it is well worth it.

Our robotics team is all designed already and we will be beginning our chasis on Sunday.

Re: Yeah.....Its Good
 

Yes, we have always used 30x30 and made our own corner brackets (gussets) from .25" T6 aluminum plate. We will use 3/16" or .25" aluminum plate to mount everything. (electronics use 1/8" plate.) And yes, we will be starting the chassis on Sunday 1/12/03.

we are using the extrusion system from "item" last year our bot was made almost entirely of the stuff (20x20) and was very robust and reliable.

"item" is known for its high quality and QC. Very high yield strength, tight mfg tolerances, etc.

(by the way, we used their fastening system and did not use ANY corner brackets, gussets, etc.)

do you know if your allowed to order the extruded from bosch this year, no book on it was in the kit, and only the parker extruded is in the msc book

It's not on the restricted materials list, so any component from the Bosch catalog is legal. The system they have developed is amazingly thorough and there's a lot that can be done with it.

It is heavy, though, and expensive.

For LI teams, look to Atlantic Industrial Technologies (www.aitzone.com) as a supplier. Last season, they offered a discounted package of materials to FIRST teams.

Actually, we checked up on it today, they are giving a discount this year too.

I have a question: how does one go about ordering Bosch extrusions or similar products. My team has never used anything like that (we've always been fans of steel), and don't know all that much about extruded aluminum.

Re: Bosch Aluminum Structural Framing
 

we are using 10/10. You can go with a fairly small size and still have plenty of beefiness, probably even more than you need. Keep in mind that extrusion is VERY heavy in the larger sizes, heavier than steel I believe.

Cory

Well, once you have the size that you want determined, you can order the peices. Hardware wise, there are many types of connectors you can use, some better than others. Also there are hundreds of attachments and special, specialized peices for certain functions. I think it best to get the catalog and flip through that before ordering anything.

There's a link to the entire catalog (I pasted all seventeen chapters together) here: http://www.cvhsrobotics.org/resources.htm. There is also a link to the Rexroth/Bosch web site.

-Kevin

Okay, so now that I know how to get materials, how do I decide what to buy? Is there a particular size that works best for robots?

if you read the rest of the thread, u'll get a good understanding the best way to decide the optimal size for what you are using it for.
another note is that it is all in metric! :( , so be warned!

Im not sure, but I think that you can get it in standard sizing also. I know that 10/10(what were gonna use) is 1"x1"

Cory

Not exactly. The 10x10 is specifying the demensions in metic measure. Though it looks close enough to 1inch, it is still metric. You will realize this thoroughly when you try to use standard bolts in the bosch, metric hardware.... It just don't work:)

Question: has anyone welded Bosch extrusions? Is this necessary, or is bolting it sufficient?

We have never welded the extrsion...and as long as your bolts are secure (ie put the rolt right thru the extrusion) and you have your gussets doubled up in high stress areas, it holds fine.

Keep in mind it does require occasional tightning (like any part).

keep in mind extruded aluminum is a 'practical application' product. It's not intended for unsupported forces. You can build a beast out of it, but only if it's forces are well distributed. The attached picture is a piece of 247's bot from last year. (Section of the tether). It took a pretty hard side force

:yikes: :yikes: :yikes:

Did a transport truck hit that?

Last year we used Bosch extruded alum. for the bottom part of our chassis and then used 1" and 1.5" alum. Angle for the rest of the structure and we only has one little bend when a clamping bot grabbed us and we tried to pull free.

When we built our chassis we cut the pieces to length then bolted them together. Then once we liked how it was set up we started replacing the hardware with welded joints. We never had our extruded alum. welds break but we did have some of the welds for the angle break. I think the person that did the welding touched and wasn't exactly sure what he was doing. If you touch the tungsten electrode from a TIG welder to the metal you are welding then it contaminates the tip and the welds you make after you touch become very brittle if you don't grind out the part where you touched and break off the end of the electrode and start again.

Welding anything is as strong or stronger then the parent metal that you are joining. So it's definitely better then bolting. If you weld it together then you can save up to five pounds of fasteners.

For those people that want a fractional sized extrusion may I recommend you go to 80-20 extruded aluminum they have fractional and metric extrusion that is practically identical to the Bosch extrusion.

Nope, team 33 (I think). (They destroyed almost every section of the top part. I think 1 was spared.. lesson learned)

I prefer just welding the entire frame together out of 1 inch square aluminum pipe.

We bought 80/20
 

Several people pointed me to 80/20, http://www.8020.net. They carry both Fractional and Metric sizes of framing. They online catalog is the best.

We ordered 80/20's 1010 1" x 1" Modular T-Slotted Aluminum Framing for this year's robot. They are quick, one-day turnaround, and less expensive than Bosch.

Jeff, you should be able to get it locally from the Distributer Micco right over by 696 & Dequinder, I think you guys are working at the Tech Center this year right so it's pretty close.

We have welded it, it works. If the joint is critical we usually bolt through the extrusion instead of using the TNuts since as other people have noted the TNuts can break through the extrusion with enough force, however it will be pretty impressive if you break off a thru-bolted. I think the picture that was bent was a 20x20 on a tether that got pinned into the side of the field pretty hard.

Will Kidder - willkidder@kidderassoc.com
MICCO (Moddular Industrial Comp Co)
25831 Commerce Dr.

Madison Hgts, MI48071
PHONE: 248-584-4440
FAX: 248-584-1117

TOBOR V was made from Bosch (30/30)...



The stuff is fun, just like an erector set. It's strong too. If you plan on getting very physical (ramming people), then use the 30/30. If you plan on just stacking boxes and shoving people on the side, 20/20 should be fine, but it may bend a little. We used 30/30 but still bent it (about 1/2" of a bow) when we rammed a goal in a match last year @ ~12fps (we bent that bar with the polycarb bumper on it).

It's better to bolt the stuff directly, like how we did it. Brackets suck. We never broke a bolt.

http://www.item.ca/products/

This is a good online catalog.

If you want to order some of this stuff call item-midwest at
262-363-4800. They are our team's main sponsor.

Through bolting is usually not necessary with the higher grade systems like item and bosch.

Tobor was/is a great robot. Marge (our fair lady) proved robust and relaible, too (we used 20x20). I think we are using 20x20 again this year, but I may suggest a switch to 30x30 lite.

Welding is very strong, but can't welding cause base metal fatigue/weakening to the areas just outside of the weld on aluminum?

nothin' better than the bosch :)

Extruded strut pros/cons
 

Extruded strut is some excellent stuff. It is strong, but hard to weld because it is thicker/thinner in places. Also the anodizing make for difficult welding. We welded our frame last year and removed 10 lbs of nuts and bolts from the chassis!:]