fatbillybob

Guys who are making the "taco style" rollcage gussets I got a question. How are you making them? card board pattern, punch the holes, bevel the holes for stiffness, hammer form the taco over a piece of rollcage tubing? What kind of hole puncher are you using? Greenlee hydralic puncher? Bimetal hole saw? The a Home made lathe cut aluminium hole beveler? I'm just looking for ideas of what others do to speed up my job. It seems that I am doing it the long way.


Thanks!

Adam Richman

FatBB, how I did mine (this was my job on my cage) was as follows. My cage tubing is 1.5" dia. so I took a shoe one size up from that. All the flare punches and the initial taco bends were done w/ a 10 ton hydraulic press (way more than you need but that's what was offered up to me to use).

Took two pieces of scrap 1.5" dia., one as long as the longest hypotenuse, of my "tacos." The other should be a tad longer than the longest distance from the hypotenuse to its opposite angle. Weld the latter to the mid point of the former at 90 deg.

Like you said, use cardboard (or heavy construction paper) and form it (if you have a paper towel roll or something in a similar diameter to help get the actual shape, the better) so the edges meet up on tangent to the roll cage tubes you will attach it (not shorter). It will take a lot of cutting and trimming but its worth it.

Buy yourself a flare punch tool (like this - http://www.fournierenterprises.com/punch_flare.gif) and ALWAYS use the guide screw even though it seems unnecessary (I own a chipped one now cause I ignored this fact using a friend's ). Determine the OUTSIDE dia. of the flare itself and mark that on your cardboard/construction paper template to make sure neither the hole nor flare's edge crosses over into the bend or edge. Trace the outline to your sheet metal and make sure you note on the metal which side is the outside (only applicable if you have non-square shapes - I had 3 of these IIRC), cut it to shape and punch your flares out (flare edge in). You have to punch the flares when the metal is flat - there will be no way to do this properly after you shape the taco.

I drew two dotted lines on the sheet metal to mark the outside lines of my bend (these would be where you notch/cut out the top and bottom to meet the circumference of the tubes) - so you can see the lines with the above mentioned T tube tool in place. Place the sheet metal over the shoe, place the T tube between your dotted lines and press it into the shoe. You will need to probably do a couple small test presses before you get it lined up exactly. You want to press it into the shoe but not really to a point that you could damage it. I took mine at this point to a table press and bent it by hand a little past parallel knowing they'd spring out a bit.

From there, just weld them into place. I would suggest you do not use a continuous weld but leave a couple small gaps (like very heavily spot welding it in) as you may run into issues w/ them collecting water w/ no means to drain. The alternative to this is to buy some thin wall tubing that fits into the inner diameter of the flare punch holes and weld them in. But only do this if you have already welded them into place on your cage (no water in therefore no concern about water needing to get out).

This (d. side) was a real tough angle as it bent around into a curve from the door bars to the b-pillar but it really came out nicely (http://www.deltagroupmotorsports.com...verside_2.jpg).

Check back in 30 mins, I'll draw a mockup and post it back.

Adam Richman

a bit oversimplified but this is what I was trying to describe.

kurt M

Home boy version of bevel maker is two sockets one the outside dia you want and one hole size or a little bit larger. Stack the big socket on bottom, sheet metal and small socket on top in a shop press. Press untill you are happy. Punch holes with hole punch after forming bevel. You can also use the hole punch base rather than the top socket. I like to use sockets as they are rounded a bita nd thus don't make sharp stress risers and I am cheap... The bevel and the holes for that matter is for the most part a looks thing unless every ounce is getting coounted.

Geo

Actually, this adds considerable strength believe it or not.

Adam Richman

kurt M, I am with George - they add a good deal or strength and moreso, the weight savings is next to nothing. I doubt if a gusset's punch is in the ounce range - we're talking about a 15/16" hole out of maybe a 10"x10" of sheet metal ?? If it were me and I wasn't going to punch and flare them, I'd do same dia. tubes in place of the solid sheet metal gussets.

fatbillybob

Thanks guys! I never thought of using my press to make the Taco's. What a dummy I am sometimes. I like Adam's "T" tool. I like Kurt's socket idea too. I also am cheap. Geo, Good thing the bent holes add strength so I can use that as an excuse to do it. Actually, I really like the cool "look" too. I'm not fast so I have to look good.

Regards!

kurt M

I think I am missing something. Is the metal stronger with a hole or without? I agree that turning stress away from an unimproved or supported edge is good and that bevels or tube sleeves help to do that but would the taco be stronger without the hole to start with? (BTW Not a snide comeback at but a real question asked to folks that have more experience than I do. This is one reason that I like and visit this fourm I learn good stuff everyday.)

Geo

The "taco" is stronger (or is that stiffer or both?) with the beveled hole than without.

I don't know the details behind it, and cannot give you a definitve reference, but everything I've read about this agrees. I imagine the dimple in the hole helps prevent bending of a flat expanse (however small) of metal. But that's my guess. Perhaps one of the engineers here knows the details.

kurt M

Holes gather stress... Flat plains don't. How about a dimple rather than a hole" or an X crease? Would they gather stress...

Damnit! Now I have a head hurting info quest to figure out. Curse you!

Geo

Hey, join the club.

Stand in line.

Adam Richman

Those creases are probably less efficient in the case of folding a piece of metal 180 deg because the creases would have to be sure to terminate before the curve itself. Now if I were going to cover a flat surface, I think that is the way to go but the punch & flare (in my mind) seem to do a better job w/ the space in use here. But heck man, why don't you create one of each type, weld each taco to two unconnected tubes, put one tube in a vice and see what kind of force it takes to move the other tube a distance of an inch (say 1" inboard and then try 1" vertical). If the creased one moves less, seems like the better route to take. I'd be interested what the force difference was.