Episode 17: Cage Fights! (This is a long one...)
I was looking forward to building the cage for the Super Snipe. I would be learning new skills while getting lots of practice on an old and rusty one -- welding, not the car, silly!
In the beginning, I thought it would be a two weekend project -- one to cut and bend the pieces and one to weld it all together. Boy was I all wrong! I learned that I had absolutely no idea of how much work goes into building a cage. The guys who do it for a living have my respect -- this is hard work and it takes a long time!
I was fortunate to have gotten excellent help and advice from Spank. I simply cannot begin to thank him enough for everything he did for me.
First of all, he clued me in to a steel supplier (Summit Steel) that sells DOM tubing for far less than my usual supplier (Industrial Metal Supply). It was $3.25/foot versus $4.46/foot when buying five "sticks" (approx. 20' lengths). IMS charges $5.21/foot when buying only two, and Summit hardly raises the price at all (yes, I ran out and had to buy more). Driving down the freeway with several 20' lengths of tubing strapped to to the top of a Volvo did get me a few odd looks:
Then Spank generously loaned me his JD Squared Model 3 tubing bender and TN-100 notcher. these are excellent products and I recommend them whole-heartedly. I have already bought my own TN-100 and will buy my own Model 3 for my next cage. He also let me use his Bend-Tech EZ 3D software, which made all the calculations simply trivial. I will certainly buy this software when I get my own bender.
First up was gutting the interior. In places, it actually pretty decent:
In others, it looked, er, awful:
When gutting a car, you never know quite what you might find. When we pulled the head liner, out poured a stash of acorns! Clearly a family of rodents had been living up there. Here is my friend Richard dealing with one of the larger specimens:
Having read "How Not To Fail Lemons Safety Tech" several times, and listened to Spanks tips and tricks, I opted for the "Main Hoop and Halo" design.
The Bend-Tech software simply needs the dimensions at critical points, then it gives you the total length of the tube, the points at which to bend, and the number of degrees to bend. Bending 1.75 x .120 DOM tubing on a JD2 Model 3 takes a bit of effort, but a 5' piece of 2" pipe on the lever made it almost easy. Having a second person to monitor the degree pointer is almost essential.
Keeping the bends in the same plane is essential if you want the finished product to lay flat. I found that a small machinist's vice and a level made this easy:
With this, the main hoop came out perfect (before trimming):
With the main hoop & halo design, I could do the impossible-to-get-to welds by dropping the main hoop through the bottom of the car floor. How do you do this? Just use a 2" hole saw in the floor (watch out for fuel/brake lines!):
Then, lower the main hoop through the holes and do those "impossible" welds:
Then cover the holes with big spreader plates when you are done:
I found myself doing this maneuver several times during construction, each time with the cage getting heavier.
Although I own a MIG welder, my preferred method is TIG. It takes a lot longer, but I originally learned gas welding, so it feels more familiar. Unfortunately, my hands shake more than they did 20 years ago, just not yet to the "jittery raccoon on dexedrine" level. I'm satisfied with the results, but not exactly proud of them.
If you have never welded a cage before, I suggest that you thoroughly study the Kama Sutra first. You will find yourself in positions that your friends with cameras will find totally amusing. You, less so. If you are over 40, you will probably need to get close-up glasses or a lens plate for your helmet in order to see your welds as you make them
Speaking of helmets, get the best auto-darkening helmet you can afford. The $49.99 ones from Harbor Freight work -- sort of -- but once you have used a high-end one you will never go back. My old helmet, one of the very first auto-darkening helmets, died at the start of this project. I splurged and bought a Miller Digital Elite and am extremely happy with it. It has a "X-Mode" which is perfect when working outdoors or with low-current TIG. In X-Mode, instead of being triggered by the flash of light, it is triggered by the magnetic field in the cable. It doesn't darken when moving your head from shade to sunlight, but triggers perfectly the instant you strike an arc.
Of course, some of the welds were in places where a helmet simply can't fit. Here I had to resort to plain goggles with a #10 filter. But, please, don't make the same mistake I did: be sure to put on lots of sunblock (SPF 50) all over your face, neck, and arms. My face looked like hell for a week after that welding session -- sort of like a reverse raccoon. Even when using a full helmet, wear long-sleeved shirts.
Most of the time was spent not on welding, but in getting the fit-up good. No matter how close you calculate and measure, the notch in the tube will not be a perfect fit against its mate. You then must then resort to the disk grinder to improve the fit. Your welds will not only look better, but be stronger and easier to do.
This then leads to the age-old problem, "I've trimmed it three times and it's still too short!" I was lucky and only screwed up two pieces, but you should plan on this. If you have two similar pieces (e.g. door bars), cut and fit the longer one first. They, when you screw it up, you may be able to use it as the shorter one.
Oh yes, before you start, stock up on burn ointment, band-aids, and (just in case) rolled gauze bandages. You *will* get cut and burned. If you are extremely unlucky, you might even need a trip to Urgent Care. I came close to amputating the end joint of my index finger (see thread http://forums.24hoursoflemons.com/viewt … p?id=14380) with the disk grinder. This cost me two weeks of downtime, and the loss of feeling in that fingertip.
Although building the cage took closer to ten weekends than the two I had originally thought, I'm glad that I did it. I am very pleased with the end result:
I now have a much greater appreciation for what goes into building one, and for the people who do it for a living. If I had known then what I know now, I probably would have paid one of them to do it!
With the cage finally finished (late February) I could turn my attention back to the engine.
Next: How do we spin this?
"I don't suffer from insanity, I enjoy every minute of it!"
IOE winner in the Super Snipe -- Buttonwillow 2012
IOE winner in Super Snipe v2.0 -- Buttonwillow 2016
"Every Super Snipe in Lemons has won an IOE!"