I bought a Bogert tool years ago. I thought it was an improvement over the "homemade" tool I had been given by
an older mechanic when I first bought my own Twin Comanche. But then I started examining its shortcomings.
Putting the stretching device into a vise and using a breaker bar to create
300 to 400 pounds of force, IMHO, is dangerous. If that vise lets loose of that stretcher or you lose your
grip on it, somebody could get hurt. I don't feel that the "outboard saddle" on the Bogert tool is adequate
either, i.e., if you dropped the "loaded" installer tool or hit it against the airframe, the outboard pulley could
come loose from its seat in the saddle and come back at you with great force.
And quite frankly, the Bogert fixed length installer tool is not that easy to use,
especially when removing it from the wing after installing the bungee onto the pulleys. I ended up modifying mine
a couple of times before I decided to "build a better mousetrap."
And so I made two or three different bungee tools that I intended to be safer and easier to use.
In my tool, you use a wrench to turn two Acme threaded rod
jack screws that stretch the bungee onto the tool itself.
And I put a much wider outboard saddle to hold the outboard pulley.
If you were to drop the tool during the process, nothing would happen. There is no way for it to "get away from you."
And when you are installing the bungee, it is much easier to remove this tool from in between the stretched bungee
because by turning the jackscrews in the opposite direction, you can collapse the tool and make it much shorter
and easier to remove.
I have gotten many many compliments from mechanics on three continents on the design and ease of use of the tool.
Two different tool companies wanted to make it, but could not because of the labor involved, and the limited number of potential buyers.
Even Bogert expressed interest in making/marketing the tools. However, they just can't be produced cheaply like their tool.
The owner of AIrcraft Spruce wrote me a very complimentary letter and wanted to sell them for us, but we knew we could not
produce them fast or cheaply enough to make that work. So we have just made a limited number of the tools when time permitted.
A friend and I buy the raw material, make these tools in our machine shop, contract the welding, coating, etc. They are
really a "labor of love" by somebody who "likes to do it right." We knew we would not put Bogert (a good company BTW) out of business.
To read more about the tool, check out the article in the Flyer:
http://www.comancheflyer.com/NS/tech_ar ... e_tool.pdf