In article ,
Stewart Kissel wrote:

What is it that these guys do to improve braking?
Assuming all ships could use help, are some (say a
Ventus) more improved then others? How much $. Thank
you.




To start with, Michael at Vintage Brake has a primary business of doing
drum brakes for vintage motorcycle racers. This means he has a lot of
experience separating inferior mechanical brake assemblies from quality
ones, he has a large assortment of pad materials on hand, he gets a lot
of feedback from the racers about what works and what didn't, so
ultimately he's got a good grasp of all the variables involved in
picking a compound to match the mechanism and the application.

So, I sent him my LAK-12 main wheel assembly, as the brakes just weren't
up to the task of adequately slowing down a 1000# glider. Although my
glider is Experimental, he won't reject other types; it's up to you and
your mechanic to know what you can/can't do to your glider.

He looked it over, and says the brake components are strong, well made,
good materials used, etc; I think it comes straight out of a Blanki. We
then discussed the typical operating conditions such as runway surface,
temperature, wet/dry, weight. He also wanted cable length and
dimensions of the brake lever pivot assembly.

After all that, he recommended a pad material suited to stopping
something heavy, low duty cycle, no glazing. He installed the new pad
material on the existing shoes, cleaned and examined all pivoting parts,
made sure the drum itself was smooth, then arced the pads to exactly fit
the drums. Total cost was about $150.

What I found was vastly improved braking. It worked great time after
time, with no fading. Only drawback was that it worked a little *too*
well, as vigorous braking at low speeds would lift the tail off the
ground. I spoke with him and he recommended removing material from the
leading edge of the pads, 0.5" at a time, just enough to keep the pad
off the drum.

This improved the situation, but I feel it's really more of an issue
about where the brake is located with reference to the CG. Above
10-15kts full back stick keeps the tail planted, even with full brakes.
Below that speed the tail starts coming up. Some say SZDs exhibit the
same behavior. I'm going to take another 0.5" off this winter and put
on a new tire.

Ken
San Jose, CA