Glider Wheel Brakes

On Mon, 12 May 2008 10:19:31 -0700 (PDT), wrote:

On May 9, 9:15 pm, wrote:
I know, I know. BTDT. Has anyone purchased a NEW sailplane lately,
and been happy with the wheel brake? The ONLY glider I've ever flown
with a decent (not great, but decent) wheel brake is the LVVSA's G103
Twin Astir. For me, a GREAT brake will REQUIRE moderation on my part
to keep from grinding the nose. I'm used to relatively modern
motorcycles, that will lock the front wheel with 2 or 3 fingers. I
would vastly rather scrape my nose, than hit the barbed wire at the
far end of a landout.

The Antares gliders use a Beringer brake and master cylinder.
These are very light, and stop this glider easily (I'm 550kg dry,
660kg at max gross). Only negative: remember not to touch
down with spoilers out full or you may end up replacing a tire !
I'm extremely happy with this system.

A good brake system is comprised of a lot of bits that need
to all be done properly. Here are some of the screw-ups
provided with existing offerings:
- bicycle cables that stretch (even actuating hydraulics)
- cable routing that shreds cables (sharp turns)
- travel limited by badly designed mixing with spoiler mechanism
- hydraulic reservoir below slave cylinder when gear retracted
(siphon action pulls slave cylinders away from disc)
- excess tension blocks open system from venting
- fluid type change leading to corrosion
- single leading shoe drums
- inadequate support for actuating cam in side casting
(wear and slop prevent proper actuation)
- bearings sized inadequately for static load of glider
at max gross (flats bearings which will burn out
on Minden take-offs)

I could go on...

See ya, Dave "YO electric"


This topic was in vogue back in 2002. There was mention of a cycle
brake shop in California called VINTAGE BRAKE. I contacted Mike Morse
the owner, and eventually sent him my 5" Tost wheel. What he did was
to install a set of 'advanced composition' brake shoes designed to
minimize fading and to improve the overall performance of vintage
motorcycle drum brakes. He needed my actual wheel so he could first
true it and then 'arc in' the brake shoes to an exacting tolerance.
My DG200's braking went from virtually non-existent to nose-scrapingly
effective Make sure you keep full aft elevator if you lean on
these... I found the braking very very effective, yet progressive. I
also changed out the stock 'bicycle brake" quality handbrake lever
and cable, and installed a Harley clutch cable and a higher quality
bicycle handbrake lever on the control stick. It's a must to minimize
stretch in these cables if you want to deliver full force to your
brake shoes. The brake is now overdue for a new set of shoes. It has
been over 6 years since this overhaul was done, and I can tell that
the effectiveness is slipping a bit. Even though I'm overdue, the
braking is still much superior to the original 5" Tost. It was also
very inexpensive as I recall.
www.vintagebrake.com Mike Morse was very pleasant to work with.
I've tried some of the other exotic drum brake fixes out there without
success. One of these 'fixes" is downright dangerous, as it can
induce a lockup of the brake....hopefully one would not accidentally
touch the lever during a takeoff roll... Hope this will help
someone. It has served me well. RW

RW wrote:

This topic was in vogue back in 2002. There was mention of a
cycle
brake shop in California called VINTAGE BRAKE. I contacted
Mike Morse
the owner, and eventually sent him my 5" Tost wheel. What he
did was
to install a set of 'advanced composition' brake shoes
designed to
minimize fading and to improve the overall performance of
vintage
motorcycle drum brakes. He needed my actual wheel so he could
first
true it and then 'arc in' the brake shoes to an exacting
tolerance.
My DG200's braking went from virtually non-existent to
nose-scrapingly
effective Make sure you keep full aft elevator if you lean
on
these... I found the braking very very effective, yet
progressive. I
also changed out the stock 'bicycle brake" quality handbrake
lever
and cable, and installed a Harley clutch cable and a higher
quality
bicycle handbrake lever on the control stick. It's a must to
minimize
stretch in these cables if you want to deliver full force to
your
brake shoes. The brake is now overdue for a new set of shoes.
It has
been over 6 years since this overhaul was done, and I can tell
that
the effectiveness is slipping a bit. Even though I'm overdue,
the
braking is still much superior to the original 5" Tost. It
was also
very inexpensive as I recall.
www.vintagebrake.com Mike Morse was very pleasant to work
with.
I've tried some of the other exotic drum brake fixes out there
without
success. One of these 'fixes" is downright dangerous, as it
can
induce a lockup of the brake....hopefully one would not
accidentally
touch the lever during a takeoff roll... Hope this will
help
someone. It has served me well.

Makes one wonder how/why Tost built such poor brakes for so many
years.

--
Regards
-Doug

** Posted from http://www.teranews.com **

On May 29, 2:22*pm, (Doug Hoffman) wrote:
Makes one wonder how/why Tost built such poor brakes for so many
years.

Maybe because glider manufacturers kept buying them? Maybe because a
good brake is not much use on wet grass?

Anyway they were not a bad as some people make out. I serviced mine
(ASW-19b) at every annual inspection and it was good for a season
unless called upon to do a max energy stop. Each year I dismantled
the brake, cleaned the drum and gave it a light wipe with 600 grit,
cleaned the shoes and busted any glaze with 600 grit, cleaned and
greased the cam faces and shaft and the pivot point. Its important
that the brake is applied as the wheel spindle nut is tightened to
ensure the brake plate is properly aligned. It's also important that
the cable and cam arm make an angle of about 85 deg to each other when
the brake is full on to get maximum mechanical advantage.

None of this was strange to me as I had years of experience dealing
with British motorcycle drum brakes before I got into gliding.

Andy