TOST brake mod?
John Shelton
was to get the braking shoe (the one engaged to stop when rolling forward)
to push the non-braking shoe (used to stop when rolling backwards) against
the drum thereby actually being able to stop.
One friend did it to his DG300 and it worked great and is still working
great. I have also heard that if done wrong, you end up on your nose.
Does anyone know where I can get accurate sketches and description of this
mod? Apparently, the sketch in Soaring was wrong. And, do I really want to
do this?
TimTaylor
I would not do the modification. I have heard too many mixed results. I
have heard much better results from sending your hub to Vintage Brake and
letting them reline the shoes with good material and blue printing the shoes
to exactly fitting your drum. They have done many gliders now so know
exactly what to do. They were working on a solution where you just send
him accurate I.D. of your drum and he could send you new shoes. Not sure if
they got that worked out.
Tim
"John Shelton" <imd...@earthlink.net> wrote in message
news:Jmu7a.4358$M85.4...@newsread2.prod.itd.earthlink.net...
Bob Kuykendall
The terms you're looking for are 'leading shoe' and
'trailing shoe.' They both contribute friction under
braking, though as you've surmised, the leading shoe
is somewhat self-energising and so usually contributes
more friction.
The usual 'mod' bandied about for the Tost 4-inch and
5-inch wheel/brakes converts the brake from a leading/trailing
unit to a self-energising unit.
Having used self-energising drum brakes back in my
roadracing days, I can contribute this snippet: Such
setups tend to be more sensitive to the type of compound
used in the brake shoes. And some compounds tend to
be somewhat sensitive to temperature and humidity.
I stand by my earlier recommendation that you just
send it off to Michael Morse. He'll at least convert
it from the as-manufactured state to the As-intended
state. And that's a pretty big improvement.
Bob K.
John Shelton
up to 9500 feet over the hills today. The season has started in California.
Nobody will arch brakes due to OSHA strictures on letting your employees
breathe asbestos dust.
"TimTaylor" <tta...@cc.usu.edu> wrote in message
news:b3lu42$uhp$1...@terabinaries.xmission.com...
Dave Nadler "YO"
if I don't disclose his identity, prevailed upon me to give him a copy of
KS's sketch for this mod. "Remember John", I admonished, "you need to
pay attention to the bit about the return spring function"... The glider was
an Elfe with a teeney tiny Tost. The assembled multitude was extremely
impressed by the test landing, where the brake locked, the side castings
and axle broke, and the glider stopped with the remains of the wheel
lying on its side under the fuselage. But, the modification achieved its
intended result because the glider stopped really fast !
See ya, Dave "YO"
"John Shelton" <imd...@earthlink.net> wrote in message
news:Jmu7a.4358$M85.4...@newsread2.prod.itd.earthlink.net...
TimTaylor
> Vintage Brake currently has a 10 week turnaround. Lift at my home field is
> up to 9500 feet over the hills today. The season has started in
California.
>
>
John,
Talk to them about just making shoes for you. This was something they were
working on the idea last year. You carefully measure the diameter of your
drum and they can arc the shoes for you.
You need to take your current wheel apart anyway before the season and
lightly sand the glaze off the shoes and lube the moving parts anyway,
right? You measure the drum at the same time and fly with the old shoes on
your glider for 10 weeks, then put the new shoes on.
Tim
John Shelton
Good input.
I guess that pretty much changes my mind on the brake mod idea.
Dave Nadler "YO"
cam bushing, which of course isn't the same as the intended path from
the fixed pivot out to the landing gear structure. I bushed the cam when
the hole started to elongate but... Good thing my V2 has a real Cleveland.
Now if we could only get them to arrange so that the bleeder screw isn't
rock-bait during a land-out...
Best Regards, Dave
"John Shelton" <imd...@earthlink.net> wrote in message
news:kZy7a.4725$M85.5...@newsread2.prod.itd.earthlink.net...
George William Peter Reinhart
I bought the glider (Nimbus 2C with the brake mod already done.
I nailed the brakes one afternoon to see how effective they were and they
locked up,
collapsed the gear, and caused minor internal damage to retract circuit.
I repaired the damage and have been extremely careful in brake usage since.
Now that I have time to work on the glider I'm wondering if anyone can tell
me what I need to know to re-convert to the standard configuration.
I think I'd rather take a chance with weak brakes than what I have.
Cheers!, Pete
Eric Greenwell
\"" <d...@nadler.com> says...
> Yea, I did this mod once, but the braking loads are transfered through the
> cam bushing, which of course isn't the same as the intended path from
> the fixed pivot out to the landing gear structure. I bushed the cam when
> the hole started to elongate but... Good thing my V2 has a real Cleveland.
> Now if we could only get them to arrange so that the bleeder screw isn't
> rock-bait during a land-out...
> Best Regards, Dave
Sounds like an interesting story there .... Can you tell us why a
motorglider pilot lands out, and in a rocky field? Maybe this is a
"teachable moment" for other motorglider pilots.
--
!Replace decimal.point in my e-mail address with just a . to reply
directly
Eric Greenwell
Richland, WA (USA)
Doug Hoffman
he outlines, not difficult if you are somewhat handy with tools. It
worked/works great. I can lift the tail off the ground if I want. The feel
is progressive and has no tendency to 'grab'. If you botch the job, not
likely in my opinion, then you simply have to replace one brake shoe because
that is all that is modified.
This has all been discussed here before. Do a google search on the newsgroup
for "brake".
Regards,
-Doug
Doug Hoffman
> Does anyone know where I can get accurate sketches and description of this
> mod? Apparently, the sketch in Soaring was wrong. And, do I really want to
> do this?
Yes, one of the sketches is slightly wrong. But it is very obvious and will
not be a problem. If you read the article and can't figure out this error,
then perhaps you should have someone else do the modification. Do you
really want to do this? In my opinion "absolutely!". Just ask you friend
with the DG.
Regards,
-Doug
Dave Nadler "YO"
nipple sticks down and can get knocked off by a small stone, which
has happened to at least one other glider with this fuselage and wheel
assembly. Hope that clears up any confusion,
Best Regards, Dave
"Eric Greenwell" <egreenwell@prodigydecimalnet> wrote in message
news:MPG.18c98a6c8...@news.charter.net...
Doug Hoffman
load path. He's right. I think the question of whether or not to do
the mod might depend on your setup and braking habits. In other
words, if you have an undersized brake drum for the weight of your
glider you probably don't want to do this. I have no idea of what
undersized might be. Sorry. My Tost drum is about 4" in diameter on
a 700 lb total flying weight 15-meter.
With the Schreder large span 90 degree landing flaps I rarely need
much braking power. But if I ever do need it, it's there big time.
Maybe someday I'll have to bush the cam pivot. I'll keep an eye on
that pivot. Thanks Dave!
Regards,
-Doug
"John Shelton" <imd...@earthlink.net> wrote in message news:<kZy7a.4725$M85.5...@newsread2.prod.itd.earthlink.net>...
C.Fleming
considering the mod for my LS1-f. Any comments?
Chris Fleming, "L9"
John Shelton
buy a glider that has them already. Apparently, the only sentient creature
capable of working on a glider internally (Gollum) has another job at this
time.
"C.Fleming" <cjfl...@rcn.com> wrote in message
news:b41hbd$acj$1...@bob.news.rcn.net...
Roger Druce
mainwheels and in every case the result has been a vast improvement. Tost
supply a hydraulic disc brake retrofit kits for a wide variety of gliders.
Yes the kits cost, but that cost is far less than the cost of running into
something on the ground. You can contact them via www.tost.de
Roger Druce
"C.Fleming" <cjfl...@rcn.com> wrote in message
news:b41hbd$acj$1...@bob.news.rcn.net...
Walt Konecny
>I have retrofitted two Janus B's and a Puchacz with
>hydraulic braked
>mainwheels and in every case the result has been a
>vast improvement. Tost
>supply a hydraulic disc brake retrofit kits for a wide
>variety of gliders.
>Yes the kits cost, but that cost is far less than the
>cost of running into
>something on the ground. You can contact them via
>www.tost.de
>Roger Druce
Hydraulic brakes are great, but overkill in a glider,
and add about 15 lbs if I remember right.
wk
W.J, Dean.
The ASK21 has had factory fitted disk brake on all models, most pilots find
it very satisfactory and would not want to be without it.
The version of the ASK13 built by Jubi with a front wheel instead of a skid
also has a disk brake fitted new.
I have always understood (I am sure we shall be told if I am wrong) that
later versions of the Janus are fitted from new with a disk brake, so
fitting one to an old version is an obvious update.
The Puchacz owned by the British Gliding Association for coaching (training
instructors) is fitted with a disk brake similar to that on the K21, this
was done in the UK before putting it into service. The original wheel and
brake were considered rather high maintenance and not very effective.
There are quite a few other types fitted with disk brakes from new.
Bill.
W.J. (Bill) Dean (U.K.).
>
>Walt Konecny wrote in message ...
Bob Kuykendall
> Hydraulic brakes are great, but overkill in a glider,
> and add about 15 lbs if I remember right.
I think that the Cleveland unit on my HP-18, and the Matco I've seen
on other -18s, weighs only slightly more than the 5" Tost unit that I
recently carried over to the Vintage Brake shop. The plumbing and
master cylinder (I used nearly weightless 1/8" NylaFlow hose and a
Yamaha cycle MC) also add a pound or two. I think that the
as-installed weight is more than a Tost setup. But it's nothing like
fifteen pounds. More like three or four.
Bob K.
Roger Druce
worthwhile modification/replacement for the original drum brake if that is
what was fitted. The weight penalty is very little, perhaps 1 kg or 2 kg at
the most. With the Puchacz the mod gets rid of the Polish drum brake with
all manner of issues to keep it serviceable in our dusty environment, and
you get a mainwheel with normal access to the mainwheel tyre valve which
facilitates people to keep the tyre pressure in order (the original hidden
and non capped valve is done away with).
You get repeatable breaking capability. These mods were well worth every
hour spent I on them in the workshop installing them.
Roger Druce
"Walt Konecny" <REMOVE_TO_REP...@hotmail.com> wrote in message
news:b4fkjh$1up8u4$1...@ID-49798.news.dfncis.de...