hydraulic brake actuation

[Brad[_2_]]

Am researching the brake system for my glider project and am pretty
sure a disc brake is the way to go. The cost for a suitable drum brake
is about 2x what a disc brake from Grove or Matco costs, Azuza makes
drum brakes, but they don't seem robust enough for my needs.

I plan on using a bike grip type handle to actuate the brake, not a
problem with a drum brake, but not so easy with the disc brake, as far
as what I have been able to find out. There is a stick mounted hand
grip style Matco makes, but it has the reservoir attached and will
interfere with my control stick geometry.

What I am leaning towards is a bike grip, with the cable running to a
lever with mechanical advantage to actuate the hyrdraulic master
cylinder. (DRN.........you sent me a pic of this?)

Do any of you guys out there with disc brakes have a bike grip type
actuator? and how does it actuate the master cylinder?

Do not want to brake actuated by the airbrake circuit, nor a heel
brake.

I did a search of this group on this subject, and did find some useful
info, but wanted to start a more specific thread..................ok,
so I am lazy!

TIA,
Brad

[Udo Rumpf[_2_]]

Brad,
make your own handle.
On my projects I used 5/16" 6061 Aluminium.
You can shape it and size it to meet your needs. Make it a bit longer and
you can use two hands for max braking.
I used Matco and a generic master cylinder and I was able, with two hands
to leave rubber on the pavement.
Udo

At 18:26 07 January 2009, Brad wrote:
>Am researching the brake system for my glider project and am pretty
>sure a disc brake is the way to go. The cost for a suitable drum brake
>is about 2x what a disc brake from Grove or Matco costs, Azuza makes
>drum brakes, but they don't seem robust enough for my needs.
>
>I plan on using a bike grip type handle to actuate the brake, not a
>problem with a drum brake, but not so easy with the disc brake, as far
>as what I have been able to find out. There is a stick mounted hand
>grip style Matco makes, but it has the reservoir attached and will
>interfere with my control stick geometry.
>
>What I am leaning towards is a bike grip, with the cable running to a
>lever with mechanical advantage to actuate the hyrdraulic master
>cylinder. (DRN.........you sent me a pic of this?)
>
>Do any of you guys out there with disc brakes have a bike grip type
>actuator? and how does it actuate the master cylinder?
>
>Do not want to brake actuated by the airbrake circuit, nor a heel
>brake.
>
>I did a search of this group on this subject, and did find some useful
>info, but wanted to start a more specific thread..................ok,
>so I am lazy!
>
>TIA,
>Brad
>

[[email protected]]

I built such a system for my former AS-W12 using a Cleveland system.
Worked fine but make sure the entire system is as stiff as you can
possibly make it. Use heavy motorcycle bowden cable and make the run
as short as possible. Also make sure the master cylinder mount is
rigid.

The ratios from brake handle throw (e.g., what is the max throw you
can get with your hand on the stick) to the throw on the master
cylinder actuator is an interesting geometric cut-an-fit. Making your
own handle will help a lot.

I much prefer spoiler-actuated brakes due to the additional force you
can apply with your entire arm/shoulder, the fact that both drag
devices are appropriately on one handle and the difficulty in mixing
fine-scale pitch/roll inputs on the stick with the gross-scale motor
skills of pulling like hell on the wheel brake.

[Greg Arnold[_2_]]

wrote:
> I built such a system for my former AS-W12 using a Cleveland system.
> Worked fine but make sure the entire system is as stiff as you can
> possibly make it. Use heavy motorcycle bowden cable and make the run
> as short as possible. Also make sure the master cylinder mount is
> rigid.
>
> The ratios from brake handle throw (e.g., what is the max throw you
> can get with your hand on the stick) to the throw on the master
> cylinder actuator is an interesting geometric cut-an-fit. Making your
> own handle will help a lot.
>
> I much prefer spoiler-actuated brakes due to the additional force you
> can apply with your entire arm/shoulder, the fact that both drag
> devices are appropriately on one handle and the difficulty in mixing
> fine-scale pitch/roll inputs on the stick with the gross-scale motor
> skills of pulling like hell on the wheel brake.


I installed a Tost disc system (modified Cleveland) in my Discus A.
Just uses bicycle cable, and the run is from the handle on the stick all
the way back to the master cylinder alongside the wheel well. The
problem was that the lever on the stick (designed for a drum brake) hit
the stick before there was much braking action. This was due both to
the shape of the lever and the long run of stretchy cable.

After spending considerable time surfing bicycle shops on the internet,
and ordering several different bicycle brake handles, I found one that
is a perfect replacement for the SH handle. It is shorter and curved
away from the stick, and allows you to apply any pressure you want
without the handle hitting the stick.

Thus, you can make such a system work with bicycle components.

[DRN]

On Jan 7, 1:26*pm, Brad > wrote:
> ...
> What I am leaning towards is a bike grip, with the cable running to a
> lever with mechanical advantage to actuate the hyrdraulic master
> cylinder. (DRN.........you sent me a pic of this?)

The picture I sent you was spoiler-actuated (which I still
recommend). I just emailed you and Bob pictures of a
setup as you describe above.

Hope it helps !
See ya, Dave "YO electric"

PS: I have a Matco disc brake and wheel from an abandoned
project (disc brake mod kit for LS-6, almost finished) and an
actuator too.
Somewhere in the back of my shop under a decade's detritus...
Contact me if you're interested...

[DRN]

On Jan 7, 3:38*pm, Greg Arnold > wrote:
> wrote:
> > I built such a system for my former AS-W12 using a Cleveland system.
> > Worked fine but make sure the entire system is as stiff as you can
> > possibly make it. *Use heavy motorcycle bowden cable and make the run
> > as short as possible. *Also make sure the master cylinder mount is
> > rigid.
>
> > The ratios from brake handle throw (e.g., what is the max throw you
> > can get with your hand on the stick) to the throw on the master
> > cylinder actuator is an interesting geometric cut-an-fit. *Making your
> > own handle will help a lot.
>
> > I much prefer spoiler-actuated brakes due to the additional force you
> > can apply with your entire arm/shoulder, the fact that both drag
> > devices are appropriately on one handle and the difficulty in mixing
> > fine-scale pitch/roll inputs on the stick with the gross-scale motor
> > skills of pulling like hell on the wheel brake.
>
> I installed a Tost disc system (modified Cleveland) in my Discus A.
> Just uses bicycle cable, and the run is from the handle on the stick all
> the way back to the master cylinder alongside the wheel well. *The
> problem was that the lever on the stick (designed for a drum brake) hit
> the stick before there was much braking action. *This was due both to
> the shape of the lever and the long run of stretchy cable.
>
> After spending considerable time surfing bicycle shops on the internet,
> and ordering several different bicycle brake handles, I found one that
> is a perfect replacement for the SH handle. *It is shorter and curved
> away from the stick, and allows you to apply any pressure you want
> without the handle hitting the stick.
>
> Thus, you can make such a system work with bicycle components.

Um, why didn't you just replace the Bowden cable with something
more appropriate ??
See ya, Dave

[Uncle Fuzzy]

>
> Um, why didn't you just replace the Bowden cable with something
> more appropriate ??
> See ya, Dave- Hide quoted text -
>
> - Show quoted text -

Such as?
I've been playing with this a bit too. I built a new cable using
motorcycle brake cable, (BTW, cable, and end fittings can be found at
Flanders web site, very reasonable) which is considerably stouter than
anything found on a bicycle. I'm still stuck with the very limited
cable movement (about 1/2"). The original lever very nearly hits the
instrument panel, so extending it isn't an option. I could set up the
master cylinder actuator to deliver more stroke than the cable
movement, but I need to test that to see if I can generate enough
pressure. I'm MOST inclined to follow Mark's advice and set it up on
the spoiler handle, but only after I've wasted several weeks trying to
make the joystick lever work!

[DRN]

On Jan 7, 4:14*pm, Uncle Fuzzy > wrote:
> > Um, why didn't you just replace the Bowden cable with something
> > more appropriate ??
> > See ya, Dave- Hide quoted text -
>
> > - Show quoted text -
>
> Such as?

Stiffer housing, stronger cable, matching end-fittings...
Reduce required throw on master cylinder.

> I've been playing with this a bit too. *I built a new cable using
> motorcycle brake cable, (BTW, cable, and end fittings can be found at
> Flanders web site, very reasonable) which is considerably stouter than
> anything found on a bicycle. *I'm still stuck with the very limited
> cable movement (about 1/2"). *The original lever very nearly hits the
> instrument panel, so extending it isn't an option. *I could set up the
> master cylinder actuator to deliver more stroke than the cable
> movement, but I need to test that to see if I can generate enough
> pressure. *I'm MOST inclined to follow Mark's advice and set it up on
> the spoiler handle, but only after I've wasted several weeks trying to
> make the joystick lever work!

I'd recommend the spoilers as well.

Thanks for the pointer to Flanders cable parts:
http://www.flandersco.com
Anybody know if there's a site where these parts can be ordered
on the web (it looks like Flanders isn't set up for web orders) ?

Best Regards, Dave "YO electric"

[Greg Arnold[_2_]]

DRN wrote:
> On Jan 7, 3:38 pm, Greg Arnold > wrote:
>> wrote:
>>> I built such a system for my former AS-W12 using a Cleveland system.
>>> Worked fine but make sure the entire system is as stiff as you can
>>> possibly make it. Use heavy motorcycle bowden cable and make the run
>>> as short as possible. Also make sure the master cylinder mount is
>>> rigid.
>>> The ratios from brake handle throw (e.g., what is the max throw you
>>> can get with your hand on the stick) to the throw on the master
>>> cylinder actuator is an interesting geometric cut-an-fit. Making your
>>> own handle will help a lot.
>>> I much prefer spoiler-actuated brakes due to the additional force you
>>> can apply with your entire arm/shoulder, the fact that both drag
>>> devices are appropriately on one handle and the difficulty in mixing
>>> fine-scale pitch/roll inputs on the stick with the gross-scale motor
>>> skills of pulling like hell on the wheel brake.
>> I installed a Tost disc system (modified Cleveland) in my Discus A.
>> Just uses bicycle cable, and the run is from the handle on the stick all
>> the way back to the master cylinder alongside the wheel well. The
>> problem was that the lever on the stick (designed for a drum brake) hit
>> the stick before there was much braking action. This was due both to
>> the shape of the lever and the long run of stretchy cable.
>>
>> After spending considerable time surfing bicycle shops on the internet,
>> and ordering several different bicycle brake handles, I found one that
>> is a perfect replacement for the SH handle. It is shorter and curved
>> away from the stick, and allows you to apply any pressure you want
>> without the handle hitting the stick.
>>
>> Thus, you can make such a system work with bicycle components.
>
> Um, why didn't you just replace the Bowden cable with something
> more appropriate ??
> See ya, Dave


I don't know what would be "more appropriate" than an arrangement that
works perfectly.

[DRN]

On Jan 7, 4:56*pm, Greg Arnold > wrote:
> DRN wrote:
> > On Jan 7, 3:38 pm, Greg Arnold > wrote:
> >> wrote:
> >>> I built such a system for my former AS-W12 using a Cleveland system.
> >>> Worked fine but make sure the entire system is as stiff as you can
> >>> possibly make it. *Use heavy motorcycle bowden cable and make the run
> >>> as short as possible. *Also make sure the master cylinder mount is
> >>> rigid.
> >>> The ratios from brake handle throw (e.g., what is the max throw you
> >>> can get with your hand on the stick) to the throw on the master
> >>> cylinder actuator is an interesting geometric cut-an-fit. *Making your
> >>> own handle will help a lot.
> >>> I much prefer spoiler-actuated brakes due to the additional force you
> >>> can apply with your entire arm/shoulder, the fact that both drag
> >>> devices are appropriately on one handle and the difficulty in mixing
> >>> fine-scale pitch/roll inputs on the stick with the gross-scale motor
> >>> skills of pulling like hell on the wheel brake.
> >> I installed a Tost disc system (modified Cleveland) in my Discus A.
> >> Just uses bicycle cable, and the run is from the handle on the stick all
> >> the way back to the master cylinder alongside the wheel well. *The
> >> problem was that the lever on the stick (designed for a drum brake) hit
> >> the stick before there was much braking action. *This was due both to
> >> the shape of the lever and the long run of stretchy cable.
>
> >> After spending considerable time surfing bicycle shops on the internet,
> >> and ordering several different bicycle brake handles, I found one that
> >> is a perfect replacement for the SH handle. *It is shorter and curved
> >> away from the stick, and allows you to apply any pressure you want
> >> without the handle hitting the stick.
>
> >> Thus, you can make such a system work with bicycle components.
>
> > Um, why didn't you just replace the Bowden cable with something
> > more appropriate ??
> > See ya, Dave
>
> I don't know what would be "more appropriate" than an arrangement that
> works perfectly.

Apologies if I mis-understood your email.
You say you have "long run of stretchy cable".
If you didn't replace it, you're using up lots of travel stretching
the cable.
If you fixed the cable problem, you wouldn't have needed to change the
handle ?
And you would have better leverage ?

Sounds "adequate" but hardly "perfect", especially as soon
as any additional deficiency develops...

Sorry if I mis-understand !
Best Regards, Dave "YO electric"

[Andy[_1_]]

On Jan 7, 3:19*pm, DRN > wrote:
> You say you have "long run of stretchy cable".
> If you didn't replace it, you're using up lots of travel stretching
> the cable.

May be a minor point but the lost motion in light weight bowden cable
systems is typically not caused by stretching of the inner, rather by
compression of the coiled outer sheath.

On a cable with any bends the compression shows up as a change in the
shape of the cable run. Cable length change caused by compression of
the outer is the reason that special non compressible cable outers
were developed for 9 and 10 speed indexed bicycle gear systems.

The compression of the outer sheath can be reduced by minimizing
bends, optimizing bend radius, and/or by going to a heavier gage. All
cable fittings should butt square when relaxed or under max load.
Optimizing the cable run can work wonders even if the materials are
not changed.

Andy
(Years of experience with British motorcycles and now relearning it
all building and modifying mountain bikes)

[Greg Arnold[_2_]]

DRN wrote:
> On Jan 7, 4:56 pm, Greg Arnold > wrote:
>> DRN wrote:
>>> On Jan 7, 3:38 pm, Greg Arnold > wrote:
>>>> wrote:
>>>>> I built such a system for my former AS-W12 using a Cleveland system.
>>>>> Worked fine but make sure the entire system is as stiff as you can
>>>>> possibly make it. Use heavy motorcycle bowden cable and make the run
>>>>> as short as possible. Also make sure the master cylinder mount is
>>>>> rigid.
>>>>> The ratios from brake handle throw (e.g., what is the max throw you
>>>>> can get with your hand on the stick) to the throw on the master
>>>>> cylinder actuator is an interesting geometric cut-an-fit. Making your
>>>>> own handle will help a lot.
>>>>> I much prefer spoiler-actuated brakes due to the additional force you
>>>>> can apply with your entire arm/shoulder, the fact that both drag
>>>>> devices are appropriately on one handle and the difficulty in mixing
>>>>> fine-scale pitch/roll inputs on the stick with the gross-scale motor
>>>>> skills of pulling like hell on the wheel brake.
>>>> I installed a Tost disc system (modified Cleveland) in my Discus A.
>>>> Just uses bicycle cable, and the run is from the handle on the stick all
>>>> the way back to the master cylinder alongside the wheel well. The
>>>> problem was that the lever on the stick (designed for a drum brake) hit
>>>> the stick before there was much braking action. This was due both to
>>>> the shape of the lever and the long run of stretchy cable.
>>>> After spending considerable time surfing bicycle shops on the internet,
>>>> and ordering several different bicycle brake handles, I found one that
>>>> is a perfect replacement for the SH handle. It is shorter and curved
>>>> away from the stick, and allows you to apply any pressure you want
>>>> without the handle hitting the stick.
>>>> Thus, you can make such a system work with bicycle components.
>>> Um, why didn't you just replace the Bowden cable with something
>>> more appropriate ??
>>> See ya, Dave
>> I don't know what would be "more appropriate" than an arrangement that
>> works perfectly.
>
> Apologies if I mis-understood your email.
> You say you have "long run of stretchy cable".
> If you didn't replace it, you're using up lots of travel stretching
> the cable.
> If you fixed the cable problem, you wouldn't have needed to change the
> handle ?

Either "fix" would work, but changing the handle seemed easier and as
effective.


> And you would have better leverage ?
>
> Sounds "adequate" but hardly "perfect", especially as soon
> as any additional deficiency develops...
>
> Sorry if I mis-understand !
> Best Regards, Dave "YO electric"

[DRN]

On Jan 7, 5:44*pm, Andy > wrote:
> May be a minor point but the lost motion in light weight bowden cable
> systems is typically not caused by stretching of the inner, rather by
> compression of the coiled outer sheath.

Absolutely right, sorry I wrote imprecisely...
The sheath (housing) is after all a wound spring !
Best Regards, Dave

[Udo Rumpf[_2_]]

Brad,
I found a picture of the break handle I made
http://www.soaridaho.com/Schreder/HP-18/C-FETQ.html
5th picture down.
Udo

[Brian[_1_]]

Here is some photos of the stick/cable system I built for my HP16.
While It won't stand the glider on the nose it is adequate.

http://www.soaridaho.com/Schreder/Construction/HP-16_Stick_Mod/HP-16_Stick_Mod.htm

Brian
HP16T

[Brad[_2_]]

Thanks for all the ideas, suggestions and links guys!

Looks like I'll be using a wheel and brake combo listed as a C-90. It
uses an Azusa 5" wheel with a hydraulic disc brake. For my
"lightweight" version of the HP-24 it should work quite well, and the
brake disc is set on the "inside" of the wheel rim so there will be a
slimmer overall package.

The trick I guess will be fitting a stick mounted handle and cable
setup to give me good actuation of the master cylinder. I really do
want the brake handle on the stick, so I'll just make it work, and may
as suggested end up making my own handle.

Cheers,
Brad