Smooth stop leaks, alternative?
 

Who else makes a air brake valve that will be more reliable? Had a leaky smooth stop and replaced it with a brand new one, it leaks just as bad.Ovberhauled it with no change. Running a jetcat 80 if that makes a difference.
Thanks

Ultra Pecision
 

Makes a very good brake valve. It is not truly proportional, but it does vary the air pressure to the brakes in 4 incements. And best of all, I've never seen one leak.

Smooth stop leaks, alternative?
 

michael1

I can take the leaky ones off your hands. Shoot me a PM on how much you want for the 2.

Regards
Ben

Smooth Stop
 

The only time I have had one leak is if the travel adjustment is not correct.
David

Smooth stop leaks, alternative?
 

Michael, my guess is you have done something incorrectly in the setup or installation. See if these hints help you out.

Here are what to look for if you have a smooth stop leaking on you:

1) Travel adjustment too far for the "brakes off" position. Pushing the plunger in all the way can cause leaks at times. Try having it come out about 1/8" in the brakes off position.
2) Travel adjustment too far for the "brakes on" position. Pulling the plunger out too far can cause leaks as well.
3) Not using the supplied servo/brake valve mount included with the system. You will want to use the supplied light ply plate mount to mount a JR 341, 321, or 351 servo which is to the bottom of the plate. Mount the smooth stop to the top of the plate, holes are laser drilled for both. Use the small arm that comes with the servos listed above and install a clevis on the threaded pushrod that comes out of the valve. I personally use a hayes clevis.
My guess is one of these items have been missed. Take another look and see what you get. Feel free to give me a call and I can walk you through the setup as well.

John Redman
Team BVM, Jet Cat USA
(661) 256-2357

Smooth stop leaks, alternative?
 

Just a thought-I know that the Smooth Stop is very sensitive to the arc of the servo arm- I have seen a linear output conversion for servos (cant for the life of me remember where-but i just saw it advertised somewhere). Wouldnt this remove the arcing of the pushrod from the equation? Just thinking- Scott

Smooth Stop Leaks
 

John's comments are right on....I had fits until I finally mounted the 341 correctly, UNDER the pre-cut ply plate that comes with the SureStop...if you don't have a plate, save yourself a headache and get one from BVM...

Also, my SS in my Bandit always takes about 3-4 on/off cycles prior to the first flight of the day for the O-rings to seat...

I re-lube with Parker O-ring lube about every 25 flights.....

Since then, no problem....I really like the full proportionality...with BVM W/B, I preset the brakes with the R slider about 1/2-2/3 on prior to landing, and it really plants the Bandit and shortens the roll, without flattening the tires....

If you don't have an instruction sheet, there is a nice write-up on the BVM site under Tips and How To's....

Tom

Smooth stop leaks, alternative?
 

I have a up6 valve in my F-15 and a jettronic electonic proportional valve in my Stingray and both work flawless without having to cycle them before flight and hope they work, no servicing required either. A friend of mine has a leaky smooth stop to, seems to be a lot of leaky valves.

Chris

Leaky UP6
 

I have a UP6 valve and it leaks after a couple of years. It does not appear to be user serviceable. I have replaced it with a Smooth Stop. I now use Smooth Stops in all my jets.

You cannot use the UP6 for a parking brake. The internal spring is so strong it will return an unpowered servo to the off position with the radio off. For me, the parking brake is a great feature to have. I have had to replace o-rings in the SS from time to time, but it only takes a few minutes, and hasn't been a problem. The main issue with a SS is keeping it clean and lubed.

I also have a Jettronic valve, but haven't installed it in a model yet.

My 2 cents.

Dennis Lott

Smooth stop leaks, alternative?
 

The best alternative I've come across is the MINI Hobby Digital Proportional Brake Valve. This thing is $60.00 and mine holds 80 PSI for over an hour. It also has parking brake capability. www.minihobby.com or mini-hobby.com something like that.

Smooth stop leaks, alternative?
 

I have finally pulled the Smoothstops out of my airplanes and replaced them with the Jetronics brake valve.

I have had a minor problem with the Smoothstop on my Bobcat for well over a year, that I was never able to fix ... and it was a really strange problem too. I noticed that I seldom, if ever, had a problem with losing air for the brakes on the Bobcat, yet everytime that I let one of my buddies fly the aircraft, it always lost all air before the landing.

We eventually noticed that he applies the brakes as he lines up for take-off, whereas I don't touch the brakes until I'm on the down-wind to land. Tests then confirmed that for some reason, excercising the Smoothstop prior to takeoff causes it to lose all air during the flight (even though the brake control is verified to be in the full-off position during flight). I never could reproduce the problem on the ground either, in order to trouble-shoot it, so I finally just pulled the valves out. If you can't fix it - replace it.

Gordon

Smooth stop leaks, alternative?
 

Dennis,

You CAN use the UP-6 valve as a parking brake!!! :D Just set the servo up so that at max brake the servo arm is in a straight line with the control rod to the UP-6. Turn off the receiver and VIOLA!!! If properly adjusted the spring in the brake valve will not push the servo back. It worked for me in my HotSpot!!!

Kevin

Smooth stop leaks, alternative?
 

Originally posted by Kevin Greene
Dennis,

You CAN use the UP-6 valve as a parking brake!!! :D Just set the servo up so that at max brake the servo arm is in a straight line with the control rod to the UP-6. Turn off the receiver and VIOLA!!! If properly adjusted the spring in the brake valve will not push the servo back. It worked for me in my HotSpot!!!

Kevin

Hi Kevin,

I'll bet it won't work after it leaks all the air out! ;) I like the Smooth Stop. I may try the Jettronic valve in one of my T-33s or F-86s, but I like the way the SS works.

Dennis

Smooth stop leaks, alternative?
 

You can prevent lost air inflight by plumbing the brake valve to the "down side" air pressure. Learned this from the B-737 where the brake hydraulic pressure is taken from the down side hydraulics. Works great, the only time the brakes are pressurized is when the gear is down.

Smooth stop leaks, alternative?
 

That is how all mine are plumbed, works like a champ!

Chris

Smooth stop leaks, alternative?
 

Hi Tom,

That is the way I plumb mine also. I sure has saved the day when the brakes leaked.

Dennis

JetTronic Valves
 

Actually, the new tiny JetTronic Valves are an improvement over the old big black ones. I have one of the old ones on my HotSpot.

Talked to Horst L. at FJ this year. The redesign includes a broader pulse width when braking is actually applied. The old one only started braking when you had the slider 3/4 of the way to the end. You could help that a bit by fiddling with the ATV, but the new one beats that...plus it is very small.

He also improved the pulsing with a more rapid pulse and using less air. This can be finely adjusted with a short piece of airline alone or with a restrictor on the air outlfow port to really cut down on the air usage. But it still uses air continuously when the brakes are partially or full on.

I still like the SS for presetting the brakes the best....keeps most of the bouncies out of my Bandit, and most other planes.

My drill on takeoff on the Bandit is gear up, flaps up, and R slider full on which sets the SS to about 2/3 braking. Then forget about it until I am down and ready to taxi back. I also have my brakes on the snap roll button...when depressed, it puts the brakes full on.....

I have a UP-6 in my Roo.....no problems with that unit either, but the heavy spring seems to work best holding a preset position with an intermediate size servo, rather than the 341 size. Just takes up a bit more room....


Tom

Smooth stop leaks, alternative?
 

Dennis,

I've never had a UP6 valve leak!!! True, some parts do wear out---Are you sure it's not user serviceable???? I know you and your boys do a lot of flying. I'll have to take a closer look at mine.... EVERY BVM smoothstop I've EVER had leaked!!!

Think about what people are saying here...."The Smooth stop is sensative to the arc of the servo arm, you must change the "O" rings every so often, you have to clean it every so often, the plunger is too far in or too far out...." The list goes on----I'm no dummy when it comes to setting up a plane and the Smooth Stop is a BIG PITA!!!! :mad: I just prefer things that simplify my aircraft maintenance, not things that increase it. That is why I got rid of my Smooth Stop. The new JetTronic valve looks promising if it really does use less air.

Kevin

Smooth stop leaks, alternative?
 

Kevin,

I have had a grand total of one UP6, so it definitely is not a scientific sampling, but that one did leak.

I am not trying to debate the merits of one valve over the other. I like the SS. The SS may be a bit more sensitive to setup than others, but it does work very well when set up properly. It is not rocket science to set it up. If it were, I guess I wouldn't be using it. :D

To each his own.

Dennis

Smooth stop leaks, alternative?
 

I have had the Smooth Stop in my Bobcat for OVER 430 flgihts now I have never lubed it, nor have I ever had an air leake with it. As a matter of fact it is still bolted into the same position it was in when I rigged the plane. Every smooth stop that I ever had that leaked only needed cleaning, adjusting, or changing out the O-rings. I had a UP-6 in an old F-16 of mine and it leaked. I used the Mini Hobby valve on my first Phantom and it was OK but it used a lof of air. I also use a seperate air system for my brakes in every airplane.

Smooth Stop
 

I had two of them. They both leaked. One was destroyed in a crash, and I threw the other one out. I now use Trims or UP6s. No problems with them.

Smooth stop leaks, alternative?
 

Any of you guys that want to throw their smooth stops out let me know and I will send you the postage to send them to me.

Smooth stop leaks, alternative?
 

A few more bits of advise on the proper setup for the Smooth Stop.

Pull the valve out and look at the tubing that is coupling the push rod to the valve. Make sure that there is about 1/16” – 1/8” gap between the push rod and the rod coming out of the valve. This is required for flexibility.

I have to disagree a bit with John Redman’s advise to leave the system on 1/8” on the off side. I usually set the lever all the way off and then start with the travel set up so that the valve is on a bit and then adjust the travel until the large brass tube stops going in and then add just a little more travel, about 1/32” – 1/64”, this will assure that the valve is off.

Since I invented the thing I have several people every year come to me with problems. Most are setup problems, a few have been hooked up backwards, some have had leaks down stream of the Smooth Stop (but guess what get blamed for the leak), a couple had dirt in them that damaged the O-rings. Once the issues were resolved they all worked correctly.

A bit of trivia:

The number one prototype (which looks nothing like the current design) was built more than six years ago, and was installed in my Bandit when I finished it. Due to a badly machined bore it leak all its air out before a start up and I nearly ran over BV and his Bandit at Mississippi five years ago. That is how he became aware of what I was doing.

The number two prototype flew about 4-1/2 years ago and is still in my Bandit and has not been touched in 3- 4 years.

The number three prototype went to BV and was installed in his Rafale before it was introduced at Florida Jets.

The name came from Frank Tiano.

Smooth stop leaks, alternative?
 

Originally posted by DavidR
"Any of you guys that want to throw their smooth stops out let me know and I will send you the postage to send them to me."

Gee David, I wish I had thought of that. ;)

I have a leaky UP6 I will trade for a SS. I will send it post paid and send a UPS call tag for the Smooth Stop.

Dennis Lott

Smooth stop leaks, alternative?
 

UP-6 is all I have used used, they would be proportion if is was not for the air we use. I use it for parking brakes by using a lock up when full on. As for leaks the manufacturer guarantees them for ever I believe.
Darryl Usher