Braking ideas

[SDQDI]

Just thinking a little more about it and instead of having a flat plate pulling on those angle plate you could use a triangular shape with the same angle as the plates which would help in a couple of ways, it would be stronger for a start and would put a more even pressure on the angled plates

 

 

[Camel]

Hi I remember reading this a while ago, had to google to get his story, it was on this website as well http://www.coastalleader.com.au/story/1557198/on-a-wing-and-a-chair/#slide=1

 

http://davejacka.com

 

http://www.recreationalflying.com/threads/on-a-wing-and-a-chair-dave-jacka.63024/

 

Quote,"He operates the plane by levers that he can slot his arms into to control the movement of the plane, he uses the brake by flicking a large black toggle with his hand and he sucks and blows through a plastic tube to control the speed of the plane."

 

It's a Jabiru so single master cylinder operating both wheels, I can't see why two switches could operate each side, would need normal toe brakes one side and second set mounted so electric operated rams could actuate brake. What ever ram mechanism Dave Jacka used I sure would work on independent brake operation. Hope this helps.

 

 

[limpee]

Hi I have a castoring nose-wheel and I opted for a differential hand brake, although not on the stick it might be something to think about

 

Greg

 

 

[hihosland]

Thinking from automotive ABS tech.

 

It should be possible to electronically apply differential braking.

 

ie sensor recognises a yaw and then activates differential hydraulic brakes as required to keep aircraft tracking straight.

 

Software could be developed to facilitate required changes in direction

 

Safety would require an on/off switch

 

Just thinking

 

Davidh

 

 

[Soleair]

Thanks, Pylon, good to know heels are a workable system. I don't know of any Lightwings hereabouts, but Google is my friend.

 

Bruce

 

 

[Downunder]

Would it be easier to make the nose wheel steerable and not go differential?

 

 

[Deskpilot]

Would it be easier to make the nose wheel steerable and not go differential?

If you can come up with a really light, retractable system, then go for it. Must be mechanical, no hydraulic or electrical requirements. Must also be capable of being built by a rank amateur. Not asking too much, am I!

 

 

[facthunter]

Your hardest brake applications are probably during engine run-up or turning when taxiing when a significant wind exists. Keeping straight is mostly done with rudder at other times. Nev

 

 

[Guernsey]

I learned to fly in an Auster and found no problems with heel brakes (didn't know any different) except being drum brakes, a strong cross wind when taxiing would cause brake fade and sometimes necessitate a 360 ground loop and pick up direction again the next time around. Strong cross winds on Guernsey were common so the tower controllers became used to this scenario.

 

Alan.

 

 

 

[Yenn]

I have seen differential brakes similar to the ones pictured above, but they had two lugs down to the top of the cables and you could pull both cables by keping the handle vertical, or twist the handle one way and get one brake only. I think it was on a Borabee, but it may not be in the original design. Will see if I can get a photo next weekend if that plane is still at Rodds Bay.

 

 

[Old Koreelah]

I have seen differential brakes similar to the ones pictured above, but they had two lugs down to the top of the cables and you could pull both cables by keping the handle vertical, or twist the handle one way and get one brake only. I think it was on a Borabee, but it may not be in the original design. Will see if I can get a photo next weekend if that plane is still at Rodds Bay.

Sounds intriguing, Yenn. Any reports on how easy it was to use?

Meanwhile, I have just tightened my tailwheel springs by changing the attachment points. Hopefully this will improve ground handling.

 

 

[facthunter]

Have them in compression if you can. Gives a more positive action when they coil bind. Bev

 

 

[Old Koreelah]

Have them in compression if you can. Gives a more positive action when they coil bind. Bev

Coil bind?

 

 

[Downunder]

Have them in compression if you can. Gives a more positive action when they coil bind. Bev

Finally had the op? ?........Bev:laugh:

 

 

[dunlopdangler]

The Yak 52 has a hand operated differential braking system albeit using air but could be done with hydraulics.. you squeeze the brake handle on the joystick at the same time having the rudder bar turned into the direction you want to go (which is attached to a proportioning valve) and wallah around she goes with the castering nosewheel. Can turn a Yak novice into a quivering mess just taxying to the holding point..

 

 

[facthunter]

OK coil bind is when the spring compresses as far as it can. It's a common term. DD air brakes are something else. You need a special sensitivity to be smooth with them. Nothing like hydraulic. Nev

 

 

[Old Koreelah]

OK coil bind is when the spring compresses as far as it can. It's a common term. DD air brakes are something else. You need a special sensitivity to be smooth with them. Nothing like hydraulic. Nev

My original tail wheel was steered via a cross-arm with a single central spring from a New Holland cultivator. It worked well for several years, then broke when far from home. I was all over the paddock until I tied it up with string. The current ones are in tension, and I can adjust the "bite" by moving the anchor point in and out.

I agree about the "feel" of hydraulic brakes. I spent the last few weeks riding an excellent mountain bike with hydraulic front disc. I'm a convert.

 

 

[Dafydd Llewellyn]

You won't get as much sensitivity with heel brakes. You have to move the whole of your leg to actuate the heels, at the same time you are still trying to steer the plane with the pedals via the rudder and sometimes nosewheel or tailwheel. Toe brakes are pretty much universal for a good reason. Nev

Nev, I agree, having owned several Austers - but the problem with the Auster heel brakes has two causes, neither of which is a result of the basic principle: Firstly, the brakes themselves were Bendix "duo-servo" drum brakes, and without going into too much detail, they are the worst possible design for brake fade. Secondly, the operating cables turn through a right angle in guide tubes under the floor. Over time, the cables wear a groove in the wall of the tube, at the bend. But the cable wears also, so the groove is just a bit undersize to fit a new inner cable. So, when the brake cable need replacing - somewhere around 2000 hours TIS - the new inners will lock in the worn grooves, and the harder you push on the pedals, the more firmly the cables jam in the grooves. Combine the two effects, and an Auster becomes impossible to taxi in a crosswind.

The heel brake concept has a lot going for it in my view - but it does need to be properly engineered. However, most people just fit toe operated hydraulic disc brakes and have done with it.

 

 

[turboplanner]

Bev might be trying to compete with that other cross-dresser.

 

 

[facthunter]

Yes the Auster brakes are not high capacity and the system seizes up when not maintained. Heel brakes have the whole weight of the lower part of your leg on them. Not fun on rough ground and combined with actuating the rudder, I feel you can modulate the brakes more accurately by rocking the feet, (Toe brakes) which is almost universal in aircraft . I didn't mind the Chipmunk system actually, where pulling on the handbrake progressively makes the brake apply on the side the rudder is applied most. Full brake and you had no rudder movement and just before it you would be steering on differential brake with virtually no rudder action. Thinking about a go around from a braked situation there would be some difficulty, especially if there was some directional control problem happening.

 

I reckon you need both hands free to cope so the Chippie doesn't meet the requirement. . Oh well nothing's perfect Nev

 

 

[Deskpilot]

When I started this thread, I mentioned "brain fade" Well it's proved to be the case.........this time. It has dawned on me that I don't need a brake lever of any sort as, using independent, twin rudders that operate out-wards only, I can link my brakes direct to the rudder pedal so that the corresponding brake is applied when ever the rudder is activated. This will provide me with the variable brakes needed for taxiing, the only minor short coming is that the bakes will be activated in the air as well. Apart from some potential for brake cable wear, I don't see any problems. I can still operate both rudder together for air-braking, just have to remember to take my feet off the pedals just prior to touch down (assuming landing way too fast)

 

In case you're confused, each rudder is held neutral by bungee cords. It cannot go over center. Pushing a single pedal(the other doesn't come back at you) pulls the cable that's connected to an outside horn only. The brake cable is just joined to the same cable. Some sort of pressure or length of movement compensation will probably be needed as well.

 

 

[bexrbetter]

just have to remember to take my feet off the pedals just prior to touch down (assuming landing way too fast)

I would urge you not to use such a system.

 

 

[Old Koreelah]

DP it looks like you could be introducing a failure mode that was not there before. One day you'll land with a bit more boot on the rudder than you realise...and base over apex you'll go.

 

 

[Deskpilot]

Take your point but I alway try to touch down with no rudder input, that means, sometimes side ways ;-))

 

 

[facthunter]

I don't get that.... Why no RUDDER input?. You certainly don't want the nosewheel turned the wrong way. Nev