Brakes or no brakes.

[Deskpilot]

I'm pondering the question of fitting brakes to my 95- category design. Obviously weight is of prime concern but I think it can be done by using cable operated disc brakes as used on bicycles. I checked with a local bike dealer today and was surprised as to how cheap it can be done.( eg. single calliper assy - $65.00)

 

So, now I have a few questions and a favour to ask.

 

My options are:

 

No brakes with a rear skid only to slow me down.( more difficult to steer I'm guessing)

 

No brakes with a castoring tail wheel.

 

Single operation brakes with castor t/w.

 

Single operation brakes with steerable t/w.

 

Differential brakes with castor t/w.

 

Differential brakes with steerable t/w.

 

Differential/proportional brakes with castor t/w.

 

Differential/proportional brakes with steerable t/w.

 

Forget weight, which is best and why?

 

The favour; can anyone sketch me the linkage for differential (proportional or not) operated by a single lever on the control stick.

 

Note; I'm not keen on toe or heel brakes.

 

 

[cscotthendry]

If you're building a tail dragger, I reckon the simplest option would be single operation brakes with steerable tailwheel.

 

I have used independent braking on a tailwheel A/C (lightwing with heel brakes) but the brakes weren't terribly effective. Nor would you want them to be on a taildragger for the possibility of a noseover. The steerable tailwheel is more effective for taildragger taxying than independent brakes and safer. Also, it's very easy to implement a steearble tailwheel with a couple of short lengths of bungee between the rudder cables and the tailwheel.

 

Simplicate and add extra lightness.

 

 

[Deskpilot]

Just a thought that might influence you decision. My plane will have twin, widely spaced, contra-rotating props that turn at the same speed. Don't know how that will effect steerage on the ground.

 

Scott, I don't get your comment "I have used independent braking on a tailwheel A/C (lightwing with heel brakes) but the brakes weren't terribly effective. Nor would you want them to be on a taildragger for the possibility of a noseover." Excessive braking on any tail dragger could result in a nose over, as you put it.

 

 

[cscotthendry]

Excessive braking on any tail dragger could result in a nose over, as you put it.

Yep, that was pretty much what I meant to say. but also to say that a steerable tailwheel is more effective for taxy steering than independent brakes.

 

 

[facthunter]

Done a fair bit of tailwheel. I reckon you could do with individual main gear brakes to manoeuver with when taxying. I don't think the twin props that both run at the same speed will matter much. IF your tailwheel steers really well you might get away with it on grass and perhaps no brakes at all. I've flown drifters and thrusters with no working brakes and tiger moths ( but they had a tailskid), but always on grass. You CAN have good brakes on a T/W and not put it on it's nose. just be carefull. The Citabria had cleveland discs and they can smoke the tires on bitumen, but rarely used at speed. You can get used to toe brakes. Most planes have them. Nev

 

 

[turboplanner]

The favour; can anyone sketch me the linkage for differential (proportional or not) operated by a single lever on the control stick.Note; I'm not keen on toe or heel brakes.

Yes but it will cost you a fortune.

 

Simplest way is 2 L levers (side view) on the control column pulling/pushing master cyliners.

 

If you cast them in al. with offset handles (front view) you can operate left or right with fingers of both.

 

I'd suggest you drop in to a go kart shop - you'd be surprised how tiny and light the components are, and to me the limiting factor on disc brakes in RA aircraft is the limit on diameter imposed by tyre diameter. Increase the diameter of the disc and aim to be able to produce lock up under extreme braking.

 

Test by putting them on your push bike and loading it with 350 kg ballast (No, I only made that up)

 

 

[pylon500]

G'Day Doug,

 

I find it best to have independent brakes and steerable tail wheel, handles cross winds and smooth runways.

 

Without a lot of running around and/or scrounging, I just ordered a set of wheels, tires and brakes from AircraftSpruce.

 

These were the cheapest, AZUSA 8 INCH ALUMINUM WHEELS AND BRAKE KIT from Aircraft Spruce , they are a larger diameter (which rolls well on rough ground) bit a narrow profile, so don't cause much drag.

 

It is a complete 2 wheel kit.

 

Arthur.

 

 

[Old Koreelah]

...Simplest way is 2 L levers (side view) on the control column pulling/pushing master cyliners.

If you cast them in al. with offset handles (front view) you can operate left or right with fingers of both.

 

I'd suggest you drop in to a go kart shop - you'd be surprised how tiny and light the components are...

This is what I have, and it greatly helps ground handling. When the tail wheel control fails you will be glad to have differential brakes. They weigh bugger all.

 

 

[turboplanner]

Just a thought that might influence you decision. My plane will have twin, widely spaced, contra-rotating props that turn at the same speed. Don't know how that will effect steerage on the ground.Scott, I don't get your comment "I have used independent braking on a tailwheel A/C (lightwing with heel brakes) but the brakes weren't terribly effective. Nor would you want them to be on a taildragger for the possibility of a noseover." Excessive braking on any tail dragger could result in a nose over, as you put it.

That's why tricycle undercarriages were invented - why make things hard.

 

 

[turboplanner]

Just a thought that might influence you decision. My plane will have twin, widely spaced, contra-rotating props that turn at the same speed. Don't know how that will effect steerage on the ground.

You mean something like this old Howard Huges clunker from the 1940's?

 

http://2.bp.blogspot.com/-XbX4XgHC9_M/Ti5XMfMwdiI/AAAAAAAACcQ/6FZ7eJsg0ww/s1600/xf11.jpg

 

 

[Deskpilot]

You mean something like this old Howard Huges clunker from the 1940's?http://2.bp.blogspot.com/-XbX4XgHC9_M/Ti5XMfMwdiI/AAAAAAAACcQ/6FZ7eJsg0ww/s1600/xf11.jpg

Hells Bells, that's a powerful looking plane. Beautiful to.......in it's own way.

 

So, the major liking is differential mains and steerable t/w. Can't say I like the 2 lever system though. Too easy to pull the wrong one in a moments distraction and make matters worse. That being said, how do I connect single lever to rudder system for correct differential braking?

 

 

[facthunter]

Check out the way the DHC-1 and the moth Minor had the brake working. It's interconnected with the handbrake lever and the rudder pedals. No toe brake. Nev

 

That Howard Hughes plane was the last thing in technical intricacy. The engines were dual prop contrarotating. The design may have contributed to the Lockheed Lightning design. Nev

 

 

[Deskpilot]

GOT IT.

 

The night before last, I retired early as I'd had enough Olympics for one day. 9.30pm is really early for me but......................at 2.30am the next day, I had solved my brakes dilemma. I've quickly knock off this model to use as a basic design reminder.(could forget it by the time I build )

 

The mode of operation is simplicity itself. Brake lever centered, pull lever and both brakes work in unison.

 

Twist the hand controller/lever assy through 30 degrees to the dirrection you want to go, and pull the lever, only the selected wheel is braked. So easy. Only cost me 5 hours sleep.

 

 

 

 

This is a simplified disc and calliper assembly that completes the system.

 

We're getting there, slow but sure.

 

 

[turboplanner]

Your graphics are getting bloody good!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

 

[Deskpilot]

 

Don't look too closely. There are plenty of mistakes, but thanks for the compliment all the same. I guess it's time for some proper foot pedals now.

 

 

[corvairkr]

[ATTACH=full]18643[/ATTACH]Don't look too closely. There are plenty of mistakes, but thanks for the compliment all the same. I guess it's time for some proper foot pedals now.

Hey credit where credit is due Doug they look bloody inpressive to me too.

 

jason

 

 

[Pilot Pete]

Good idea.I would like to do similar on the Nieuport

 

 

[turboplanner]

What system are you using Doug?

 

 

[Deskpilot]

Pete, be my guest, just give me credit if anyone asks.

 

Turbs, Google SketchUp, free download. Takes some time to get the hang of it, find out short cut etc but the are plenty of good instructional pages on the web. There are also Ruby addons for simple animations etc.

 

 

[Deskpilot]

Just to keep you all interested.............

 

New foot pedals.

 

 

FWIW, the fancy cut-outs, read from the bottom, DWM, my initials. Well, why not I put a high heel rest to stop ones feet from sliding off the pedals during a remotely possible bumpy landing. This is going to be so cool to fly. Oh, pedals can pivot fore and aft so that the pilot can flex his calf muscles on those long flights he's looking forward to.

 

I can almost see myself sitting in this now.

 

 

Next question though, is, Will it be too heavy?

 

 

[Guernsey]

How much do you weigh ?

 

Alan.

 

 

[turboplanner]

2" pipe is strong though!

 

 

[Deskpilot]

How much do you weigh ?Alan.

Too much...............100kgs

 

 

[Guest nunans]

Wow, you sure can draw. I had a fiddle with autocad at work and I can see it would take years to learn to draw something like that grip alone. If you're not working in the industry then you should be that's for sure.

 

 

[Deskpilot]

Wow, you sure can draw. I had a fiddle with autocad at work and I can see it would take years to learn to draw something like that grip alone. If you're not working in the industry then you should be that's for sure.

The one thing I didn't model was the grip. Down loaded it from the warehouse and then modified it to suite my needs. Same goes for the wheels. I did the legs and brakes. If you don't cheat in this world, you get now where. Just don't steal.

I think, at 70, I'm a bit long in the tooth to go back into the work place. By the by, cad work isn't exactly 'drawing'. I think 'modelling' is nearer the mark. I thank you for your kind comment though.