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PostPosted: Sun Sep 12, 2004 7:48 pm
by dynera
I'd like to install some brakes on my bird, but unfortunately I only have part of the original brake assembley. I'd like to try something new. Has anyone had any luck using mountain bike disk brakes or anything else for that matter?


PostPosted: Mon Dec 15, 2008 6:45 pm
by sustainflight
Me too. The project I just acquired has the wide track, low stick etc. as shown in the Series III assy manual. The wheels have disks, but I don't see any other brake parts.

The assy manual indicates I should have separately articulated brake pedals at the top of the rudder pedals and caliper parts mounted at the wheels. I don't.

Does anyone have some photos of the Series III set up with brakes? Anyone have extra parts to complete my braking system?

Would you guys suggest the original brake components or mountain-bike disk-brake components?

Interestingly, someone bolted swiveling furniture casters below what looks like the original hardware for fixed tailwheels. That had to be handful for a taildragger with no brakes.

For ground-handling and crosswind landings, what's the consensus on swiveling vs fixed tailwheels?

Craig in Oklahoma City

PostPosted: Mon Dec 15, 2008 9:27 pm
by ozzie

PostPosted: Tue Dec 16, 2008 8:23 am
by uscgairdale
I've been using Avid mountain bike disc brakes with good results. I think that Ozzie beat me to the punch by putting a link to my thread about it.

FYI.....A lot of aircraft are starting to use mountain bike disc brake systems. Phantom, Falcon ULs, a handful of trikes, and even some larger WW1 replicas. I've thought about coming up with some sort of a retrofit kit for the series III/wide gear series II. Axle modifications and a braket to hold the caliper assembly are the biggest obstacles to overcome.


PostPosted: Tue Dec 16, 2008 12:13 pm
We are working on an Avid/8" Azusa wheel mod for our Lazair III. We purchased the fitting needed to attach the Avid disk to the Azusa wheel from an ultralight manufacturer. We will mod our axel using an aluminum bar insert that fits the axel ID on one end and is machined to ¾ inch to fit the Azusa wheel bearing on the other end. A fitting to hold the Avid calipers will be welded to this bar. I will send pictures of this assembly when we are finished. This mod will add weight to the plane. You may want to work out a way to use the Avid calipers with the original wheels and modified disks. The original break system did not work well and had to be constantly adjusted. We end up taking our off and flying without it. Control with differential power is possible but difficult and you have to stay ahead of the situation or you may end up doing a quick 180. You also may need to use a Flintstone brake as a last resort.

PostPosted: Tue Dec 16, 2008 1:44 pm
by sustainflight
Charlie: I'll be interested to see your photos when your Series III brakes done.

Charlie and David: Any thoughts on mechanical vs. hydraulic Avids and which fit the airplane better, Avids meant for the bike's front or rear?

Conventional aircraft typically have the rudder pedals translate fore/aft, then the brakes are actuated by tipping the pedals forward. I like this because you have independent and instantaneous control of both rudder and brakes without having to shift your feet up and down on the pedals. This is helpful for tailtraggers and castering nosewheel planes like Grummans in situations where you might need a tap of a brake to assist rudder. Such a mechanism is probably heavier that what we have on Lazairs. Any thoughts preferred ways to actuate rudder/brakes, particularly from those who fly both conventional planes and Lazairs?

To keep things simple, I might just use fixed tailwheels, no brakes, and light winds initially, then mess with brakes as time and experience dictate.


PostPosted: Wed Dec 17, 2008 5:55 pm
by JPXman

have you flown a taildragger before? I had LOTS of hours on taildraggers (certified's) and it did not help me master landing a lazair at all. its just a different kettle of fish. i think the only thing that prepared me the most was the times i spent coasting on an empty grocery cart in the parking lot on the way back from the car....

post some pics of your project and we can tell you what you're up against.


PostPosted: Wed Dec 17, 2008 8:08 pm
by sustainflight

> have you flown a taildragger before?

Sure, but most of my flight experience is in a castoring nosewheel Grumman AA5 (the rudder is pretty effective except when taxiing downwind), Mooney, and whatever light twin I manage to scam a ride in.

> prepared me the most was the times i spent coasting
> on an empty grocery cart in the parking lot

I'm pleased to hear that I'm not the only adult who does that :)

> post some pics of your project and we can tell you what you're up against.

Will do.


PostPosted: Fri Dec 19, 2008 11:05 am
by Shannon
Really doesn't matter what you have flown before. You must spend a few hours (starting off oh so slowly) getting to know a Series III Lazair. The guys that got in and slammed the throttles forward almost always bent up their planes. Why spend months and months building-restoring a plane and 5 minutes getting to know how to handle it ?

No brakes..No way ! Never put your feet down on a Series III flintstone style if at all possible as you could easily wrench an ankle or break a leg. The Series III can slew around fast enough to catch a foot...OUCH ! I never once put a foot (feet) down when initially practicing in my Series III.

Fixed tailwheels on a III...No way as you will tear up your tail. Find some factory tailwheels or use one for a pattern to make a new set.

PostPosted: Fri Dec 19, 2008 12:44 pm
My comments regarding Flintstone breaks was only meant as a last resort before running into something and only at a very slow speed. I would not attempt to fly the Lazair from a narrow or hard surface runway without breaks. We fly from a 300 foot wide grass glider field which gives plenty of room for wandering off course. With a lot of practice we have learned to control our lazair with rudder and differential power but that is not a substitute for good toe breaks. I believe mechanical Avid toe breaks will work well. I will post the results once we finish and test this mod.