Original Azura Drum Brakes 25th May 2008.
Some of the parts I had to make for the brake mechanism, I had done some previous work on the actual brakes on the wheels because they were running out of true (See the lathe section). The little bits had to be made out of 1/2" x 1/2" aluminium but I could not find any in my dwindling pile of metal so I made them out of the old bus bar stock.
The brake handle in position with the flap handle. The brake handle nicely slots into the first flap position for parking.
Fixing up the cam mechanism. I had to modify the bush that holds the camshaft as it did not protrude
far enough into the backing plate. Which meant the camshaft was rubbing on the aluminium plate and also when you tighten up the lever the whole thing locked up. First I removed the bush from the backing plate and machined the step a few
thou so it protrudes through the backing plate and stops the camshaft running on the aluminium. Then I machined a few thou
off the other end so the lever did not lock. THEN I had to machine a few thou of the square that holds the lever so it could be tightened. Otherwise the nut hit the square section before the lever was tight. I could have fixed that problem with a washer larger the square section.)
Oh and one other thing. There is meant to be a left hand and a right hand lever, I had 2 right hand ones so I had to bend
one the other way.
Brakes done , There is a saga attached with these things. I got 3/4 into the drum brakes and decided to scrap them
in favour of a set of disc's of my own design. I got 3/4 into that when I ran into one problem too many so I gave up
and installed the original drums. I wasted about 4 weeks and I am not saying how many dollars.
Might do it later when I have nothing else to do. Or there is always the Tracy Obrien hydraulic setup if you want hydraulic I did not , I prefer a mechanical setup. I purchased a lovely set of cable operated disc callipers
I put an extra little cable clamp on the brake cable as I found with the original you had to tighten it very firmly to stop it pulling through. The second clamp has double (In fact 4x if you consider the 2 screws) the mechanical advantage and tidies up the cable end nicely. It's really an electrical connector with the insulation cut off.
15th June 2010 my new Tracy O Brian Hydraulic disc brakes.
I have done 3 hours now with 4 landings and a fair bit of taxiing and the standard brakes and wheels have to go they are so far out of true there is a very good chance of a locked wheel which could be very nasty in a tail wheel AC.
I replaced the Azura wheels with the spun wheels from TO and they look lovely and run perfectly true.
I also bought the T O axels because they look stronger , you can remove the axle without removing the end of the strut. Most importantly it gives you a much better jacking point when the tyre goes flat.
The Master Cylinder , I purchased the Matco unit because it has a reservoir, foolishly thinking it would be easier to bleed and would not lock up if the fluid got hot.
After thinking about it the fluid will not heat up for the short time you use the brakes plus it leaked all over the place.
I installed a shutoff valve to provide a parking brake. I had been using a piece of velcro wrapped around the brake lever
but it was a bit fiddly. With the valve you just pull on the brake , turn off the valve and the pressure
remains when you let go of the lever.
28th January 2013 I upgraded the master cylinder
This is a Hagar unit also supplied by Tracy O (They don't stock the Matco master cylinders any more presumably because everybody else had the same trouble )
I ordered the one with the 1/2" bore to give me a lighter lever pressure , (The origional Matco had a 3/4" bore) I have not tested it in anger yet but I can say it's harder to bleed as you need ALL the air out of the system or it bottoms out.
They have 3 sizes 3/4 , 5/8 ,and 1/2" and you can just buy the cylinder if you want so if I am not happy with the 1/2" I can easily get the 5/8" cylinder.
A parallel project , July the 28th 2010, my expermental mechanical disk brake system.
The callipers are after market items made by AVID , designed for racing mountain bikes.Bearings are low precision ball
races with a flange , they have no load on them 99% of the time.The plates in the chuck are all
parts of my system. The large disk will be the brake disk. The smaller ones attach to the tube which carries the bearings. The whole thing is driven by three pins attached to the wheel similar to the TO system. This way if the wheel is not running true the disk is not effected. The wheel can be removed without touching the brakes.