extreme frustration with Shinn brakes

[Forrest Barber]

Re: extreme frustration with Shinn brakes

The new linings have no asbestos ; they are 'soft" they burn very easily. Bill is correct they can be scuffed up again . AND , yes sometimes they recover when cooled. the new linings work best if you do not use them :joy: I break them in with three hard stops then try to use for run-up only and those special times to keep from crashing.
Rumor has it that some old sources still have good old linings, hang around old farm dozer repair places and do not smell the asbestos. They usuall have to be trimmed to fit.

[NY86]

Re: extreme frustration with Shinn brakes

Most brake materials require some sort of conditioning before they will perform to specs. You got lucky.

[flyguy]

Re: extreme frustration with Shinn brakes

Took off the high spots. Better and more surface area now. You betcha, for shore.
DC

[N74DV]

Re: extreme frustration with Shinn brakes

I'm happy to announce that Skybound has offered to refund my $180 for the shoes since they never got them correct.

I'm also happy to announce that with the shoes we modified I was able to hold a full static runup of 2100rpm Was never able to do that before.

Here's something interesting though. After installation of the new linings and these shoes I did a runup at home on the street and only got to about 1700 before they would not hold. Then we towed the plane to the airport about 1.5 miles at about 45 mph. The brakes were just slightly dragging. When we got ot the airport the wheels were rather warm and I could smell the brake linings.

Seems that towing the plane to the airport with shoes slightly contacting the linings did something to improve the braking friction. go figure.

[flyguy]

Re: extreme frustration with Shinn brakes

Brake linings that I thought I had burned slick the other day seemed pretty much back to normal when I did some landings today. Go figure. I guess being new linings has something to do with it. "Roughing" them up was pretty much what I was thinking too, Bill.
Darryl

[Hank Jarrett]

Re: extreme frustration with Shinn brakes

Several questions.
1) Do the new linings even have Asbestos in them? I didn't know it was still legal to sell them with Asbestos (not saying there isn't any in them, I just don't know).
2) Are you talking about machining the shoes, or the linings in the wheels? In a car the pads or linings are part of the shoes, unlike our wheels where the "wear out" part is attached to the wheel.
3) Is anyone thinking about "grinding" the pad material? In the pictures they are being "turned" which is MUCH safer when working with a potentially toxic dust. If you are thinking of grinding the shoes (I don't know why you would) there shouldn't be much, if any, asbestos dust on them. Clean them well first (which is a good idea even it we aren't talking about Asbestos).

The wheels might need to be "trued" (turned to make the surface the linings attach to round again) but there are probably some pretty tight limits on that and if the wheel is out of round I would look for a new wheel before I started machining it. Machining (turning, not grinding) the linings sounds like a great solution and even if you are turning, not grinding, and even if there is NO Asbestos in the new linings, I agree completely with Dick. USE A RESPIRATOR and assume any dust or particles can kill you. We had over a century of using Asbestos with everyone believing there was no health hazard. Want to be the test case for something in the new linings everyone feels is safe now to save using a respirator you probably have in your tool box?
Hank

[Dick Smith]

Re: extreme frustration with Shinn brakes

Tribe, be careful grinding on brake shoes...use a good respirator or some form of filter. My brother is in Anchorage today for some more chemo...the result of working and living around asbestos while in the Navy. The newer lining materials may not cause the same health problems, hopefully, but old brake shoes should be suspect. Dick

[Larry Lyons]

Re: extreme frustration with Shinn brakes

Don't forget to wear a dust particle mask and try to stay upwind from the asbestos dust.

Maybe that is my problem! I ground a few thousand brake shoes with absolutely no protection back in my high school days while working at the local gas station. :boxing: Not saying it was smart it was just the way we did things in the 50's and 60's.
Larry

[Pearson]

Re: extreme frustration with Shinn brakes

Don't forget to wear a dust particle mask and try to stay upwind from the asbestos dust.

[VictorBravo]

Re: extreme frustration with Shinn brakes

Must have burned them,

Bummer, but not that bad to fix.

Take the wheel off, scuff sand the linings with Scotchbrite or fine dry sandpaper using a small sponge pad until the sheen (burned lining) is off, then scuff the shoes good with Scotchbrite, then clean it all real good, and put the wheel back on. Should solve the problem. It did when I burned mine up the same way.

Bill

[flyguy]

Re: extreme frustration with Shinn brakes

As Bill said, my brakes would hold my 85 at full power--right up until yesterday. Came in a little long yesterday and stood on the brakes to avoid a Cessna taxi-back. Dumb. Swore I would never do that with 3000 feet of runway left in front of me. Must have burned them, as I really had to stand on them to hold at 1800 or so today. Might handle more but would REALLY have to stand on them hard.

I had good luck with Skybound on my linings, fit was perfect, thickness probably good as this design gets. They sent them before I even sent money.
DC

[Hank Jarrett]

Re: extreme frustration with Shinn brakes

Several good mechanics, FAA guys, machinists, manufacturers and engineers on this group. I'm open to helping. Any manufacturer who wants our help only needs to contact us.
Hank

Going to be off line for about a week soon on travel. If no response, I'm not ignoring you, I'm at sea.

[Larry Lyons]

Re: extreme frustration with Shinn brakes

Maybe the group should approach Skybound (with an attitude of "let us help you fix this", not a "what the heck is wrong with you guys"). We have the talent and knowledge in this group to provide all of the manufacturers with some help so they can serve our needs better. They want our money. We want good products. We should be able to work with them (all of them). Anybody know who their manufacturing engineers are?
Hank

Hank, I could not agree more with you here. I/we need the help! Larry

[Hank Jarrett]

Re: extreme frustration with Shinn brakes

Maybe the group should approach Skybound (with an attitude of "let us help you fix this", not a "what the heck is wrong with you guys"). We have the talent and knowledge in this group to provide all of the manufacturers with some help so they can serve our needs better. They want our money. We want good products. We should be able to work with them (all of them). Anybody know who their manufacturing engineers are?
Hank

[Robert Lees]

Re: extreme frustration with Shinn brakes

I am not an engineer here but I beleive if machined and adjusted correctly almost the entire shoe will come in to contact, because of slight deformation, with the drum under load. Most brakes around the world in use today work on a very similar principle. Larry

My engineering self thinks you are correct, Larry. The greater the brake pressure, the more shoe comes into contact with the lining, because the shoe flexes (each shoe is basically "fixed" at one end).

Mr Shinn knew his stuff.

I'm sad that poor service is being received from Skybound; perhaps folk should try Donna Losey (Partsangel).