Brakes and Hand propping.

[Len Petterson]

Every body tells me the shinn brakes are not much good, this what have found.
They will hold to max 1600 Rpm on a run up. Ok I do some run up with the tail tied down. Just to do one to 1750 Rpm once in a while.
The parking brake is not secure, the ratchet will not hold securly.
I have the tailed tied down during normal operation.
It happens what I land some there what they dont have a palce there I can tie the tail, so I use a bunge cord of the black truckers type dubble over the brake handel and to the stay by the door. Over both sides of handel so it can not turn, and hooks onto the stay, The hooks have a hose sliped over them so they can not slip and protect the paint.
Make shure the trottle is set to idle!AND LOCKED.
Mine is adjusted so all the way back is idle. (Works well for me, It goes klunk then I pull it all the way in, now I know it's in idle.)
The bunge cord goes over the brake handel, and I set the brakes with a firm
push on both brake pedals. A puch on the strut to check if the brakes are holding.
I tryed this out up to 1000 Rpm (with me in the plane) any more and she wants to move. Therefor the check of the idle possistion!
It may not be legal, but it works in a pinch.
Like anything else, use it to it's limits and KNOW the limits of your equipment.
Safe Flying is happy Flying.
Len Petterson

[lktiller]

Re: Brakes and Hand propping.

one thing left. Chock the front wheels! Chocks with a long rope attached. wrap the rope around the strut where it can be reached from inside the cockpit.
I never use or trust the parking brake.

note: my shinn's will hold the t-craft at full throttle. 2200 RPM (by my heels, not the parking brake)

[Bob Waldron]

Re: Brakes and Hand propping.

My Shinn brakes are GREAT. I can hold to MAX RPM on cement. I sometimes have trouble finding the pedals with my fat heels. I would NEVER trust any parking brake. I ALWAYS use chocks, two lightweight ones, tied together, and the left one has a long cord with a loop to hook onto the step.

[jgerard]

Re: Brakes and Hand propping.

I've been thinking that one of the reasons people can not get the Shinn brakes to work as well as other people is that the somewhere along the line an owner or mechanic has tried to make them work better by adjusting the cable tighter. This only reduces the amount of leverage/travel the cam is able to impose on the shoes.

If you back the adjusters at the wheel all the way out and adjust the brake cables so as the cam is flat against the shoes. Make sure you have the brake cable return springs from the bell-crank to the axle. Then adjust as per service manual they should be able to hold the plane at MAX rpm.

I have also noticed that if you push the brake lining in flush to the edge of the drum the shoes only end up contacting 75% of the lining. If you leave them out about 1/8" you will have more contact area.

My breaks work great, but the parking break still sucks. Could use a new Parking break cable assembly.

I have heard that when replacing the brake cables to step it up from 3/32" to 1/8". Can someone tell me why that is?

[mhorowit]

Re: Brakes and Hand propping.

Make sure you have the brake cable return springs from the bell-crank to the axle.

Does everyone have the hole for the return spring on the axle end? I don't think I had one on mine - Mike

[lktiller]

Re: Brakes and Hand propping.

I have heard that when replacing the brake cables to step it up from 3/32" to 1/8". Can someone tell me why that is?

Just replaced both of mine during the annual. Both cables were 1/8" so someone replaced them in the past.
BOTH cables were almost broken in two around the 90 deg pulley under the floorboard. One also had half the strands broken at the pulley that turns down the gear leg.
The cross-connect cable for attaching the parking brake was also broken completely. That didn't bother me since I have never even pulled the lever.
What did bother me is I didn't catch this problem last year! Another good hard application would have broken the cables. Not good, since some of my landings have been on narrow runways with aircraft & people within a wingspan at touchdown.
I WILL be more diligent in checking ALL control cables!
I WILL be more dilligent in Lubricating ALL control cables!

Seems that the 3/32" cable would be more flexible, longer lasting around the pulleys? but I did replace them with 1/8".