New member - Question re Champ drum brakes

[jtrapp]

I'm Jerry Trapp, Fallbrook, CA, owner of 1946 Champ 7AC N84305, ser# 2998, engine a65-8, non-electric. First, I am glad to have found this board and am hoping to learn more about my Champ as well as offer others assistance when possible. My first question is regarding the Champ drum brakes (C7000). On my Champ they are installed with a rotation that positions the drum with the activating lever shaft at 12 o'clock. According to factory drawing number 7-806 the brakes should be installed with a position that places the activating shaft at the 9 o'clock position. Does anyone know of any good reason to have the activating shaft at 12 o'clock or should I just assume it is an installation error that happened somewhere along my Champs long life?

[james gevay]

First of all, welcome Jerry.
I think that the drawing that you reference is drawn rotated from what it's supposed to be on the plane. Is that clear?
Some years ago I ran into a drawing or information that says how to have the brake backing plate in relation to the axel strut. I've looked at many Aeroncas over the years and I've seen some that have their backing plate installed incorrectly, their rotated slightly off from what they should be.
I think mine should be correct and maybe the pictures will explain things.

I think the way to think about is to have a straight or nearly so, run for the brake cable, from the cable guide, on the bottom of the strut, to the pulley and then to the brake lever. I don't think it really matters where the brake shoes are in relation to the axel strut. The important thing is have a smooth and friction free run for the cable.

This shows the right brake and strut. Disregard all the grease.

[jtrapp]

Thanks for the information and the great photos. My brakes are mounted very close to what yours show in the photos - they may be rotated one bolt hole different than yours - can't tell for sure from the photos. I do believe that I am reading the factory drawings correctly. I have full training and experience in engineer drafting and reading drawings (blueprints). But, I respect your opinion and would ask, that if you have the time, to review the factory drawings. They do seem clear to me. My Champ brakes seem to function about as good as could be expected for old drum brakes. Since, I have only flown this Aeronca, I really have nothing to compare them to. I am currently in the process (about 1/2 way through) of getting the required tail-wheel dual training required by my insurance underwriter, so this is my first go around with tail-wheel and/or drum heel brakes.

[james gevay]

Jerry, the only drawing I have is the one in the service manual.
As for cable actuated drum brakes, their not as effective as hydraulic disc brakes, and you don't want them to be. Their mostly used for tight turning around the ramp area.
Hope you're enjoying your tailwheel training. Champs are a fun little plane.

[Mikek]

I'm Jerry Trapp, Fallbrook, CA, owner of 1946 Champ 7AC N84305, ser# 2998, engine a65-8, non-electric. First, I am glad to have found this board and am hoping to learn more about my Champ as well as offer others assistance when possible. My first question is regarding the Champ drum brakes (C7000). On my Champ they are installed with a rotation that positions the drum with the activating lever shaft at 12 o'clock. According to factory drawing number 7-806 the brakes should be installed with a position that places the activating shaft at the 9 o'clock position. Does anyone know of any good reason to have the activating shaft at 12 o'clock or should I just assume it is an installation error that happened somewhere along my Champs long life?

Mine and several other here at 3OH0 are at about 9:00 like the drawing, but would need to look at the effects of 12:00 stress on cable & pulley.

Mike K

[jtrapp]

I did fine one Aeronca 7AC on the ramp at French Valley (F70) and found the brake lever to be located at the 9 o'clock position as well. Thanks for the information. I will install my at the 9 o'clock position when relining takes place (soon). I do have drawing from the Owners Manual and the factory floor engineering drawing and both seem to show the 9 o'clock position. I do admit that it is impossible to tell from either drawing what the engineers wanted as the views are not indicated on either drawing and the full wheel view (the one with the tire mounted) seem conflicting to the full front (and/or back) view. The tire mounted view appears in the drawing to be a "top" view - which would be strange I think. Again many thanks for the responses to my question. I really appreciate it.

[james gevay]

Maybe I'm missing something here, please explain how you can have the brake lever pivet at 9:00 on the wheel without having the cable rubbing severely on the cable guide under the strut.
One wheel would have to be at 9:00 and the other at 3:00, is that correct too?

Signed, confused.

[jtrapp]

Now, it should be clear why I ask the question in the first place. Mike Knemeye'sr post says that several aircraft on his field have the brake lever at 9 o'clock and he is concerned how it could work at 12 o'clock position. I guess the best thing for one to do is to try at both locations and see what works best. From the answers I have received, there seems be about half the fleet with brakes at 9 and the other half with them at 12 so they must work either way. I was hoping to get a solid agreement of what was the right position - so far that has not happened. Maybe we need more owners to check and report on how their brakes are positioned. Thanks again for everyone's help in trying to solve my question. jtrapp