Does anyone know the required elevator travel in degrees on a Brodak P40 ARF?

In degrees? not really, but its a LOT less than you may think. I would guess that on each of the ones I have had and flown, I am using between 15 and 20 degrees max deflection.
unfortunatly they are all gone to profile heaven so I cant measure .
I do know that I was totally flabergasted when I set my first one up,, I was of the " more is always better cause then I can get out of trouble" philosophy,, didnt take long to be educated away from that one!

I may be OK then.  The reason I asked is I have a new stab and elevators from Brodak to replace the existing ones that the hinges were too tight (my fault).  The new parts are the earlier style that were designed for CA hinges, which came with them.  I didn't use the CA hinges but made new ones out of Tyvek.  I set them up as tight as I could to minimize the gap.  Once assembled, it was obvious that the movement is restricted by the radiused elevators and the square faced stab.  The flap movement is considerably more, but I think the flaps will be limited by the elevators once everything is hooked up.

Dick,
you used CA style hinges? is there a reason you didnt use barrel ( dubro or Keltt) style hinges? I have found that the barrel hinges have a much better chance of being friction free,,

The original hinges in the P40 kit were barrel hinges, similar to Dubro.  I installed them as per the instructions using CA thin.  I had never used that adhesive before and I ended up using too much.  The result was that most of the hinges got some glue in them and tightened up.  I tried to clean them and was able to free them up some, but they were far from being right.  I ended up having a mishap on the maiden voyage which broke the tail off.

 I obtained new parts from Brodak and they sent the earlier style that were not notched for barrel hinges, but were slotted for CA hinges, which they also furnished.  I chose not to use the CA hinges because they seemed a bit stiff.  I cut similar hinges out of Tyvek which is very thin and very strong.  I installed those hinges with CA, which was applied sparingly through pin holes I made through the wood where the hinges were.

They are very limp and the elevators will droop of their own weight and flip the opposite direction when the stab is turned over.  I just wish I hadn't closed the gap up so much so the joint had more room to bend.

The original hinges in the P40 kit were barrel hinges, similar to Dubro.  I installed them as per the instructions using CA thin.  I had never used that adhesive before and I ended up using too much.  The result was that most of the hinges got some glue in them and tightened up.  I tried to clean them and was able to free them up some, but they were far from being right.  I ended up having a mishap on the maiden voyage which broke the tail off.

If you haven't been educated on this by now, the way to deal with this issue is to grease the hinges (most recommend petroleum jelly: I just use wheel grease), then glue.  It's nearly impossible to keep the glue off the working parts of the hinge, but the grease will keep it out of the hinge itself.  Then you just wait for the glue to harden, and chip it off.

After a few bad experiences with hinges permanently stuck halfway into the slot, or up my nose, or whatever, I just don't use CA for hinges any more.  I use barrel hinges, grease them as mentioned, and glue them in with 30 minute epoxy (5 minute if I'm in a hurry, although I'm not always able to outrun it).  Since I've taken to doing that, I've always been happy with my hinge jobs.

I gotcha,now,, sounds resourceful, I wonder how the Tyvek will hold up? I will be interested to see..

I read somewhere on this forum or SS that someone had used Tyvek hinges for years with great results.  It wasn't clear if he installed them over and under like cloth hinges, but I installed them like CA hinges by gluing them in slots in the mating surfaces.  All t takes is a couple of pin holes in the wood and a tiny drop of CA into each hole.

I cut them from a large Tyvek mailing envelope, which was enough for many years of hinging.

Dick

I use nothing but CA hinges. There are some ways to do them that work better than others. First, if possible, do not us Brodak CA hinges. They are very stiff. Get some good RC ones. Great planes makes some with a slot, they are very good. But there are lots of good RC ones. Then if yours do not have a slot, cut them in half so they are only half as wide. Use both halfs, but having them half the width makes them more flexible. In the middle of the slot for the hinges drill a hole about 3/32 dia into the hinge slot. Place your hinge material on each side. This lets CA penetrate further down the hinge in theory. In reality I am not sure it makes much difference. I have never taken a CA hinge out that did not have wood bonded its full length even when I do not drill the slot. But its good practice.

In installing them use thin CA, not med or thick. You need the thin to wick along the hinge material to the depth of the hinge. You can put the all the hinges into one surface and glue one surface completely then put the other surface on the hinges and glue them. Or you can place a pin midway along the length of the hinge and put them on one surface then slide on the other surface and glue them both at one time. Both work. But if you glue both at the same time you need to use the in or you risk pushing the hinge in real far on one surface and not far enough on the other. Finally the key to avoiding what you ran into with the surfaces too tight, before you glue the final surface push the elevator, flap, or rudder tight against the other part to completely close the hinge. Then deflect the hinge in both directions the amount you want the surfaces to move when you are done. Now glue, do not push things back together. The gap will be the smallest you can make it and still get that amount of deflection with the shapes you have created. The further you want to deflect, the wider your gap will be. BUT you will have free movement. In 3D planes for RC now I routinely hinge to 90 degrees of throw on all surfaces. Ailerons we usually throw 45 to 50 degrees but we are going upwards over 75 degrees on elevators, and I'm not sure where its gonna stop there. Planes can do some pretty amazing things with that kind of elevator throw.  If you are not happy with the gap when you are done then gap seal the hinge.  When you apply the CA do not overdo it. 4 to 6 drops on each side is all you need and by each side I mean top and bottom of the hinge. You have to glue both. I flex the control surface to my max deflection goal as soon as I get the CA on the hinge. This makes it penetrate further also.

When you are done the hinges should drop under their own weight before being hooked up to the controls and they should do it in both directions. I've read lots on CL forums about CA hinges having memory or not moving freely under low line tensions. All I can say is I have never encountered this in any system I have done in CL. Prior to going to electric I flew a lot of maneuvers with not much line tension and the planes always did it. In electric its not an issue, too much line tension is the issue there. Also I have never worn out a CA hinge, either in CL or RC. I have seen RC CA hinges 20 years old that have not failed. I have however managed to have every other kind of hinge fail at one time or another regardless of adhesive used and I have used all adhesives. As with anything in our hobby, your mileage may vary. Do it the way that works best in your hands. This is the way to make CA hinges work though and avoid the problems you ran into. 

bob branch

Bob

Fun to know the truth (what a nightmare it must have been to do)... but I think it really looks cool!

bob branch