Hi Guys:

I would be doing a Tiger Tail stab Saturday but there is a new leak (pinhole in copper pipe) in the well water feed pipe that needs changing tomorrow. HD wants $38.60 for 10Ft of 3/4 copper so SCH 40 it is. Thirty feet of pipe is a new Quic-Fly or Primus shorty + Oh well. It's amazing how all this stuff gets in the way of the already too short building time.


Peace

Mark O

Everything's looking great. The wing looks awesome. One question, how much dihedral does the wing have? I don't see very much in your photo.

David

Boy, you're up late.

Dihedral is 2 3/16 under the bottom of each wingtip, at the last rib. That photo must have an optical illusion. Here's a head-on shot:

So now I'm starting the fuselage. We have several problems here. First, as I mentioned before, I need to make a 1/4 ply firewall to use a standard mount and nosegear bracket. You can see that in the first photo. None of these are glued in, they are just placed there for now.

Also in that photo is the second former, which is at the wing LE. This is a big problem. 1/16 ply just isn't going to be strong enough for the wing dowels. Plus, the fuel tank will extend through that bulkhead. My solution will be to face it in 1/8 ply at the bottom and sides, then cut out the middle for the tank. That should work OK.

The former behind that is OK as is. (middle of wing saddle)

The stub former at the TE of the wing is again not adequate for the plate that will have the rear screws of the wing. Plus, it does not go up all the way on the fuse. Again, I will add material. This time I think 1/8 behind, and some 1/16 ply up to the top, with a cross member.

Which brings us to the rear of the fuse. This bulkhead is totally wrong. Look at the photo, the left edge is where it should go. Notice that it does not go far enough up, it is about 1/2" short of where it should be. Also, it is not notched out for the stab doubler that is already glued in place.

Actually, some of the fun tonight is that my 14-yo was putting a metal-gear steering servo in his car as I was doing these photos. We finally broke down and bought one after he stripped the gears off two standard servos. We'll see if this lasts.

Looking Great!! I love the wing too...

Have Fun...

Chuck

Nick, I really was not in love with the original bulkhead design. Thats why I changed them to more convential design. I opened up the bulkhead in front of the wing to allow for a 8 oz square fuel tank. Also used 1/8 ply but will double it for the bolt on dowel holes. I really don't understand some of the fuselage construction design. May have been for the Ambroid glue!! I really like that tail though!! Still may go back and add and sand!!!

Bob Harris

Yes, Tom Brett was an Eningeer's Engineer. Remember, in the early 60's both the material and the tools and the hardware were different. He spent a lot of time only putting strength where needed, shaving off every fraction of an ounce he could. Parabolic sheeting, cross-grain, hollow tips, balsa doublers, almost no bulkheads, or short ones, all contribute to lighter weight. Today, I would use 1/32 ply doubler, and build it like a Kaos fuse. Of course, the only straight lines on this are the LE and the hinge lines. He must have loved his french curves. That's why the plane is so visually appealing.

Yea, go back and sand an airfoil into the tail! Takes less than an hour to do, except for the glue drying.

I have been flying my Perigee for over 5 years now, built from the AAM plans. With the engine bearer design, and using rubber bands to hold the wing on there is no need to `beef' anything up. I can see that without the bearers, and going to the `modern' but heavy radial engine mount and bolt on wing thing then some redesign needs to done, but it will be heavier and weaker, and you need to keep the thing light. Don't mess with a good design.
Evan.

Pimmnz,

You are correct, for rubber bands, the design is good, he put ply where it counts. I am hoping for a 5 1/2 pound finished weight. What does yours weigh? Size of tank? The one I chose requires the LE bulkhead to be cut. I think the trade off of maple bearers vs glass-filled mount is a wash. I am saving weight by putting the nosewhell on the firewall, instead of building up the nose to put it further forward. Not quite pure, but I think acceptable. The 1/4 ply firewall does not weigh much.

Speaking of engine mount, here's what I decided to do, put the 2 degree offset into the mount, rather than tilt the firewall. I will put the downthrust in the mount also, by washers under the rear engine screws. This way, I can keep the nosewheel true. Choices, choices.

Next order of business is to plug the pre-made pushrod exits. I think mine will be different, and now is the time to do it. Very easy, carve to shape and plug in with CA. Flip over, and sand lightly on the outside.

Lastly, the time-honored tradition of building one side over the other to assure they are symmetrical. In this case, the right side is put upside-down, then wax paper laid down, and I will start to make the left side to match. Maybe more tonight, or tomorrow.

As far as tools go, I have just been using an Xacto knife, french curves, straight edges, T-pins, sandpaper (60 grit and 220), nothing exotic.

WEDJ, I have to admit I too cheated with Toms design...mines 10% bigger (66" span) which was easy, given that I used the mag size plan and just enlarged it at the local copy shop. I used the same wood sizes as the plan called out, uses an LA.46 inverted where the nosewheel should be and the wheel on the firewall former behind the engine. 8oz tank with plenty of room behind the engine, 1deg washout on the wing tips, 5lb 0oz. unfuelled. Still snaps on command, but lands like a *****cat. Hard to choose between this and a Taurus, but the personality of each is really different.
Evan.

WEDJ, instead of using washers behind the mount to get your thrust angles, take a paper cup the diameter of the mount. Tilt the cup by placing a wedge under one edge and pour in some 30min epoxy. When it's dry tear away the paper cup and you have a solid, round wedge to place behind the mount. The epoxy will also absorb a bit of vibration from the engine.

David

That's a good idea! Years back, they used to make thrust plates, but I haven't been able to find any.

How interesting. Photo? Nice light plane! I hadn't thought of inverting the engine.

Location, Location, Location

That's right. Tonight I put the fuel tank and the servos on the body sides, figured out where I want the triangle support stock, and marked it on both sides. Will make installation much easier later.

Oh, and I have a plastic cup with about 1/2 ounce of epoxy curing at an angle. 3/32" across the width of the bottom. Thanks, Dave

Here's the only pic of Perigee I have, and the photo's got 08-2000 on the back, so its been flying for at least 7 years...
Evan.

Dynamite photo - thanks!

Regarding the epoxy thrust wedge - it snapped in half as I was wrestling it from the cup. Re-try tonight, using cooking spray as a release agent.

I consider these life's little learning lessons.

You can also take a piece of fiberglass cloth and pull out a handful of strands from along the edge, cut them into short lengths and mix them in with the epoxy. That shouldn't break.

David

WEDJ, I found some Ernst thrust wedges at a LHS. I'll pick them up if you like. I believe there are 3 in the pack, 1 each of 1, 2 & 3 degree. Let me know.

FB

Free Bird, that is great! Pick me up at least 2 sets, I'll pay you next time we meet. Hey, the getting them to me IS a good way to meet across the winter. Want to come to my house and see the messy building room? I'll hand off the wing saddles to you at the same time :-)