PassTime Perigee Build thread
 

OK, here goes. I got a PassTime Perigee, and am starting to build it. Don't expect this to be a fast-moving thread, I hope to have her ready by early summer 08. Also, this won't be a stick-by-stick build, just the highlights, insights, and lots of assembly photos.

First impression of the short kit - very nice quality, light balsa, laser cut.

My biggest surprise as I started to assemble the wing - the spars are curved forward! Lots of pins into the board are needed to keep things aligned. One of the plywood dihedral braces needed a slot widened. A word about the spars, they are delicate. Read as in "I broke it several times playing around and fiddling with the ribs"

The center rib has only one supplied, not two as shown on the plans. This rib is out of thicker stock, but not thick enough to fill the slot. I added a doubler of 1/16 balsa to fill it out. Since I'm planning on outboard aileron servos, the center cutout was not needed, so the 1/16 atually strengthens this area.

Photo 1 - center rib doubled

Photo 2 - assembled egg crate

Photo 3 - curved spars

RE: PassTime Perigee Build thread
 

Nice to see that a real classic is on the boards! Keep us posted Nic!

FB

RE: PassTime Perigee Build thread
 

Hey Nic,
I think I need contact info for PassTime.
And to think that I scoured the jungle just to find a set of Perigee plans!

best regards,
Dean

RE: PassTime Perigee Build thread
 

Dean,

I've had a set of Perigee plans for a number of years, but no one has asked for a copy!

FB

RE: PassTime Perigee Build thread
 

Looking Good...

Wow...Check that wing out!! That's pretty wicked!!

Looking forward to seeing her come together!!

Have Fun...

Chuck

RE: PassTime Perigee Build thread
 

That is looking great WedJ. Your building table looks so neat!
Makes me want to stay home all day and build!:D


DM

RE: PassTime Perigee Build thread
 

Hi Dean,

Here you go:

http://www.mybloo.com/coosbay/laser/beaver.htm

I actually bought 3 kits. I have sold one to Free Bird, and am building one, but there's one more just sitting in the corner of my shop now if you're interested.

RE: PassTime Perigee Build thread
 

Last night I looked at the leading edge of the wing. The original had a perforated sub-leading edge, that's why the tabs are there. The kit does not include this, although it does for the TE. I thought about cutting the tabs off, but then I would have just a butt edge from the sheeting to the LE. Today I'm going to get some 3/32 x 1/4 strip and put them above and below the tabs. That way, the sheeting has a "landing" to glue to, and the LE will have a more solid gluing surface, too.

CA sure makes building a lot more fun. This construction with Ambroid would have been a nightmare of pins, jigs, and weights.

RE: PassTime Perigee Build thread
 

Well, I put the LE sub-strips on earlier tis week, but haven't had time to post it until now. Looking at it, I would highly reccomend this step. It forms a continuous gusset between the sheeting and the LE, adds a tremendous amount of strength and rigidity, for almost no weight penalty.

RE: PassTime Perigee Build thread
 

Also started the stab, too. those little rib feet are delicate. I sanded a taper on them, both fore and aft, and thinned the sheeting a bit. Makes starting them into the tab slots a lot easier.

RE: PassTime Perigee Build thread
 

Now I see what you mean w/ the leading edge WEDJ. You are doing one hell of a nice job on this bird.
Please keep sending us notes on your changes. I just got a link from Roguedog to PassTime, I'm getting a Perigee!

DM

RE: PassTime Perigee Build thread
 

Looking good Nic! At the rate you're going, you'll have it finished in no time!

FB

RE: PassTime Perigee Build thread
 

I wish. Just bought some carbon paper (had to buy 100 sheets) So I could trace the top sheeting curves onto 1/16 sheet.

RE: PassTime Perigee Build thread
 

I've got plenty of carbon paper, I could have mailed you some. ;)

RE: PassTime Perigee Build thread
 

Hi Nic:

Looking great so far. What are you thinking of using for a power plant? Wasn't that about a 45 size plane back in the day? Those new 39 size motors are pretty hot.

I should do some pics of my Tiger Tail but might need a 20 yard dumpster to get my shop ready for the pics. Only kidding but your shop is a really neat building area.

Good luck and keep us posted.

Peace

Mark O

RE: PassTime Perigee Build thread
 

I'm going to put an OS 46 LA into her.

RE: PassTime Perigee Build thread
 

Nic;

A 46 LA should work well. Small case and nice and lite. A real powerhouse compared to a Veco or Enya 45 from the old days.

Keep on building.

Peace

Mark O

RE: PassTime Perigee Build thread
 

Progress, slow but steady.

Finished the stab ribs, and added sub-LE and TE. To sand the correct taper into the LE/TE, you have to be real careful not to sand down the ribs. My solution is to put a double layer of masking tape over the ribs. From photo two you can see how well it works.

RE: PassTime Perigee Build thread
 

Great idea! I used a sanding block positioning the stab on the edge of the building table. I just watched the brown laser burn being hit by the sand paper for a guide. I like this idea better!! The tape idea would be more forgiving!!

Bob Harris

RE: PassTime Perigee Build thread
 

Making the wing sheeting fit. Sure looks odd at this point. the grain really does go that way. I suspect to add torsional rigidity.

RE: PassTime Perigee Build thread
 

For those who thought I had a neat building area, this photo will dispell the myth..........

RE: PassTime Perigee Build thread
 

I almost forgot to show this part. The plans call for 4 of these plywood bridges at the wing root. I believe they were for strength where the rubber bands curve around to attach at the LE (the TE is hardwood in the center).

I thought about not putting them in, but then realized that for the LE dowels, they would have no internal support, just where they glued at the LE. Soooo, I'm going to put a shear web between these pieces, which will give the dowel some purchase at the rear.

RE: PassTime Perigee Build thread
 

And here's the next pieces of sheeting in place. Starting top look like a T-pin forest here.

RE: PassTime Perigee Build thread
 

Taking the T-pins out, I made an interesting discovery this morning. It may explain why the Perigee has the reputation of falling out of the sky on landings. Of course, I had the wing weighted down so the rib tabs were all well seated. Once the top sheeting is on, you would think the wing would be rigid and maintain its shape, right? WRONG!

When I took the tip weights off, the LE at the tip rose up about 1/8 inch off the board. If I didn't notice that, and sheeted the bottom, then the wing would have wash-in at the tips. This surely would cause bad low-speed behavior.

When I stacked up the ribs, I very carefully measured them to make sure there was no wash-in or out, and that the wing would build true.

But now, the question is "why?" Why would the LE tip rise up? The answer lies in the lay of the grain of the sheeting. Conventional sheeting puts the grain parallel to the LE of the wing. That way, it curls to the airfoil with the least resistance. Tom Brett chose to move the grain diagonally, for increased rigidity. However, now with the wing only sheeted on the top, the tendency of the grain (long direction) is to straighten out. If built like normal, the long grain is already straight, so there is no bending moment. If you think about it, it's like having your fingers slightly bent, then straightening them out. If course, once the bottom sheeting is on, that will provide a counter-acting force.. IF it is applied with the wing jigged to be true, that is.

I believe this is what caused the Perigee to have a reputation as a hot plane, and why some people swear it handles just fine.

The more I get into building this plane, the more interesting it becomes.......

RE: PassTime Perigee Build thread
 

Been thinking aobut this problem while putting the capstrips on.

I'm going to build a few cradles to hold the wing upside down. Root and tip, of course, and probably two others in the middle. It's all relative, so they will all have the rib CLs at the same distance off the table. Maybe 1/4 inch stock, with some right angle supports on the table. Will keep all posted.

Do you guys find this interesting?