RE: PassTime Perigee Build thread  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: dwaynenancy
  Printable Version
       

All Forums >> RC Airplanes >> Pattern Flying >> Classic Pattern Flying >> RE: PassTime Perigee Build thread
Page: <<   < prev  1 [2] 3 4 5 6 7 8 9 10   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: PassTime Perigee Build thread - 11/18/2007 11:01:55 PM   
rainedave



Posts: 4766
Joined: 7/21/2005
From: Greensboro, NC, USA
Status: online 		Yes, that is interesting. And, I can see how that diagonal grain could twist the wing.

Your cradle idea sounds like it will work fine. But, here's how I would do it:

For the LE I would use a piece of balsa about 2" wide x 3/16" thick, draw a centerline lengthwise on it and line up the centerlines of the ribs with that line. Do the same for the TE. Then, the wing will be suspended above the board on LE and TE which you can pin down. I call this the "lost jig" method because after you remove the wing from the board you saw off the extra pieces of the LE and TE.

Here's an old drawing I did a while back.

David

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to WEDJ)
       Post #: 26

RE: PassTime Perigee Build thread - 11/19/2007 3:29:16 AM   
Dean Pappas


 

Posts: 163
Joined: 1/27/2004
From: South Plainfield, NJ, USA
Status: offline 		Hi Nic,
Of course we are interested. One really good way is to make "lost foam" wing cradles. You can even sheet the panels with white glue or poly and weight up the cradles like a foam wing. That ends up making things straight.

Dean

(in reply to rainedave)
       Post #: 27

RE: PassTime Perigee Build thread - 11/19/2007 2:57:59 PM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		Dave & Dean,

both are really good ideas. Let me think on this.

I like the lost jig.
Foam cradle would be great, but alas, no foam nor way of cutting it.

(in reply to Dean Pappas)
       Post #: 28

RE: PassTime Perigee Build thread - 11/20/2007 1:23:49 AM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		OK, here's the left wing panel, all the top sheeting and cap strips in place. Still have to sand down the LE and TE to final dimensions, so they are looking rough yet.

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to WEDJ)
       Post #: 29

RE: PassTime Perigee Build thread - 11/20/2007 1:27:01 AM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		And now the bottom view of the center. The two ply pieces are clearly visible, I intend to put a shear piece between them as I mentioned so the LE dowels will have something to glue to at their rear end.

Next, build the jig to sheet the bottom. Maybe by the end of this week?

I have been following BobHH's prototype Perigee kit build with interest.

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to WEDJ)
       Post #: 30

RE: PassTime Perigee Build thread - 11/20/2007 1:36:21 AM   
rainedave



Posts: 4766
Joined: 7/21/2005
From: Greensboro, NC, USA
Status: online 		Really nice work, Nick. What a sexy wing for a plane of its date. The Perigee must have really turned heads when Brett first flew it.

I really like these early/mid '60s pattern planes. I have been thinking of building deBolt's Interceptor for a while, which was from a couple of years later, I guess.

David

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to WEDJ)
       Post #: 31

RE: PassTime Perigee Build thread - 11/20/2007 1:42:52 AM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		Since the wing is progressing, I have to look at the aileron servo arrangement. I want to use mini-servos out on the wings. I would like to put them between the last two ply ribs, but then the pushrod will overlap the landing gear. Although I don't think this is would create a problem, what do you guys think? Closer in means less moment of inertia on the roll axis, but I think it is such a small difference that you will not notice it in real life.

The use of ply ribs on each side of the servo is very obviously a strength issue.

Discuss.

(in reply to rainedave)
       Post #: 32

RE: PassTime Perigee Build thread - 11/20/2007 7:15:57 AM   
pimmnz


 

Posts: 447
Joined: 11/9/2005
From: Auckland, NEW ZEALAND
Status: offline 		You won't need ply ribs to mount the servos, so long as the spars are not compromised then you could even mount them on a plate glued to the spar web and one rib. I mean, the servo is only moving one aileron, the biggest force on it will be a bit of 'G' on a hard landing.
Evan.

(in reply to WEDJ)
       Post #: 33

RE: PassTime Perigee Build thread - 11/20/2007 2:15:30 PM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline
quote:

ORIGINAL: pimmnz

You won't need ply ribs to mount the servos, so long as the spars are not compromised then you could even mount them on a plate glued to the spar web and one rib. I mean, the servo is only moving one aileron, the biggest force on it will be a bit of 'G' on a hard landing.
Evan.


Good point. I'll run across 2 ribs like an extended cap strip, then reinforce from inside for servo mounting.

(in reply to pimmnz)
       Post #: 34

RE: PassTime Perigee Build thread - 11/20/2007 10:36:46 PM   
Dean Pappas


 

Posts: 163
Joined: 1/27/2004
From: South Plainfield, NJ, USA
Status: offline
quote:

ORIGINAL: WEDJ

Dave & Dean,

both are really good ideas. Let me think on this.

I like the lost jig.
Foam cradle would be great, but alas, no foam nor way of cutting it.

Call Bob Hunt
(610) 746-0106 lost foam jigs, built wings and everything!

Dean

(in reply to WEDJ)
       Post #: 35

RE: PassTime Perigee Build thread - 11/23/2007 2:20:00 AM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		It's amazing how doing this build thread keeps me motivated. I can't stay away, knowing I should keep posting progress.
Here's the next step. I put the ply block in between the ply bracing, so the wing dowel will have a rear purchase. Also note the holes drilled for servo wiring out to the wings.

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to Dean Pappas)
       Post #: 36

RE: PassTime Perigee Build thread - 11/23/2007 2:24:15 AM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		Next step is to make the jigs to hold the wing upside down and level. I decided to take the quick & dirty method. I put each wing rib from the other side on the upper edge of a 1/4 x 2 x 36 piece of balsa, leveled the centers at the LE and TE then traced it. Remember, you have to do this upside down, since the top of the wing is sheeted, and we want the bottom to be face-up. I got three ribs out of it, then used the remainder of the piece to make some "feet" to make it easier to keep them level and upright.

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to WEDJ)
       Post #: 37

RE: PassTime Perigee Build thread - 11/23/2007 2:27:42 AM   
WEDJ



Posts: 842
Joined: 2/21/2007
From: East Haddam, CT, USA
Status: offline 		OK, now the moment of truth..................

Put the wing, upside down, on the jigs, and what do I see, WOW, a huge amount of wash-in at the tip. Just look at that! I am convinced this is why some people have had problems with Perigees in the past. By weighting the wing against the jigs while I sheet the bottom, it will be true, and I am sure my Perigee will land like a ****cat.


Purrrrrrrrrrrrrr

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to WEDJ)
       Post #: 38

RE: PassTime Perigee Build thread - 11/23/2007 11:20:06 AM   
Free Bird


 

Posts: 574
Joined: 11/20/2005
From: Somewhere Out There, USA
Status: offline 		WOW! That's quite a twist! I think that I would over compensate just a hair though on the jig. Wood has a way of "bouncing" back some. Just my .02. Looking good though Nic!

FB

(in reply to WEDJ)