VQ P-40 Build
 

I received the new and improved VQ P-40 not too long ago. This new version has built-in wing wash out to help eliminate tip stall tendency. For more info, check out

[link]http://www.vqmodelaircraft.com/products/aircraft/p40.html[/link]

http://www.whitetyphoon.com/rc/vq_p40/pic01a.jpg

http://www.whitetyphoon.com/rc/vq_p40/pic01b.jpg

http://www.whitetyphoon.com/rc/vq_p40/pic01c.jpg

http://www.whitetyphoon.com/rc/vq_p40/pic01d.jpg

http://www.whitetyphoon.com/rc/vq_p40/pic01e.jpg

RE: VQ P-40 Build
 

I will tackle pneumatic retract installation. Since the plane comes with free oleo struts, I will try those dreaded Robart 615 rotating retracts.

First, trim the stock mounting rails to accomodate the retract housings, which are close to 1" wide. Note that I cut out notches in the rails for the screw heads to clear:

http://www.whitetyphoon.com/rc/vq_p40/pic03d.jpg

RE: VQ P-40 Build
 

Next, 5/16" thick hardwood rails get epoxied on top of the stock rails to bring the mounting surfaces out flush with the wing surface:

http://www.whitetyphoon.com/rc/vq_p40/pic03a.jpg

Care must be taken to ensure that the rails lay perfectly flat and parallel to each other. Otherwise, the retracts might bind. It's a good idea to glue the extra wood in using 30-minute epoxy, and then lay the retract mechanism on top of the rails while the epoxy cure:

http://www.whitetyphoon.com/rc/vq_p40/pic03b.jpg

RE: VQ P-40 Build
 

Here is a picture showing the retract in the wing:

http://www.whitetyphoon.com/rc/vq_p40/pic03c.jpg

RE: VQ P-40 Build
 

I use an aluminum miter box clamped to a vise, together with a small hack saw with fine metal cutting blade to cut the oleo struts to proper length.

http://www.whitetyphoon.com/rc/vq_p40/pic04a.jpg

You could also use a Dremel tool with a cut off wheel to do the task, but you run the risk of not making a straight 90-degree cut.

RE: VQ P-40 Build
 

Cut off excess wire strut, leaving around 3/4":

http://www.whitetyphoon.com/rc/vq_p40/pic04b.jpg

RE: VQ P-40 Build
 

Spread a thin coat of JB Weld to the inside of the oleo strut and insert a metal bushing for 3/16" dia. music wire into it. While holding the oleo strut in one hand, use a small hammer in the other hand to pound the metal bushing in. Don't miss or you will be hitting your hand with a hammer, and it might not be very pleasant.

http://www.whitetyphoon.com/rc/vq_p40/pic04c.jpg

RE: VQ P-40 Build
 

Retract with oleo and wheel in place:

http://www.whitetyphoon.com/rc/vq_p40/pic04d.jpg

RE: VQ P-40 Build
 

Mark two spots for the set screws that are 1/8" and 3/8" from the end of the oleo respectively:

http://www.whitetyphoon.com/rc/vq_p40/pic04e.jpg

RE: VQ P-40 Build
 

Micro-Mark MicroLux mini drill press and vise come in handy when drilling holes for the set screws:

http://www.whitetyphoon.com/rc/vq_p40/pic04f.jpg

RE: VQ P-40 Build
 

Drill and tap two holes for 6-32 set screws. Use 1/16" drill bit and cutting/tapping fluid to drill pilot holes:

http://www.whitetyphoon.com/rc/vq_p40/pic04g.jpg

Make sure to wear eye and nose protection because metal shavings will be flying.

RE: VQ P-40 Build
 

Final size drill bit is then used:

http://www.whitetyphoon.com/rc/vq_p40/pic04h.jpg

That mini drill press can do the job with ease.

RE: VQ P-40 Build
 

Tap for 6-32 set screws:

http://www.whitetyphoon.com/rc/vq_p40/pic04i.jpg

Set screws in place:

http://www.whitetyphoon.com/rc/vq_p40/pic04j.jpg

RE: VQ P-40 Build
 

Retract with oleo and wheel in place:

http://www.whitetyphoon.com/rc/vq_p40/pic04k.jpg

RE: VQ P-40 Build
 

I just installed some Robart oleo's and they suggest putting the set screws on opposite sides. FWIW...

RE: VQ P-40 Build
 

On my 7/16" Robart oleos and 3/8" straight Robart oleos, the instructions say to put the set screws on the same side. This way, both set screws press the music wire against one side of the oleo, resulting in a tighter fit, more friction between the wire and the interior oleo wall, and less play. If you think about it, putting the set screws on opposite sides would create a pivot point where they meet, and the music wire would want to rotate around that point.

RE: VQ P-40 Build
 

Also, putting the set screws on opposite sides means that the oleo and wheel are held only by the tips of the set screws. Putting the set screws on the same side means the oleo and wheel are being held by the much stronger frictional force between the music wire and the interior wall of the oleo, in addition to the tips of the set screws. This is like clamping the music wire against the oleo.

RE: VQ P-40 Build
 

Well gee whiz, my Robart's are 3/8 offset oleo's and the instructions specifically stated placing the set screws 180* from each other.

I think you should be sure to grind the flats on your music wire too. The tension is not supposed to be pressing the music wire against the oleo wall but instead the locking force of the set screw against a flat area (that you grind).

Now think about this: two opposed flats are double the area of one flat. Two set screws on two opposed flats are double the locking tension compared to two set screws on one flat. The opposed set screws will have much greater resistance to twisting than the same side set screws. ;)

RE: VQ P-40 Build
 

Well, here are the instructions for the 7/16" diameter offset oleos:

http://whitetyphoon.com/rc/vq_p40/pic04l.jpg

Here are the instructions for the 3/8" diameter straight oleos:

http://whitetyphoon.com/rc/vq_p40/pic04m.jpg

Yes, I always grind flat spots for the set screws to press against.

Consequences of opposing set screws:

http://whitetyphoon.com/rc/vq_p40/strut.jpg

RE: VQ P-40 Build
 

I don't have my instruction sheet anymore. Maybe it has been changed since mine were manufactured.

In anycase, your drawings are cool. How do you make those? As for the opposiing set screws, they are still at 1/8 and 3/8 positions just on opposite sides.

RE: VQ P-40 Build
 

I thought this was a ARF-I guess you mean to assemble and not to build?

RE: VQ P-40 Build
 

I used Macromedia Flash MX to make those drawings. Any other vector programs such as Adobe Illustrator or Corel Draw can also be used.

RE: VQ P-40 Build
 

If you have a minor accident with the plane and have to repair some structure, how are you going to recover the area to match ?

I don't know where you would get covering to match that stuff

Crazy Scottie Mon

RE: VQ P-40 Build
 

The plane comes with some extra trim sheets, so you can either use those or clear tape to do minor repairs.

RE: VQ P-40 Build
 

Is that a heat shrink covering or that shelf paper stuff?