AllTheGoodNamesAreTaken

My Feedback: (180)

Thanks for the offer. I know I've bought at least 10 HS 81's, but I can't locate any of them.... [&:]

Taurus Flyer

Jeff,

That wasn't the message, only when doubling the spar, I only can tell you the whole story, I have to.
If I didn't people would have say: xxxxxxx

What you do isn't my case.

Normally we cut also all he "too much wood" away that isn't usefull for strength.
Think about what Ed Gregger did write in this thread, these are the little secrets.
Post 48 page 2 of this thread, "Master pattern pilots seldom shared their flying secrets, and especially back then"

I show the details in my own thread, so not have to hitch hike anymore, an example, see post 633 page 26.
Jeff, this was also my last input about the retracts and spars, success with the construction


Cees

AllTheGoodNamesAreTaken

My Feedback: (180)

Hello Cees.
I appreciate yours and everyone elses input and opinions.

I understand and agree with your theory for removing excess material. The spar doubler does need, and will be trimmed. I was teasing about the gram scale....every bit of excess material removed can make a big difference in the overall weight and flight performance.

I've been trying to come up with a paint scheme - stealing ideas from the internet, but nothing has struck me yet. This is where I lack all artistic creativity... My planes have to be Red/White/Blue, not only 'cause I love the Dutch, but that's the colors I have in my shop.

Taurus Flyer

Jeff,

We understand each other.

I do want to show the tricks, not want to force to use them.
A Gram scale I not use for construction only for selection of materials, You cannot measure the strength with that
When you try to keep the cross section of every part you change the same as in the old situation and grain direction, then you nearly cannot do it wrong.
That also was the reason of the channel of the pianowire,
I look in all the pictures and drawings for the tricks and calculate the dimensions of the spars for minimum cross section.

Cees

CollectivelySpaced

My Feedback: (18)

If its HS-81's you're looking for, I may be able to dig a few out...

AllTheGoodNamesAreTaken

My Feedback: (180)

Not much accomplished tonight, but I did manage to build the second aileron servo mount, sheet the top center section.
The leading edge sheeting is tacked to the spar, moistened and pinned to the leading edge. Tomorrow I can glue it in place.
The last photo is for Cees...

Taurus Flyer

Feff,

What do you think yourself?

I see you did a great job but also give the response to stimulate the communication.

I am an inventor, so for me it is an never ending story, and for that do not try to follow me!!
When my Orion is finished again all the "normal"aileron (no frise) linking is hide in the wing coupled with one central servo to be belly landing proof.
How I do that will still be my secret in the future, because I did not see it anybody doing on RCU just as many other features I do have in my planes.

I will see the next pictures with pleasure.

Still one little tip to think about, that never ending story, when I look on any place in the wheel bay and I can see the top sheeting I am not happy, think about starting in wet weather and what the wheels will do with that water trowing it against the top sheeting of the wing?

A never ending story
Nice project, nice plane , nice friend

Cees

doxilia

My Feedback: (3)

This is where glass cloth and epoxy come into play prior to paint.

David.

doxilia

My Feedback: (3)

Jeff,

nice job on the retracts.

Here are a few pics for finishing inspiration including a red/white/blue scheme used by Joe in his construction article build. Note that the picture was flipped as shown by the muffler location and switches and retract valves on the fuse.

I've also always like the scheme shown in GP's 1982 brochure showing their pattern offerings (photo 2). You can see that the last three photos are inspired from this scheme although the detail on the canopy is missing. Joe's scheme's are of course classic and simple to reproduce though.

David.

Taurus Flyer

I want to win with my plane, not with words.

My way of thinking.
Why use such a heavy materials to stop some drops?
Only what will that top sheeting do, that top sheetin of the D tube, and not now , not tomorrow also in the winterday when the grass is wet.
At least some lack of paint, only in my plane you can never see the top sheeting. D tube is always closed. That's why I can blow away a part of the wing without problems, that's why I never have to talk about flutter.

A never ending story, success

Cees

doxilia

My Feedback: (3)

Because this is a high wear area and durability of the retract bay is paramount to my mind (not that I'm saying cloth is mandatory). I also don't consider finishing glass cloth such a "heavy material". I've also never attempted to cover retract wells with plastic film and I'm sure I won't entertain the idea any time soon - hence, paint.

David.

Taurus Flyer

David,

Someway you have to protect the inside of the wing topsheet on any place I can see it and rain can reach it.
I never glass any plane and never use plastic film.

Silk and dope and after that paint on any place.
When I have a deadstick and cannot reach the field I make a belly landing
My planes are designed for that to protect the gear, prop and engine.

It does not matter what is on the outside on top of the wing when the wood indside isn;t protected against raindrops of the rotating wheel in wet grass.
(difficult language)


Cees

AllTheGoodNamesAreTaken

My Feedback: (180)

I'm not sure I understand the issue. The wheel wells are capped as shown in many of the photos. The only exposed top sheeting is under the retract mechanism.
Once I'm done with the wing structure, the wing will be doped with nitrate prior to covering with Sig Koverall (polyester fabric).
Regardless, all exposed wood will be painted. - first with a nitrate sanding sealer and then with KlassKote (epoxy based).

AllTheGoodNamesAreTaken

My Feedback: (180)

Thank you for the photo's David!

Is the yellow plane yours - it's beautiful!? I would LOVE to have some good quality 3 view photos of a Dirty Birdy.

doxilia

My Feedback: (3)

Jeff,

I didn't think there was an issue either. I'm not sure what Cees was trying to point out. It is usually apparent that wheel wells are finished in some fashion to prevent damage from debris and weather. Thanks for describing your technique.

David.

AllTheGoodNamesAreTaken

My Feedback: (180)

Not a lot accomplished over the last couple days, but that doesn't mean I haven't been working. [&:]

I've got the wing set in the fuse with about 3/4 deg positive incidence. The wing hold down bolts are drilled and tapped. All is square. Once the epoxy sets up on the wing dowels, I can remove the wing and add the remaining sheeting and cap strips.

AllTheGoodNamesAreTaken

My Feedback: (180)

I've been working on the stab mounting while the wing sets.
I made a template from a scrap piece of light ply and cut it into a 2" wide by aprox 8" long rectangle. I drew a center line and parallel lines 3/4" on either side of the center line. Then I roughed out the shape of the stab with pencil. I rough cut out the shape of the stab with a scroll saw and slowly worked the template down the stab while adjusting the opening with the dremel.
I'll line up the center line I drew on the side of the fuse with the center line on the template and duplicate the opening on either side of the fuse.

AllTheGoodNamesAreTaken

My Feedback: (180)

I've run into a snag that I should have caught earlier in the construction of the wing. The wing is double tapered with strip ailerons, so the trailing edge is thicker at the root than at the tip. The tickness of the root rib at the trailing edge is 3/8" and the tip rib trailing edge is 3/16". When you add 3/32" sheeting to the top and bottom, the root becomes 9/16" and the tip becomes 3/8". The supplied trailing edge stock is 3/8" so this is fine at the tip, but poses a problem at the root. I realized this when I attempted to sand the top and bottom sheeting at the center of the wing to match the trailing edge stock. I sanded through the sheeting before matched it up to the trailing edge... Crap!
OK, so this is a VERY old design and LOTS of people have built this plane, so what was done to solve this problem? Filler material on the trailing edge at the root? Poor fitting trailing edge and ailerons?
These are not options for me so I've decided to rip off the trailing edge and the trailing edge sheeting and start over. I bought some 1/2" trailing edge stock and have decided to sheet the entire wing as opposed to leading/traling edge sheeting and cap strips. This will eliminate some of the drawbacks of having to deal with sanding/painting open bays.
I know the first though of some of you will be that I'm adding lots of weight by fully sheeting the wing. Maybe so, but it's not that big of an issue to me. I'll be using contest grade balsa for the sheeting which will help some with the added weight of the additional material.

NM2K

My Feedback: (14)

I would ignore the difference in sizes and just make sure that the ailerons are centered on the wing's trailing edges.

The Dirty Birdy, and other Bridi pattern ships of the era, appear to be focused on utility and not aesthetics. This is one of the reasons that I liked them so much. We have a job to do. Let's go do it and not waste myriad hours on building a static display model with a super-duper finish. Just my $.02.


Ed Cregger

anuthabubba

My Feedback: (102)

Laminations of balsa can be made to whatever thickness needed (could be stiffer than single thickness) then shaped (planed, sanded) to become a tapered aileron. A built up aileron could be built.

Terry in LP

gkaraolides

Greetings,

Problems with matching tapered trailing edge / strip aileron sections to the wing are often encountered when building double tapered wings.

I'll detail one way to deal with it which in my opinion is quite simple. It's best to match the TE section to the wing, and not the wing to the TE section.

Please refer to the image below. First measure the required thickness and width of the section at the tip. Then select or make a section that has the same proportions of width to thickness but is slightly larger to cover both the larger thickness and the larger width required at the root. Cut this to length. Mark the required width and thickness at the tip.

Then find the place at the root of the section where the thickness matches that required at the root and mark that. Measure from there and mark the required width at the root.

If this is slightly narrower than the section, mark this and relieve the back of the section. This will give a slightly thicker trailing edge at the root but this should have no significant effect on anything. What matters is to match the thickness at the front of the section where it should follow the wing contour and not disrupt airflow. Round the back off, or feather it, as preferred.

If on the other hand, when the thickness at the root is matched, the section turns out to be slightly narrower than required at the root, this should also not have a significant effect on anything. Again, it's the match of the section to the wing that matters, and we got both the thickness and the width perfectly right at the tip where it's most critical. Make a small modification to plug the gap at the back of the fuselage opening, either by adding material to the back of the opening, or by checking the fit of the back of a wing fairing or bellypan, if fitted. Re-check the incidence (which you'd do anyway after fitting a trailing edge section) and you should be OK.

Best regards.

Ed Lyerly

gkaraolides,
Thank you for this simple and elegant solution to sizing the ailerons for double tapered wings.
Ed

AllTheGoodNamesAreTaken

My Feedback: (180)

Maybe this will clear up what I'm talking about. I'm goint to change the 3/8" trailing edge stock for 1/2" of the same width. Then I'll temporarily glue the TE stock to the wing, then sand to shape.

gkaraolides

Greetings,

@ Ed: Many thanks for your appreciation. Coming from you this is praise indeed! I have seen your Curare build thread, it remains one of the inspirations for me to [link=http://www.rcuniverse.com/forum/m_9121303/anchors_9121303/mpage_1/key_/anchor/tm.htm#9121303]re-enter the hobby and once again build the pattern ships I used to love.[/link]

@ Allthegoodnames...: If instead of getting 1/2 inch trailing edge stock of the same width as your existing 3/8 inch stock, you get 9/16 inch stock which is half again as wide, you will be able to cut it down as I describe above within minutes, and save yourself a lot of sanding. Your trailing edge at the root will probably end up wider than the plans but that won't matter. You can relieve the back as I show in my post, or relieve only a bit at the root to clear the fuselage opening, or a combination of both. Please note that with the method you propose, you will end up with a trailing edge that is the same width at the root and tip, but different thickness. There's nothing wrong with that per se, but if you try and sand that to a uniform feather edge at the back the angle you'll be sanding at will vary along the span. This will be quite difficult to get right.

With best regards,

George

doxilia

My Feedback: (3)

Jeff,

If I understand correctly, you are saying that the maximum thickness of the aileron stock provided (at its hinge point) is narrower than the TE of the wing at the root where the wing has it's maximum thickness.

If that's the case, then the aileron stock provided is clearly undersized. One would alter the airfoil of the wing by sanding the TE (sheeting or not) at the root down to the thickness of the provided ailerons. I have never come across a situation like that as typically the reverse process applies - one sands the ailerons to follow the contour and airfoil of the wing.

If this is a Bluejay kit, then they should be informed of the error in the aileron stock.

David.