Scratch Build for PAW .049

TD ABUSER Sat Aug 17, 2024 1:26 am

Well I sort of did a close copy of a well known sport model...but it's just loosely based on a photo and it isn't built like the original Flight Streak.
At this point it weighs 7 5/8 ounces minus silkspan and dope.
26 inch span and an average chord of 6.5 inches...169 sq inches.

akjgardner Sat Aug 17, 2024 4:00 am

Very nice workmanship, what did you use for elevator hinges ?

getback Sat Aug 17, 2024 4:48 am

Very clean , has nice lines , should make a good flier ! Hope to see it finished Very Happy

TD ABUSER Sat Aug 17, 2024 8:53 am

akjgardner wrote:Very nice workmanship, what did you use for elevator hinges ?

thanks.!
I think they were Carl Goldberg SMALL nylon hinges. These have a real hinge pin.
They will push into medium dense balsa that has just been slitted with an Xacto.
I don't use glue.
I cross drill and insert a round toothpick to pin them in place, then use a tiny drop of thin CA to secure the toothpick.
It's not a bad idea to pre-treat the hinge pin with a drop of transmission fluid just in case the hinge gets accidentally glued or painted shut.

TD ABUSER Sat Aug 17, 2024 11:12 pm

Got the plane covered and in plain dope and it added an ounce to the unfinished weight...so it weighs 8 5/8 ounces now but.....
I had to add some lead to the nose to make the plane "groovey" instead of too sensitive.
I figured this might be the case..but when checking a 1/2A CG with fat fingers it's easy to be off by 5%.
Where this plane is balanced now is at 25%.
The engine and tank needs to move forward so I can ditch the lead.
It flies pretty nice on 35 foot long .012" steel lines...but the line tension is marginal
The engine turns a Cox 6 x 3 at 12,900...[which is about what it was running at when I first bought it for a failed project a couple years ago.
APC 5.7 x 3 revved higher but it didn't pull the plane any better.
APC 5 x 3 revved to 17,000 but barely flew this plane.

I want to build another Flight Streak now but for either a TD or a Norvel .049

One of the photos show how I was living dangerously with no "keeper" for the control horn connection..... Smile

roddie Sun Aug 18, 2024 8:16 am

TD ABUSER wrote:
It flies pretty nice on 35 foot long .012" steel lines...but the line tension is marginal
The engine turns a Cox 6 x 3 at 12,900...[which is about what it was running at when I first bought it for a failed project a couple years ago.
APC 5.7 x 3 revved higher but it didn't pull the plane any better.
APC 5 x 3 revved to 17,000 but barely flew this plane.

It seems to me that your little .049 diesel should be able to swing a 7" propeller. I found these 7 x 4's on eBay.. X3 for 10 bucks.. and they're designed for IC engines.

eBay link

Might be just what the doctor ordered.. Smile

TD ABUSER Sun Aug 18, 2024 11:05 am

roddie wrote:
TD ABUSER wrote:
It flies pretty nice on 35 foot long .012" steel lines...but the line tension is marginal
The engine turns a Cox 6 x 3 at 12,900...[which is about what it was running at when I first bought it for a failed project a couple years ago.
APC 5.7 x 3 revved higher but it didn't pull the plane any better.
APC 5 x 3 revved to 17,000 but barely flew this plane.

It seems to me that your little .049 diesel should be able to swing a 7" propeller. I found these 7 x 4's on eBay.. X3 for 10 bucks.. and they're designed for IC engines.

A couple years ago I bought this PAW .049 to power a larger 1/2A control line project. It failed to produce enough power. I tried a 7x3 APC prop and the PAW output was worse than with the 6 inchers.
I think there are applications where you want reduced output with a big prop / little engine combo...[like with free flight].
I think of the Cox TD .049 as marginal power for a fully capable stunt plane and this PAW puts out about 3/4 the power of a Cox TD.
After reading about diesel fuel mixing...maybe I need to get some "real" kerosene instead of using lamp oil...?
I had dieselized a few Cox .049s in the past, but this was my first PAW.
In the past I relied on Eric Clutton for my fuel....and so I want to rule out every possibility that I don't know what I'm doing yet when it comes to mixing my own.

TD ABUSER Sun Aug 18, 2024 12:12 pm

Here it is with the engine and tank moved forward.
Master Airscrew 6x3 prop
https://youtu.be/j4KVrjzRTZc

roddie Sun Aug 18, 2024 3:33 pm

TD ABUSER wrote:Here it is with the engine and tank moved forward.
Master Airscrew 6x3 prop
https://youtu.be/j4KVrjzRTZc

I'd say that's a winning combo..!!

TD ABUSER Sun Aug 18, 2024 4:40 pm

roddie wrote:
TD ABUSER wrote:Here it is with the engine and tank moved forward.
Master Airscrew 6x3 prop
https://youtu.be/j4KVrjzRTZc

I'd say that's a winning combo..!!

It's a juggling match between flying slow enough to make executing square corners doable and having enough line tension to keep the model from falling out of the sky... Smile

TD ABUSER Sun Aug 18, 2024 8:08 pm

Here's the same plane with an old Norvel .074 on 5% nitro
MAS 7x3 cut down to 6.25" [This prop was cut down back when I was testing various props for the PAW .049]
Muffler pressure plumbed into a single vent
This tank holds 3/4 oz.
Line tension is real good, but I lost the ability to do square corners that I had with the PAW.049.
Oh well, tough shi..... Smile

Model seems worthy of painting.
Now it's time to piece together a Cox .049 TD and build another plane similar to this one, running on a bladder...
It seems like 7 ozs instead of 9 ozs is doable with the same wing area...?

https://youtu.be/-VQPTnKVGjI

getback Mon Aug 19, 2024 7:04 am

Man that thing was cooking Looks dialed in to me , but I cant fly like that ! Can tell you have been into combat for along time .. Yea go ahead and paint it / silk span wings covering ? Clean my glasses

TD ABUSER Mon Aug 19, 2024 8:51 am

getback wrote:Man that thing was cooking Looks dialed in to me , but I cant fly like that ! Can tell you have been into combat for along time .. Yea go ahead and paint it / silk span wings covering ?

So far the silk span is holding up OK.
I don't know why the heavy grade is unavailable,,it seems that medium is all that Brodak has.
I think it's the way to go with diesel fueled 1/2A planes.
With larger planes the heat shrinkable cloth seems to be popular with The Dopers. I just covered a .35 sized Voodoo with Sig Coverall and dope and air brushed a light coat of automotive grade catalyzed paint over it.
Otherwise the lightest covering I know of for 1/2A is cellophane that has been misted with 3M spray adhesive. It's functional [not the best looking] and very cheap.
The dollar stores stopped stocking the kind that is shrinkable, the metallic stuff they stock now doesn't shrink.

getback Mon Aug 19, 2024 1:47 pm

Is this the stuff for larger planes ur talking about > https://www.cableorganizer.com/categories/cable-management/heat-shrink/tubing/shrinkflex/ if so never new .. some of the guys have been using Doc paper >> https://www.homesupply.net/product/deluxe-smooth-exam-table-paper-1-roll/ I am about to monkote a .15 size clown .

TD ABUSER Mon Aug 19, 2024 1:52 pm

getback wrote:Is this the stuff for larger planes ur talking about > https://www.cableorganizer.com/categories/cable-management/heat-shrink/tubing/shrinkflex/ if so never new .. some of the guys have been using Doc paper >> https://www.homesupply.net/product/deluxe-smooth-exam-table-paper-1-roll/ I am about to monkote a .15 size clown .

Thanks for showing me the exam paper..!
Is it applied the same way you do tissue...?

roddie Mon Aug 19, 2024 2:09 pm

TD ABUSER wrote:
getback wrote:Is this the stuff for larger planes ur talking about > https://www.cableorganizer.com/categories/cable-management/heat-shrink/tubing/shrinkflex/ if so never new .. some of the guys have been using Doc paper >> https://www.homesupply.net/product/deluxe-smooth-exam-table-paper-1-roll/ I am about to monkote a .15 size clown .

Thanks for showing me the exam paper..!
Is it applied the same way you do tissue...?

CEF member @DanMc has used the "Doctor's Paper".. and told us about it. See THIS THREAD which has a reference to the Stunt Hangar forum.

Ken Cook Mon Aug 19, 2024 5:41 pm

Covering a 1/2A with silkspan or whatever dope and tissue you decide on is not a good idea. You will be repairing more than flying. Iron on coverings are not too heavy and a helluva lot easier to repair or remove a warp. As for the Doc paper, this subject was brought up many years back on Stunthangar. I was getting low on silkspan and tried this TIDI brand paper. I thought it absolutely sucked. It doesn't shrink like silkspan does and it certainly didn't take less paint to cover the abortion I made of it . I'm not a advocate of this so called silkspan replacement as I found it to be more troublesome than good. Polyspan works miles better not too mention it's proven, you don't need to purchase a truck load to get a good deal and it's stronger. Polyspan is readily available and it can be glued on or doped on and it shrinks with a iron prior to doping. Some have problems with compound curves with it but I haven't and the Flite Streak style tips are the most difficult to cover. I've done several Streaks with it. I used silkspan on the tips to the first bay and Polyspan in the field. I had a trim line there so I could make a paint break. I did use a entire piece on my next Streak.

TD ABUSER Tue Aug 20, 2024 12:14 am

Ken Cook wrote:Covering a 1/2A with silkspan or whatever dope and tissue you decide on is not a good idea. You will be repairing more than flying. Iron on coverings are not too heavy and a helluva lot easier to repair or remove a warp. As for the Doc paper, this subject was brought up many years back on Stunthangar. I was getting low on silkspan and tried this TIDI brand paper. I thought it absolutely sucked. It doesn't shrink like silkspan does and it certainly didn't take less paint to cover the abortion I made of it . I'm not a advocate of this so called silkspan replacement as I found it to be more troublesome than good. Polyspan works miles better not too mention it's proven, you don't need to purchase a truck load to get a good deal and it's stronger. Polyspan is readily available and it can be glued on or doped on and it shrinks with a iron prior to doping. Some have problems with compound curves with it but I haven't and the Flite Streak style tips are the most difficult to cover. I've done several Streaks with it. I used silkspan on the tips to the first bay and Polyspan in the field. I had a trim line there so I could make a paint break. I did use a entire piece on my next Streak.

Ken I was hoping for a vote of confidence for the Exam Paper...but thanks for your honest appraisal.
Polyspan from BMJR Hobbies it is for me...https://www.bmjrmodels.com/control-line

Ken Cook Tue Aug 20, 2024 3:56 am

Resist sanding Polyspan until you get some coats on it. I really thin my dope quite a bit. You can fuzz the material which takes a lot more coats to fix. In addition, there's a top and bottom to this material. Insure you orientate it correctly when doing top to bottom and vice versa.

TD ABUSER Mon Aug 26, 2024 7:23 pm

Here she is with her custom paint job Mad

I didn;t have any luck finding Butyrate thinner so I just used lacquer thinner and it dries so fast that the paint practically has to be "dabbed" from the paint brush. The black line is a magic marker and I sprayed a couple coats of clear over the black to preserve it. The clear dope was forming clots in the air brush [thanks to the laacquer thinner I guess] so I didn't waste any time dragging a thin wire through the siphon tube / jet.

Flying on 50 foot long 40 pound test Spiderline Supreme....the .074 Norvel / 7x3 APC has just enough oomph to do anything you want on a nice calm day.
https://youtu.be/JhHhF7r1uW8

getback Tue Aug 27, 2024 8:10 am

Alot slower but effective , I could keep up with that one ... Do those trees in the background mess with you ? Well i know not to use lacquer thinner anyway Very Happy

Still looks good though you had to fight with it a little . Thumbs Up

TD ABUSER Tue Aug 27, 2024 11:03 am

getback wrote:Alot slower but effective , I could keep up with that one ... Do those trees in the background mess with you ? Well i know not to use lacquer thinner anyway Still looks good though you had to fight with it a little .

Yes the trees cause TURBULENCE...!!!
Funny how after the paint dries on a little model like this..how I can look at it and forgive the imperfections.

If I saw the same sloppy work on a .35 sized model I wouldn't be as forgiving. Cool

What I learned here is you could do all the color with marking pens and just shoot a few clear coats of butyrate afterwards to seal in the ink.
This must be obvious to a lot of you but this was the first time I tried it.

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