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Old Dec 27, 2013, 12:19 AM
Slow 'n Steady...Grease 'r In
kpriddle's Avatar
Maine
Joined Oct 2008
1,263 Posts
Build Log
Ace Simple Series Corsair

Hey, everyone:

I've figured this build was worth sharing, mostly so I can pester you all with my plethora of questions! We'll see!

So far, the fuse has been partially assembled, as well as the wing. I'm waiting on just about all of the guts, so a lot of the work has stalled. Hopefully, that gear will arrive in a couple days. She's gonna have a Norvel .074 up front and a Berg 4L, three micro servos (HS-55 elevator, HXT900 throttle, HS-81 aileron), and 260mAH battery installed for a radio. Hopefully, this will help keep it between 21oz.-23oz.

I need to finish up the wing but I've run into an issue. Originally I wanted to cover the wing in Doculam, but apparently Doculam is a hot temp film, so I risk melting the foam. Regardless, the Doculam is being shipped as well (I'd like to give it a shot in any case). The alternative is to first sheet the wing. Although this is the less preferred method, I am leaning this way. What type of adhesive is recommended to bond the balsa to the foam? Has anyone used 3M 45?

Also, if there's anyone who has used Doculam, can you explain how you have painted it? I'm considering painting the popular 3-tone scheme as opposed to the solid Navy blue, but I'd need to airbrush the outside of the film (many just paint the inside then apply). Does anyone have any recommendations for airbrush-able fuel-proof paint?

Best,
KP
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Last edited by kpriddle; Dec 27, 2013 at 12:28 AM.
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Old Dec 28, 2013, 09:03 AM
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Florida
Joined Dec 2001
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You could just glass the wing. It's pretty fast and easy to do.

How much wing area is there? From the first photo, the wing looks way too big for a 1/2A engine. Could just be the type of zoom on your camera.
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Old Dec 28, 2013, 09:08 AM
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Beaumont tx
Joined Oct 2004
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Low Temp film like Tower's Econokote; or glass with Wter Based Polyurethane. I have heard that Rustoleum rattlecan is fuelproof.

howell
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Old Dec 28, 2013, 01:20 PM
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Canada
Joined Nov 2000
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I've had No problems applying MY doculam ..there are dozens of Varieties though.. to Depron foam. Which is typically less heat tolerant than Styrofoam
One can paint Doculam with acrylic paints even $1 store types. Wipe down the film with decent vinegar first.
I've found that Glidden 'Gripper' primer mixed with Acrylics (colour) sticks well enough so I can't scratch it off with finger nails.
Dunno about fuel proof though. as $ store Paints are erm.. Cheap.
However Liquitex brand artists acrylics have proven Nitro proof for me....albeit after a few weeks cure time . Mebe sooner? never tested that though
Although I think that Rustoleum spray paints will both stick to Doculam and be fuel proof.. Test some ?.
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Old Dec 29, 2013, 12:08 AM
Slow 'n Steady...Grease 'r In
kpriddle's Avatar
Maine
Joined Oct 2008
1,263 Posts
The plans state that the wing area is 190 in^2. If the length of this plane were to be to scale, it would be 29", but it's closer to 24.5".

The Doculam came in last night, so I gave it a shot on a test piece of EPS. Although the application temperature of the Doculam is supposed to be from 290įF-300įF, I found that it sticks fantastically to the EPS without any melting. Even when I tried to melt the foam, I couldn't do it. So, it looks like I'll cover all of the plane in Doculam. To cover the fuse, what is a good balsa prep? Some say Balsarite is necessary to get the Doculam to stick well. Thoughts?

In addition to testing the Doculam, I mounted the engine on the test stand. I'll try to get it running tomorrow. For those of you who have experience with the Norvels, how worthwhile is buying a starter? I guess I'll see tomorrow!

Bare, do you use the $11, $22, or $41 stuff? Link. It seems like a lot of guys are using just about any type of acrylic lacquer.

KP
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Old Dec 29, 2013, 12:05 PM
Master of the Figure "9"
hogflyer's Avatar
Wichita, Kansas
Joined Dec 2005
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I've used Top Flight Econokote in the past on Ace foam wings and it was great. Being a low temp covering, it basically stuck with the heat from my hand, and sealed tight with an iron at low temp.

If you want to try painting the model, I've seen the craft paper/deluted carpenters glue used on foam. It produced a very hard surface that sanded to a very smooth surface that was painted.

I have a fellow club memeber who paints his 1/2A planes with rattle cans, but not sure if he uses Rustoleum or Krylon. He hasn't had any issues with the 1/2A fuel attacking the paint.

Hogflyer
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Old Dec 29, 2013, 01:05 PM
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Most likely be Rustoleum. If it is Krylon please find out which one. It is the lighter.
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Old Dec 29, 2013, 03:09 PM
Slow 'n Steady...Grease 'r In
kpriddle's Avatar
Maine
Joined Oct 2008
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The reason that I want to use Doculam on this plane is due to the high price of the "Kotes". Nonetheless, I'll keep Econokote in mind. I've never used low temp covering before.

Rustoleum seems to be popular for fuel-proof paint. There are mixed reviews about Krylon. Hogflyer, if you could figure out which he has luck with, that would be great. Otherwise, I'll just have to test one.

Today, I tried to start the Norvel. Although the previous owner said that it had been run around 12 times, the piston jammed in the cylinder after a minute of hand flipping (no starter was used). I unscrewed the cylinder, but I still couldn't break the piston loose. Then I heated the cylinder which did the job. Upon reassembling the engine, it still stuck at TDC. The strange thing is that I can spin the prop quickly with little friction, but as soon as I slow the rotation, it binds again at TDC. I have to force it through to rotate again. It seems like the problem has something to do with the conn rod or the taper in the liner. How can I fix this problem? Might it have something to do with the fact that the engine was run in CA while it has been sitting in my basement in Maine for a couple of days? Maybe the cylinder needs a new break-in to fit the tighter cylinder? Just thinking out loud...

KP
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Last edited by kpriddle; Dec 29, 2013 at 03:22 PM.
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Old Dec 29, 2013, 05:49 PM
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Western KY
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Quote:
Originally Posted by kpriddle View Post
I unscrewed the cylinder, but I still couldn't break the piston loose. Then I heated the cylinder which did the job. Upon reassembling the engine, it still stuck at TDC. The strange thing is that I can spin the prop quickly with little friction, but as soon as I slow the rotation, it binds again at TDC. I have to force it through to rotate again. .........How can I fix this problem?
KP
KP ---

There's nothing wrong with your engine, other than it's still in the break-in phase. Flipping the engine quickly maintains the oil film between the cylinder and piston. Turning it slowly allows the oil to be dissipated and the piston sticks. This is common with all NORVELs I've worked with. When trying to start your engine, use your heat gun to pre-warm the cylinder before flipping.

When the engine does start up, get it up to operating temperature quickly --- don't run it in a sloppy 4-cycle like most other engines, but run it in a rich 2-cycle. The heating is necessary to allow the piston/cylinder fit to stabilize. NORVELs can be difficult to start initially and probably caused many to be returned as defective when in fact they were just well-fitted.

andrew
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Old Dec 29, 2013, 06:24 PM
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Canada
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Good your film works. On mine the film prevents the heat from getting thru enough to keep the foam safe. I haven't bothered to 'prep' sheet balsa fuses. My stuff sticks well enough.. removing balsa surface if forcibly removed.
Apply the stuff as smoothly as humanly possible... Before going near it with your iron..Tape it if needs be.
Do be careful at corners and curves as Doculam only shrinks a little and if you overheat it trying for more shrink.. it ain't pretty.
Practice .. some.. on scraps. You will be glad you did.
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Old Dec 30, 2013, 08:14 PM
Slow 'n Steady...Grease 'r In
kpriddle's Avatar
Maine
Joined Oct 2008
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Quote:
Originally Posted by Andrew0820 View Post
KP ---

There's nothing wrong with your engine, other than it's still in the break-in phase. Flipping the engine quickly maintains the oil film between the cylinder and piston. Turning it slowly allows the oil to be dissipated and the piston sticks. This is common with all NORVELs I've worked with. When trying to start your engine, use your heat gun to pre-warm the cylinder before flipping.

When the engine does start up, get it up to operating temperature quickly --- don't run it in a sloppy 4-cycle like most other engines, but run it in a rich 2-cycle. The heating is necessary to allow the piston/cylinder fit to stabilize. NORVELs can be difficult to start initially and probably caused many to be returned as defective when in fact they were just well-fitted.

andrew
Thank you for the information. I only got a 2 second spurt out of it today before, my glow starter died on power. I'll try starting it again tonight.

The heat gun has worked very well for me. I've had to ensure that I don't over heat the cylinder and lose compression, but it has worked well to free up the occasional "stuck" piston. When you go out to the field, I assume you go without the heat gun. Is the engine broken in well enough by that point that the piston doesn't lock up, or do you deal with the prop/spinner breaking lose when the piston sticks? I seem to have this problem a lot when hand flipping.

KP
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Last edited by kpriddle; Dec 30, 2013 at 11:33 PM.
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Old Dec 30, 2013, 08:18 PM
Slow 'n Steady...Grease 'r In
kpriddle's Avatar
Maine
Joined Oct 2008
1,263 Posts
Can anyone tell me how this ON/OFF switch should REALLY be wired?

The two positives have been spliced together and soldered to an end tab while the negatives have been spliced and soldered to the middle tab. The bottom lead goes to the battery, and the top lead goes to the RX.

KP
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Last edited by kpriddle; Dec 30, 2013 at 11:54 PM.
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Old Dec 30, 2013, 11:27 PM
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Western KY
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Originally Posted by kpriddle View Post
The heat gun has worked very well for me. I've had to ensure that I don't over heat the cylinder and lose compression, but it has worked well to free up the occasional "stuck" piston. When you go out to the field, I assume you go without the heat gun. Is the engine broken in well enough by that point that the piston does lock up.......

KP
I use a monokote gun for heating --- you won't get it too hot when preheating before starting. NORVELs take a lot of time to break in initially. By the time I take an engine to the field, it's had sufficient time on the bench to start easily, usually on the second flip.

When SIG bought the distribution rights for NORVEL, their user's guide included instructions to cold flip the engine enough to remove most of the pinch at the top. I'm convinced that this caused premature wear rather than getting a good running fit from a hot engine. I'm also convinced suggesting cold flipping was SIG's attempt to get the engines to start and run like the conventional engines of the time. Keep in mind that NORVELs (an acronym for Northern Velocity) were originally imported for use in 1/2A fast combat and were run by folks that understood high performance engines. When the engines hit the mass market, the starting problems arose due to lack of experience with this type of piston/cylinder fit. I have some NORVEL .15's that were squeaky tight at the top, much like the engines found on pylon racers. They can be cantankerous at first, but a good break-in will result in a long lasting and strong running engine.

Other folks posting here may have had a different experience and certainly may have different or better advice for starting and breakin.

andrew
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Old Dec 30, 2013, 11:38 PM
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Western KY
Joined Sep 2003
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Quote:
Originally Posted by kpriddle View Post
Can anyone tell me how this ON/OFF switch should really be WIRED?

The two positives have been spliced together and soldered to an end tab while the negatives have been spliced and soldered to the middle tab. The bottom lead goes to the battery, and the top lead goes to the RX.

KP
Cut both negative leads off the switch and solder them together. Cut the red lead from the RX off the end tab and solder it to the middle tab. As shown in the picture, you will get a dead short when switched on.
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Old Dec 31, 2013, 12:06 AM
Slow 'n Steady...Grease 'r In
kpriddle's Avatar
Maine
Joined Oct 2008
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As of now, the negative leads are soldered together and then to the middle tab. You don't mean that it should look like this, do you?
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