LA7 Info / Research / Build - Scale Wings
10-11-2011, 12:34 PM
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RE: LA7 Info / Research / Build - Scale Wings
Mick,
I saw your modification in post 32. I was curious if it solved the issue. Also, I didn't quite understand the comment about a "large hole in the fuselage" aft of the oil cooler. Can you exhaust air from the cowl through the fuselage?
I saw your modification in post 32. I was curious if it solved the issue. Also, I didn't quite understand the comment about a "large hole in the fuselage" aft of the oil cooler. Can you exhaust air from the cowl through the fuselage?
10-11-2011, 12:57 PM
#52
RE: LA7 Info / Research / Build - Scale Wings
Yes you would have to, you will never get all the air out of the exhaust exits. That's why mine overheated in the beginning.
m
m
10-11-2011, 01:06 PM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: mick15
Yes you would have to, you will never get all the air out of the exhaust exits. That's why mine overheated in the beginning.
m
Yes you would have to, you will never get all the air out of the exhaust exits. That's why mine overheated in the beginning.
m
Do you have any photos of how you did this on the inside of the plane? Just trying to understand the mod.
10-11-2011, 01:24 PM
#54
RE: LA7 Info / Research / Build - Scale Wings
No pics I'm afraid but, the engine mount is fitted to a large carbon fibre dish, this dish has five large holes drilled to let the air out. Also the dish is opened up as much as posible around the carburettor. The disadvantage with this is the internals of the fus get very hot, so as a precaution I piped some air from the front of the oil cooler directed to the receivers through the large hole I cut into the fusalage above the oil cooler scoop.
m
m
10-11-2011, 01:45 PM
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RE: LA7 Info / Research / Build - Scale Wings
John,
They never did it in the full size aircraft. The problem the Russians had to solve was how to keep the engine warm. Ours is obvously the opposite. That's why the slots around the nose cone could be opened or completely close along with the flap around the exhaust port.
I have to assume that Mick has found a way to funnel cowl air through the fuselage and exit it behind the oil cooler. Looking at the Dave A. plans, there may be a way to funnel air over the center section and out through an opening in the back of the oil cooler. That way I wouldn't have to open the fuselage. Mabybe, maybe.
They never did it in the full size aircraft. The problem the Russians had to solve was how to keep the engine warm. Ours is obvously the opposite. That's why the slots around the nose cone could be opened or completely close along with the flap around the exhaust port.
I have to assume that Mick has found a way to funnel cowl air through the fuselage and exit it behind the oil cooler. Looking at the Dave A. plans, there may be a way to funnel air over the center section and out through an opening in the back of the oil cooler. That way I wouldn't have to open the fuselage. Mabybe, maybe.
10-11-2011, 01:57 PM
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RE: LA7 Info / Research / Build - Scale Wings
My current plan is to cut two openings in the carbon fibre dish and build air tunnels for air to exit the exhaust ports.
Based on mick15 post, I will likely route air from the oil cooler to the SBUS PSS2018 and receivers to help cool them and build some type of covered/louvered air exhaust ports to the rear of the oil cooler.
Based on mick15 post, I will likely route air from the oil cooler to the SBUS PSS2018 and receivers to help cool them and build some type of covered/louvered air exhaust ports to the rear of the oil cooler.
10-11-2011, 03:53 PM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: germrb
John,
Look on the bottom of page 83 of the La-7 book
John,
Look on the bottom of page 83 of the La-7 book
Hi Bob,
I'll be starting aq Dave Anderson LA 7 and would love too know what "boob" you are talking about. Where do I get it?
Dave
10-11-2011, 04:05 PM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: dpav8r
Sorry Bob, that should read "book".
Dave
Sorry Bob, that should read "book".
Dave
Dave,
Here is a link to the book Bob spoke of:
http://www.amazon.com/gp/product/8086524051
I am sure if you search, you can find a lower cost than Amazon. Here is another link:
http://www.aviationmegastore.com/lav...id=1&art=33445
John
10-11-2011, 04:27 PM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: dpav8r
John, thanks for that, is it worth it?
Dave
John, thanks for that, is it worth it?
Dave
To me it was because it has the only image of the plane no/scheme Iam building. I think it really depends on how scale you are trying to make your bird.
John
10-20-2011, 10:07 AM
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RE: LA7 Info / Research / Build - Scale Wings
Picked up the Scale Wings LA-7 and Moki 250 yesterday from Gotz; now just to finish up a build for a friend this weekend.
10-20-2011, 11:20 AM
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RE: LA7 Info / Research / Build - Scale Wings
John,
I'm seriously jealous! I have been considering the AT-6, but the extra $925 for import and shipping was a bit of a surprise. Besides, I am going to have my hands full with the 25% La-7 build this winter. Maybe in the spring. Keep us posted.
I'm seriously jealous! I have been considering the AT-6, but the extra $925 for import and shipping was a bit of a surprise. Besides, I am going to have my hands full with the 25% La-7 build this winter. Maybe in the spring. Keep us posted.
10-21-2011, 06:29 PM
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RE: LA7 Info / Research / Build - Scale Wings
Will be watching this build with interest... I'm scratch building an LA-7 from Enlarged Andersen plans, mine is about 30% with a 120" span... It's in the primer/detailing phase now... Good luck, looking forward to seeing another big Russian take flight!
10-22-2011, 03:51 AM
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RE: LA7 Info / Research / Build - Scale Wings
I have been discussing Seidel Props with Götz for the LA-7 and CARF P-47. Waiting on a quote from Germany for these.
http://www.seidel-props.de/
I can read some German, but here is a translated German to English version of thier website (Click here).
http://www.seidel-props.de/
I can read some German, but here is a translated German to English version of thier website (Click here).
10-22-2011, 04:23 PM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: cmreefer
Will be watching this build with interest... I'm scratch building an LA-7 from Enlarged Andersen plans, mine is about 30% with a 120" span... It's in the primer/detailing phase now... Good luck, looking forward to seeing another big Russian take flight!
Will be watching this build with interest... I'm scratch building an LA-7 from Enlarged Andersen plans, mine is about 30% with a 120" span... It's in the primer/detailing phase now... Good luck, looking forward to seeing another big Russian take flight!
I would love to see some photos of your build...
10-23-2011, 08:05 PM
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RE: LA7 Info / Research / Build - Scale Wings
There is a photo in "my gallery" here on rcu and about 200+ photos of the build here...:
http://www.rcscalebuilder.com/forum/...TID=15345&PN=1
-Danny
http://www.rcscalebuilder.com/forum/...TID=15345&PN=1
-Danny
10-26-2011, 11:54 AM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: wxman2
One item I am trying to find is what material was the exhaust shield area made of; does anyone know?
One item I am trying to find is what material was the exhaust shield area made of; does anyone know?
As for cooling the engines in our models, mimicking the way they did it in the full size plane is a good start....first off, the LA 7 did not have a fan despite some sources claiming they did. A close study of photos will depict cooling louvers used to control the amount of cold air entering the engine which was a considerable concern when dealing with -60 degree temps! We don't fly in -60 degree weather so we have to cool the engines....the best way is to start with a thin annular gap (distance between the edge of the spinner and the cowl lip) and create a sealed plenum chamber in front of the cylinders. This does two things: it slows the air down which causes the pressure to increase. Slow moving, high-pressure cool air is much more efficient at scrubbing heat from the cylinder fins than fast moving low pressure ram air. Next, make sure the exit area is three times the volume of the entry. Then, let the physics of fluid dynamics work its wonders! it works and can be seen in none other than the mighty air-cooled Reno Air Racers. Here is a cool link to how it works on the air racers although they do use ADI and spray bars as well but what do you expect when they are boosting the engines by twice their design!
http://www.supercoolprops.com/articles/gwhite.php
10-26-2011, 12:31 PM
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RE: LA7 Info / Research / Build - Scale Wings
ORIGINAL: LA7flier
The LA 7's contained much more duraluminum than the LA 5. They still had wood skinned wings and fuselage, however. The shields are duraluminum...not anything exotic like stainless steel. The Russian government calculated the combat life of these planes in weeks and built them in massive numbers so nothing exotic went into them.
As for cooling the engines in our models, mimicking the way they did it in the full size plane is a good start....first off, the LA 7 did not have a fan despite some sources claiming they did. A close study of photos will depict cooling louvers used to control the amount of cold air entering the engine which was a considerable concern when dealing with -60 degree temps! We don't fly in -60 degree weather so we have to cool the engines....the best way is to start with a thin annular gap (distance between the edge of the spinner and the cowl lip) and create a sealed plenum chamber in front of the cylinders. This does two things: it slows the air down which causes the pressure to increase. Slow moving, high-pressure cool air is much more efficient at scrubbing heat from the cylinder fins than fast moving low pressure ram air. Next, make sure the exit area is three times the volume of the entry. Then, let the physics of fluid dynamics work its wonders! it works and can be seen in none other than the mighty air-cooled Reno Air Racers. Here is a cool link to how it works on the air racers although they do use ADI and spray bars as well but what do you expect when they are boosting the engines by twice their design!
http://www.supercoolprops.com/articles/gwhite.php
ORIGINAL: wxman2
One item Iam trying to find is what material was the exhaust shield area made of; does anyone know?
One item Iam trying to find is what material was the exhaust shield area made of; does anyone know?
As for cooling the engines in our models, mimicking the way they did it in the full size plane is a good start....first off, the LA 7 did not have a fan despite some sources claiming they did. A close study of photos will depict cooling louvers used to control the amount of cold air entering the engine which was a considerable concern when dealing with -60 degree temps! We don't fly in -60 degree weather so we have to cool the engines....the best way is to start with a thin annular gap (distance between the edge of the spinner and the cowl lip) and create a sealed plenum chamber in front of the cylinders. This does two things: it slows the air down which causes the pressure to increase. Slow moving, high-pressure cool air is much more efficient at scrubbing heat from the cylinder fins than fast moving low pressure ram air. Next, make sure the exit area is three times the volume of the entry. Then, let the physics of fluid dynamics work its wonders! it works and can be seen in none other than the mighty air-cooled Reno Air Racers. Here is a cool link to how it works on the air racers although they do use ADI and spray bars as well but what do you expect when they are boosting the engines by twice their design!
http://www.supercoolprops.com/articles/gwhite.php
Thanks for your help LA7flier and the link....
John
11-07-2011, 01:47 PM
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RE: LA7 Info / Research / Build - Scale Wings
Just a few more items to obtain before I start the LA-7 assembly. I like to have as much as I can completed in my head before I start a project like this and I am still working out how to make the elevator mechanism hidden and conceal the rudder horn better.
Anyways... I am going to be making a few special parts for this plane and have taken the plunge on obtaining a desktop CNC machine.
Anyways... I am going to be making a few special parts for this plane and have taken the plunge on obtaining a desktop CNC machine.
11-12-2011, 04:44 AM
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RE: LA7 Info / Research / Build - Scale Wings
Here are some of the items Iplan to create with my new CNC/Laser cutter. The CAD data came from Markus Enzinger in Austria.
http://www.institutfuersehtraining.at/fotos/Cockpit/
I want to thank Markus again for sharing the CAD data...
http://www.institutfuersehtraining.at/fotos/Cockpit/
I want to thank Markus again for sharing the CAD data...