RE: 1/6 Scale F4U Corsair Group Build

RE: 1/6 Scale F4U Corsair Group Build
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RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 7:39:00 PM

Remklep

Posts: 95
Joined: 12/10/2007
From: Haarlem, NETHERLANDS
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Thank you very much for the offer Tom.

I have already changed Chad's CAD drawings to metric and modified them to be used with my CNC router.
The first sheet of 1.5mm balsa has been cut :-)
It isn't as much work to make these changes as I thought, took me about 2 hours.

But when the time comes for getting ie. some canopies distributed, I wouldn't mind to make use of your offer.

Cheers,

_____________________________

Danny "Remklep" Busch
Its better to beg for forgiveness, than to ask for permission.

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Post #: 251

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 8:24:32 PM

Remklep

Posts: 95
Joined: 12/10/2007
From: Haarlem, NETHERLANDS
Status: offline

Guys I have heard back from Neil from http://www.laserengines.com.
I asked him if the Laser 300v would be able to turn a 20x8 or even better a 22x8 3 blade prop and if he could manufacture prop shaft extenders to create a little room for a scale dummy engine.
This is his answer (it were 2 emails, but I merged them into one):

quote:

Hi Danny,

The 20" 3blade prop would be too heavy for the Laser-300v. You need to achieve over 7,000 rpm and this would normally mean a 20 x 8 2 blade prop. The Laser-360v would be able to swing a 20 x 8 3 blade.

The Laser-360v is 114mm from centre of crankshaft to top of rocker box. It is 14mm taller than the 300v. Other dimensions are the same. Cranksft thread is M10 x 1.5 . weight 1750g
Regret we cannot make individual extensions. It is not difficult to make an extension if you have access to a lathe.

Regards, Neil

I'm a little concerned if a Laser 360v would fit inside the cowl, as it would at least have to be 228mm inner-diameter, but even then the engine would touch the cowl, so preferably a couple of mm more.
Could someone with the blown-up plans measure the inner diameter of the cowl please?

Cheers,

_____________________________

Danny "Remklep" Busch
Its better to beg for forgiveness, than to ask for permission.

(in reply to Remklep)

Post #: 252

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 8:42:16 PM

Chad Veich

Posts: 2747
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: online

The cowl is ~239 mm (9.4 inches) at the rear of the cowl ring and only gets bigger as you go back. Subtracting the thickness of the fiberglass you still should have somewhere near 235 mm so I would say the 360V would fit easily.

< Message edited by Chad Veich -- 4/30/2008 8:45:52 PM >

(in reply to Remklep)

Post #: 253

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 8:52:03 PM

SMUGator

Posts: 1364
Joined: 10/28/2003
From: Sammamish, WA, USA
Status: offline

I have admittedly not done my homework on engine choices yet, and am really hoping to get some advice. I'd love to go with a DA-50R. However their web site says that it would be perfect for 14-18 lb planes and I think this one will come in at or above the high end of that range. The G-62 seems to be the gasser of choice on the larger TF models, but it seems like overkill for this one. Anyone have a good feel for what has been used successfully on the similar sized BT models? Having everything inside the cowl and accomodating a scale exhuast are are big deals to me and will supercede other considerations like cost. I'm not biased toward either gas or glow at this point, but I don't want to do 2-stroke glow.

Tom

< Message edited by SMUGator -- 4/30/2008 8:53:33 PM >

_____________________________

Currently building a 1/6 Scale F4U-1A Corsair (BuNo 17777) and finishing a TF 1/8 Corsair

(in reply to Chad Veich)

Post #: 254

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 9:00:07 PM

Chad Veich

Posts: 2747
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: online

Tom, I would think that any decent 45-50cc gasser would be more than ample for this bird. I agree that a G-62 is more than you need, although it certainly would work. I owned and flew a Byron Corsair with a G-62 up front and it flew fantastic at just over 30 pounds! A friend of mine had a Byron Corsair that flew decent on a Quadra 50 at the same 30+ pound flying weight. I don't think the blown up Royal airplane will come in anywhere near that heavy. They must be thinking more along the lines of 3D type airplanes when they call for a 14-18 pound airplane for a DA-50. I'm really considering a G-45 for my Corsair because they are relatively cheap, they are reliable to a fault, and they are a bit heavier than some of the others which will be a good thing in this application. Just my .02 cents.

Chad

< Message edited by Chad Veich -- 4/30/2008 9:01:17 PM >

(in reply to SMUGator)

Post #: 255

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 9:23:05 PM

Remklep

Posts: 95
Joined: 12/10/2007
From: Haarlem, NETHERLANDS
Status: offline

Chad,
Thanks for measuring the cowl

quote:

ORIGINAL: SMUGator

I have admittedly not done my homework on engine choices yet, and am really hoping to get some advice. I'd love to go with a DA-50R. However their web site says that it would be perfect for 14-18 lb planes and I think this one will come in at or above the high end of that range. The G-62 seems to be the gasser of choice on the larger TF models, but it seems like overkill for this one. Anyone have a good feel for what has been used successfully on the similar sized BT models? Having everything inside the cowl and accomodating a scale exhuast are are big deals to me and will supercede other considerations like cost. I'm not biased toward either gas or glow at this point, but I don't want to do 2-stroke glow.

Tom

Tom,
I am going to try to build my Corsair with a maximum wing-loading of 100 grams/dm^2 or 2 pounds/feet^2.
The higher the wingloading, the greater the tendency for a model to snap-roll during ie. low speed turns.
100gr/dm^2 is a limit I have choosen for myself as being still well flyable, so at 80dm^2 wing area, the maximum weight for me will be around 8kg or 17.5 pounds.
So that would suit a DA-50 just fine. :-)
The question is, will it fit inside the cowl, and for me very important, can it turn a near-scale-size 3 blade?

The Laser 360v is a 3.6 cubic-inch V-twin 4 stroke that fits inside the cowl and can turn a 20x8 3 blade (I'm hoping it will do a 22x8 3 blade), although a 26.6" prop would be full scale, the engine needed for it would be way too heavy for our Corsair.

I'm not biased towards gas or glow either, I just want an engine that will turn a near-scale size 3 blade.
At the moment, the Laser is the only one I have researched.

I just looked at the side-view of a DA-50R, it has a height from the middle of the crankshaft to the top of the engine of 130.78mm, which means it would stick approx 13.2 mm outside the cowl, which is not an option for me.

Cheers

< Message edited by Remklep -- 4/30/2008 9:28:32 PM >

_____________________________

Danny "Remklep" Busch
Its better to beg for forgiveness, than to ask for permission.

(in reply to SMUGator)

Post #: 256

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 10:03:32 PM

SMUGator

Posts: 1364
Joined: 10/28/2003
From: Sammamish, WA, USA
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quote:

ORIGINAL: Remklep

I just looked at the side-view of a DA-50R, it has a height from the middle of the crankshaft to the top of the engine of 130.78mm, which means it would stick approx 13.2 mm outside the cowl, which is not an option for me.

I didn't catch that dimension, so that won't work for me either. Best I can tell from the manual, the G-45 is going to have the same issue with a crankshaft to spark plug distance of ~140mm. Keep me posted on the Laser research. It looks interesting.

Tom

< Message edited by SMUGator -- 4/30/2008 10:54:08 PM >

_____________________________

Currently building a 1/6 Scale F4U-1A Corsair (BuNo 17777) and finishing a TF 1/8 Corsair

(in reply to Remklep)

Post #: 257

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 11:04:08 PM

Chad Veich

Posts: 2747
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: online

quote:

ORIGINAL: SMUGator

quote:

ORIGINAL: Remklep

I just looked at the side-view of a DA-50R, it has a height from the middle of the crankshaft to the top of the engine of 130.78mm, which means it would stick approx 13.2 mm outside the cowl, which is not an option for me.

I didn't catch that dimension, so that won't work for me either. Best I can tell from the manual, the G-45 is going to have the same issue with a crankshaft to spark plug distance of ~140mm. Keep me posted on the Laser research. It looks interesting.

Tom

Keep in mind the dimension I quoted is at the rear edge of the cowl ring. The cowl at the trailing edge is 9.83" diameter, or 249.6 mm, tapering down to the previously stated 239 mm. I can send a full size PDF file of the side view of the cowl to anyone who wants it.

Chad

(in reply to SMUGator)

Post #: 258

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 11:13:12 PM

SMUGator

Posts: 1364
Joined: 10/28/2003
From: Sammamish, WA, USA
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quote:

ORIGINAL: Chad Veich

Keep in mind the dimension I quoted is at the rear edge of the cowl ring. The cowl at the trailing edge is 9.83" diameter, or 249.6 mm, tapering down to the previously stated 239 mm. I can send a full size PDF file of the side view of the cowl to anyone who wants it.

Chad

From eyeballing the plan view and guestimating where the cylinder head will end up, I would estimate that we have about 120mm or 4 11/16 inches from the centerline of the prop hub to work with.

Tom

< Message edited by SMUGator -- 4/30/2008 11:22:22 PM >

_____________________________

Currently building a 1/6 Scale F4U-1A Corsair (BuNo 17777) and finishing a TF 1/8 Corsair

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Post #: 259

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 11:22:40 PM

Chad Veich

Posts: 2747
Joined: 12/13/2001
From: Litchfield Park, AZ, USA
Status: online

A quick question for the group. I have several folks not associated with this build who are wanting copies of the tailwheel drawings. Does anyone have issue with them being distributed? I did not originate this design, nor even the initial set of CAD drawings, and I don't want to step on anybody's toes.

(in reply to SMUGator)

Post #: 260

RE: 1/6 Scale F4U Corsair Group Build - 4/30/2008 11:33:22 PM

SMUGator

Posts: 1364
Joined: 10/28/2003
From: Sammamish, WA, USA
Status: offline

quote:

ORIGINAL: Chad Veich

A quick question for the group. I have several folks not associated with this build who are wanting copies of the tailwheel drawings. Does anyone have issue with them being distributed? I did not originate this design, nor even the initial set of CAD drawings, and I don't want to step on anybody's toes.

That's an interesting question. Based on my e-mail exchange with Mr. Aune, the drawings have been in the public domain for some time now, so there are no copyright issues with distributing them. As far as the minor contributions to the design that I have made - I feel like I've taken away far more than I've given from these collaborations over the years, so I am more than willing to share them with whoever might be interested.

Tom

_____________________________

Currently building a 1/6 Scale F4U-1A Corsair (BuNo 17777) and finishing a TF 1/8 Corsair

(in reply to Chad Veich)

Post #: 261

RE: 1/6 Scale F4U Corsair Group Build - 5/1/2008 12:38:18 AM

Riddle4U

Posts: 319
Joined: 11/1/2007
From: Denver, CO, USA
Status: offline

Tom, I have been planning on using the Laser300 for some time now. Their website gives some dimensions of the engine. I concluded that the 300 fits, albeit closely, inside. Because it is a V-twin glow 4-stroke, each cylinder has less displacement (and height), compared to most single cylinder engines. Remklep, I think the 360 is a little big to fit inside. A fourstroke of comparable size usually turns a bigger prop than a two stroke, so you are making head way to your goal there. If you want the largest "fan" spinning up front, I think you need to stick to a 2 blade obviously. I posted pictures of the engine on the early part of our first thread. Maybe we can have one of our guys with the fancy 3 in 1 machines turn the shaft extension assembly and propnut.

(in reply to SMUGator)

Post #: 262

RE: 1/6 Scale F4U Corsair Group Build - 5/1/2008 1:17:55 AM

rwright142

Posts: 1752
Joined: 9/2/2004
From: Beech Grove, IN, USA
Status: offline

quote:

ORIGINAL: Chad Veich

A quick question for the group. I have several folks not associated with this build who are wanting copies of the tailwheel drawings. Does anyone have issue with them being distributed? I did not originate this design, nor even the initial set of