Sopwith Baby Project

Joe Perkel · 14 September 2008, 06:01 AM

OK,...It would seem I needed a bucket of cold water and a good slap. I received several PM's convincing me that this is another problem to be resolved but, not by scaling down. OK I needed a push, thank you!

As someone pointed out, I have not yet begun to build because of contractor and renovation issues. Once started, it would indeed be "therapeutic"!

Thanks to all!

Quote:

Would it be practical to bury a flat-six like Chad Wille did with his Sopwith?

David,

I did a quick search and found his Triplane with an M14. To what A/C and flat six do you refer? I would like to see what was done.

David Paule · 14 September 2008, 07:47 AM

I believe it was the Triplane with a Lycoming O-540.... His website doesn't seem to currently list it that way. The engine bay was longer, that is, the rest of the fuselage was one bay shorter.

David Paule

Maxim08 · 14 September 2008, 10:20 AM

Guys,
Chad's triplane went to New Zealand some time ago. Check 'The Vintage Aviator' site. All your info is there.
Regards,
John

baldeagle · 14 September 2008, 12:20 PM

That's a different one, the one with the buried flat-6 (O-470?) was flying at Ryder's in Alabama in the '90s, don't know what happened to it. One of the pilots told me that it didn't fly well and was very tailheavy since moving the engine back like that kept a lot of the weight of the engine aft of where it needed to be to have any moment arm.

John Shively also built a Camel for Ryder with a buried O-360, now in the Lafayette Foundation collection, where I think they're considering putting a Warner on it.

By the way, nothing wrong with a 50+ year old Warner, especially a 165, if you can find a good one.

-

Joe Perkel · 15 September 2008, 03:31 AM

Thanks all for the information on the Sopwith Triplane and the Camel with the alternative solutions. Anything adversely moving the CG (to aft) would be ruled out. I have the advantage of accurately calculating weights & moments as long as I have accurate material density. Or I can just assign a given weight to a given mass, (say an alternator for example). A rough estimate to be sure all of which is to be confirmed of course with the scales.

Quote:

By the way, nothing wrong with a 50+ year old Warner, especially a 165, if you can find a good one.

Andrew,

It occurred to me yesterday that I would allow my family to ride in Aluminum Overcast. Why?,...because it's a first class operation. With that thought in mind, I'll relax now and keep my options open including possible collaboration (partnership) when it comes time to power.

Thanks!

RobW · 16 September 2008, 01:19 PM

Quote:

Originally Posted by Joe Perkel

I've found a number of online calculators for various propeller and thrust calculations, mostly marine and, or hovercraft.

Is there something that exists, calculator or formula, to estimate static thrust of any particular prop, pitch, hp, rpm, @ standard conditions?

Thanks!

Hey Joe,
In my prep for my fly-in I came across this calculator... still not exactly what you are looking for, but a lot closer.

Culver Propellors - Prop Pitch Calculator

Alaina at Culver Props is good people... maybe you should give her a call and see if they can help you with what you need...

Rob

brinesharks · 16 September 2008, 01:28 PM

Quote:

Originally Posted by baldeagle

By the way, nothing wrong with a 50+ year old Warner, especially a 165, if you can find a good one.

-

I potentially have access to one of these. The owner is keen to help but he thinks the Warner is a boat anchor. Are spare parts available? I'm having trouble finding anyone in Australia that would overhaul it and get it flying. I get met with a lot of scepticism.

Anyone know what a fair price would be to get a Warner?

US95Damiani · 16 September 2008, 01:51 PM

Quote:

Originally Posted by David Paule

Would it be practical to bury a flat-six like Chad Wille did with his Sopwith?

A Continental O-470 weighs about 480 pounds and has about 80 hp at 1,300 rpm, if my memory is correct. That gives around 320 ft-lb torque.

Obviously the weight and form factor would need to be dealt with.

Incidentally, the O-470 swings an 82 to 88 inch prop on a Cessna 180.

An O-470 is generally 230 HP up through 260 HP depending on the application. trying to prop down a modern engine such as the O-470 would be expensive from a maintenance standpoint and could be disastrous. It was not designed to run continuously at those RPM's. or loadings.

The C-85 is 80 HP

David Paule · 16 September 2008, 07:35 PM

The only thing you'd need to ensure is that the O-470 had sufficient oil flow to lubricate at 1,300 rpm safely. In any other respect, it's got a lot more strength, cooling capacity, etc., than needed. After all, it can run at up to twice that rpm. Rather than being "disasterous," it's a robust engine.

The 85 hp Continental produces its 85 hp at a much higher rpm than 1,300, so that's not a valid comparison.

The issues regarding center of gravity are entirely realistic. Also, if the object is to make an accurate example of the aircraft, then clearly a round engine is needed. Hopefully the right one.

David Paule

Joe Perkel · 16 September 2008, 08:04 PM

Quote:

Originally Posted by RobW

Hey Joe,
In my prep for my fly-in I came across this calculator... still not exactly what you are looking for, but a lot closer.

Culver Propellors - Prop Pitch Calculator

Alaina at Culver Props is good people... maybe you should give her a call and see if they can help you with what you need...

Rob

Rob,

Congratulations on your Fly In! I'm happy the weather turned in your favor. A nice start, you can likely look forward to steady growth.

The calculator is helpful, thank you. This one is similar to some marine versions but still quite neat. A thrust simulation is beyond my capability but sure would be something quite useful.