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Aug 24, 2019, 08:58 PM
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pathfinder's Avatar
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Help!

What is it's name?


......
Last edited by pathfinder; Aug 24, 2019 at 09:05 PM.
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Aug 24, 2019, 09:22 PM
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Leadchucker's Avatar
1937 Carl Goldberg Comet Clipper Mk1
Latest blog entry: 1938 Rambler build
Aug 24, 2019, 09:33 PM
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pathfinder's Avatar
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Quote:
Originally Posted by Leadchucker
1937 Carl Goldberg Comet Clipper Mk1




What's a good engine choice for it ?
About a year or so ago I posted here about what would be a good old timer airplane to get . Well I just acquired this for free. He made a really nice aluminum cowl for it too. And it's in like new condition..


thanks
Last edited by pathfinder; Aug 24, 2019 at 09:47 PM.
Aug 24, 2019, 11:26 PM
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Monza Red's Avatar
Given that it has a 6ft (1.8 metre) wingspan, a fourstoke 40 would be nice.
Aug 24, 2019, 11:54 PM
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Reginald's Avatar
used to fly mine with a good old O&R 60
Aug 25, 2019, 01:47 PM
Balsadustus Producerus
Just as a point of reference...my Steve Kowalik 'Air Chief' has a 60" wing and flies very well with an Astro Flight .05 geared cobalt motor and a seven cell NiCd battery, and OK with a six cell. My father had a 'Miss Arpiem' by Kowalik, and it flew enthusiastically with an OS 26FS, very close to same wing as the Chief. Don't know what his Arpiem weighed, but my Chief ended up at 2 1/2 pounds with flight battery and separate receiver battery, ready for launch.

Sounds like a 40FS would be about right.
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Aug 26, 2019, 01:36 AM
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pathfinder's Avatar
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OK I found an old FP 40 I had lying around and it looks like it was set up for that engine. It should be just the right amount of power. I can't wait to get the old bird up in the blue sky.
Aug 26, 2019, 02:17 AM
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Monza Red's Avatar
The OS 40 FP is a fine, reliable and very smooth-running engine. Not by any means a ball of fire, I had one in a sports model which it flew well enough until transmitter problems caused its demise. Don't know why the picture's come out sideways. The original wasn't and I'm too incompetent in computer-related matters to alter it!
Last edited by Monza Red; Aug 26, 2019 at 05:14 AM.
Aug 26, 2019, 08:34 PM
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pathfinder's Avatar
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Where would the cg be?
Aug 26, 2019, 09:07 PM
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Leadchucker's Avatar
Quote:
Originally Posted by pathfinder
Where would the cg be?
35% ish or where she glides best
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Aug 27, 2019, 11:37 AM
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BMatthews's Avatar
An FP40 will actually be a lot of power if the total weight comes in at around 5'ish lbs. As in so much that it may not actually come down even at idle. The suggestion for a .40 four stroke was a good one. And for sport flying with a low enough idle power to allow to land at idle I'd say a .25 would do the trick and still provide a decent climb rate.

I believe that for SAM climb and glide competitions that an FP40 would not be a bad choice. Not a total rocket but still a LOT more power than the old spark engines it was designed for. On the other hand for lazy sport flying it would be way over the top.

A data point for you. My big 84" Flamingo is powered with an old loop scavenged OS35S. So not even the power level of an FP35. It's also 5.5 lbs. At idle the glide is noticeably stretched. And literally two clicks of throttle off idle it starts "gliding uphill" at a very shallow climb angle. The power from an FP40 even at idle may not be low enough to let your Clipper actually land. You'll likely need to cut the engine completely and glide it in.
Aug 27, 2019, 09:26 PM
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pathfinder's Avatar
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OK I'm learning.. I have one of these. The timeline says ,1964.. I just need a muffler for it. It's an OS, s30
Aug 27, 2019, 10:49 PM
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BMatthews's Avatar
That could well be a nice engine for the model.

It all comes down to the final flying weight. The covering is pretty basic so no "handicap" in terms of the weight of the finish. But what does the airframe weigh? And if you start adding some radio gear and that OS to it what does it look like it may come in at?

If it's up around 4 lbs, which is not at all unreasonable, it'll fly like a champ on that .30 loop scavenged engine. The climb won't be rocket like by any means. But it would be a nice balance of power for a reasonable "full size Cessna" sort of climb on takeoff yet be low enough in power to glide and land and shoot touch and go's.

I also fully agree to start with the balance at 35'ish percent. But try some dive tests similar to that done by glider guiders to set the CG and pitch trim to where the model is still positively stable but not strongly so. That'll give you the best all around flying manners and will likely also allow you to remove a good size lump of nose weight in small amounts following each test flight. Don't be surprised if it ends up flying well with a nice but not strong amount of positive stability when the CG is back around 50%. However I truly do not suggest you start there unless someone with direct Clipper experience happens along and says it's good. This is the sort of thing that you want to test and alter in small amounts until you find a spot where both you and the model are happy. And yes, the final balance point and pitch stability amount certainly does depend to some extent on the comfort and skill level of the pilot.
Aug 28, 2019, 06:45 PM
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pathfinder's Avatar
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Interesting . It looks like some are saying the 40- 4 stroke might be the better choice over the fp 40 .2 stroke.
What is the theory behind this ?
I have this never run Saito 40.
Aug 28, 2019, 08:12 PM
Culper Junior
I know youíre talking glow power, but I have an electric .25 size motor with a 3S battery in mine. 20-30 seconds at full power and itís hard to see.


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