An Old School “pattern" plane , finally with plans - Page 3 - RC Groups
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Aug 07, 2017, 11:10 AM
Registered User
Birdofplay, I like your take/conversion, looks really nice with the built up fuselage. I was thinking the same way but was thinking of a KFM4.
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Aug 07, 2017, 02:15 PM
Registered User
I put a 2-cell on the plane and was able to fly it, just above stall speed on full throttle, but that was about it. I put a 39g, 1200kV motor on with a 10 x 6 prop and was able to roll a few times but it was still pretty sluggish. Smaller plane and lighter components is probably the answer for two cell unless you can find an 1800-2000 kV motor that can swing at least a 9-inch prop (just guessing).

When I put the 3-cell back on with the 1200 kV motor the Wattnot really showed its stuff. My box of tricks is pretty limited – rolls, inside & outside loops, inverted, knife-edge and hybrids of these. This plane did everything I asked it to do, and did it in moderate wind. In fact, it did so well with the wind I’ve decided not to put the wheel pants on for fear of losing this ability. I also noticed that at full throttle this plane can move right along with no handling problems. I was looking for smooth and graceful flights and this thing delivers it. Thanks GPW for digging this out of your archives.

I think this plane can handle a pretty wide range of components but this is where I landed:

Emax CF2822 motor (39g, 1200 kV)
20 amp esc
4 (qty) 9-gram servos, but three should do (see posts 24, 25 & 29)
9 x 5 prop or something close to that
1300 mA 3-cell battery (about 3.5 ounces)
CoG at 32% of inside wing cord
AUW of just under 13 ounces
Aug 07, 2017, 06:36 PM
Retired CAD guy
birdofplay's Avatar
With my plans you could easily NOT cut out the Big Fat Symmetrical section and stick in what ever YOU want.

I had just thought that "we" wanted to revive that Old Time Pattern thang.
Just in Foam.

However, it appears that a bigger Build is not whats popular.

I'm sure that KFM (whatever) would be fine for most fliers.
Aug 07, 2017, 06:38 PM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
Fish, I’m Happy that you’re Happy !!!
Aug 07, 2017, 07:01 PM
TonyS
Quote:
Originally Posted by birdofplay
With my plans you could easily NOT cut out the Big Fat Symmetrical section and stick in what ever YOU want.

I had just thought that "we" wanted to revive that Old Time Pattern thang.
Just in Foam.

However, it appears that a bigger Build is not whats popular.

I'm sure that KFM (whatever) would be fine for most fliers.
Bob,

Because the Kline-Fogelman airfoils work rather well on the very light foamies, I think the 10-12% airfoil max thickness of the old, 1960s-70s pattern ships may be a bit too thick and draggy for a 'competitive pattern' style small foamy. Especially if one includes larger radius leading edges. Unfortunately, I have had little to no success in attempting ribbed airfoil foam wings in the 8-10% max thickness and 1/8-5/16 inch diameter leading edges. So, I just use symmetrical KF style instead.

What is/are max thickness and LE radius of your rib design?

TonyS
Last edited by tonystro; Aug 07, 2017 at 07:02 PM. Reason: to correct typos
Aug 07, 2017, 08:54 PM
Registered User
The original plans are just a little too big for Dollar Tree foam so I scaled them down a little. I think the whole plan will fit on one sheet. I also scaled down to 75% for those that might want to try a 2-cell battery and lite build. I moved the parts around on each to avoid difficult page joins (i.e. a tiny piece running onto another page).
Aug 08, 2017, 04:54 AM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
Cool !!! 3/4 Watt …
Aug 08, 2017, 07:59 AM
I Look, Listen, and Learn
Timbo383's Avatar
Quote:
Originally Posted by fishflying
The original plans are just a little too big for Dollar Tree foam so I scaled them down a little. I think the whole plan will fit on one sheet. I also scaled down to 75% for those that might want to try a 2-cell battery and lite build. I moved the parts around on each to avoid difficult page joins (i.e. a tiny piece running onto another page).
Now you're in my foam of choice.
Glen, nice looking plane, one more to add to my "I'll get to it when I can list".
Aug 08, 2017, 09:02 AM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
Tim, Good Luck , if your list is as long as my list to do is …Likely we’ll never be able to catch up now , just working on what we can , when we can …

Now then , we’d have had our plane together if other things hadn’t happened that required my more immediate attentiion …
Aug 08, 2017, 11:58 AM
Retired CAD guy
birdofplay's Avatar
Tonystro:

You may be r9ignt re the foil choices for these Old Stye pattern foamy adaptations.
I guess I strayed a bit from the Foamy Montra.

Since many of these used Double swept wing ALL the ribs are different and consequently
much more difficult to develop.

Making the Box Fuse and KF section is much easier than doing a bunch of tapered ribs.

As for what I have bene up to ...
I was just suing the ORIGINAL foils and but allowing for the following changes ...
6mm foam Covering top and bottom
hence smaller ribs than original but with CF spars.
I planned to CUT SLOTS in the Bottom Covering to allow the LOWER building tabs
to protrude and "align" themselves.

I did technique that with a Big Fat Foiled Horten III like wing of ~7' span.
It was from Blue FF and I color packing taped the WHOLE wing.
It was a real Floater and thermaled nicely.

So in conclusion :
I will FOREGO all my big fat ribs and make changes for a KFM4 foil.
Aug 09, 2017, 05:17 AM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
… or here’s a novel idea ...just stick with what the designer used, a flat plate , which flies just fine !!!


Gentlemen , to be totally Honest , we’ve built and crashed so many planes in the past 50+ years of modeling , that now we like REALLY SIMPLE planes … Quick to build , quick to repair and get back flying …
Aug 09, 2017, 11:47 AM
flyin' fool
goldguy's Avatar
Quote:
Originally Posted by gpw
… or here’s a novel idea ...just stick with what the designer used, a flat plate , which flies just fine !!!
Never had a flat plate that disappointed, but had a few KFs' that did.
Aug 09, 2017, 11:53 AM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
Gold , for me it’s never been one airfoil that fits every plane … I like to fit the airfoil to the flying style …and honestly we’ve had the best results with the KF on LAR aircraft … Just from what we’ve observed.
Aug 09, 2017, 11:54 AM
Registered User
I was thinking of a KFM4 as I was building this plane. Given this discussion, I taped some on my model to see what the differences were. I used DTF with paper removed and tapered the front edges flush with the flat wing so I would not add to the cord. Step was at 50% of cord - no spacer under trailing edge. I spot taped the rear edge of the addition to the wing so I could maintain a sharp edge there.

PROS: Rolls improved slightly in that they were even more axial than without the KFM4. It also cut through the wind better than the flat wing. I did not have a great problem with these characteristics with the flat wing but the KFM4 did improve them.

CONS: The additional foam and tape added about an ounce to the plane; which required more throttle and shortened battery time. Gone were the nice long, slow, aesthetically pleasing loops. The additional ounce of weight was obvious. The model was far more responsive, which in my case, was what I was trying to get away from. I want to be able to perform my limited bag of tricks in a smooth, relaxing way. I nosed in again (more overcompensation spasms) and this time was not as lucky, the extra weight tore the wings off the plane. No big deal, it can be repaired since, as GPW said, it is a simple plane.

Given my particular desired flight characteristics, the KFM4 took away more characteristics than it added. It might be great for others but I’m sticking to the flat wing. I have 3D planes I can fly if I need an adrenaline rush.
Last edited by fishflying; Aug 09, 2017 at 03:10 PM.
Aug 09, 2017, 03:01 PM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
“ I have 3D planes I can fly if I need an adrenaline rush.” Fish … That’s the same exact way I felt … I love the in your face waist high 3D maneuvers , but sometimes you just feel like 100’ dia. loops …and other BIG maneuvers…


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