Plane for OS LA 25

[Motorman]

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[Brett Buck]

. I'm thinking of something with a longer fuselage big tail and about 450 Sq. In. wing. Not opposed to making it custom from scratch or maybe a scaled down FTwister but does anyone have suggestions for this size engine?

   Why would you scale it down? At any reasonable weight, a Full-sized Twister would be fine - assuming the engine runs *as stock*. Put on an APC 9-4, fire it up with 10% fuel, and assuming *stock* choke area, it should get to about 14000-14200 at a "peaked" setting, and will drop into a 4-stroke around 13100 as you back the needle off. If not, put it back to stock, try again.

      Brett

[Brent Williams]

@Motorman, You have successfully made a few scaled down versions of the ThunderGazer. You could scale it down a bit further and it should be fine.  If a true 450sq.in. is the desired number, ask for a 85% reduction of the plans.  With the high aspect ratio wing, it wouldn't be a super small plane at ~51" span.  Asking for a 80% reduction would yield a 48.5" wing and around 404sq.

You might take a look at Igor Burger's "Middle", it surely is as modern as it gets for .25 sized planes.  Seems to fly very well in the video in this other small plane thread.
https://stunthanger.com/smf/stunt-design/can-small-fly-beautiful/msg573300/#msg573300

[Guy B Jr]

John Lowry's Stuka and Wingmaster (400 sq in +/-) were designed around that engine. Walter has the kits.

[GregArdill]

Motorman,

I have a ringmaster with a Thunder Tiger 25 (much the same as your LA). Flies really nicely smooth about 4 second laps. Run it on a 10X4 prop with 10%nitro. A real pleasure to fly.

[C.T. Schaefer]

I've been flying a Shark 402 with standar LA with muffler for a numbr of years.  Flys nice. Maybe not a contest bird though.  TS

[Brett Buck]

Before you start cutting wood, *do the test I suggested* and see if the many changes you have made have reduced the power or hurt the run quality.

    Brett

[John Park]

For what it's worth, my own-design 'April Witch' is the same size and weight as a Fancherised Twister (48" span, 490 sq. in. wing area, 37 oz. ready to fly) and is more than adequately powered by a box stock .25FP-S turning a 9x5 Graupner grey glass/nylon prop. on 5% nitro fuel.

[Dennis Nunes]

Motorman,

Attached are pictures of my Circulas 25 that I've been flying in Stunt 25 events since 2017. It has a 48" wingspan with a wing area of 425 sq. in. Mine weights 38 oz.

I started out with a stock OS 25LA engine with a stock muffler on a APC 9x4 prop and PowerMaster GMA 10/22 fuel which has more than enough power for this size plane.

My Circulas 25 came out a little nose-heavy with a stock muffler and aluminum spinner. I later changed to a tongue muffler and nylon spinner. However, a problem developed in that the engine picked up an additional 750 rpm with the tongue muffler and Circulas 25 flew too fast. To reduce the speed I installed a 0.240 delrin venturi and I'm running a 10x3 APC prop.

Circulas 25 is a blast to fly. I only wish that there were more Stunt 25 events in my area.

If you want, PM me your email address and I will send you a PDF file of my plans for Circulas 25.


Dennis

[Mike Bush]

Motorman,
Maybe look at a Steve Buso Bobcat if looking for a full fuse modern design. 464 sq in.

Mike B

[Craig Beswick]

Hi all,

does anyone have the plans for Steve Buscos Bobcat?

I have tried here, Outerzone, Frog and a number of other online sources. Randy does not list it at his Aeroproduct.net web site.

TIA
Craig

[Mike Bush]

Craig,
I can give you Steve’s contact info tomorrow if you would like to contact him directly.

Mike Bush

[Dane Martin]

Late reply... sorry. But here's my stock twister with a stock 25. I also fly a primary force with a stock 25. Dennis Nunes' Circulas would be an awesome choice also

[Tim Wescott]

So what's a reasonable weight for a Twister with a 25?  My -- very unreasonable -- Twister weighs 54 ounces with a 46LA, and flies nice with that engine.

Walter -- a Sig Skyray is a very nice plane for a 25LA, if you're looking for beginner/intermediate competition, or relaxed sport flying.  No flaps to mess with, way easy to trim, etc.  The only mods I'd recommend are to straighten the rudder (if it isn't already), a two-wheel gear, and either nail the leadouts down where Line III recommends, or put in an adjustable guide.

[Dane Martin]

Reasonable, I don't know yet. I've only built the one. But pull test weight at contests is 38oz and my PF is 36oz (may have been 34, i don't fly it as much. Can't remember)

[Allen Eshleman]

Shark 402.  I have one with an LA 25 and one with an FP25.  Great match.  I have one with a Magnum GP 25 but I cut my thumb including a tendon when I first got it started.  I am still healing.  Brodak kit.

[John Craig]

"For Corehouse planes-
The RST is the basic trainer and stunt trainer.  It's designed for an FP or LA 25 with the stock 20-30 muffler and an 8/4 or 9/4 prop.  It needs the muffler for training and stunt.  The motor runs better.  Without a muffler it becomes a beginner combat plane.  When trimmed out it will easily do the whole stunt pattern.
Fly over grass if possible.  Crashes on pavement are always worse.  Over 3-4inch reasonable turf it will fly straight in with no damage.  Off angle and stiff cross winds will do more damage.  It's usually easy to repair since it tends to break into a couple a big pieces that can be easily put back together with some glue and splices."           

 See  Core House in the Vendor's Section.

I added wheels & it will fly the full pattern, quick build, nothing fancy.

[Dave Rigotti]

Dennis,
What size and length lines do you use with this?

Motorman,

Attached are pictures of my Circulas 25 that I've been flying in Stunt 25 events since 2017. It has a 48" wingspan with a wing area of 425 sq. in. Mine weights 38 oz.

I started out with a stock OS 25LA engine with a stock muffler on a APC 9x4 prop and PowerMaster GMA 10/22 fuel which has more than enough power for this size plane.

My Circulas 25 came out a little nose-heavy with a stock muffler and aluminum spinner. I later changed to a tongue muffler and nylon spinner. However, a problem developed in that the engine picked up an additional 750 rpm with the tongue muffler and Circulas 25 flew too fast. To reduce the speed I installed a 0.240 delrin venturi and I'm running a 10x3 APC prop.

Circulas 25 is a blast to fly. I only wish that there were more Stunt 25 events in my area.

If you want, PM me your email address and I will send you a PDF file of my plans for Circulas 25.


Dennis

[Dennis Nunes]

Hi Dave,

I fly Circulas 25 on .012" x 60' 7-strand stainless steel lines (eye-to-eye). The weight is 37 oz.

Dennis

[Fredvon4]

Phill Cartier Rugged Stunt Trainer near ARF...$89 last I bought ----may be a tad more these days
34 Sweet Arrow Dr.
Hummelstown, PA  17036
phone: 717-566-3810  6-10 pm EST
philcartier@earthlink.net
or
Tom Dixon..UKEY 35/40 True ARF
around $100 bucks
Woodstock GA 30189
770 592 3279

[Dennis Leonhardi]

When I read "a little squirrely as in over sensitive" the old Guillow Galaxy came to mind.  Very capable but "grooves" extremely well.  Several good suggestions above; add the Brodak Galaxy to the list.


Dennis

[Guy B Jr]

Top Flite TUTOR

45" wing span, 410 sq in

Designed for a .25; would also be great for an OS FP 20

[Phil Spillman]

Brodak's F-51/ Sterling and Yak plus their Ringmaster kit fly super with LA .25's as well as OS FP .20's even with muffler pressure! I have had them all and they are all a joy to fly and build!

Phil Spillman

[Brett Buck]

Brodak's F-51/ Sterling and Yak plus their Ringmaster kit fly super with LA .25's as well as OS FP .20's even with muffler pressure! I have had them all and they are all a joy to fly and build!

   They're not s world-beaters, either, but, (as I have been trying to get across to people for 25 years..) *sticking these little high-rev engines on them and using 4" of pitch* makes them pretty OK sport models. the 33 ounce Ringmaster with a 15FP was what finally kicked me off into the entire "small engine" experiment - after having been beat over the head with it for 25 years prior!

   No muss, no fuss, negligible vibration, and the "gravity cancellation effect" is very real. And at least at one time, you could get a 20FP from Tower for a mere $49, and the props were $1.94. No mods, no need for any knowledge except how to twist the needle.

    Brett

[Mike Griffin]

   They're not s world-beaters, either, but, (as I have been trying to get across to people for 25 years..) *sticking these little high-rev engines on them and using 4" of pitch* makes them pretty OK sport models. the 33 ounce Ringmaster with a 15FP was what finally kicked me off into the entire "small engine" experiment - after having been beat over the head with it for 25 years prior!

   No muss, no fuss, negligible vibration, and the "gravity cancellation effect" is very real. And at least at one time, you could get a 20FP from Tower for a mere $49, and the props were $1.94. No mods, no need for any knowledge except how to twist the needle.

    Brett

I believe you Brett and have been doing exactly as you suggest with these smaller models.  A SIG Skyray with a stock FP .20 flies as well as anything in that size range that I ever had in my hand.  It is amazing what you can do with that combination. 

Mike

[Randy Cuberly]

With an LA25 set up like you described I wouldn't be at all afraid to build a light Geiseke Nobler (maybe 36 to 37 oz)...which can be easily done with careful wood selection and a relatively simple paint job.

I built such an airplane a number of years ago with an OS FP 25, and found it to be a delight to fly on 58.5 ft long .015 lines (eyelet to eyelet).  Use a 10-3 or 10-4 prop (depending on how much nitro you want to use and the altitude you fly at) and you will be astonished at how well it flys!

In fact if I can stay healthy for while, what you've said has inspired me to build another one.  I have an LA25 set up exactly as you've described and it is a power house!  Seriously it is twice the engine that even a very good FOX 35 could be, and Mr Geiseke won the worlds with a set up like that.  Try it and you will be amazed at what the airplane engine combination is capable of!

Randy Cuberly

[Tom Luciano]

With an LA25 set up like you described I wouldn't be at all afraid to build a light Geiseke Nobler (maybe 36 to 37 oz)...which can be easily done with careful wood selection and a relatively simple paint job.

I built such an airplane a number of years ago with an OS FP 25, and found it to be a delight to fly on 58.5 ft long .015 lines (eyelet to eyelet).  Use a 10-3 or 10-4 prop (depending on how much nitro you want to use and the altitude you fly at) and you will be astonished at how well it flys!

In fact if I can stay healthy for while, what you've said has inspired me to build another one.  I have an LA25 set up exactly as you've described and it is a power house!  Seriously it is twice the engine that even a very good FOX 35 could be, and Mr Geiseke won the worlds with a set up like that.  Try it and you will be amazed at what the airplane engine combination is capable of!

Randy Cuberly

Good to see Randy posting. I agree look at al ferraro's thread on the ARF Nobler. I flew this plane last week! It performed quite well!