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Classic Designs => Classic Planes => Topic started by: Terry Caron on December 06, 2016, 02:03:07 PM
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One of my "if I ever get the shop set up to build" projects is completing a Banshee started ~20 years ago by my nephew (high school and girls came along, y'know).
While I have old school .35s that'd haul it just fine, and some fly 'em with up to .46 LAs, how would a .25 FP do for it?
On the bench (10% N) it turns a 10x3 APC to 13.5+K, 10x5 APC to 11.7K. Seems that oughta be enough poop.
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What does the plane weigh?
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Plan says 36-42 oz, Brent.
Since, unless I build something else first, it'll be my first c/l build (not counting 2 Flite Streak ARFs) I'll go with the upper weight.
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Thanks, that'd be great, Ty!
I'll be in touch.
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The FP.25 would fly the model OK in calm weather, but will lack for extra power in anything above a stiff breeze. The airplane had better be on the light side to help out with vertical stuff. If you are just sport flying with an occasional loop, lazy eights and inverted, you will be OK. For a beginner to intermediate flyer who is making mistakes and will be over controlling the airplane at times, that is where it will suffer, when the airplane gets near stall speeds and needs to accelerate through a bad maneuver. Horse power is like money, it's better to have it and not need it than to need it and not have it!
Type at you later,
Dan McEntee
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For sure, I'm that beginner you mentioned, Dan, and I'm confused.
I've read many comments on SH that the .20 FP is equal to a Fox .35, and the .25 is even more.
Mine (an ABN) turns those props as well as any of my .35s - would they also be marginal for a Banshee?
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Terry, 65% nitro, an ll x 7 prop and the Banshee will flat out fly. for how long is another matter. LL~ LL~ LL~ LL~ LL~ LL~
I'd say for about the 2 microsecs it'd take to jerk the nose off. ;D
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For sure, I'm that beginner you mentioned, Dan, and I'm confused.
I've read many comments on SH that the .20 FP is equal to a Fox .35, and the .25 is even more.
Mine (an ABN) turns those props as well as any of my .35s - would they also be marginal for a Banshee?
In the opinion of many, the Fox 35 is marginal for that sized plane -- which is why, starting in the late 70's, you saw 46's showing up in a lot of "35 sized" planes. However, there's a lot of holdouts, so to some extent you have to decide which camp you belong in.
Build it light, put in a 25FP, and it should be adequate, although possibly more challenging to fly. Just build it, put a 46LA in it, and once you get the engine set-up right it should be a solid, no-nonsense contest plane.
If you can stand going non-original, consider Fancherizing it. The Banshee was designed with early 70's design rules, and for an unmuffled Fox 35. That means that the tail is too small and too close to the wing compared to current contest planes, and that the nose is too long for balance with any engine with a muffler. You can fix two of the three problems by moving the wing forward a couple of inches, and then you can solve the last one with bigger tail feathers.
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OK, thanks for the clarification, Tim. I was under the impression that a .35 was fully adequate.
I was planning on the mods for it, so guess it depends on how light it turns out.
May hafta reconsider that Anderson .65 Ty has. ;D
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Considering what Tim said about the Fox 35 being marginal--- I would tend to not comment because I have zero experience with a Banshee or any other supposedly Fox 35 plane in that weight range
My observation is about Terry's note/comment: "I've read many comments on SH that the .20 FP is equal to a Fox .35, and the .25 is even more.
Mine (an ABN) turns those props as well as any of my .35s - would they also be marginal for a Banshee?"
I currently have a 4 flying planes in the 30~32 oz range each pair with a good Fox 35 and it's sister plane with either a LA 25 or BBTU OS 20 (ABC--N)
When I do get to fly--- if the wind is down- I start with the Fox powered model and it does OK for my sport flying
However, I find that the OS powered planes launched at 10,800 to 11,200 RPM handle any gusts and constant breeze much better
This does not answer the question about the Banshee....
But is intended to be another vote for the OS LA 25 or FP 20 BBTU as viable and good Fox 35 alternate power plants----for most models in the 30~34 oz range like my Ringmasters or RSTs
If Terry and Ty can get the Banshee built in the 30~34 oz range I say the OS 25 FP will most likely be a great engine for the model
I hope the two can collaborate and let us know how this final build and flights work out
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A fellow in our club had (till upgraded to Vector 40) a Fancherized Banshee with the mods Tim describes, powered with LA40 with muffler. (Longer rear fuselage rather than moving wing forward.) That motor hauled the airplane with authority, got him into 500-point range patterns. My feeling from seeing them fly is that the Banshee is too large to fly well with the older engines. An LA46 would be even better and actually weigh a bit less but will need another ounce of fuel in the pattern compared to the LA40. Don't know if you have any of these engines but they are readily available used, cheap and probably for the asking among your club mates.
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I very much appreciate your comments, Fred and Mike.
I've flown (read crashed) ARF Flite Streaks with both Fox .35 & .20 FP and either seemed to do OK.
My RingStreakster (FS wing/RM fuselage & tail feathers) currently has the .20 FP but has also had a Fox on it.
I have other projects available so guess I need to rethink my options.
Add:
I think it was either Brett or Dirty Dan (both?) who said the .25 FP was too much for a .35-size and that's why I thought it maybe good for the larger Banshee.
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I very much appreciate your comments, Fred and Mike.
I've flown (read crashed) ARF Flite Streaks with both Fox .35 & .20 FP and either seemed to do OK.
My RingStreakster (FS wing/RM fuselage & tail feathers) currently has the .20 FP but has also had a Fox on it.
I have other projects available so guess I need to rethink my options.
Add:
I think it was either Brett or Dirty Dan (both?) who said the .25 FP was too much for a .35-size and that's why I thought it maybe good for the larger Banshee.
Well, back in the good old days, guys would fly 50 ounce Noblers and such with Fox .35s because they could pull a 6" pitch prop. You had to run 10-6s to fly those back then to haul the weight, and Fox.35 that was broken in properly, and maybe a touch extra nitro, could do that. An FP-.25 would not fly a 50 ounce airplane. To say the one engine has the same power as another is a vague statement. The Fox .35 and the FP.25 both make their power in a different way, and at different RPMs. Same as the FP-20. The Brett Buck set up for the FP.20 may work with the ARF Flite Streak, because it is SO light, but I would like to see one on a typical, kit built Flite Streak or an ARF Nobler. For the Brett Buck set up, one of the keys is the 9-4 APC prop to let it rev. I don't think that combo could effectively pull a heavy AND big, draggy air frame. In this day and age of easy video, some one that has the correct collection of stuff out to try it and video it for us all to see.
Type at you later,
Dan McEntee
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Peter Chinn noted the Fox .35 making .45 hp @ 11.5-12K rpm and OS lists the .25 FP making .6 hp @ 15K rpm.
While Chinn says the Fox developed 46 in. oz. @ 7K rpm, I don't find a torque spec for the FP.
Could the difference in "haulability" you speak of, Dan, be due to more torque from the Fox (or other .35) rather than hp?
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If you're still undecided you could build the plane with aluminum engine bearers bolted onto the maple motor mounts and set it up for more than one engine. Of late I've been building all my planes this way, because it minimizes the damage to the motor mounts in crashes and generally firms up that area. On a profile I relieve the outboard plywood doubler so that the bearer sits right on the maple.
This adds a very small amount of weight, but gives you a setup that lends itself to engine swaps -- just make up a set of bearers for each engine. You can build your Banshee for the 25LA, try it, and if it doesn't work it'll be a snap to swap in a bigger engine.
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That engine looks familiar, Tim! LL~ Yep, plus I bought another XLS .36 at the Swap Meet this weekend. Great little engines! Are you still using the OS muffler/anchor on it? Sounds almost like a 'lectric with that muffler/anchor...excellent combination with the TT 11 x 4.5 prop and 10-22 fuel. y1 Steve
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Great idea, Tim.
I was given a couple of busted ARFs with that mount.
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If you're still undecided you could build the plane with aluminum engine bearers bolted onto the maple motor mounts and set it up for more than one engine. Of late I've been building all my planes this way, because it minimizes the damage to the motor mounts in crashes and generally firms up that area. On a profile I relieve the outboard plywood doubler so that the bearer sits right on the maple.
This adds a very small amount of weight, but gives you a setup that lends itself to engine swaps -- just make up a set of bearers for each engine. You can build your Banshee for the 25LA, try it, and if it doesn't work it'll be a snap to swap in a bigger engine.
That engine would be an ounce lighter if you cleaned the castor off the outside,,
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Tim - are the bearers d&t'd for the engine mount bolts?
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Free Flight, y'say there Sport?
We have something(s) else to discuss then!
Done any .020? I have a few.
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Tim - are the bearers d&t'd for the engine mount bolts?
Yup. The bearers are 3/16" thick, drilled & tapped for 4-40 mounting bolts. For a bigger engine they'd be drilled & tapped 6-32. (And yes, 3/16" is pretty much the minimum thickness for 6-32 holes -- but it gives five full threads, which is enough if you don't abuse your mounting bolts).
The downside is that you need to drill with pretty good precision or you can't get the screws in -- at the very least you need to do this on a drill press, with center-punched holes, a steady eye, and a willingness to throw away the odd reject piece. At best you'll do it on a milling machine, or have a friend you can suck up to.
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at the very least you need to do this on a drill press
Got that covered then, Tim - thanks.
Three .020. A tiny replica of a Brooklyn Dodger, and 2 1/4 A gassers.
Well, how 'bout that, now - I have a Dodger and 3 others.
I'll bring 'em along for a Show & Tell. :)
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This post (http://stunthanger.com/smf/arf's/la-25-in-a-arf-nobler/msg469670/#msg469670).
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Well.
42-50 oz Nobler with a .25 LA.
While maybe not overenthusiastic, Brett seemed to think it workable.
Looks like the only thing to do is build the Banshee, modded, with interchangeable mounts and see how the .25 FP will do.
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25FP should be very comparable to the "good" 25LA, if you have an E2030 muffler on it.
Or a pipe, if you want to be absurd in a "makes things fly good" sort of way.
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I have the E2030 muffler and thanks again for the mount tip, Tim - makes it worth trying, with an EZ engine upgrade if necessary.
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I have a Brodak 40 on my Banshee and it handles strong winds no problem. I would suggest putting half ribs in between all the ribs from the spar to the leading edge to give the wing more lift or better yet sheet the whole leading edge.
MM
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... or better yet sheet the whole leading edge.
Only if your title in your local chapter of the Knights of the Round Circle isn't "Sir Crashalot". That wing construction is very durable in a crash, as long as the covering material isn't too strong (Monocoat is fine). The bulk of the fore-aft rigidity in the wing comes from the covering, so in a crash the covering bursts and the LE, spars, and TE all flex forward without (we hope) breaking. Repair is often a matter of running CA along the long-wood to rib joints and recovering. If worse damage occurs, it's usually the entire outboard wing panel snapping off right where the center section sheeting ends -- and as horrible as that sounds and looks, it's actually an easy repair to make as long as you either don't have flaps, or you've made your flaps easily removable (I use one long hinge pin made of music wire, with the flap coupling wire running into a bit of brass tubing or a "lucky box" embedded in the flap. For an after-crash repair I just pull out the wire, set aside the flap, and fix the rest of the wing).
With LE sheeting the wing is rigid -- which is a Good Thing if you don't crash much, but in a crash it means that the damage is much more severe. With such a wing structure, a fairly common failure is that the wing structure is crushed right at the fuselage, with a lot of crushing damage to the LE. That's a bear to fix.
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Tim, if the guys here knew me better they'd likely give me that title. ;D
But, as I mentioned, the Banshee was started by my nephew. He assembled the wing without a fixture and the ribs don't mate to the LE properly, so I need to sheet it anyway.
Guess I'll just hafta learn to fly without crashing. LL~ LL~ LL~ LL~
Luckily though, I do have a spare wing kit for it.
Ty's building a Magician (a bit larger than a Banshee, I think) that shows a .25 LA on the plans and the FP has the same power so I'm going with the .25 FP.
I can always up-engine it if needed (if it lasts long enough for that to be an issue).
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Yup. The bearers are 3/16" thick, drilled & tapped for 4-40 mounting bolts. For a bigger engine they'd be drilled & tapped 6-32. (And yes, 3/16" is pretty much the minimum thickness for 6-32 holes -- but it gives five full threads, which is enough if you don't abuse your mounting bolts)....
In the same type bearers in my Magnum, I actually added 4-40 Heli-Coils in my engine bolt holes with red thread locker(or a light coat of JB Weld). I could put a bit more torque on the bolts without worrying about stripping the aluminum.
Rusty
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In the same type bearers in my Magnum, I actually added 4-40 Heli-Coils in my engine bolt holes with red thread locker(or a light coat of JB Weld). I could put a bit more torque on the bolts without worrying about stripping the aluminum.
Rusty
If I had the capability I think I'd have used Heli-Coils or King-serts or some such, too.
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If I had the capability I think I'd have used Heli-Coils or King-serts or some such, too.
I was glad I did. The hard alloy lets you feel a positive hard stop(you know when they're tight) when the bolt stops, without inducing the cringing fear I always feel when tightening into aluminum.
I just looked up Keenserts and they look like they might be even better with less chance of a pullout. I think it's a solid threaded cylinder rather than a wire coil. Thanks for turning us onto that, Tim.
Rusty
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Hinges are doped on, Doc, similar to your method.
Here's pix so far.
Fuselage tail will be rounded to compliment the new rudder and I'll round the inner edges of the elevator since we built/hinged it before reshaping the rudder.
Fuselage will have carbon fiber eventually and weight box/adjustable l-o guide in the wing.
No, it won't be Classic eligible but it'll be Beginner eligible. ;D
It'll be Jan before I can put much more time into it but I'll post pix if I get anything done worth mentioning.
I have a 2nd wing kit that I'm planning as a follow-up to put a resized Tucker Special fuselage on just 'cause I think it the most beautiful stunter ever and I like pretty viewing while in the circle. y1
BTW, Ty - it's 64.5 miles. >:D
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Did you glue or dope your hinges. I'm getting ready to do another session of hinging on a plane. I dope both surfaces until there is a slight sheen to the dope, sanding between the first couple of coats. Then using really thinned dope putting the hinges in place.
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I was glad I did. The hard alloy lets you feel a positive hard stop(you know when they're tight) when the bolt stops, without inducing the cringing fear I always feel when tightening into aluminum.
I just looked up Keenserts and they look like they might be even better with less chance of a pullout. I think it's a solid threaded cylinder rather than a wire coil. Thanks for turning us onto that, Tim.
Rusty
The ones I saw were just that -- a solid cylinder, threaded inside and out. The mechanical engineers used them anywhere there was a high-stress bolt hole into aluminum, particularly if it was one that was going to see a lot of assembly/disassembly cycles as the equipment was serviced.
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Check your fuselage clearance on the flap push rod. Might be the camera angle but it looks kinda' close to center.
I tried to crash my Banshee a few weeks ago but it wouldn't go in, dang thing just kept flyin' good, maybe next year.
MM
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Haha LL~, yeah, Ty it does seem that way, and I had to read back to see why we went off on this tangent.
We got on this aluminum mount idea since Terry was undecided on which engine, and maybe wanting to try some misfits without butchering the nose by plugging and redrilling bolt holes. Tim, in post#16, suggested an aluminum mount that could be used several ways; seperate plates for each engine, or my favorite-like a universal clamp, or even one that could be safely drilled in several places.
Nutty as it may seem, it actually is a quick and neat solution that wouldn't tax the brain or shop time. And something that would be good to add to his builder's box-o-tricks.
Rusty
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Check your fuselage clearance on the flap push rod. Might be the camera angle but it looks kinda' close to center.
I tried to crash my Banshee a few weeks ago but it wouldn't go in, dang thing just kept flyin' good, maybe next year.
MM
Tnx for the heads-up on that, MM - close but it clears.
That mount method is a good idea, we're just going for simple on this one - it's not likely to be as long-lived as MM's. ;D
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I had an OS FP25 in my Twister when it was new. It went pretty good if there wasn't much wind. I've since switched to several different 35's and 40's for all weather performance.
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Hi Rusty. Big irony is Terry already has those type mounts. We just didn't use them, this time. I still feel the OS.25 FP is going to do the job, as the model will be built light, minimum paint, as it is gong to be a trainer, thus all the fancy paint isn't needed, not a super finish, all of which add weight. I am going for the KISS principle here. H^^
If you're flying in beginner you definitely don't want a high-effort plane that you're going to sob over if it crashes.
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That combination will get him going on the basics even may have to go shorter lines. H^^
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If you're flying in beginner you definitely don't want a high-effort plane that you're going to sob over if it crashes.
Tim, I cry when I crash an ARF Flite Streak! :'( :'(
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Har de Har
Ty
Go ahead with 35' lines but I bet you all end up nearer to 60' than 42'...
jest sayin
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Hey Fred - since a .25 FP may not be quite enough engine, we decided to go with 35' lines to cut down on drag and keep the speed up. LL~
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Tim, I cry when I crash an ARF Flite Streak! :'( :'(
Then you need uglier planes!!
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what can I say, Tim - I'd be proud to own either one. :)