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Jan 23, 2020, 05:43 PM
A man with a plan
Balsaworkbench's Avatar
Have you flown a pattern plane before? Even if you're not a competitor, they're a ton of fun. It's just another unique style of flying, and everybody ought to try it some time. Your Trainer 60 is basically an upside down Kaos with a little cabin on top and constant taper wings. On the Kaos, everything is balanced around the center. It really makes you look like a better pilot. Unless you do something terrible, then it reveals all of your mistakes. If you want to have some real fun, put your Saito twin on a 60 size Kaos. That would be a hoot.
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Jan 23, 2020, 10:47 PM
Lookin' up at the centerline
taildragger1589's Avatar
I have to mention this, if you're looking for high revving engines, why not go to the classifieds and pick up a 2 stroke. They won't plague you with valve float and bent metal.
The appeal of 4 stroke to most of us is the high thrust low speed combo. It makes the ships more scale in performance and sound.
As proof to their pull...
Pics one and two were my 7 lb. Stafford Ercoupe, built in 1986. Look close at the nose and you'll see my OS 60 FS open rocker with a Kavan 12/6.
It made a nice long scale takeoff and flew around nicely.
Before the Ercoupe, it was in my Taurus, replacing my OS goldhead 60. It flew a bit slower but handled very nicely.

Pic three...
Got a wild hair in '88 and put an OS 90 FS in a 44" 7 lb. Sig Smith Miniplane. It flew about the same speed as with the K&B 40 but it looked like the full size the way it flew. Recovered it in Solartex around 2015 with an ASP 90 and flew it til 2018 when it finally came apart.
Just my 2 cents.
Jan 24, 2020, 01:27 AM
Living in the south of France
paulinfrance's Avatar
Quote:
Originally Posted by taildragger1589



If I could find one, maybe a new ring would help a little too?
Been a while since I did any rebuilding, should I blow a little hot air on the cylinder base before loosening the bolts?
Still use toothpaste to lap the valves?



Nick
Yes I forgot, I fitted new rings to my 3 Saito's .45S but not to my .45, it was all coked up, and yes toothpaste will do,,
Jan 24, 2020, 04:54 AM
What could possibly go wrong?
Quote:
Originally Posted by Balsaworkbench
Have you flown a pattern plane before? Even if you're not a competitor, they're a ton of fun. It's just another unique style of flying, and everybody ought to try it some time. Your Trainer 60 is basically an upside down Kaos with a little cabin on top and constant taper wings. On the Kaos, everything is balanced around the center. It really makes you look like a better pilot. Unless you do something terrible, then it reveals all of your mistakes. If you want to have some real fun, put your Saito twin on a 60 size Kaos. That would be a hoot.
I've flown a Kaos with electric power and not enough battery so it was terrific for about 1 circuit before it began to sag. I did note how easy it was to fly, how you could hold any turn nice and steady and none of that roll couple that makes people want to graduate from their trainers. based on that experience and the advice of some seasoned flyers, I've decided to build exactly what you suggest, a Kaos with a twin on it. In this case I reckon a Kaos 90 with the 182T (I'm wondering if I should really go with the Kaos 120 for that engine but in the name of fun, I'd like to try it on the 90). The 130TD is getting a much modified Ugly Stik built for it, no dihedral, that should be a similar experience.
PS At th moment I think I like either a UFO or Dirty Birdy, probably the UFO. I could scale it up to take the 182T or fit that YS 91AC as is
Last edited by BernardW; Jan 24, 2020 at 05:14 AM.
Jan 24, 2020, 04:57 AM
What could possibly go wrong?
Quote:
Originally Posted by taildragger1589
I have to mention this, if you're looking for high revving engines, why not go to the classifieds and pick up a 2 stroke. They won't plague you with valve float and bent metal.
...
I probably will at some point. I read a review of that NoaRossi, for a reasonable price it sounds like quite a beast and is said to run incredibly smoothly. I was quite surprised at whatever engine model the current OS around 65 size is, that was almost vibration-free. Yes for simplicity and cheapness they have their merits... my problem is I'm really a 4-stroke snob, I just like them. And the sound of a screaming, hi-revving 2c... I'll bring ear plugs
Last edited by BernardW; Jan 24, 2020 at 05:14 AM.
Jan 24, 2020, 01:51 PM
Lookin' up at the centerline
taildragger1589's Avatar
Rossi engines have always been beasts!
Last one I saw fly was on a pattern ship called the "Eyeball". Purportedly the first model to do a knife edge loop.
It hit a vertical I-beam on a construction site beside our field at full speed.
Sounded like Big Ben at one o'clock.
The biggest piece we could find was the bottom half of the crankcase connected to one of the maple mounts.

Now that I'm 66, I'm clearly beyond that sort of performance and love my Saitos with big props and slow speeds.
(we need a smiley with a long white beard)
Jan 25, 2020, 01:30 AM
Living in the south of France
paulinfrance's Avatar
Quote:
Originally Posted by taildragger1589
Rossi engines have always been beasts!
Last one I saw fly was on a pattern ship called the "Eyeball". Purportedly the first model to do a knife edge loop.
It hit a vertical I-beam on a construction site beside our field at full speed.
Sounded like Big Ben at one o'clock.
The biggest piece we could find was the bottom half of the crankcase connected to one of the maple mounts.

Now that I'm 66, I'm clearly beyond that sort of performance and love my Saitos with big props and slow speeds.
(we need a smiley with a long white beard)
Beyond Rossi motors at 66 ! OMG at 68 I am still flying my Ballistic Rossi powered planes, up with my Saito's laser rcv ,
etc 4 strokes, they wake the club members up,,,
Jan 25, 2020, 04:07 PM
What could possibly go wrong?
From some posts I've seen the true equivalent of a high-performance 60 2c with pipe is probably a YS FZ115. It seems a piped Rossi 60 can do something like 2.5hp, to get that output from a 4-stroke it'd have to be either that YS or in Saitos probably an FA-150. That would perform quite differently, as the piped 2c would be very peaky, making most of that power in a very narrow rev range, while a Saito 150 or YS 115 would be a lot more tractable with that broad 4-stroke torque curve. But they'd still reach similar max output when you want it.
Imagine that - a nice flying pattern plane with a generous 4-stroke, so you'd have that lazy thrust available any time. You could beetle around comfortably on part power, or open it out to go ballistic when you want. Keep the weight down and that could be a fun model!
Someone mentioned their OS 65AX at 22oz, I believe that was with a pipe. So the 730g of the FZ115 is not too far out from that, for my purposes maybe even my as-yet unused FZ91...? (in say a UFO, Dirty Birdy etc... even a Kaos 60? Input welcome). That would be a faster, heavier and more powerful model for its size than anything I've used. I really should do something with that engine and I'm leaning towards a pattern type plane. A Kaos is probably worth building but I've half settled on a bigger one to take that FA-182, so for the YS I'd choose a different design. I'm turning into a bit of a Joe Bridi fan at this rate...
Last edited by BernardW; Jan 25, 2020 at 04:14 PM.
Jan 25, 2020, 08:06 PM
Registered User
Bernard, you kind touched on it there, no need for a speedy pattern plane when you have 4 stroke torque to pull the uplines. Also the bigger prop disc used by a 4 strokes helps to slow your down lines and the additional thrust gives ample authority to the small control surfaces found on vintage pattern birds.

You can run a saito 82 on a 5.5-7.0 lb. 60 sized pattern ship and perform all of the SPA pattern sequences with no trouble. The air speed will be slower than with a piped .60 2 stroke but you'll have unlimited vertical on demand!
Jan 25, 2020, 08:15 PM
Lookin' up at the centerline
taildragger1589's Avatar
And you have to move the firewall back about an inch for carb clearance.
That also helped the balance problems when fitting the 90 to the smith.
Jan 25, 2020, 08:22 PM
Registered User
Didn't have to on my Kwik Fli MK III. Out with the OS55 and in with the Saito 82. I may have moved the battery to maintain cg, can't remember.
Jan 25, 2020, 08:37 PM
What could possibly go wrong?
Quote:
Originally Posted by Notme2
Didn't have to on my Kwik Fli MK III. Out with the OS55 and in with the Saito 82. I may have moved the battery to maintain cg, can't remember.
That sounds worth investigating as a model-engine combo. The 82 has served me well, of course so has the 56. With such easy-to-use engines that have good performance too it makes the idea of a pattern model as a sports flyer pretty attractive. To help with balance I did move the firewall back in the trainer I installed that in, as I figured the mass was further forward with the four stroke. Right or wrong, it worked, that model balanced almost perfectly with about a 30mm shift aft. Far as I know those OS's around that size are similar weight to an engine like the FA-82 but in the trainer the design called for a K&B that was a good bit lighter than the 56 and with its cylinder well to the rear too. I'd be prepared to move the firewall if I made any engine change that was much different to the design.
This is a big benefit of being prepared to build your own models rather than just buy ARF's, the flexibility of setup you can have. That and being in a position to repair them if something happens, I see people go into the hobby store asking to buy a replacement wing or whatever and I'm glad I learned some building. Of course you could be like me and be a terrible procrastinator and take much longer than you should to get them done but the satisfaction is still there. I like this feeling of choice, having an engine I'd like to use and the door wide open to many designs out there, usually at little or no cost. As I improve my tool set and experience it's less daunting to take on a project
Jan 25, 2020, 09:06 PM
Registered User
Yeah, the 82 is a good running engine. They power my 46-60 size models quite well, even though I've never had one make the rated 1.5 hp without modifications. It is, in fact, the only saito that has not made rated power on 15% nitro for me in stock form no matter what prop I try. My 45,50,56,62,91,100,115 & fg21 have all made advertised hp or better in stock dress. It doesn't matter much because peak hp isn't the whole game in and of itself but I'd be lying if I said it didn't erk me just a little.
Jan 25, 2020, 11:20 PM
Registered User
the 82 is my fav, engine . U cant kill them , although some could with little effort . Cheers
Jan 26, 2020, 01:06 AM
Still gassin' it.
Quote:
Originally Posted by BernardW
From some posts I've seen the true equivalent of a high-performance 60 2c with pipe is probably a YS FZ115. It seems a piped Rossi 60 can do something like 2.5hp
Yeah, well.... it CAN do thatů. if you prop it and tune it to do 20K or something. But it is rather pointless, and here's the reason:
The prop you need, to get that kind of performance, will be so poorly matched to an F3A plane, that you burn a lot of fuel, make a lot of noise, but get by and large the same performance you would get from 1,5 [email protected]

But most engines including their tuned pipe, are NOT tuned for those kind of RPMs, and they will, in real life, produce a lot less hp, but have better performance in the air.
OS's Hanno Special in competition trim only produced 1,5 hp, no more, and in its days it blew away the competitionů.


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