OS .35 max-s c/l stunt  
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OS .35 max-s c/l stunt - 5/14/2007 6:46:08 PM   
rcdude7


 

Posts: 1025
Joined: 4/12/2003
From: Maryland
Status: online 		Can someone tell what a good prop size would to start with? This engine will be used in a TF flite streak. This will be my first C/L plane larger than 1/2A that I have flown. I would like to learn to fly stunt with this rig, however C/L is unheard of in my area, so I am pretty much on my own here. I am a experienced r/c pilot also and just want to try something new. Any other help getting started would be appreciated. Thanks

Mike

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RE: OS .35 max-s c/l stunt - 5/14/2007 10:48:29 PM   
smcouch77



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Joined: 10/31/2006
From: Indianapolis, IN, USA
Status: offline 		Hi mike. In my opinion the Max S .35 is one of the best stunt engines around. I use a wide blade 10-6 prop and 10% fuel. I get good consistent runs flight after flight. Good luck with Flite Streak.
Steve

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(in reply to rcdude7)
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RE: OS .35 max-s c/l stunt - 5/15/2007 3:03:28 AM   
downunder



Posts: 3198
Joined: 10/10/2002
From: Adelaide, AUSTRALIA
Status: offline 		Yep, they're a great little stunt engine but be careful what fuel you use in them. They really need 25% all castor for long life.

(in reply to smcouch77)
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RE: OS .35 max-s c/l stunt - 5/15/2007 7:27:56 AM   
rcdude7


 

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Joined: 4/12/2003
From: Maryland
Status: online
quote:

ORIGINAL: downunder

Yep, they're a great little stunt engine but be careful what fuel you use in them. They really need 25% all castor for long life.


Not easy to find this mix in a shop anymore, however I have located a semi-local shop (1 hour drive) that sells this type of fuel, at least I won't have to order it and pay shipping and haz-mat costs.

(in reply to downunder)
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RE: OS .35 max-s c/l stunt - 5/17/2007 2:06:00 AM   
greggles47


 

Posts: 51
Joined: 7/5/2006
From: Sydney, AUSTRALIA
Status: offline 		G'day Dude,

You could always add enough castor to bring whatever you have up to 25%.....or even make your own. If you have access to the components it's easy as can be. And then you KNOW for sure what went into it and the measurement protocol. Some fuel makers measure by weight rather than the more preferred by volume.

good luck.

Greggles


(in reply to rcdude7)
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RE: OS .35 max-s c/l stunt - 5/17/2007 8:59:07 PM   
culver


 

Posts: 131
Joined: 6/18/2005
From: TELFORD, PA, USA
Status: offline 		If the local shop has Powermaster see if they will get some 10-11-11 for you, it's a blend of synthetic and castor 22% total or Sig champion 10% and add some castor to it.

(in reply to greggles47)
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RE: OS .35 max-s c/l stunt - 6/3/2007 12:06:04 AM   
rcdude7


 

Posts: 1025
Joined: 4/12/2003
From: Maryland
Status: online 		I bought a case of Fox Duke's fuel today, 10% nitro, 20% castor, then I added 4oz S&W castor to each gallon, bringing it to 23%. I bench ran the engine for 5 or 6 minutes and it runs great on this fuel. The flite-streak is still in the works, but hope to have it ready in a week or so, I'm a slow builder.
I ran the engine with a new APC 10.5X4.5 prop, would this be good for initial flights to slow the plane, making it easier to learn? or is a 10X6 the prefered prop for stunt?

Thanks, Mike

(in reply to culver)
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RE: OS .35 max-s c/l stunt - 6/3/2007 12:52:44 AM   
Alan Hahn


 

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Joined: 11/11/2002
From: IL
Status: offline 		I am not sure if you are referring to the TF ARF version or not, but if it is, I would warn you that the fuse is weaker than the original kit solid plank. The OS35S, while better than a Fox35 in smoothness, still may cause problems for the ARF nose. I would really recommend going to a smaller engine, like an FP20, 25, or LA25 or other equivalent. These have aluminum pistons and run smoother in general than a OS35S four stroking.
I run my Flite Streak ARF with a Fox15BB. I know, it has a steel piston, but it is considerably smaller, than a 35 size. My Arf tips the scale at 24oz (with some weight in the front to balance it near the leading edge) and flies great on 52 foot 00.012" lines.

If you don't have the Arf, then what I said doesn't apply.

(in reply to rcdude7)
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RE: OS .35 max-s c/l stunt - 6/3/2007 1:28:34 AM   
rcdude7


 

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From: Maryland
Status: online 		It is the ARF that I am refering to. I do have a .15 max-s here, but I doubt it has the power of your fox and so is probably not up to the task. Is it worth while to strip the covering off the nose and maybe sheet it with some thin ply or something along those lines?

Mike

(in reply to Alan Hahn)
       Post #: 9

RE: OS .35 max-s c/l stunt - 6/3/2007 4:13:01 AM   
Alan Hahn


 

Posts: 21
Joined: 11/11/2002
From: IL
Status: offline 		Maybe that might work. The basic fuse construction (sheeted stick frame the best that I understand without actually cutting into it) leaves a few "hollow" areas. One possibility would be to remove the covering from the nose doubler and the fuse just from the end of the doubler to roughly the point where the wing is thickest. Then add a balsa layer, the thickness of the front doubler back the where the covering was removed. Just trying to make a continuous layer here from the front back to the midwing area. Now add a thin sheet (1/32" of ply (or maybe fiberglass if you are into that) which goes over the original doubler and ties the balsa you just added to the original double. If you do this on both sides it should stiffen and toughen up the front end.
Kind of a PITA, I agree.
I do agree the OS15 max S may not be enough. But do you have an rc 20->25 size engine (like an FP)? You can always wire the carb open. In that case you want a 9-4 or 10-4 prop to run in "high rpm/low pitch" mode. Just an idea to avoid a rebuild!

Your 35S would be great in the ARF Nobler!

(in reply to rcdude7)
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RE: OS .35 max-s c/l stunt - 6/10/2007 5:34:58 AM   
rjbranchii


 

Posts: 351
Joined: 4/9/2004
From: Harsens Island, MI, USA
Status: offline 		Mike

Alan in right on for what folks are flying the flight streak arf's with. Most are using .25 size motors. "Back in the day".... when I was a young buck.... and the flight streak was what we were flying, we used .35's on them, 10X6 props and they went so fast you had to really keep up with them. Today, they are being flown alot slower and are much easier to fly. If you are going to use the OS .35 be very careful to run it rich. Never launch it in more than a 4 cycle with occaisional 2 cycle breaks. It will be about 75 to 8500 rpm. If it breaks into a 2 cycle, do not do any maneuvering. The heat can kill the motor and let it land and cool. Keep the nitro 10% or lower. Prop wise, keep the diameter no higher than 4 inches and you will be fine. Castor oil and total oil package 22 to 25% is key.

Hi Alan! Still got some grease under the nails I see.

Bob Branch

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RE: OS .35 max-s c/l stunt - 6/10/2007 7:21:40 PM   
hothandle


 

Posts: 13
Joined: 11/1/2003
From: Broken Arrow, OK, USA
Status: online 		I believe he must have ment 4inch pitch, not diameter. Even a 4inch pitch seems rather small however, I would probably go with a 10/5, and needle it to where ilt was in a 4 cycle with occasional 2 cycle bursts. By all means use lots of Caster, the rod is a weak point and a lean run will ruin the piston/liner fit.

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RE: OS .35 max-s c/l stunt - 6/10/2007 10:36:58 PM   
smcouch77



Posts: 655
Joined: 10/31/2006
From: Indianapolis, IN, USA
Status: offline 		This is a very interesting thread. I have a 22 year old OS 35 Max S in a 22 year old Nobler. I have always used synthetic blends at about 15% to 18% oil. This combo has flown smoothly and consistently all these years. I use SIG 25% Castor in my fox engine. It won't run on anything else. So I tried some in my OS. It ran very rough and I couldn't get a good 4-2 break. You guys that are using the pure castor in your OS engines might want to try a synthetic blend. You'll like it.
Steve

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RE: OS .35 max-s c/l stunt - 6/11/2007 2:32:04 AM   
rjbranchii


 

Posts: 351
Joined: 4/9/2004
From: Harsens Island, MI, USA
Status: offline 		Hothandle

You are right, I ment 4 inch pitch. With 5 inch the plane will be too fast and the motor will tend to overspeed into the lean end. I used to compete with full stunters (550 to 600 sq inches) scratch builds with Rev Up 10X6 EW's. But when a lean run hit I was careful to not let it out of level flight so I didn't ruiin the piston/sleeve. These were full bodied planes in the low 40 ounce range. The profile flight streak just doesn't need anywhere near that kind of power and if you give the motor half a chance it will go zoom, especially in the wind. One of the real suprises to me when I returned to stunt last year after about 20 years away was that most everyone is flying with 3 to 4 inch pitch props. They have done alot to solve the overspeeding hot lean run issue. Not completly, but alot better and especially in the wind where they would really take off in maneuvers.

Fuel wise, blends of synthetic and castor are what I was talking about. A 50% ratio of each and at least 22% oil total. I agree, modern motors don't need pure castor like the old fox's did. Interesting aside, in ducted fan motors we want castor in there for the same reason, to dissapate heat and still be there to lube at the high temps we get turning 22 to 28000 rpms in .90 range motors. There are some custom stunt motors (Ro Jett in particular) that are designed around an all synthetic fuel. Randy Smith's PA custom stunt motors are recommended for a blend fuel. Most stunt fliers today use a blend.

Bob Branch

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RE: OS .35 max-s c/l stunt - 6/11/2007 4:53:12 PM   
gcb



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