News:



  • March 28, 2024, 06:10:19 AM

Login with username, password and session length

Author Topic: A question about small stunters  (Read 26134 times)

Offline Martin Quartim

  • 22 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 802
    • StuntHobby
Re: A question about small stunters
« Reply #50 on: July 05, 2009, 06:24:40 PM »

Would a Brodak .25 be a good choice? it weighs only 5.4Oz

The other nice choice is the Enya 19, it  weighs 5.3 Oz w/o muffler and it spins a 9x4~5 at the speed we need with no or little nitro. It is very common to find them on Ebay for under $40 NIB. I got lucky and got a couple for under $20.00

I would like to find out more about is the AP .15 with rear exhaust. It seems it is made from the same factory as the Magnum and it is a real ABC engine with 2 BB.

Also, looking at the HiModel web site there is yet another .15 offering from ASP with S.E w/o the blue head.

Martin



Old Enya's never die, they just run stronger!

https://www.youtube.com/user/martinSOLO

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #51 on: July 05, 2009, 06:38:27 PM »
Martin, I've made it easy to extend the wing to 3 sizes. 380 for a 15, 400 for a .19, or older .20' and 25's, and 428 for ,25's.

All the engines you've mentioned should be fine for one of these variations.
Getting a line on life. AMA 1601

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #52 on: July 09, 2009, 01:17:38 PM »
Here are the finished drawings, or at least as finished as they will be until after the prototypes are finished.

I hope you enjoy checking them out.
Getting a line on life. AMA 1601

Offline Bill Little

  • 2017
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12676
  • Second in COMMAND
Re: A question about small stunters
« Reply #53 on: July 09, 2009, 03:05:03 PM »
HI JIm,

I have a Mackey Bluebird (similar in size to what you have here, I think) ready for paint.  I like the idea of *smaller* stunt planes!  It isn't a strength thing to fly big planes, it is a *feel* thing for me.  Of course, I am trying to get BACK flying now! LL~

A side note:  I have had SEVERAL conversations with big name pilots who are interested in *smaller* planes.  Personally (if it means anything), you can have a smaller plane with a more powerful engine than in the old days which will pull through a LOT of junky air.  That is a good thing.  I have not been in the least bit disappointed when I went to a bigger engine in any of my planes.  The performance only improved (all things being equal otherwise).  Going from a .40VF to a PA .51 and then a PA .61 (no weight problems encountered) was a boon to my *smallish* Saturn based Geo Juno.

How wil it be accepted at the highest levels?  I dunno.  *Perception* is an inescapable part of CLPA, and *big* planes have had the table for a long time now.  Being an outstanding flying design might not be enough in the *beginning*, it may take a while to be accepted.  I am NOT bashing anyone who judges!  I just know that we all, as humans, get into a set of expectations which are not usually a conscious part of our thinking.

Keep on, I am really interested in seeing how this goes!
Bill 
Big Bear <><

Aberdeen, NC

James Hylton Motorsports/NASCAR/ARCA

AMA 95351 (got one of my old numbers back! ;D )

Trying to get by

Offline c.maikis

  • Trade Count: (0)
  • New Pilot
  • *
  • Posts: 14
Re: A question about small stunters
« Reply #54 on: July 09, 2009, 03:12:31 PM »
This is an interesting topic. But before we recommend engine sizes, I’d want to know what John’s goal is.
John, did you just design an airplane and now look for a suitable engine size? Or do you want to create a 15 size stunter?  The answer depends on your intentions.
I’m convinced that the 15 engine is about the smallest size for a decent stunt design. So I have tried to design  just that. It shouldn’t be a model to just “somehow” fly the manoeuvres, but to fly the FAI schedule as good as possible. The result was an airplane which flew better than I had expected. I even flew it in competition,  and I didn’t make a fool out of myself. My scores were just a little lower than those with my “serious” airplane ( at the same contest !).
I cannot see how big John’s Li’l Elle is. The numbers of my model is:  span 105 cm = 42 inch;  area about 327 sq inch;  weight  25 oz;  OS 15 FP; prop 8 x 5; line length 17 m = 56 feet. Longer lines is not possible because there will be no line tension any more. Lap times around 4.6 sec.  I need all the power this little engine can deliver. In a slight breeze the performance is surprising. As soon as the wind starts to blow, you’d better use your “normal” size stunter.
Just a thought: I don’t think it makes much sense to design an airplane and then to look for a suitable engine. Because: everytime you look at the design and decide for an engine size, you think: a bigger engine should be better. But then it might be better to slightly increase the wing area. But then again a bigger engine should be better  etc. etc. etc. . . .
I think it makes more sense to pick an engine size ( or even a particular engine ) and then try to design the best possible airplane for it. It’s a challenge!  Apart from the decision  about what you want: a fun model or a small airplane or a serious fully grown up super stunter.
John, I’d really like to see you build a high performance 15 size aerobatic airplane.
Regards,  Claus

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #55 on: July 09, 2009, 03:36:49 PM »
Thanks Claus and Bill for your input.

I understand exctly what you are saying Claus. I knew you had worked on this, and am happy to see a report on your findings.

The Lit'l Elle started out as a purpose scaling, and redesign based on Gordan Delaney's Pathfinder L.E. , for use as a small full blown stunter.  It's set up to use a more powerfull BB version of OS and Magnum .15's.

Wing area is 380 sq. inches, span 44". Prop should be some where from 8X4-9X4, but it'll take flying to make the decision.

The reason for setting up some helps to increase the span is that most potential builders, here, will want to stuff in a bigger engine, and make it "stronger".

It happens all the time, and usually works well, but weight will probably be the worst enemy of these smaller planes. I'm figuring that for a .15, weight must be held to 25-28 oz's for absolute best performance. The only way I can see to handle excessive weight is to go to more power, and lower the wing loading with more area. Ergo, the builders choice as to wing area.

Myself, I'm going to stick to the original concept, and use the more powerful .15, with the smaller wing. I will do all that is needed to keep the weight in the right zone.
Getting a line on life. AMA 1601

Offline john e. holliday

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 22752
Re: A question about small stunters
« Reply #56 on: July 10, 2009, 09:46:11 AM »
If you do decide to do a short kit with full size plans, put me on the list.  The kit I got from merry ole England came in a box about 12 inches square andless than two inches deep.  Has landing gear, control horns, laser cut parts, instructions, parts list and full size plans folded.  49 inch wing.  DOC Holliday
John E. "DOC" Holliday
10421 West 56th Terrace
Shawnee, KANSAS  66203
AMA 23530  Have fun as I have and I am still breaking a record.

Offline RogerGreene

  • 21 supporter
  • Trade Count: (0)
  • Commander
  • *
  • Posts: 365
Re: A question about small stunters
« Reply #57 on: February 05, 2010, 07:08:07 PM »
Why so many ribs in the "Li'l Elle"?

Fly Stunt <><
AMA 435R
USAF Veteran 1962-66 SAC
Life is 10% what happens to you and 90% of how you react to it. FAA #FA3RFLPAN7

Offline Howard Rush

  • 22 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 7805
Re: A question about small stunters
« Reply #58 on: February 05, 2010, 08:00:07 PM »
All seriousness aside, I'd point to the later comment about Gordon's success with long span combat models - efficient ift and good penetration are nice to have when you have limited power and are trying to penetrate in the wind.  I think it WOULD be good to to review some of the best ideas in combat models as they are roughly the same size as your target.  I too wil be watching this thread, got some ideas I'd like to try too...

I hesitate to show a plane I made in the same thread as the pretty ones above, but you did mention combat planes and the absence of seriousness.  I wanted to try out some stuff for Mr. Walker's bomber, so I took a store-bought F2D model and bolted on some 1/2" plywood and a 3/8" OD aluminium tube fuselage to ballast it appropriately.  The upchuck was a tolerably good stunter.  I was thinking about making a similar bolt-on, indestructible fuselage to adapt an F2D model to a control line trainer.  One could also put a regular stunt fuselage on an F2D and get to budget a lot of weight for paint.
The Jive Combat Team
Making combat and stunt great again

Offline Dennis Adamisin

  • 2019 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4338
Re: A question about small stunters
« Reply #59 on: February 06, 2010, 01:53:41 PM »
Howard
That is a REALLY intersting experiment you got there!  Could have posted in the TVC or Stabilator discussions too.  Would that stab normally be installed on the TE in F2D configuration?   Same size?

What are the sizes & weights and other info.  Looks kinda like a mini-Teosawki 
Denny Adamisin
Fort Wayne, IN

As I've grown older, I've learned that pleasing everyone is impossible, but pissing everyone off is a piece of cake!

Offline Jim Rhoades

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 124
Re: A question about small stunters
« Reply #60 on: February 16, 2010, 10:45:16 AM »
John and Martin,

I just weighed my Magnum 15 xl and it weighs 4.85 oz without carb or NV assy.  I threw on a nylon venturi and a NV assy I had laying around and it came out 5.10 oz.  These weights were without muffler.

I checked the himodel site and only saw the ASP 15 blue head which is identical to the magmum except for the brand label on it.  According to the info they are all made by the same MFG.  I did not see any mention of a rear exhaust 15.  Just the side exhaust ASP.

Jim Rhoades

Offline Kim Mortimore

  • 2013 Supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 621
Re: A question about small stunters
« Reply #61 on: February 16, 2010, 12:26:24 PM »

All y'all,

In general, would you say that the smaller engines benefit from some engine offset for added line tension (if you're not using any on your big planes), or more offset, if you are using some on your biggies?

Thanks,
Kim Mortimore
Kim Mortimore
Santa Clara, CA

Offline Douglas Ames

  • 2014 Supporters
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1299
Re: A question about small stunters
« Reply #62 on: February 21, 2010, 11:25:38 AM »
John- The ASP .15A is very similar to the Magnum. I believe they're made by the same Co. - Sanye?
AMA 656546

If you do a little bit every day it will get done, or you can do it tomorrow.

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #63 on: February 21, 2010, 05:16:26 PM »
All y'all,

In general, would you say that the smaller engines benefit from some engine offset for added line tension (if you're not using any on your big planes), or more offset, if you are using some on your biggies?

Thanks,
Kim Mortimore

Kim, Line tension is often a combined force including the weight of the plane, and aerodynamic loads. As a general rule, for myself, I'm of the school that only uses enough out thrust, on a single engined design, to make sure there is no in-thrust. Line tension will still be affected by the aerodynamic loads caused by flying on a hemishere, and weight of the planes.

I do use downthrust, about 1 to 2 degrees, but that's more for grooving than tension, though in manueverfs, it can help tension.

Any chances of introducing yawing, or rolling forces, I try to avoid.

Getting a line on life. AMA 1601

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #64 on: February 21, 2010, 05:17:48 PM »
John- The ASP .15A is very similar to the Magnum. I believe they're made by the same Co. - Sanye?

I think you may be right.
Getting a line on life. AMA 1601

Offline RandySmith

  • Administrator
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 13747
  • Welcome to the Stunt Hanger.
    • Aero Products
Re: A question about small stunters
« Reply #65 on: February 21, 2010, 06:56:58 PM »
I think you may be right.

You are correct.  Another  very goos motor for this size is the Enya 20, It has good power and runs well

Randy

Offline Leester

  • 2014 Supporters
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2530
Re: A question about small stunters
« Reply #66 on: February 23, 2010, 05:49:19 PM »
The Magnum 15 XLS's days may be numbered as Hobby People has them on sale for 39.99. Or they got a boat load of them  ??? ???
Leester
ama 830538

Offline Steve Helmick

  • AMA Member and supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 9920
Re: A question about small stunters
« Reply #67 on: March 20, 2010, 06:16:09 PM »
I also went to the HiModel website and easily found the ASP/AP .15 with rear exhaust. Hobby People sell these as AP's, whatever that means. Attached is the picture from their site. They are made by the same factory that makes Magnum engines, as we get from Hobby People and their dealers here in the USA.

The price out of HiModel is excellent, at $43.17US...and then I noticed the phone number...the country code is 86, which is China. The phone call might cost more than the engine? Might be interesting to order one online, but then the shipping for one unit might be more than you'd save over ordering from Hobby People. If you're in Brazil, then it would make sense, perhaps.  H^^ Steve

Edit: Just went to Hobby People, out of curiosity. They listed all the parts for the AP .15, but I couldn't find the entire engine listed anywhere. The .061 and .09, but not the .15.  Maybe listed in the Tower catalog?
« Last Edit: March 20, 2010, 09:43:52 PM by Steve Helmick »
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #68 on: March 21, 2010, 11:49:15 AM »
I would really like to find out if the AP .15RE is available here before I start on the Litl Elle. It may just be perfect for it. I would rather have A rear exhaust than a side 'cause I'm spoiled rotten with how clean my RE planes stay.
Getting a line on life. AMA 1601

Offline Steve Helmick

  • AMA Member and supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 9920
Re: A question about small stunters
« Reply #69 on: March 21, 2010, 06:26:34 PM »
John...I looked at Tower's site and again at H.P.'s site, and I think you'd have to get your AP .15 from China, or perhaps "Just Engines", in England. But you might try calling H.P. and see what they have to say. They could have some sitting around, but not enough to put on the website. It appears they have the parts to assemble one (which seems odd), and maybe you could ask about the power curve and stuff like that. I seem to recall that they once had them, but with the new XLS .15, maybe decided that two .15's was one too many. The AP .061's seem to be well accepted by the 1/2a crowd. If you do call, please nag them about the XLS .36...to bring them in again!  H^^ Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Jim Pollock

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 948
Re: A question about small stunters
« Reply #70 on: March 22, 2010, 03:19:47 AM »
Well Steve,

Hopefully it's an Olly Tiger diesel!  It would go really good in a full fuselage Peacemaker....

Jim Pollock   %^@

Offline John Miller

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1695
Re: A question about small stunters
« Reply #71 on: March 23, 2010, 08:46:27 AM »
Steve, I checked both Tower, and Hobby People. Not in their catalog. HP does still carry replacement parts. I got in touch with someone at HP to ask if there might be any available. The answer was no, that they are no longer produced. They carry the replacement parts for those who have them from when they were available.

They suggested contacting their dealers to see if they had any left over in their shops.
Getting a line on life. AMA 1601

Offline Pinecone

  • AMA Member and supporter
  • Trade Count: (0)
  • Commander
  • *
  • Posts: 235
Re: A question about small stunters
« Reply #72 on: March 23, 2010, 12:32:21 PM »
The Magnum XLS .15 might need more prop to run stunt RPM.  We run these in RC Combat with a Master 8x3 prop (spec prop).  In SSC combat, you are limited to 17,500 RPM leaned with the spec prop.  You need to get the Magnum down in the 5% nitro range or lower to get the RPM down to this.

BTW the 8x3 at 17,500 RPM is about a 55 MPH model. 
Terry Carraway
AMA 47402

Offline Kim Mortimore

  • 2013 Supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 621
Re: A question about small stunters
« Reply #73 on: March 23, 2010, 02:49:16 PM »
The Magnum XLS .15 might need more prop to run stunt RPM.  We run these in RC Combat with a Master 8x3 prop (spec prop).  In SSC combat, you are limited to 17,500 RPM leaned with the spec prop.  You need to get the Magnum down in the 5% nitro range or lower to get the RPM down to this.

BTW the 8x3 at 17,500 RPM is about a 55 MPH model. 

Terry,
Does "Master" mean Master Airscrew?  What is a "spec prop"? 

Thanks,
Kim Mortimore
Kim Mortimore
Santa Clara, CA

Offline Pinecone

  • AMA Member and supporter
  • Trade Count: (0)
  • Commander
  • *
  • Posts: 235
Re: A question about small stunters
« Reply #74 on: March 29, 2010, 08:28:21 AM »
Yes, Master Airscrew.

In SSC they specify the prop that everyone must use, and the max lean launch RPM.  Keeps the speeds in check and similar.

In competition world, if they specify specific things, they are called Spec.
Terry Carraway
AMA 47402

Offline Steve Berry

  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 445
Re: A question about small stunters
« Reply #75 on: September 12, 2016, 03:54:14 PM »
Sorry to dredge up an old topic, but I was wondering if the prototype of this was ever built, how it flew, was it ever kitted, etc.  Thanks.

Offline Dennis Adamisin

  • 2019 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4338
Re: A question about small stunters
« Reply #76 on: September 18, 2016, 07:33:16 AM »
Sorry to dredge up an old topic, but I was wondering if the prototype of this was ever built, how it flew, was it ever kitted, etc.  Thanks.

I believe this John Miller design became the Brodak "Lil Elle".

http://brodak.com/litl-elle-kit.html
Denny Adamisin
Fort Wayne, IN

As I've grown older, I've learned that pleasing everyone is impossible, but pissing everyone off is a piece of cake!

Offline Scott Richlen

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2084
Re: A question about small stunters
« Reply #77 on: September 18, 2016, 07:34:08 AM »
The fuselage does not look very "tall".  Might increased side area help line tension in overhead maneuvers?

Also, at this point would you consider electric power?

Offline Steve Berry

  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 445
Re:
« Reply #78 on: September 18, 2016, 01:33:55 PM »
Thanks

Sent from my Venue 8 3830 using Tapatalk



Advertise Here
Tags:
 


Advertise Here