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Building Tips and technical articles. => 1/2 A building. => Topic started by: Bill Little on July 14, 2012, 08:11:26 PM

Title: Prop suggestions
Post by: Bill Little on July 14, 2012, 08:11:26 PM
Hi All,

I have built some Killer Bee .049 clones and am wondering which props would be best to use for stunt. ???

Thanks!
Bill
Title: Re: Prop suggestions
Post by: kenneth cook on July 15, 2012, 03:18:10 AM
            Bill that  may be a tough to answer. The Killer Bee even though it may be cloned should still be quite a runner. I would say pretty close to TD performance. I would say it would do great on a plane that likes a bit of speed such as a Flite Streak for instance. Cox engines unlike modern engines seem to be very happy using the Cox 5x3 rubber ducky black props. These props seem to just have the proper diameter and blade area. However, I use a APC 5x3 for flying my Jr Lightning Streak which has a modified Sure Start with some Killer Bee similarities. You do need to get used to the $4 price tag of the APC and the fact that they break quite easy which makes the Cox rubber ducky a good choice.  Rather than adjust speed with the prop, I went out on the line length and let the engine sing were it's happy. I'm flying with 42' Spider wire lines and the plane does just fine. I've tried several APC props such as the 6x2 which was absolutely horrible in my experience as it just beats air and allows the engine to over rev with no drive. The lower pitch props such as the APC 5.5x 2 work great for the modern Norvel's and similar engines, but they just don't seem to work well on Cox engines. The old stand by used to be the Cox 6x3 and the Top Flite nylon 6x3's which may just work well for you but since I've switched to the smaller 5" props I let let them turn up, I found that they just don't load the engine as bad causing sagging through the maneuvers. Ken
Title: Re: Prop suggestions
Post by: ray copeland on July 15, 2012, 08:04:14 AM
Bill, my conclusions are exactly as Kenneth's!
Title: Re: Prop suggestions
Post by: Larry Renger on July 15, 2012, 08:11:58 AM
The Cox 5x3 prop is an excellent choice.  BTW, I have recently been using it on the AP Wasp with good results.  The master for that and the 6x3 were carved by Bill Atwood who also designed the Tee Dees and Conquest engines. (Along with the Holland Wasp and Atwood Shriek, plus some big sparkie engines).
Title: Re: Prop suggestions
Post by: kenneth cook on July 15, 2012, 08:59:55 AM
                 Bill, I should've mentioned the Tornado props as well. I love the Tornado line of props white and black. It's quite sad that these are difficult to obtain. Maybe you already have some as some of us that have done 1/2A through the years keep a small stash. I've found these to work excellent even up to 4 pitch. They have a slightly smaller blade area than the Cox which I believe allows for the larger pitch. They just amazingly work. The 5 1/4 x 3 is a good choice and Top Flite made this prop as well, both of these are hard to find. In my above posts, I mentioned what's readily available but if you can find some Tornado props they do work. I intend to complete the pattern using a Cox 1/2A and I'm pretty close to doing so. My Jr Lightning Streak is a prime candidate as it certainly has some good flying characteristics. My son can fly it quite well with some nice clean maneuvering. I on the other hand need some work as my maneuvers aren't quite as graceful. I have a lot of admiration for the guys out west that fly the 1/2A events. Ken
Title: Re: Prop suggestions
Post by: john e. holliday on July 15, 2012, 02:21:45 PM
I know these guys like high rpm engines.   My results have been good with 6-3 or 6-4 props.  All brands for stunt work. H^^
Title: Re: Prop suggestions
Post by: Bill Little on July 15, 2012, 06:01:01 PM
Thank you, Gentlemen, for the quick responses and good advice.  I have almost all of the props mentioned plus a large stash of Top Flite wood props in the 6" range.

I will start with the Cox 5-3 "rubber ducky" and go on from there.

The engines have the double ported/boost ported sleeves with the lightened/machined pistons, Killer Bee .051 backplates and some have Galbreath/Nelson head adapters.  I haven't been able to run them all yet, but I believe they will be plenty "strong".

Eventually I am going to build a true "miniature stunter" like Bart did last year and just might use one of these clones.  Another choice is some of Dick S.'s "sheet" models.

Bill
Title: Re: Prop suggestions
Post by: Jim Thomerson on July 15, 2012, 06:13:08 PM
I flew quite a bit of 1/2A stunt competition with a TD 049 and a MAS 6 x 3 cut down to 5 1/2 in.
Title: Re: Prop suggestions
Post by: ray copeland on July 15, 2012, 07:24:32 PM
Bill, don't forget Ray Stone's Skywriter 1/2a kit! That plane flies pretty darn well with a Cox or Norvel, and the price is right!! Good luck, Ray
Title: Re: Prop suggestions
Post by: Bill Little on July 15, 2012, 09:38:39 PM
Bill, don't forget Ray Stone's Skywriter 1/2a kit! That plane flies pretty darn well with a Cox or Norvel, and the price is right!! Good luck, Ray

Hi Ray,

I have the Snapper kit from Ray, it just needs covering and paint applied.  Ray has some awesome stuff.  I also got one of his Queen Bee Kits.

Bill