Lets try again and see if we can make this last only a couple weeks too.

littles bipe post 21 & 22

1st thread with plans see first post for info.

http://www.rcgroups.com/forums/showt...light=bird+Dog

plans are found in this thread on post numbers as follows:

Bird Dog post 125
Hellcat post 253
Zero post 271
P-39 post 291

2nd thread, just plain fun oh and lots of good info.

http://www.rcgroups.com/forums/showt...hreadid=193543

3rd thread

http://www.rcgroups.com/forums/showt...5&pagenumber=1

thanks tog,
i won't be trying to use a 250, i bought some to have later when i get some experience and try something faster than the fun jet and bird dog. i have an isp-a i'm going to try to use.

in following the posts it seems that when members use a j250 at the tail of a plane they usually use it direct drive, but when used up front as a tractor it is usually geared.
is there a reason or just a coincidence?

TOG i have a name for the new plans..
how about The SL1?

SL1,?

Tom its just a pitch speed thing. Direct you can get more pitch speed but the plane will need to travel fast, which is mostly wing and such. Now floaters need more tractor than speed so we gear them and use larger props. Most times same thrust just differant speeds of thrust and trying to make the prop work more efficant in the speed range you want.

[QUOTE]Originally posted by Thatovalguy
SL1,?



Stewart little 1 or SLB (stewart little bipe) or SLBD (stewart little bird dog)

Maybe i'm just tired sorry about rambling.

thanks tog, that makes sense. some day i'll learn enough to not have to ask so many questions.
six months ago i hadn't even seen an electric r/c plane. then a couple months ago kirkpul, a fellow pusherpropplanes yahoo group told me about the frog. i ordered the plans and built it but made it too heavy and had to use an eps 300c to get it in the air. it flew great but was no longer a slow flyer.
then kirkpul told me about the fun jet and i found these forums. i'm hooked now on your planes.

somewhere in one of the threads i read where someone used the motor from an isp-a in an edf-50. i can't remember for sure but i think he said it worked but just didn't have quite the same power. has anyone else tried this motor?
i'd be willing to give up some power in exchange for longer motor life if the fun jet would still fly good. right now i'm not looking for a speed demon, just a nice slow easy flyer.

Hi Tom, and welcome.

The CN12-RXC (7.2v IPS motor) would work fine in the EDF-50, given enough power. The problem is that the CN12-RLC (4.8v, or EDF motor) is a very high speed motor. The edf motor pulls about 4 amps at 7 volts (I'm pulling numbers out of the air, here), where the IPS motor would be about 2a at 7v for the same pack, rotor, etc. That's right at half the watts. Given that prop curves are exponential (HP or watts increases by the square of the speed), you could maybe use a 3 cell Li pack, or a 10 cell Ni pack, to get the power out of the system. In fact, here it is as a complete unit: http://www.balsapr.com/catalog/motor...ductId=T205030

As you can see, there's a lot of guess work and then testing that goes on to figure out a good power system. That's why, once you've found a good combo, it's hard as heck to get you to try something else.

For example, I bet the J250 would be a great motor in the EDF-55. And, it should slide right in. Some have jambed them into the EDF-50, but looks too much like work to me... Soon, I'm sure BP will have the 55 parts, so we can try.

Gene I'm thinking anywhere you use a gws350 you could use the J250 with better numbers all around.

TOG:

The pest is back, I built 4 BDs and flew the first yesterday and it had a mushing attitude. I may have my CG at the wrong location, I know I have seen it mentioned but after reading 1000s of threads I can't recall. Where is the CG located?? The AUW is 7.26oz- HS 55s RP4II C5 2S1200s and S1w/9/4.7. I know the "normal" callout is an A but shouldn't it fly on a S1? There was a lot of interest in the BD at the fly-in.

Thanks in advance,

George

George,

CG is 1/3 behind the LE, S1 is OK I use one with a 9x7 prop.

KC9 is correct on all counts. I normally maiden with the CG forward and keep moving it back till I get it where I want it to be. And thats just to get the feel I like in a plane. Most times I need to move the battery more forward when I let guy's fly them as I normally run it back a little farther than most like to fly a plane at. But that being said move it forward some and give it a go.

preview time

KC/TOG:

Thanks for the reply, I am pretty close to 1/3rd chord so I will change to 9/7 prop and see what happens.

Thanks

George

TOG,

I suggest you cut the mouse's profile in the foam and then paint it accordingly. I see you moved the wing down on the fuse. This deviates from the original. I suggest you move it up 1" but continue supporting it with a solid section of the double fuse.

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