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Dec 08, 2008, 07:19 PM
is it flying time?
Jerry Combs's Avatar
Quote:
Originally Posted by leadfeather
Jerry, Photos? Auw?
Here is a photo of the bottom side. AUW is not that great as I used fairly heavy equipment such as 6.7 gram servos etc......142 grams with a 2c 400mAh pack.
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Dec 08, 2008, 07:59 PM
Registered User
This motor http://www.hobbycity.com/hobbycity/s...idProduct=6547 seems to be popular in this weight class.
Not a lot of weight saving over the Blue wonder though.
Dec 08, 2008, 08:27 PM
is it flying time?
Jerry Combs's Avatar
Hey Dan,

Will you be at the Clearview Field E-Fly this weekend? I am coming up Friday for the F3P C comp.

Jerry
Dec 08, 2008, 08:33 PM
is it flying time?
Jerry Combs's Avatar
Quote:
Originally Posted by dkselw
This motor http://www.hobbycity.com/hobbycity/s...idProduct=6547 seems to be popular in this weight class.
Not a lot of weight saving over the Blue wonder though.
Excellent motor!
Dec 08, 2008, 08:49 PM
Ken's CAD Models
dz1sfb's Avatar
Quote:
Originally Posted by dkselw
This motor http://www.hobbycity.com/hobbycity/s...idProduct=6547 seems to be popular in this weight class.
Not a lot of weight saving over the Blue wonder though.

I agree with Jerry. These are excellent motors. I use them in 33 inch Blu-Babys. On 2s they will swing a 9x4.7 SF prop. This gives near vertical performance on an 8oz airframe, while pulling less than 10 amps. This is a 70 watt motor. Duration is fabulous as well. We have timed this motor with 900Mah 2s Mystery battery as long as 40 minutes in the air on the aforementioned Blu-Baby.

Dan,
At your 190g airframe weight this motor has great gobs of power and less weight over the BW. I prefer to get mine from www.lightflightrc.com . Theirs are labeled as Suppo brand and come with screws that have countersunk heads on them. They hang onto the o-ring better, and they come with 1.5mm bullet connectors. I forgot all about this one in our earlier conversations.

Ken
Dec 08, 2008, 09:32 PM
Winging it Ò>
leadfeather's Avatar
Thread OP
Quote:
Originally Posted by Jerry Combs
Hey Dan,

Will you be at the Clearview Field E-Fly this weekend? I am coming up Friday for the F3P C comp.

Jerry

Jerry, I'll be there. I'll be helping out with the event and hopefully I'll be doing plenty of flying. I'll look for you there.

On your 32" Extra, I think 140 grams is very good!

It is good to know that range of weight is attainable with epp. The trade off appears to be adding a little more complexity to the build.
Dec 08, 2008, 10:07 PM
Winging it Ò>
leadfeather's Avatar
Thread OP
Quote:
Originally Posted by dz1sfb
I agree with Jerry. These are excellent motors. I use them in 33 inch Blu-Babys. On 2s they will swing a 9x4.7 SF prop. This gives near vertical performance on an 8oz airframe, while pulling less than 10 amps. This is a 70 watt motor. Duration is fabulous as well. We have timed this motor with 900Mah 2s Mystery battery as long as 40 minutes in the air on the aforementioned Blu-Baby.

Dan,
At your 190g airframe weight this motor has great gobs of power and less weight over the BW. I prefer to get mine from www.lightflightrc.com . Theirs are labeled as Suppo brand and come with screws that have countersunk heads on them. They hang onto the o-ring better, and they come with 1.5mm bullet connectors. I forgot all about this one in our earlier conversations.

Ken
lightfliterc is out of stock at this time. The price looks good from either vendor.
Dec 08, 2008, 10:16 PM
is it flying time?
Jerry Combs's Avatar
Dan,

BP Hobbies stocks the same motor labeled as the BP 2204.

You know, as fast as you build you could get a Yak 55 built out of 6mm EPP in time for Friday.

Jerry
Dec 08, 2008, 10:19 PM
I don't want to "Switch Now"
pmackenzie's Avatar
What are you using for the spar and bracing in the 6mm plane?

(6mm EPP is all I have on hand )

Pat MacKenzie
Dec 08, 2008, 10:25 PM
is it flying time?
Jerry Combs's Avatar
Pat,

On my Extra I used a single 1.5mm rod at about 1" behind the leading edge and then added two 1.5mm rods like on a shock flier to keep the wing aligned with the fuse. Sounds flimsy but it works out pretty well if you build light. See the pic in post #46. Dan may have a better idea.

Jerry
Dec 09, 2008, 06:27 AM
Ken's CAD Models
dz1sfb's Avatar
Quote:
Originally Posted by leadfeather
lightfliterc is out of stock at this time. The price looks good from either vendor.
Balsa Products sells these also. Although they seem to indicate a little lower Kv. If I understand the labeling correct, it is a 19 turn motor versus the other vendors 14 turn. I would stick with the 14 turn.

http://www.bphobbies.com/view.asp?id...7&pid=B2171399


Ken
Dec 09, 2008, 08:21 AM
Winging it Ò>
leadfeather's Avatar
Thread OP
Thanks for the feedback on the motors. I'm glad to see there is one in the F3P class that is more affordable.

I am so pleased with the Yak as it is. I was pleasantly surprised that it could hover and get reasonable flight times on the 360 2s battery.

But...if I can save weight the plane will only get better. If I can make it lighter and retain the simplicity of construction I will be very happy.

My thinking cap is on, but I appreciate ideas from others...there is such a huge wealth of experience out there.
Dec 09, 2008, 08:33 AM
Winging it Ò>
leadfeather's Avatar
Thread OP

Lighter thoughts


Thinking out loud, here are some of my thoughts on making the Yak lighter without sacrificing the simplicity:

1) lighter motor and esc...obviously after the previous posts
2) Make all control surface from 1.3# 6mm epp.
3) Make the fuselage from 6mm epp
4) Move the esc as far forward as possible so the tail servos can go further back which means lighter push rods.

The rear side fuse pieces probably need to stay at 9mm epp to keep the tail stiff enough. Other wise it might twist and if the tail wags at all the wing will rock.

All these ideas, if they work; don't violate the original simplicity of this design.
Dec 09, 2008, 12:21 PM
Twisted Realm's Avatar
Well leadfeather, I got my EPP foam yesterday YEAH!!!!. I finish cutting out all the pieces and I'm starting to carbon fiber rod her up. I'm unsure the best lightest hinges for this plane,,, do you have a close up of all the hinges?
Dec 09, 2008, 12:58 PM
Winging it Ò>
leadfeather's Avatar
Thread OP
Quote:
Originally Posted by brad65ford
Well leadfeather, I got my EPP foam yesterday YEAH!!!!. I finish cutting out all the pieces and I'm starting to carbon fiber rod her up. I'm unsure the best lightest hinges for this plane,,, do you have a close up of all the hinges?
Hey alright!

My preferred hinge is the Welders' glue method. Easy, light, tough and paintable.

After beveling the foam butt the two pieces together. Run a very small bead of Welder's glue along the hinge line. Smooth the bead down with your finger or a Popsicle stick.

The first time I tried this I put too much on and the hinge was stiff. You need very very little glue to do the job.

Best of luck with your Yak!


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