I am wondering if the 49" Yak is capable of holding a 10oz 2 stroke engine. I will plan to modify the firewall of course. At 2.6 lbs without battery I think the plane would like the .32SX. Any ideas?

Hey

I too am about to start this. I just ordered the .32 but i got a 8oz tank. Dont forget the .32 is not gonna drink alot. Have you started this yet?
In between the hacker motor and controller its about 6.7oz. That almost cancels out the tank. OS engine is 9.5oz, batts for electric, 9.87oz. As far as weight goes it about even.
I was also thinking that i should use a lipo for the receiver. What do you think?

This motor seems to have plenty of power for a 3lbs.

I have not started it yet. But will continue to investigate. I will cut off the motor box and design one around the .32SX. Should be great fun without the expense of 10 min flights and having to charge. I, as well will use a Fromeco 2600 cell batt.

Thats the reason I cant go with electric. That and the fact I love the sound of an engine. lol. Lets keep this thread going. Post some pics of your work and I will do the same.

Do you already have the plane?

I'm using a OS.32sx/Macs pipe combo for a 3 lb. Diamond Dust and I'm expecting speeds of 120mph.

If I'm not mistaken, a lot of guys use the 32 for a Model Tech BF 109 and thats about the same size as your Yak.

http://www.rcuniverse.com/product_gu...fm?kit_id=2754

Sounds good to go.

root

Thanks for the info root. I hope you get your plane past 120. Too fast for me.

I dont have the plane yet. Living in Mn gives me the misfortune of conjuring up ideas 4 months a year. I still have time but want to get this on done soon. Before I start something it has to be thouroughly planned, and once I can determine that this will work properly I will get the plane. I dont see any problems as of yet. If you have yours, what is the exact weight of components to discard. Whats the flying weight?

Thats good to know root. I figured it would be fine. Someone at the field also thinks it will work fine. I have the plane already and just ordered everytning i need. Hopefully I will be able to start this weekend. I''ll take some pics as i go.

components to discard........I don't think you mean that.....lighten up where you can - servos, Rx, control rods, battery, tires, LG, pilot figure, etc.

Yeah, components to discard, ESC, motor, mount, battery, battery tray, etc. I will go to the shop now and weigh all components I intend to use.

.32 SX = 9.5oz 12.6oz with muff and screws
10x4 APC prop= .6oz
micro servo and hardware= .4oz
fuel tubing and dot= .2oz
8 oz tank= 1.3oz 4 oz tank= 1oz
throttle pushrod= .2 oz
engine mount and hardware= 1.2oz
One could use carbon for the pushrod and use a wood prop for even more weight savings, but I come up with 16.2oz without fuel with a 4 oz tank. Your previous post with motor and batt are a total of 16.57oz. I believe we are already ahead of the game. Add fuel and we are very close to being even power plant swaps. With the airframe cosiderations I will end up cutting the firewall out and making a shorter one. Save more weight also, but will probably put more beef in the firewall. So the weight may stay the same. **** I forgot the battery.

OK Add the battery. Due to less weight I will use Li-Po 1320 mah 7.4v Apogee pack.
Battery= 2.3 oz
MPI switch with regulator= 1oz
Total dry weight is 19.5 oz.

The numbers are fine. Are you flying 3d with this plane? I am. The reason i ask is because your gonna use a 10x4 prop. I was gonna use a 11" or even a 12"x4. Also i dont plan on using the stock muffler. I think it will look bad with this huge thing hanging there. Im gonna guess the pits style one i ordered will be less weight too.

So with your number we our 3oz heavier? Thats fine, mount the batt in the tail somewhere and cg is gonna be easy to set.

I will 3D this plane and want it to fly like my 86". I wasnt sure what prop to choose yet so I just weighed one quick. Once I get the plane I will decide what pipe to run, but for measure purposes the stocker gets us close. If the new one is lighter great!
Adam

Cant wait for everything to get here!!!

Finally got an email confirmation that my stuff has shipped. They must of been closed on Monday. Hopefully I'll get it Friday and i'll get to start this weekend.

Build it like a thread so others can also enjoy this plane with nitro. I will post pics of my setup and modifications as well.

Here are some pics of the front

I did some quick measurements and it looks like i need to remove about an inch and a half.
Any idea, tips for the best way to do this?

Over lap and inter lock the firewall like the factory did. Before you cut it mesure and mark your mount with the thrust in place.

I have my .32 ready for action. Tore the crank out of it and knife edged the port wall. I hope to spin an 11x5 or 6 effectively.
Adam

We didnt get much help here so i started a thread in the crash rebuild because basically i needed help with a rebuild.

[link]http://www.rcuniverse.com/forum/m_6630612/anchors_6630612/mpage_1/key_/anchor/tm.htm#6630612[/link]

Do you still have the crank out? Wouls love to see a pic..

Hello, a battery 7.4v 1,320 mAh is very large, I am using in my Funtana 90. With Lipo 600 or 700mAh is sufficient for microservos.

Greetings.

I took the engine apart for ya! Only takes 5 minuets.
Your firewall looks good. A .32 will work fine.

I broke in my 32 today and this little thing has tons of power. Can wait!!!!

Gonna order the parts and plane now. HS 81MG servos for surfaces. HS 56 for throttle. 4 oz tank. Start with an 11x4 prop. Also order a 12x4 to be safe. Electron 6 reciever.
I am wondering if I should look for a servo that uses 4 screws instead of two for mounting. I prefer 4 for stability, but didnt really find one that Futaba or Hitec offered. Will not use JR unless its for my trucks, so dont mention it.
The electric bird has a 14" prop. I will be 2" short with a 12" prop. Will this affect the thrust? What diameter is the cowl anyhow? I hope it dosnt look like a retarded Gee Bee. Never understood the Gee Bee design. The prop is what 2' larger than the cowl? Imagine how fast the plane would be if the prop didnt have to force air into the front of the cowl.

Should still be a fun plane though. Besides modifying the factory muffler or getting a performance one ,I am running out of ideas to help this build along. Is there a carbon prop available in a 12x4?
Adam