Aeroworks 35% Edge 540 ARF-QB

[bodywerks]

	Quote: Originally Posted by Hammbone
	I don't see how end grain balsa capped with ply or G-10 will be "magnitudes more rigid" than high grade ply. I'm going to disagree with you on that. The ply will be more rigid. I'm not going to use balsa to mount my engines. There are certain things I will do to save weight, and there are certain things I won't do. Jim

All the plywood grains in your block are perpendicular to the compression loads of the backplate bolted to it. Those grains are going to crush as soon as you tighten the bolt. If they were parallel they would resist crushing.
My balsa stand-offs have been working flawlessly on both my 100 and 170cc planes for over a year - just sayin'...

[diviatix]

I have heard reports that the 116 runs pretty hot and needs especially effective baffling.

It looks like you have a number of BME's in operation, my reference to you about baffling is based on your experience with the wants and needs of BME's on a day to day basis. Any insights you can offer regarding their operational cooling requirements or quirks and how to address them would be greatly appreciated.

Cheers,

Andrew.

[Hammbone]

The main thing you need to do to keep an engine cool is to stop the air from going under the engine and bypassing the cylinders. A simple baffle going from the bottom of the cowl opening back to the cylinders accomplishes this.
Doing this gives you a big boost in cooling. Also, make sure the air can not go around the sides of the cylinders. Depending on the shape and size of your cowl, you may need to put baffles on the sides. A top baffle will help too, but not as much as bottom and side baffles do (my opinion). You also need to make sure your air inlets and air exits are large enough to allow for good air flow. There are other things you can do as well, like the pic you posted above, but in my opinion, the main thing is what I just mentioned.

Jim

[flatspinjim]

I can attest to the 116 ripping the 28/10, I've heard it many times. I was also there when he tached it a 7000. It's dang sure got some grunt!

[Hammbone]

I think Flatspinjim is going to have a BME before too long. He has seen the light.

Things are going a little slow today, but I have the ignition and the throttle servo installed now. I put the throttle servo inside the fuse just behind the firewall. This gave me a good angle for my linkage going to the throttle arm on the carb. I raised the back side of the servo 1/4" to make the servo sit at the same angle as the linkage.

I programmed the throttle servo in my tx, and cycled it back and forth several times. This JR DS3517 servo is fast and precise. I think I'm going to like it.

Time to install the mufflers , cut out the cowl, and do the baffles..........

Jim

[raptobob]

If that fuel filter has a brass type element inside of it you better get rid of that problem now. Whats your bottom $$ on that boat anchor DA?

[almmendes]

	Quote: Originally Posted by Hammbone
	I think Flatspinjim is going to have a BME before too long. He has seen the light. ... ... ... Jim

Looking good Jim... keep those pics coming...

[Hammbone]

	Quote: Originally Posted by raptobob
	If that fuel filter has a brass type element inside of it you better get rid of that problem now. Whats your bottom $$ on that boat anchor DA?

No brass in the fuel filter. This is a Dynamite brand fuel filter from Horizon Hobbies. I've been using them for a while with no problems at all:

http://search.horizonhobby.com/index...d=123A666BD651

I'll send you a PM on the DA.

Jim

[Hammbone]

Here's what I'm doing with the baffling:

I took some fiberglass cloth and wrapped it around each of the pre-existing baffles in order to extend them. I glued the fiberglass cloth onto the pre-existing baffles with thin CA. When I did the outer sides of the baffles, I pulled the fiberglass cloth around the corner tightly to bring in the sides and close up the gap I had between the side of my cowl and my cylinders. Once I had the fiberglass cloth glued to the pre-existing baffles, I then wicked thin CA into the part of the fiberglass cloth that "extends" the baffles. This stiffens the cloth up a little, and makes it easy to cut with an exacto knife. Then I carefully cut and fit the fiberglass cloth up to my engine cylinders by putting the cowl on the fuse and test fitting it over and over until I got it right.

Now, I just finished coating the fiberglass cloth on both sides with 30 minute epoxy. This will stiffen it up more and hold it in place better.

If you try this, be careful with the thin CA. It can run to places where you don't want it to go.

After the epoxy cures overnight, I will see how it looks tomorrow and then decide if I want to paint it or not.

This was fairly easy to do, and I'm sure it is going to help cool my BME.

I'll take some pics of the cowl mounted in place on the fuse (up to the engine cylinders) after the epoxy cures.

Jim

[Hammbone]

Here's pics of the cowl in place:

Jim

[almmendes]

	Quote: Originally Posted by Hammbone
	Here's pics of the cowl in place: Jim

Awesome... your are building my next airplane for sure... How much do you charge by the hour?

[RC4x4]

Looking good Jim. What time should we pick it up

Those BME 116's are awesome motors. I may have to try one if I do another 100cc plane.
Sunday is the day? I'll come out to check it out.


Cory

[6443jb]

Im just wondering what prop brand and what exaust u using to get 7000rpms on a 28/10?

[Hammbone]

It was the stock mufflers and a Mejzlik 28x10 prop, and remember, that's at 5,000 feet altitude after only 5 flights on the engine!

I'm switching over to Menz 28x10 props now, hoping to tone it down a little. It was ripping that Mejzlik like nothing I've ever seen before. I may end up going to a 28x12 or something.

Jim.

[flatspinjim]

I'm thinking 30/10!
Yep, I might need to replace my DL with the 116, they are impressive!