Anyone flying the Aeroworks 42% 260

[ace20]

I just ordered one and was wondering how well do they fly. I have had the 100cc one and wonder how they compare. Any info would be a big help.

Thanks,
Anthony

[bodywerks]

I just did a maiden on mine today. It was windy and bumpy, so I didn't really achieve anything except a break-in run on the engine. It seems to fly just fine, and very similar to its little siblings, only bigger and better.
If you build it as advertised, it will not come in at the advertised weight. With a full load of servo and typical battery setup and stock mufflers, you'd likely be a tad over 39 pounds. With Cans, you'd be over 40 almost guaranteed.
I took a hacksaw to mine, bought the CF main gear, made my own engine standoffs, and chose my equipment with weight in mind. With Greves pipes and pilot installed, RTF (only thing missing is decals), I came in at a mere 37-3/4 pounds. I will post some pics of my lightening techniques a little later...

[ace20]

Thanks, thats nice to know. I'm hoping that it does fly as well as the 100cc.What engine are you running, i'm going to be running a 3W 157.

[Boomhauer]

You made a good choice. I have 20 or better flights on mine and it will compete with the best of them. 39 lbs and all the vertical it needs with DA 150.

[ace20]

Any pictures?

[bodywerks]

I went with minimal servos, which you can easily do with 8711's or 9156's. That's only 9 servos, including throttle, compared to as many as 15 servos if built as described, with a choke servo. Right there, I saved at least a pound.
I am using two 2300 A123's on the receiver, and the receiver is the AR9100, so no power box or power expander - as well as no switches. I did use Smart-fly equalizers on the wings, but they only weigh 1/2 ounce. Compared to a typical setup of li-ions, regs, switches, a powerbox, etc., I am again a good 1/2 pound lighter or more.
I went with the CF landing gear and titanium axles, and lightened the CF gear and the gear cover even further. I also tossed the gear cuffs. This dropped another 13 ounces...
Below you can see the stock gear weight, less pants and wheels, as well as the CF gear weight and the mods done to it and the gear cover.

[bodywerks]

Now on to the hatch. Unfortunately, probably over half of the hatch weight comes from the super thick canopy, and there's no real way to lighten that without redoing the whole hatch. The canopy alone probably accounts for about half the total weight of the hatch. Still, there were places to remove some excess lumber, and I did just that. I only dropped a little over 4 ounces, but it still contributes to the big picture - in just two areas on the plane, I have now dropped over a pound.
You might be able to see in the pics how I drew out what I wanted to remove. Two hours later and a face full of sanding dust and here I am:

[bodywerks]

I went to TOWN on the fuse! In fact, I was so much on a roll that I forgot to take before pics, but I did get the before weight:

[bodywerks]

I got to looking at the front end of the fuse and, while I know it has to carry the brunt of almost all loads placed on the plane, I really saw no need for a 1/2" thick front fuse former! So that was going to get some holes put in it for sure.
Then, a common practice when building a Carden or other kit, is to skeleton the engine box a bit. The upper part of the box is 1/4" thick, the sides are 3/8" thick, the bottom is 1/8", and the engine firewall is about 1/2" thick. All I did here was enlarger the already existing holes on the top and sides(the top had a 1/8" hatch that I will not be using), and then I drilled a big hole in the firewall in the center. Again, this is pretty standard operation stuff when building a kit for light weight.
The fuse also had a rudder and radio equipment tray built into it. Since I will be mounting my rudder servos in the tail, and since I plan to mount my batteries and other equipment higher up in the fuse (this will help achieve a better vertical balance - something that is often overlooked, but can affect how true a plane flies), I cut those out. I did this on my 75cc QB Extra with no problems and with no auxiliary reinforcement, but I think I will run a couple balsa cross beams in there once I get my pipes mounted:

[bodywerks]

More pics. Notice the front fuse former thickness at the bottom of the fuse - way overkill, IMO.
Here, you can also see the big holes in the sides of the front fuse former and the engine box. I left the bottom alone for now, and probably wont touch it even after I mount the throttle servo. You will also see in one of the pics that I removed part of the tray where the tank would have mounted, as well as the cross-beam usually found right above the wing tube socket. I plan to mount the tank on the CG, so this stuff didn't need to be there:

[bodywerks]

with a weigh savings of over 3/4's of a pound, I think it was worth it...

[bodywerks]

That's probably it for the major weight savings of the airframe. I put the wings on a scale and they tipped it at 3Lb., 2 ounces - Ouch! Unfortunately, the only way to drop a significant amount of weight would be to tear all the covering off, and I still want this to be more of an ARF build than a kit build. On the bright side, the included CF wing tube only weighs 7 ounces - that is so light it actually has me wondering if they forgot to add some layers of fabric
I mounted the two wing servos in the inboard and center positions, to reduce rotational mass.

[bodywerks]

Here's another area where one can realize a significant weight savings - hardware selection:
Now, I obviously wouldn't say it is worth it to got to these lengths if you are not going to try to keep the rest of the plane as light as possible. But if you are trying to look at the bigger picture, like I am, you can see that being more creative with hardware will also pay off.
The hardware in the first pic is almost identical to what Aeroworks recommends to attach the engine. They provide aluminum stand-off spacers and recommend Fender washers on both sides of the firewall. You then bolt everything together with steel screws and a lock nut.
What I did, was make my own stand-off plates out of end-grain balsa, capped with 1/16" birch ply, with the grains around the holes soaked in thin CA to harden that part of the wood. I did this exact same setup on an 85cc single and it was rock solid. However, in order for the balsa plates to be successful, you MUST glue them to the firewall with epoxy or gorilla glue.
Also, I replaced the steel 1/4-20 bolts with 6mm titanium bolts (about half the weight per volume as steel), and used blind nuts instead of regular nuts and a washers. Doing this results in the need of a shorter bolt, which reduces weight, but I also cut the bolts to exact length, so I reduced the weight even further.

[ace20]

Thanks for the pictures, they help a lot. That gives me some perspective on the plane and where i can save a few ounces. This is great info, keep it coming.
Thanks,
Anthony

[bodywerks]

Here is the engine installed. Notice that the blind nuts are screwed in instead of having teeth. I like it this way because you don't have to worry about the blind nuts coming out, and also because you can install the screws at an angle and the screws will actually help to keep the blind nuts from crushing the wood as you tighten the engine mount bolts (see pic below).
Prior to permanently installing the engine, I soaked the firewall around the blind nuts with thin CA, and also glue the stand-off plates down. Then I safetied the bolts with safety cable to ensure they never even think about coming loose. I also torqued the bolts to only 55 in.lb instead of cranking down on them, which actually only weakens the mount due to the crushed wood.