quote:

ORIGINAL: tetsa

It is truly amazing how Raimondi's 260 can be that light!!! There simply has to be huge differences in the amount of resin in C-ARF's models. That's the only explanation I can think of...

To save some more weight I could take the alu wing tube and replace it with C/F tube and save, what, 200 grams? Then I could substitute the pipe for standard muffler and save another 200 or so grams.(And be really LOUD!) I could also remove one RX battery and save about 100 grams. That's a pound right there. But still it would be heavier than Ray' with his DA100.

I think I gotta take a trip to Thailand and pick my next C-ARF plane straight from the manufacturing line to get the lightest one... 

quote:

ORIGINAL: airlyons

Oh... Tetsa...

I'm wondering what your thoughts are on mounting the DA85 with the head on a 45 degree angle (approximately) downwards. I'm wondering if you think it would mount ok. Do you think the mount bolts from the engine would be too close to the top of the cowl? Would the head of the engine hit the cowl?

My hope is that by mounting on a 45 degree down angle the engine could be mounted a little more forward to help with C of G and also then I would be able to use a straight header with whatever drop would work so that the header would exit through the center of the dome for the KS1090.

Thanks,

Chris

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quote:

ORIGINAL: airlyons

Oh... Tetsa...

I'm wondering what your thoughts are on mounting the DA85 with the head on a 45 degree angle (approximately) downwards. I'm wondering if you think it would mount ok. Do you think the mount bolts from the engine would be too close to the top of the cowl? Would the head of the engine hit the cowl?

My hope is that by mounting on a 45 degree down angle the engine could be mounted a little more forward to help with C of G and also then I would be able to use a straight header with whatever drop would work so that the header would exit through the center of the dome for the KS1090.

Thanks,

Chris

quote:

ORIGINAL: Pro Flyer

quote:

ORIGINAL: airlyons

Oh... Tetsa...

I'm wondering what your thoughts are on mounting the DA85 with the head on a 45 degree angle (approximately) downwards. I'm wondering if you think it would mount ok. Do you think the mount bolts from the engine would be too close to the top of the cowl? Would the head of the engine hit the cowl?

My hope is that by mounting on a 45 degree down angle the engine could be mounted a little more forward to help with C of G and also then I would be able to use a straight header with whatever drop would work so that the header would exit through the center of the dome for the KS1090.

Thanks,

Chris

Have a read of this Comp-ARF 2.6 260 this is one of Chris Brislin Comp-ARF 2.6 260 with DA-85..

Damo

quote:

ORIGINAL: Zeeb

quote:

ORIGINAL: airlyons

Oh... Tetsa...

I'm wondering what your thoughts are on mounting the DA85 with the head on a 45 degree angle (approximately) downwards. I'm wondering if you think it would mount ok. Do you think the mount bolts from the engine would be too close to the top of the cowl? Would the head of the engine hit the cowl?

My hope is that by mounting on a 45 degree down angle the engine could be mounted a little more forward to help with C of G and also then I would be able to use a straight header with whatever drop would work so that the header would exit through the center of the dome for the KS1090.

Thanks,

Chris

Well not sure if Tetsa is going to chime in here or not, but I'll offer a couple of thoughts based on what I found out when I put my Comp-Arf 2.6 Extra 260 together.....

First, while Comp-Arf does show the install of a DA-85 the things they do to get it to balance are way out front like installing the ignition battery underneath the cowl inlet baffling. Mine has a DA-120 on in cowl muffs and that engine is about 12oz. heavier than the DA-85. It's also 1/4'' shorter than a DA-100 so it sits farther forward anyway and I had to move mine out another 1/4'' as well. All my batteries are in the engine dome. The pull pull rudder is setup on an SWB tray mounted right agains the landing gear block where Comp-Arf says to put the servos if using the DA-85. It has the carbon fiber wing tube since the included tube is almost a pound. With all that, I STILL had to add 6oz. of lead on the backside of the firewall to get it to balance. Granted it's a bit nose heavy for some, but if you do the IMAC CG test of doing a 45 degree upline and flip it inverted, mine will just keep going if you let go of the sticks where the IMAC guide suggests it should start to nose over after a few seconds so my CG is acutally a bit further back.

Second, up until the release of the 2.6 size Edge with the pocket hinged ailerons and such, the 260 was the heaviest of all the 2.6 size Comp-Arfs coming in even according to the factory specs at a Kilo heavier than the other models except the Edge. If you're going to run a single, I'd suggest you look at one of the other Extras because of that weight difference. I asked about why it was so much heavier and not even Andreas could tell me, or would tell me, let alone my sales rep. Turns out the 260 has a totally different fuselage with bigger rudder/stab and gear mounting than the other 2.6 size models.

Third, while mine does have the dual servos per wing which some guys are electing to avoid that's only about 6oz. extra weight which the DA-120 more than makes up for and the carbon fiber wing tube is almost a 1/2lb. lighter than the aluminum but mine still weighes 28.0lbs. There are a couple of the other Extras around here and even those come in around 27lbs. with DA-100's, so when folks say you can put this model together and have it come in at 22lbs., well let's just say I'm EXTREMELY dubious of those claims. You're NOT going to make a difference of 5 to 6lbs. based on the amount of resin in the mold and an engine that's only about 3/4lb. lighter especially when you add in the weight of a header and canister or pipe.

JMHO.....