Vertical Fin Offset

Just curious, my M2 plans have a 1/4" offset left of the nose of the vertical fin. Wondering if the RV-Xs have a similar offset and what it is. Also do you guys have offset in your engine mounts? If so how much?
Thanks

Hi Mani,

Welcome! I've flown several M-II's, & even owned a project for a while; they're great a/c.

The -7 definitely has motor mount offset; the nose of the crank is pointed to the right and IIRC, down, sitting in the cockpit. I'm pretty sure the plans show a fin offset, as well, but mine's not mounted yet.

I'd do what Bushby said to do, unless you're planning a radical departure with your powerplant (extreme HP, left turning engine, etc).

Charlie

From the -7 on up, the builders probably don't know as you just take the parts out of yhe box and assemble them. I don't recall the plans even giving those dimensions.

Yes, we are a spoiled lot!

N941WR said:

From the -7 on up, the builders probably don't know as you just take the parts out of yhe box and assemble them. I don't recall the plans even giving those dimensions.

Yes, we are a spoiled lot!

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Indeed we are!

I knew, but rediscovered, my engine twist (7) in making the baffles. The left rear is cut down further than the right rear. I did measure at the crank for vertical angle, and with the fuse level, could not detect any up/down angle measuring off the crank. The prop clearance is about 1/8" less on the right than the left side. The VS is off set, but have not measured it.

You know . . . we don't talk about dimensions like these, we just yak about primers an such. Since we stopped measuring women, things just got out of hand, now we don't even measure our airplanes. All subjective. Let me go get that ruler . . . .

Mani
Yes there is a 1/4 inch offset for the vertical stabilizer on the 7, and yes it took extensive measuring to locate that along with the vertical spar plumb in both directions.
Have fun with your MII project.
I built most of the wing ribs from scratch before coming over to the dark side.

Not all RV models are the same, so the answer is "it depends." The RV-8 has an offset engine mount, but not an offset vertical stab relative to the fuselage centerline. Others models do offset the vstab.

The 7 VS is offset, the 8 VS is not.

Must have something to do with pilot sitting on left side vrs center line.

Hey Mick, nice to see you over here on VAF! I can confirm the 6 I am building does indeed have an offset, just like my M2. Not sure on the engine mount. Would have to go measure.

Scott

Sdemeyer said:

Hey Mick, nice to see you over here on VAF! I can confirm the 6 I am building does indeed have an offset, just like my M2. Not sure on the engine mount. Would have to go measure.

Scott

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Oh Busted! Hi Scott. Don't tell the guys on the M2-yahoo that I'm over here cavorting with the Empire. I'll be banned for life haha.

In all truth, boat load of good dudes here and hey, 2 seat ships are all pretty much off the same tree, save for the canard group, esp when its paint, instruments, wheels, motors etc etc. Thanks for tolerating me VAF!

WRT offset, thanks for the offset info guys - M2 drivers have gone both ways - with set and w/o. I'm on the fence, but have to make a decision soon. Seems engine offset is not often done if fin offset is and vice versa.....

N941WR said:

From the -7 on up, the builders probably don't know as you just take the parts out of yhe box and assemble them. I don't recall the plans even giving those dimensions.

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"Just assemble them"? Uh, no...the plans specify the offset, discuss it, and call out a washer in a specific location on the rear spar to accommodate it.

At least in my case, "just assembling" meant reading the instructions and the plans, too.

YMMV.