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-   -   Sig Smith Miniplane build (https://www.rcuniverse.com/forum/kit-building-121/4870668-sig-smith-miniplane-build.html)

Cougar429 04-16-2014 02:44 PM

I prefer anything with a smoking, fire belching, honking big radial. Worked on and around quite a few and love the sound, (even more than a friends Merlin, but let's not tell him that!),

taildragger1589 04-16-2014 04:03 PM

How about a 96" ETM Bearcat with a Moki 180 radial?+
Just got thru videoing the maiden flight of one at our field.

https://www.youtube.com/watch?v=1gVTUxSh9AM

Cougar429 04-16-2014 04:49 PM

Considering I have Rare Bear, you can tell I'm a fan of the F8F. Only thing I thought was a bit leery was the gentleman sitting to the front when he was revving up. If you've seen 4-strokes chuck props at full throttle, (as I have) you'd agree never a safe procedure.

Nice to see someone enjoying decent weather. Monday night we went from shorts and shirts to 2" of snow in 8 hours.

taildragger1589 04-16-2014 06:17 PM

Seen a bunch of nitro four strokers pop a prop, but never saw one on ignition do it.
But then again, I have very limited experience with petrol four strokers, (I've just got one, the Taube on the same page as the bearcat.)

lousy weather got here tues and today.

Hope for tomorrow though.:D

taildragger1589 04-21-2014 05:00 PM

7 Attachment(s)
Well, I hope you guys are happy!
Got me all caught up in the Smith again so that I had to drag the old girl out of the attic to take a look.
Built in '88 retired in '95.
Had to give her a bigger LG and wheels so the 14/6 prop cleared the grass (usually kinda high)

Not pretty!

Nick:(

PS. Ignore the photo of the scale and bag. Loaded by mistake. That's 2 lbs of lead shot for a parachute to attach to the Taube.

Rv7garage 04-21-2014 05:38 PM

Wow, that is about as Classic as it gets! Love that OS 80- I imagine it still runs?

Definitely looking forward to seeing you breathe new life into your Mini!

rc_wings 04-21-2014 08:00 PM

Ha....looks like the old girl needs a little TLC and a bit more than just a dusting off! Looks like she is still in good shape under the tattered skin! Me too looking forward to the rebirth!

taildragger1589 04-22-2014 07:09 AM

Thanks! if I can drag out and convert the old vids of her flying I'll post a link or embed one. (never tried a vid on RcUniverse)
That's an Enya .80, the first of them to hit the hobby shops back in the late eighties and it raised a few eyebrows because it kept up with my OS .90. same rpm on the 14/6 prop.
she's revealed a few busted glue joints, mostly the butt joints at the tail (did a *lot* of snaps at full throttle) and made me glad of the wire bracing I decided to put on the tail feathers.
surprisingly, the super coverite held out 99% of the fuel. The wood is clean and strong with just a little staining where it was in contact with music wire.
Vertical fin has a small twist to it but I think I can pull it out. (if not it will probably make the snap rolls interesting)
The big heavy wheels perched out on that long gear sure made it spin weird.

Knock wood and probably we won't have to cancel this project from hidden rot.

Nick

taildragger1589 04-22-2014 07:12 AM


Originally Posted by Rv7garage (Post 11787759)
Wow, that is about as Classic as it gets! Love that OS 80- I imagine it still runs?

Definitely looking forward to seeing you breathe new life into your Mini!

No, her bearings are seized up, don't know if it's from rust or just castor oil crud.
Probably just going to pack her away for another day. (and see if the parts can still be found).

Rv7garage 04-22-2014 07:23 AM

Bearing replacement should be an easy task. What a thing it would be, to see that old motor come to life!

big_poppa49 04-22-2014 12:42 PM

Well took mine out for a flight yesterday! All went good just needs some minor tuning on the low end side of the motor, but it flies great! At first it was pretty tail heavy as I had to trim alot of down elevator to get her to fly straight, but once trimmed it flew good. You guys think I should just leave the trim where it is or trim back to neutral and add some nose weight??

Comments on this?? When i balanced it i put my fingers on the rear top wing bolts, and the plane sat almost level, maybe just a HAIR nose down, but not by much

RICKSTUBBZ 04-22-2014 01:06 PM


Originally Posted by big_poppa49 (Post 11788361)
Well took mine out for a flight yesterday! All went good just needs some minor tuning on the low end side of the motor, but it flies great! At first it was pretty tail heavy as I had to trim alot of down elevator to get her to fly straight, but once trimmed it flew good. You guys think I should just leave the trim where it is or trim back to neutral and add some nose weight??

Comments on this?? When i balanced it i put my fingers on the rear top wing bolts, and the plane sat almost level, maybe just a HAIR nose down, but not by much

Big_49,

Glad the flight went well.....

Do not rebalance based on the elevator trim. That has to do with an incidence issue and not balance. There are many references in this thread that verify there is some minor incidence issues. Almost everyone to build one of these planes as referenced the need for down elevator trim.

At least one, maybe a couple of guys that have posted in this thread built their Smith with a little positive incidence in the stab and nearly eliminated the need for the down trim.

But if you would like to play around with rebalancing, don’t let me discourage you-just don’t do it because of the down trim situation as it is surely common.

Rv7garage 04-22-2014 01:09 PM

Nice to get out, I bet :)

Adjust your CG for comfort or faster action if you want. Don't go too far all at once, but by all means experiment with it. It's just like fine-tuning a musical instrument, or a bow... it's all about what YOU like.

big_poppa49 04-22-2014 01:23 PM

Well I may just leave it along, im afraid if I put any weight up front I might be feeding the probability of nose-overs, which I dont want because I would like to continue to run wood props, and if they strike the ground 9 times out of 10 they are going to crack or break.

Its flying fine now and taking off good, so I wont mess with it. Flight seems good too. I just need to mess with the bottom end of the motor. I adjusted to factory settings and it runs OK (so so) but at idle it will cut off sometimes, the bottom might just need to be leaned a tad, I can get the top end of these nitro motors easy but the bottom is what confuses me sometimes.

rc_wings 04-22-2014 01:45 PM


Originally Posted by taildragger1589 (Post 11788104)
That's an Enya .80, the first of them to hit the hobby shops back in the late eighties and it raised a few eyebrows because it kept up with my OS .90. same rpm on the 14/6 prop.

Hey I had one of those old engines!!!! Ran fantastic in a Unionville Norseman.....the larger version. Never had any issues with it, and I sold it with the plane a few years back. Did not fly it that much and it took up a lot of room, so parted with it to fund other projects. Kinda regret selling both plane and engine. I really like the Enya engines, but hard to come by up here. Would not hesitate to purchase one if the opportunity ever came up on a decent looking specimen.

taildragger1589 04-22-2014 04:40 PM


Originally Posted by big_poppa49 (Post 11788390)
Well I may just leave it along... Flight seems good too.

More importantly, if it gets too nose heavy, you might lose the stunt it does best, the outside snap roll. No matter what angle or speed the ship has, just poke the two sticks to the forward inside corners and you'll see the prettiest little snap a plane can do. and the nice thing is that it will come out flying normally the second you release the sticks.
Or, if you're like me, keep holding for a nice flat inverted spin, then reverse the ailerons and she'll wind up like a top.

(if she doesn't add more throw to rudder and elevator)

I've heard of some people putting a 1/16" shim under the rear bolts to improve handling, but mine had a heavy enya on it and didn't need it.

Nick:)

taildragger1589 04-22-2014 04:47 PM


Originally Posted by rc_wings (Post 11788416)
Hey I had one of those old engines!!!! Ran fantastic

As you can tell by the dented intake pipe, this one's not in real good shape.
She was in a super heavy Sig Ryan STA that taught me all about a maneuver called "the secondary spin".
We made a foot deep hole in the dirt digging her out.
but she sure ran good! had a real tic over idle too.

Nick

rc_wings 04-22-2014 04:52 PM

Mine likely had the best idle of any of the engines I have run over the years! Can't remember what it clocked down to, but you could almost count the blades how low it would go. :rolleyes:

KaP2011 04-23-2014 04:32 AM


Originally Posted by big_poppa49 (Post 11788361)
Well took mine out for a flight yesterday! All went good just needs some minor tuning on the low end side of the motor, but it flies great! At first it was pretty tail heavy as I had to trim alot of down elevator to get her to fly straight, but once trimmed it flew good. You guys think I should just leave the trim where it is or trim back to neutral and add some nose weight??

Comments on this?? When i balanced it i put my fingers on the rear top wing bolts, and the plane sat almost level, maybe just a HAIR nose down, but not by much

RICKSTUBBZ is correct. The 0 incidence on the tail means you will have to fly with a little down trim because at 0 degrees the tail is not providing any lift, the down trim provides lift.

taildragger1589 04-23-2014 07:27 PM

If anyone was wondering how much pulling power the new Saito FG11 has....
This is a vid of the Balsa USA Taube weighed down to 8 lbs. (27 oz. per sq. foot) on a parachute in case I needed to dump it.
I didn't need to, but dropped it after proving it could fly it. (I also wanted to see how fast a 4 ft diameter parachute would come down with 2 lbs. on it.

Nick

https://www.youtube.com/watch?v=VJAP5DTscUs&feature=youtu.be

taildragger1589 04-25-2014 06:15 PM

3 Attachment(s)
Well, after a week of testing joints, wood, hinges and stuff. I took out the hinges and replaced a section of the rudder post and re glued all the stringer butt joints.
(years of full throttle snap rolls will take their toll.)
The worst part so far has been scraping the fuel damp rotten foam rubber that was around the tank.
Had to re glue the diagonals in the stab and elevator. (slow epoxy)
Then a little sanding, new hinges, new innards and new coverite.
(After making sure the wings are OK to restore.)

More later.
Nick:)

Rv7garage 04-26-2014 04:57 AM

Lookin' good. Keep it up!

taildragger1589 04-26-2014 08:15 AM

Click Click:cool:

big_poppa49 04-27-2014 07:32 PM

What nitro fuel do you guys recommend that will run great in both 2 strokes and 4 strokes? Mostly talking about nitro percentage and oil percentage. I do like Byrons and Cool Power brands though

KaP2011 04-27-2014 07:56 PM

I use Morgan's Omega 15% in all my engines, both 2 and 4 strokes. Omega is a castor/synthetic blend so it's a little harder to clean up than straight synthetic but nothing smells as good as castor fuel in the morning. Also, Clarence Lee recommends at least some castor for protection against lean runs. I have always used Omega.


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