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-   -   Sig Astro Hog @ 150% ? (https://www.rcuniverse.com/forum/kit-building-121/10847523-sig-astro-hog-%40-150%25.html)

Mikie 1 12-07-2011 03:04 AM

Sig Astro Hog @ 150% ?
Hi guys!! My second airplane after my trainer was a Sig Astro Hog with an OS 60. I loved that plane. I wrecked it during my second flying season.
Actually, I destroyed the fuselage...I do still have the wing. So recently I purchased, from Sig, another full kit. I figure the extra wing won't hurt to have around. I'll build the fuse and use the older wing.

The real reason for this post is to ask about the same airplane enlarged - to say...150% (or more ?). I've been watching a local hobby shop in town that took on- trade a clean Saito 90 flat twin. I'm wanting to build a plane around that engine. And I thought of the Astro Hog / enlarged. I've built several planes from scratch so I believe I can build the plane.

What do you guys thing?? Any better suggestions for that engine?

I await your seasoned and respected wisdom... ;-) Mikie

ScottMcM 12-07-2011 03:18 AM

RE: Sig Astro Hog @ 150% ?
If I'm not mistaken, (and quite often I am), the 90 twin would be about right for a 60 size plane. I have one in a Hangar 9 Cub, and in a Top Flite Cessna 182, and while the engine is plenty powerful for the cub(40 size), it is barely enough for the Cessna. I'm thinking that the engine would be right for the Hog without enlarging it......but then again, I could be mistaken. My biggest issue was dealing with the extra weight....of the engine and the onboard glow system to keep it lit.

dignlivn 12-07-2011 05:14 AM

RE: Sig Astro Hog @ 150% ?

I agree with Scott,

My Astro Hog flys with a Saito 82.


ron9844 12-07-2011 05:22 AM

RE: Sig Astro Hog @ 150% ?
Check out Jerry Bates Plans, he already has a 90" size plan set.


grimmy55 12-07-2011 10:03 AM

RE: Sig Astro Hog @ 150% ?
Hi there the way I,m reading this post is that he wants to increase the plane size 150% ie from 84inch ,,,that would be 210 inch wingspan that sure is some plane then you,d need at least a 75cc I figure correct me if I,m wrong please

CanDo 12-07-2011 10:30 AM

RE: Sig Astro Hog @ 150% ?
As I recall, my Hog was ~71" span. Counting with my fingers, I'm thinking 150% is around 107" span. FYI, I had a OS 91 4-stroke on my Hog and it was a real kick to fly!

Highflight 12-07-2011 11:51 AM

RE: Sig Astro Hog @ 150% ?

ORIGINAL: grimmy55

Hi there the way I,m reading this post is that he wants to increase the plane size 150% ie from 84inch ,,,that would be 210 inch wingspan that sure is some plane then you,d need at least a 75cc I figure correct me if I,m wrong please
Recheck your computations; increasing the Hog from 84" by 150% would be 126" wingspan, not 210".

I think the Astro Hog at a 126" wingspan (basically 10 feet) would be a great flying airplane, probably best flown with something along the line of a Q42 or G38.
I've always been a fan of the Hog but never got around to doing one. Maybe some day... ;)

cubfloater 12-07-2011 06:15 PM

RE: Sig Astro Hog @ 150% ?
Yes, the hog is 71" span. I fly mine with a Saito 72 and does well for me but I fly somewhat scale like. Not a wring it out kind of guy.


Mikie 1 12-08-2011 03:36 AM

RE: Sig Astro Hog @ 150% ?
Thanks Guys for your input. Yep, I guess I was figuring a Hog at 71 inches X 1.5 = 107 inch wingspan. Some day I would like to try to put one together. I've never tried to increase the size of a super successful plane like the Astro Hog. I have read, in many of the threads, here at R C Universe, that folks have done it and have had lots of fun during the process.
About the Saito engine... I guess I keep forgetting just because it is a twin and larger than the standard two stroke single cylendar engine for that plane, it's really not all that much bigger.
I will finish the build of the standard size Astro Hog and install the Saito 90 twin. As you guys mentioned, it shouldn't be overpowered, it should fly well and as is usual for me it will be an oddity at the field. I like that. And it will give us all something to talk about.

Thanks for your input!!! Mikie

CanDo 12-08-2011 07:08 AM

RE: Sig Astro Hog @ 150% ?
BTW, many years ago a friend built a Hog that I believe was 150%; it flew great! You will have a very special plane if you build one. Good luck!

blazer293 12-08-2011 05:02 PM

RE: Sig Astro Hog @ 150% ?
I have a set of plans designed by Dave Weigandt for a Hog and Ahalf. It's a 90 inch Astrohog for a Q35 Quadra engine. These are very old and yellowed plans that have some water and smoke damage from a house fire. They were giving to me by a friends wife after her husband died. He never built it. I plan to build it one day. It looks really cool on the plans.

fix-n-fly 12-08-2011 05:18 PM

RE: Sig Astro Hog @ 150% ?
I am thinking that for a Saito 90 twin something with a 107 inch wingspan would need to be built light like a Sig Kadet in order to fly. Maybe a Sig Spacewalker (1/4 scale) would be a good comprimise that could be bashed into an Astrohog? Sig also has the 1/3 scale Spacewalker with a 104" wing, but that would require more engine than a .90 Saito twin.

Just a thought...

Mikie 1 01-11-2012 04:31 PM

RE: Sig Astro Hog @ 150% ?
blazer 293 - Any chance you might have those plans copied some day? Would you keep me in mind...please?


Gray Beard 01-11-2012 05:04 PM

RE: Sig Astro Hog @ 150% ?
At one point years ago someone made a giant scale kit of the hog. I can't recall who but it was big.
The Saito twin is a very cool engine but for even a .90 they were under powered. Most of the ones I have seen used were in Cubs and they lend themselves very well to that plane.
Enlarging plans is nothing new. We used to project them onto a wall with big sheets of paper tacked up and just trace them. Then some of the copy services started getting in bigger copy machines that could do it a lot better.
The only trick to it is as the plans are enlarged so is the size of the wood so it's up to the builder to figure out what size wood should be used. Just because the wood is enlarged from 1/8 to 1/4 doesn't mean you need to use 1/4, it can still be 1/8 or 5/32.
It just requires some thinking on the builders part. I still do it today by making templates of the parts in a kit then going to Kinko's. The charge by the sq. in. and it isn't cheap. I just had a copy of one page of plans for a little 1/2A plane and the cost was $10.00.
Do the research first like going to Kinko's and see how big they can enlarge to.
It's easy and fun.
Also start thinking about a good gas engine for a plane that size. When I get to about 80 inches I go to 40cc. Depending on the weight of the plane you are thinking about you may decide on something bigger like a G-62 or one of the new gassers from China.
Don't forget about the servos you will now require. Big controls on a heavy plane require some good servos.
See the money adding up!!
I gave up building planes over 80 inches for several reasons, money was at the top of my list but there are others.

foodstick 01-11-2012 05:32 PM

RE: Sig Astro Hog @ 150% ?
This would be a great project !
This could be an alternative route....

the Hog bipe looks so much like a 4 star fuse with two wings, I would just by me a 120 size 4 star and a spare wing kit. then change the formers to cheat it out ;)

Of course no need for that if you like blowing up plans and cutting kits.

I have no idea why the 4 star has never been offered as a bipe?

years ago in the local club a guy built an 80-90 inch wingspan Smith Mini Plane, wow was that gorgeous !

I sure like seeing these threads where people are thinking off the normal course.. makes me feel less alone ;)

Mikie 1 01-18-2012 02:21 PM

RE: Sig Astro Hog @ 150% ?
Although I talked about a "Hog" at 150 % ... Why not go to 200%? I've built two nitro planes from scrathc, and they both fly very well, I feel pretty sure I could take my time and really create a masterpiece. If done right, at any size, it should fly very well.
I love the idea of maybe one BIG ENOUGH to fly around in!!! LOL!!!

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