I think you can buy the Hog Bipe direct from Sig, online. I just bought two of their little Kobra kits online, slightly cheaper than Tower. Tower probably also has the bipe, at least they did last year when I bought the kit. Haven't started it yet, too many others in line first, but I figure with kits going out of style, better buy'em while I can.

Clair

I am at the point where I need to balance my Sig Hog Bipe. This is my first Bipe and I’m not sure how to read the 25%, 30%, and 35% CG marks on the plans. Can someone explain this type of marking? I’m used to the “inches from leading edge�. Thanks!

The percentages are percent of MAC or mean wing chord. The center figure, 30%, is a good place to start and is 4 1/8" back from the leading edge of the top wing. Any place FORWARD of this is ok if this is your first bipe. In fact I'd suggest 3 7/8 to 4". This will make the plane very stable (noseheavy). Later you can move the CG back to get more responsiveness if you like but I'd caution you not to go back beyond the 35% figure.

Have fun!

Outstanding! Thanks a bunch! Yes this is my first Bipe and I can't wait to get it in the air!

Ah I love to see more and more into the Hog Brotherhood, I too have the 100 on mine and it flies great. I modded the rudder on mine to a more round look the resemble more of a Waco and looks good in the air. A friend and I built them together last winter and they are a blast flying together and we actually have 3 of us up together with another friends skybolt and it looks sareal having 3 bipes with Saito 100's all fly over together (all 3 are in the pick but the skybolt isn't finished yet in the photo) Mine is the red one.

Dauntae

Very nice collection!... My Hog is still on the building board..at this point the tail feathers are done, top wing is done and bottom wing is nearing completion.... I figure by next week I will be able to star on the fuse.....

Here is my Hog Bipe that I am building. I still need to sand the tips of the wings to the proper shap, cut down the lower ailerons, shape the LE of the fixed portion of the rudder (is there a name for that?), mount the lower wing, install the radio gear, hinge the control surfaces, and install the tri-stock to blend the wing into the ailerons in a scale type manner.

Plenty of work still left to do.

I also plan to cover it with SIG Coverall, and this will be my first time using that product so it should be interesting.

I put the engine as far back as I could, I doubt I could have gone any further with it. The linkage for the throtle turned out better than I expected and it now will enter down low under the fuel tank floor. Now I need to figure out how I ill route the fuel lines through the firewall.

With the engine mounted this far back, is the throthle cam necessary, or can a straight push rod be used?

What I did was to not use a "cam" but with a music wire pushrod, go out past the throttle connection on the cab, and bend a "U" shap in the pushrod, with the pushrod connector coming back from the front of the engine to the throttle connection... I know, sounds weird, but it works.

Hey, sounds like a plan for my Astro Hog and I'm sure I understand the connection part of it is there any way you can post a pic of it? My engine is mounted too close to the firewall to use the cable I'm trying to use.

I did the cam (bell crank) to lower the throttle cable under the fuel shelf. If I had not, the throttle would hit the fire wall if I wanted to get full throw. It also would be almost above the fuse if the throttle was aimed up, and it would hit the engine mount if it was aimed down. By addin the bell crank, I was able to have the throttle swing out in front clear of the engine mount and clear of the firewall. It also sloved my issue of having the throttle cable above the fuel shelf and bending down to where all the servos will be mounted. I don't like curved pushrod, and if it can be installed where they are as straight as possible there will be less friction and therefore need less power to move it, so the battery will be drained slower. Bell cranks do add a bit of slop to the controls, but I figured it would be acceptable in the throtle, but I would not do it on control surfaces.

The engine is way back there, but i would like it about 1/8" further back. I might even want it back a 1/4" further depending on how far the prop is out front when I add a spinner back plate. Right now if I mounted a prop directly it would clear the cheeks by 1/4".

I am hoping balancing this plane won't be a big issue. Right now it is really nose heavy, and I will have to mount the radio gear way back to counter balance that big engine. That is one of the reasons I am trying to get the engine as far back as possible.

I'll get a pic of the linkage tonight. I got the idea from a "hints and tips" column in RCM back in the early 80's, and have used it ever since!

http://manuals.hobbico.com/gpm/gpma1220-1221-manual.pdf Page 15 shows how to set up a 4-cycle throttle cable. I have been using this method for two years now on my Big Stik and I had to do the same on my Hog. Works great! I'll also try and get some pics of both set ups I have. I think the linkage set up is cool! But, I like to keep things "simple". The fewer failure points the better!

yep.. that's how I've done mine, works great. I've found that sometimes, if you make the "u" bend a bit too wide, you'll get a bit too much flex in the rod. When that happens, i just solder some brass across the 'u' and it stiffens it right up.

Dubro makes what they call a '4-stroke throttle linkage' which sells for about $5. Essentially, it's a one-arm bellcrank that mounts on your engine mount just forward of the engine to which you mount your throttle cable. Then a rod runs directly back to the carb. No bends to flex and very smooth. Give one a try, you'll be pleased.

I saw that linkage kit at the LHS, but did not see an easy way to make it work. You got any pictures of an installation?

Sorry, no pics. But very simple to install. The bellcrank arm mounts to the engine mount with a screw that you tap in. The rod from your servo goes straight to that arm. Then, you run the second arm (which is supplied with the linkage) back to the throttle arm on the carb. Whole job takes less than 10 minutes, provides a smooth linkage and gives you a certain amount of flexibility to avoid obstrutions and you don't need to make crazy angles on your rods which might tend to bend. There is a small diagram in the package that makes this clear.

Just wondering if anyone is flying one of these with a twin cylinder four stroke? I have just bought a Saito 100 twin and am starting to dream of a suitable airframe. I've built a few Sig kits and always enjoyed the experience.

David Smith, Finland

I guess a twin would work, I don't know if it would have enough power, and you would have to modify the fuse cheeks to accept a twin....

I would assume a saito 100 twin would have enough power as a saito 100 single has more than enough power to pull it.

I don't know how you would mount the engine though. Putting one cylinder up and one down would look odd, and to get the thing horizontal you would just about have to chop the cheeks off, and I would think that would look odd unless you made a cowling for it. Round the sides of the fuse, and make a cowling, and it would be a very sharp looking plane, but with that effort why not just go with an ultimate or a pitts?

I think you'll find the twin has less power than the single cylinder-that's always the case given the same displacement. And you really wouldn't want to mount a twin vertically. My guess is that without a glow driver you'd be running on one cylinder half the time.

Save the twin for another project. You'll have a blast with the Hog-bipe on the one cylinder Saito 1.00

I would certainly mount it horizontally, not vertically and would obviously have to resort to some re-structuring around the nose, but most of my models go through several major rebuilds due to changes in power plants during their lives!

I was just wondering whether anyone had actually done it, the main concern is the weight and nose moment.

I think you're right about the weight. I know they balance out right on the money with the single cyl saito 100. that twin is going to require some weight in the tail, and they don't call this thing a 'hog' for nothing... they can be a bit "Porky"...

I just assembled mine with the engine, wings, landing gear, stabilizers and all control surfaces pined in place. The thing balances exactly on the recomended location. I don't have the radio gear installed yet, but that can be adjusted to fine tune the balance. I was kinda worried that the saito 100 was going to be too much weight and needed some extra weight in the tail. it is good to know that is not the case.

The main reason I said the twin should be enough power is because most people say the 100 single has more than enough power. With the twin, assuming it is not way down on power, it should be the same as a OS 91 which is recomended for the kit. The weight might be an issue though, as will the lopping off the nose to fit that engine in there. The 100 single is a good fit width wise for the hog bipe. See my pictures above.

I've got a 100 saito single on mine, and yeah, you could say it's enough power... sorta like a 20 foot roll, pull to vertical, stop climbing when you can't see it anymore. If you find you do need some extra weight in the tail with a twin (which would make it a VERY cool hog bipe), put it into lumber by making the rudder and elevator a bit larger. They're ok as is, but like they say.. too much of anything is just enough.