#26 Model airplane build clinic... Astro Hog

[Dimeflyer]

Pd1
It looks like an airplane is growing on your bench guy !!
George

[pd1]

Thanks George, I guess it does look that way.

Added the fuselage nose blocks. Took all day I could only do one at a time.
Had to clamp each seam and let the glue dry completely before doing the next block so spaces didn't develop at the joints.
Pictures added in earlier post.

[Dimeflyer]

It look good so far guy , just take your time so it comes out great !
George

[pd1]

Rounded the second side of the nose, vacuumed up the workshop for a half hour afterward.

I added plywood rails for the servos. The forward rails is extra wide so I can Velcro the flight battery pack there if the CG has to shift rearward.

Plywood plates for the battery mount floor also added. The space between the front and rear plate is so I can get at the ESC for mounting and removal, if need be.

I installed nylon pushrod tubes from the servos to the aft end. Added balsa former additions to give the tubes some support.

Added a ply plate to mount the tailwheel bracket. Blind nuts on the inside.

I started the bottom sheeting on the aft end of the fuselage. When the glue dries I'll add the other side.
Pictures added in earlier post.

[baz49exe]

Great build Paul.
This plane was designed when I was 8 years old back in 1957 !!
I'm developing an interest in the planes of my childhood now as well. I'll bet it'll benefit enormously from electric conversion.
Really looking forward to it!!!

Barry

[pd1]

Second half of bottom aft sheeting added.
Top aft sheeting done and forward sheeting started.

I wanted to make the opening for the battery larger so I had to make a new former.
Once I figured out the angle of the stringers, the new former was easy to loft.

I should have the second forward sheet on later today or tomorrow, then I can start the hatch and finish shaping the front of the fuselage.

Pictures in post number 3

[Dimeflyer]

It looks nice and neet keep up the good work guy !
George

[pd1]

Remember I told you about making that extra former?
After I cut out the paper template I looked for a piece of 3/32 scrap to cut the former out of. I found a piece laying on the bench that I had already cut something out of so I cut the former from that sheet.

Guess what? The piece of scrap turned out to be the top sheeting I had cut out using a template, The piece missing was the cockpit cut out. Oops.


Time to make another sheet, this time with only one cut out.

Forward sheets are on and pictures are in post number 3.

[pd1]

Finished the opening for the battery hatch. Made a hatch and sheeted it.
Added the last block to the nose and sanded it to it's final shape.

It's still rough, 80 grit sandpaper rough.
Time to put the wing and fuselage away until I build a tail for the plane.

Pictures are in post three.

[Dimeflyer]

It takes one step at a time guy .
You are getting close to covering time now !
Don't loos patients now and get in a hurry and maybe mess it up ?
It looks so good so far !
George

[gramps2161]

Paul the astro hog is coming along great.
Your hiding the servos in the wing shamed me into doing the same. I was going to leave them hanging out you know the easy way.
After seeing what you did with the servos I decided to do the right thing, and make servo pockets in the wing. Little extra work, but It does look a heck of a lot cleaner, and proper.

Have you decided what you are going to use for a power system for this plane?

[pd1]

Hi John,
I have an Exceed Monster 46 that was given to me. I made the mount for that, I also modified a mount for the E Flite power 60 to match up. If the plane is tail heavy, it gets the 60 right off. If the 46 doesn't pull it around like I want it gets the 60.
So in answer to your question, yes and no.

[pd1]

Started the stabilizer and vertical fin.
The fin parts and stab tips were printed on balsa stock, band saw and scroll saw to the rescue.
The kit called for 5/16 square spruce leading edges. I used balsa. I think spruce is way overkill.
This plane is so strong that I could use the wing for a ramp to load my lawnmower and the fuselage for a baseball bat.

Oh well, if I want I can always build a smaller one and reduce the weight a lot.

Pictures are posted in post number 4

[pd1]

Stabilizer and fin are done and the fit to each other and the fuselage has been done.

All I have to do now is check incidences and make and hinge the control surfaces.

Time for covering...

Pictures in post number 4

[Dereck]

Great build, a lovely old design indeed.

Way back in the last century, a clubmate of mine electrocuted this kit. The motor was an Astro 40G cobalt fed by 24 nimh cells - a little over three pounds of battery. It flew fine at whatever weight - we didn't get fussy then, as weighing models like that could be depressing.

With a modern motor and battery, you'll be well on the way.

Good one on putting the aileron servos inside where they belong. The last aircraft to look good with its controls on the outside was the DeHavilland Tiger Moth biplane! I went to two aileron servos vice one and torque rods around 1988, for the first time, and never went back, it's way better to do it like you did.

A period colour scheme comes next, one hopes?

Dereck

[gramps2161]

Originally Posted by pd1

Stabilizer and fin are done and the fit to each other and the fuselage has been done.

All I have to do now is check incidences and make and hinge the control surfaces.

Time for covering...

Pictures in post number 4

Paul could you show how you check the incidences I'm sure others would learn from it including myself.

[stuart]

paul,your doing a super job and moving along pretty quick.she's going to be flying in no time.sig really does make for a solid build and i think your tail fins will be plenty strong. just don't use this beauty as a ramp...lol. you might put a ding in the wood.

if the checking incidence for surfaces means lineing them up,i always use a yard stick or the string method. i check the measurement a million times and then glue tail fins or drill wing mounts for mounting bolts. if by incidence we'er talking the degree of built in angle of the wing or stableizer....i trust the lazer or cut fuse pc's designed by sig manufacturers to be right......maybe thats why all my builds fly in circles only[jk],sig kits fly beautifully!

not to hijack your build with pictures,but i used the yard stick on my recent uproar build and the string method in these pictures on an earlyer build of one.

[gramps2161]

Ya I get all the measurements for the tail feathers and make sure there squared up and the stab is parallel with the wing. Just never did the the incidence with the stab and wing.
Stuart I always just trust the kit myself that the wing and stab will be correctly setup. Wonder if that's why my planes do loops by themselves.

Sorry for the hijack Paul.

[pd1]

Thanks guys. I finished the elevator and rudder yesterday, they are shaped and the hinge slots are in.

Stuart, the clamp to hold the stab in position is a great idea, I never would have thought of that.

Here's the rub, the plane was originally designed for single channel up to multi reeds.
An airplane that climbed under full power was a desirable trait.

The kit was redesigned in 1983 and most of the wing incidence was removed, but not all.

I have had good luck with setting the wing and stab at zero incidence so both are exactly parallel. This one still shows plus one degree for the wing.

The airplane obviously flies fine with that set up but my friend has one and flying it I found it needed a lot of down elevator when inverted, even when the CG is correct.

I'm going to check his wing and stab before I commit to gluing my stab in place.
Maybe his is an anomaly.

I'll take a few pictures to show how it's done.

Paul

I'm going to try and get some covering on it today.

[Dereck]

That high down elevator trim for inverted could be more due to the semi-symmetrical wing section. The degree of positive is for normal flight - we tend to a wider speed range than back in the single channel/reeds day, which causes trim change. Flip inverted with a semi-symmetrical section and you've got to first overcome the needed plus setting for right-side-up, then compensate for that the semi-symmetrical section isn't as good at lifting when inverted.

As pointed out by a lot of Four Star 40 hours...

Oddly enough, I have a 'kit' that an old flying buddy made of an electrocution that looks a lot like an Astro Hog. He didn't really sell them - only made a dozen or so and gave me the last one as it was cluttering his workshop up - but to avoid messing with the 'real thing', he called it the 'Pollutionless Pig'. It was a very light structured model, around 60" span and pretty aerobatic on 10 to 14 nicad/nimh cells and a geared Astro cobalt 15 or so. Not sure how 'scale' it is, but you can't mistake its ancestory.

As I once flew a 9/14th scale model of a Smog Hog, I really should do some sort of Astro Hog.

Looking forward to seeing this slice of history in the air

D

[pd1]

Dereck, 'Pollutionless Pig' that's a great name.

Problem is I really spend most of my time flying inverted, so I would rather the plane was a bit easier to fly inverted.
I've run into the semi symmetrical airfoil before and that's why I want to cheat a bit and get the incidence closer to zero.
Yes, I know I'm strange.

I balanced the wing last night. Cleaned and vacuumed the shop and started covering the trailing edge today, so I can hide the pins for the hinges. Took 7 B B's to balance, about 10 grams not bad for such a large wing. I'll try and get some pictures tonight or tomorrow.

[pd1]

I started covering the ailerons and wing. Details and pictures in post 5 previous page.

Paul

[Dimeflyer]

Looking great guy !!
It should fly great to !
We are hopeing that it will !!
George

[Slowjohn]

Originally Posted by pd1

Dereck, 'Pollutionless Pig' that's a great name...

I'd like to use that in part on my Hog Bipe if I can ever get around to building it. Maybe after the Super Aeromaster build but I'm not doing much of anything right now till my separated ribs heal

Looking good Paul as usual

Standing By,
SJ

[gramps2161]

Paul great idea on the covering never thought of doing it that way to hide the pins in the hinges. Hope you post some more pic's as you go about the covering. I am sure this will help folks out who are still learning to cover. One of my least favorite parts of the build is covering.
For me I have had to learn not to fight the covering, but to work with the covering to get good results. I hope that makes sense.