Astro Hog

[Martyn K]

Thanks all,

 

I have finished the upper planking upto the fuel tank hatch this evening and even fuel proofed the engine and tank bays. My wife would like to know what I smell of and I want to know how I managed to get fuel proofer in my hair!

 

Ian - it's a long way from being finished so this will be next seasons trainer

 

Martyn

[Martyn K]

Latest update - Fus, fin and tail

 

Been working away for a couple of days and end of year work is piling up. Nonetheless, some more progress.

 

Completed the upper decking... and a couple of coats of fuel proofer in the engine and tank bay

The decking has come out quite nicely, no big gaps, I am quite pleased with it.

This allowed me to get on with the fin and tail.

I eventually upped the fin size to 1/4" thick as I had much better quality wood in this size. The original has stitched-on rudder (and elevators), sorry, but haberdashery was never a strength so I have gone for proper hinges. The hinges on the rear of the fin are inlaid and laminated into 2 x 1/8 pieces with slots cut , all epoxied up and clamped up. This was then butted onto the rear of the fin as you can see. One thing I did spot is the 2x1/8 seems to be bigger than 1/4 so a little bit of packing was required to keep the hinges central.

The gap between the hinges is coincidentally exactly the same width at my sanding block!

The fin was simply glued into the fuselage and the forward section added. All very simple so far..

The tailplans is just a tad unusual. Probably the most important thing was the LE and TE are supposed to be manufactured from 5/16" square. Obviously the land of the free had some unusual stock sizes back in the 50's. Not really a problem, i simply stripped some 1/8 and 1/16 to 5/16 wide and laminated it up - this allowed me to overlap the LE in two directions for strength. The hinges for the Elevator were simply sandwiched between the 2 x 1/8 upper and lower.

and

Finally, the cockpit area has been cut out and the upper hump has been carved but not yet glued - I'll wait until it's covered before it get fitted permanently.

And that is it for this week... more to come.

Martyn

Edited By Martyn K on 16/12/2011 13:20:27

[Braddock, VC]

Martyn have a gold star!!!!!

[Martyn K]

Aw shucks

 

Thank you

 

M

[Martyn K]

One thing that I forgot to mention..The top of the fuselage is supposed to have a huge access hatch to get at the prehistoric Rx and actuators. I haven't bothered on this, access will be from the lower fuselage as per modern convention...

 

(I suppose my gold star will be withdrawn now..)

 

Martyn

[Braddock, VC]

No, that's fine. If you build it with the tailwheel brake you'll get Oak Leaves and if you build the original aileron hinging system there'll diamonds and swords to bling it out!

[Braddock, VC]

ps if you cut yourself during the build award yourself a purple star!

[Big Bandit]

Certainly looks good Martyn very purposeful, Can't wait to get mine stared now.

 

Cheers,

 

Chris.

[Martyn K]

Posted by John Gibbs on 16/12/2011 19:14:54:
ps if you cut yourself during the build award yourself a purple star!

 

There are more blood stains on this fuseleage already = must have lost at least an

armful..

 

Martyn

[Martyn K]

Posted by John Gibbs on 16/12/2011 19:13:52:
No, that's fine. If you build it with the tailwheel brake you'll get Oak Leaves and if you build the original aileron hinging system there'll diamonds and swords to bling it out!

 

he he - prepare those diamonds and swords. I am going for it.. Mainly as an interesting and low cost diversion. The tailwheel brake is actually more problematic but I am still looking at it.. definitely not straightforward..

 

M

[Martyn K]

Posted by Big Bandit on 16/12/2011 19:15:07:

Certainly looks good Martyn very purposeful, Can't wait to get mine stared now.

 

Cheers,

 

Chris.

 

 

Thanks Chris - you will probably get yours finished before mine. I would be really interested to see what the differences are in the kit version though

[Big Bandit]

Hi Martyn,

 

After yesterday in the garage it's so damp, it looks like re-roofing that will take priority then at least I'll have more storage space and better workshop conditions. I'll do the kit but still fancy the tail-dragger version from the original plan like yours and with inset ailerons.

 

Is the wheel brake a wire loop over a sort of pulley fixed to the tail wheel, I sort of remember something like that on Geoff Franklins back in the late 60's.

 

Cheers,

 

Chris.

[Martyn K]

Hi Chris

 

This is the tail wheel brake contraption off the plan.

 

 

 

Basically, its a rod that gets pushed into the tailwheel via a linkage from the throttle actuator. With a fixed tailplane, it is not quite so straightforward. I have also purchased a commercial tailwheel mount that makes it a little more difficult to mount so I may have have to adapt the idea a bit to make it work.

 

Regards

 

Martyn (PS you don't happen to own a 1200 Suzuki do you?)

Edited By Martyn K on 20/12/2011 10:48:07

[Big Bandit]

Hi Martyn,

 

Thanks for that, I'm just interested to see how it works, the one I remember on Geoff Franklins model, and as I said it was just a small pulley fixed to the tail wheel hub so it revolved with it, and rapped around the pulley was a fine piano wire loop. One end was fixed to the tail-wheel leg and the other was pulled by one of the servo's. So simple, but an elegant solution to the problem.

 

I did own a 1200 Bandit Mk1 street fighter, with a stage 1 kit for a micron race can, jack up kit, rear sets and a few demon tweeks. I sold it in September, and after my heart attack last year and problems with blocked arteries decided it was time to hang up the leathers for good this time lest I had a funny turn while thrashing the thing and break my body, at my age you don't heal very quick.

 

Cheers,

 

Chris.

 

 

[Martyn K]

Not much progress this week. Christmas is now getting in the way of some serious building...

 

But, I have managed to complete the tailplane. This involved adding upper and lower 3/8 x 1/8 spars then adding some 1/18 x 1/16 tapered infill from the now protruding spar to the LE and TE. In reality, I simply glued them in as strip and sanded them down when the glue was dry. The little stains are caused by cyano, I use PVA for assembly and then seal the joints with a drop of cyano. This soaks into the wood and hardens it locally adding quite a bit of extra strength. It doesn't look so neat though.

 

I also added the central sheeted area and finally added the elevators which were laminated from 2 of 1/8 sheet with the hinges inlaided into little slots. I had a bit of a crisis, I didn't have any decent 1/8 or 1/4 sheet for the elevators and my local model shop had none either. By chance I called into a model shop in Sheffield and they had 3 beautiful sheets of 1/8 x 4" quarter grain. Beautifully light and stiff.

 

Rather large elevators I think and that is a BIG tailplane (note the 12" ruler)

 

The rudder has been added tonight and in the process of doing so, I have spotted my biggest mistake.. I have managed to glue the fin about 25mm too far back... I really should have spotted this - it was quite obvious when I looked at the plan.

 

The other bit of progress this week has been the addition of the tailwheel assembly. Because of my error and as I am using a fixed tailplane, the original brake assembly wont fit (the fuselage is too narrow where the tailwheel bracket would fit) so I have selected a commercial bracket and sprung axle rather than try and bash the brass. Sorry about that..

 

 

 

Finally the last bit is to install a servo tray (from 1/8 liteply) and beech rails and started dropping the servos into place. I expect that next weeks challenge will be to get the radio installation completed, the engine mounted and the tailplane fitted. By then Christmas will be over and I may actually get some flying done as well if the weather is half decent.

 

Merry Christmas all...

 

More to come.

 

Martyn

 

 

[Big Bandit]

Looking great so far Martyn,

 

A very neat build. Where is thee model shop in Sheffield you mention it just may be worth a visit next time I'm in the area.

 

Cheers,

 

Chris.

[Andy Green]

Great build Martyn,

 

Santa delivered my kit as expected, I'll be watching with real interest now, in anticipation of my build.

 

Feel free to make as many mistakes as you like - so I don't have to.

 

Andy

[Martyn K]

Thanks Andy/Chris

 

The model shop in Sheffield is here. Not really a R/C aircraft shop, but the benefit is that the average punter can't spot decent balsa when they see it. Certainly not brilliant for R/C hardware either

 

It's walking distance from my office at the bottom of the Moor.

 

A reasonable amount of progress this week, I'll update the blog later.

 

Take care.

 

Martyn

 

 

 

[Sparks]

Nice build Martin, looking forward to seeing pictures of the completed machine.

 

I've just finished rebuilding my crashed 1/2 scale Hog over Christmas - new main wing and fus. Only the tailplane, fin and pilot (Daredevil Dudley) survived!

Happy Hogmanay to you and all Hog builders!

Sparks

 

[Big Bandit]

Thanks Martyn, next time I'm in Sheffield I'll try to look in, it's always good to have a model shop post code in the sat nav for which ever town or city your in.

 

Sparks that looks good, so is that a 36" span, looks just right to keep in the car for a play.

 

Cheers,

 

Chris.

[Sparks]

Yes Chris 36" span - model of a model.

 

I'm thinking of doing a 48" span for the mass build. Just watching how Martin's full-size Hog progresses so that I can pinch his build tips

 

Richard

[Martyn K]

Before I start - Happy New Year.....

 

I have to admit that I do like the 'Hog, lots of building in it and lots of scope for tweaks without spoiling the character. I am inclined to build a 20 sized hog later as well - about 42" span.

 

Anyway onwards and upwards..

 

Fitted the tailplane to the fuselage - the original was held on by bands, this one is well and truly glued in place. (And its in the right place).

 

As the tailplane is mounted low to mid, it needs the lower fuelage spine extending.

 

and side pieces added

 

The push rods for the rudder and elevators have been added. I have used 1/4" square spruce push rods with dual push rods for the elevator.

 

and then finally sheeted in the bottom of the fuselage.

 

and

 

The servos are mounted on a liteply servotray - lots of space available and a crap photo - sorry. The throttle servo is mounted upside down (or right way up depending which way you look at it!

 

The engine (an ASP61) is now bolted on with the throttle linkage being 22g wire inside a goldenrod snake outer with a short length of inner acting as bushing at the start and end of the tube.

 

Apart from a bit more sanding and covering, that is the fuselage finished so on with the wing...

 

A couple of minor changes to the wing from my original thoughts. I am going to use the original aileron linkage method - it is so neat (I'll publish a plan snapshot of you are not aware of how it is done) although quite complex..

 

I am going to use cappping over the ribs - it adds an immense amount of stiffness for very little weight and finally, as I could not find any decent 1/8 or 3/32 balsa for the ribs, I will make these out of 1/8 lightply. I will need to watch the weight though. The front two spars will also be 1/4 square spruce rather than balsa. I will be building the reduced dihederal version though.

 

A master template (based on W1 (the root rib)) was cut and carefully sanded to shape. Simply draw round this 24 times onto a piece of 1m x 300mm lighply and bung it through the bandsaw. A real entertaining evening. The idea was to get the initial cut just slightly too large. The blanks are then stacked and drilled using an M5 drill and 2 long bolts hold the lot together.

 

Start sanding....

 

Once they are all the same shape (possibly not the correct shape), slots for the spars are marked and cut (and lightening holes drilled).

 

By the power of stupidity invested upon me (a recurring New Years honour), I managed to make the lower rear spar slot 5/16" wide instead of 1/4", but hey ho, both the rear spars will now be 5/16" wide and spars cut to fit.

 

The next problem I have is that the wing chord of the 'hog is wider than my building board so another board is required...

 

Happy New year.

 

More to come,

 

Martyn

 

[Martyn K]

Sorry, forgot to mention.

 

Sparks - I like the baby hog (perhaps a hoglet?) these are so full of character, more golden age than vintage - a timeless classic.

 

Whil taking photos for the blog, I managed to drop the hog on the rudder. Airframe survived, the servo didn't...

 

I have also got a 10oz tank - I'll publish how I fitted that later.

 

Have a good one.

 

Martyn

Edited By Martyn K on 31/12/2011 11:28:01

[Big Bandit]

Looking very good Martyn, I like your style.

 

Happy new year,

 

Chris.

[Sparks]

Hi Martyn,

 

Happy New Year.

 

As you have started on the main-wing thought you might be interested in the enclosed aileron linkage I used on my Hoglet - see pictures below. The barn door ailerons are sufficiently deep for the linkage and horn to be completely buried in the wing, so no dangly bits. I made the horn (which extends to the trailing edge for support) from 1.5mm fibreglass sheet.

 

Richard

 

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