Hobby King's YAK55 44.4" - RC Groups
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Jul 02, 2010, 06:03 AM
The original Flying Pigs Sqd.
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Hobby King's YAK55 44.4"

After the demise of my Hyperion Su31, I'd been looking around for something aerobatic.

Leafing through Hobby King's pages I noticed this one (right at the end). I've seen a few HK models and was pleasantly surprised. In fact, they looked very much similar to the Hyperion models! (more about that later, with the pictures)

So this morning I made the trip to the post office.

The pictures tell the story.

More to follow...
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Jul 02, 2010, 07:50 AM
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Tony Oliver's Avatar
...and is it made of something, let us say, bounceable?

A ripping good model by the look of it.
Go to it, Rene!
Jul 03, 2010, 04:14 AM
Registered User
Ziet er mooi uit. Issie stevig? Marcel
Jul 03, 2010, 03:17 PM
The original Flying Pigs Sqd.
Up&Away's Avatar

First impressions

are important.

Not much time/opportunity to do much building. I did have a good look at all the bits 'n pieces though. The build looks good & solid. Very much like we've come to expect from more expensive brand models (hence the name on the wing?) There's a nice bag of good quality goodies as well, but no decal sheet (getting back to that name again?).

Ok, I've put it of long enough...
The instructions. I mean, what can you expect when on the first page right on top it says in great big letters "Before use please carefully". I've leafed through the entire badly printed 5 page pictorial, with bad dark pictures, but nowhere is stated what I should be "carefully" with.

Obviously, this is by no means a trainer, and whoever buys a model like this must have some experience. The only realy important part in the instructions is the last page: the recommended throws, and the CG.

I also realized that another order to HK is in order. The motor mount is using a front attachment, as opposed to a rear attachment more commonly used nowadays (probably because you can use a shorter -lighter- motormount?), so I need to get a prop adaptor. And while at it, I also ordered some wooden props, carbon/plastic props, and a 3-blade prop!

And while checking the motorfit, using the recommended motor (which I had in my Su31) I noticed that the pre-drilled holes for the motor where wrong!

Some work has started:
I've filled the wrong holes with an epoxy/microballoons mixture and will redrill. I've spread medium CA on all the joints, and will CA some strands of carbontow on the mount as well. The actual firewall, where the motor attaches to, I will CA two layers of very light fiberglass'
Jul 03, 2010, 04:03 PM
ExtremeFlight - 3DHS - Legacy
blucor basher's Avatar
..since HC is, among other things, a retailer of overstock, remnant, discontinued, and otherwise orphan products, I'm not sure why you're so surprised that they are retailing some Hyperion branded airplanes. That's sort of what they're in business to do.
Jul 03, 2010, 06:14 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
Like most models, the landing gear mount could do with some re-enforcement.

First I made these 1mm balsa pieces, CA'd with fiberglass. The larger ones (outside) glassed on both sides, the smaller ones (inside) on one side only.
Last edited by Up&Away; Jul 06, 2010 at 02:17 PM.
Jul 06, 2010, 02:22 PM
The original Flying Pigs Sqd.
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Didn't have much time, so I fiddled around with the motormount for a bit. It seems a bit on the flimsy side, especially considering thye length. So I CA'd some CFtow to the top and sides, two thin sheets of fiberglass cross-wise over the firewall. All medium CA without kicker. That way the CA gets the time to enter the wood pores.
Jul 07, 2010, 04:14 PM
The original Flying Pigs Sqd.
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I opened up the aileron servo cavity with a warm soldering iron. I find this the easiest way to get a clean cut opening without lifting the covering from the wood. Turns out the servo opening is way to large for my HXT900 servo (similar size to the HS65). So I made a balsa/fiberglass insert to fit the servo...
Jul 10, 2010, 04:12 AM
Registered User
I like the colour.
Jul 11, 2010, 03:43 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
Continued with the bits 'n pieces.

At first glance, the supplied hardware looked good. However....
I trial fitted the wings and tried to use the supplied bolts, Very dinky looking, with plenty of space on them to have a good grip. Unfortunately, it appears that one is metric, and one is imperial! No biggy, a trip to the LHS will remedy that, but still...

Then this evening, I was going to fit and glue in the horizontal stab. Trial fitting, a bit of sanding here and there to get a good horizontal fit, and carefully lifted the covering of the center.
Now, as most of us know, fitting the elevator connecting rod after glueing in the stab can be a problem, if not impossible. So I looked in the goodies bag for the connecting rod. Nowhere to be found. Then I looked in the instructions, where there's a picture of all the components; no connecting rod to be seen. Then I looked in the pictorial; NO CONNECTING ROD!!! How do they expect the elevator to work is a mystery to me. The elevator halves are prepared (including a pre-drilled hole) for a 2mm rod, so I cut a piece of 2mm rod from the spares drawer, two 90* bends, and presto!

I trial fitted the stab again, and measured the stab tip distance to the middle of the fuse's nose several times to make sure it was square. I then placed a piece of masking tape on the stab to mark the spot. Then it was simple a case of pulling out the stab, tape the connector rod in place, apply thick CA, and put the stab back on the line of the masking tape.
Jul 14, 2010, 01:59 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
Vertical stab was CA'd in without a hitch. Some slight sanding to get it straight.

I'm waiting for a parcel from Hobby City with CA, applicators, props, prop adaptor etc so I still can't work on the hinges.

In the meantime I decided to do the wheelpants. After figuring out how to fit them (never done this before) quite a bit of headscratching because a. the instructions are cr*p and b. the bag of goodies is becoming a puzzle in itself. Which screw/nut/bolt belongs to what and goes where, and a mixed bag of imperial and metric to boot....

Anyway, I think I got it figured out and did several trial fitting, also to measure where to drill the holes in the wheelpants. When I was satisfied I sprayed them yellow (realy didn't like the idea of white wheelpants) spraypaint, and some glossy varnish.

Tomorrow I'll attach it all to the fuse.

Also most of tail wheel assembly was done. Obviously the final fit will be when the rudder gets attached.
Jul 20, 2010, 11:37 AM
The original Flying Pigs Sqd.
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I've been very busy at work lately, so very little done. Just some bits and pieces.

I am using an SBEC, so I soldered the power leads to those of the ESC, and disconnected the red wire from the ESC wire to the Rx. Note, disconnect, not remove. I may want to change back in the future.

I attached the wheel to the wheel pants. The wheels were not centered in the pants and I didn't have any spare washers. So I used two server grommets between the wheel and the wheel pants. Seems to fit just fine that way! For the time being I will be using the supplied aluminium landing gear. If it bends too easily I'll get some carbon legs.

Now I am waiting for a package from Hobby City with thin CA, CA applicators, props (including a three blade 10x7) and prop adapters. Then I can fit the flight surfaces and cowl.
Jul 25, 2010, 04:52 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
Prop adaptor, props, CA and CA applicators arrived! (and a sheet of stickers)

So, hinges CA'd into elevators, rudder and ailerons. Ailerons CA'd onto wing.

Bent the tail wheel rod and cut to size. Unbend the rod, to fit it in the plastic holder, then bend it again...

CA'd rudder in place (with some 5 minute epoxy as well, for the wheel rod), and then CA'd elevator halves (and again some 5 minute epoxy, this time for the connecting rod).

Taped some thick paper strips on the fuse to mark where the screws for the cowl go. Moved the cowl in place, drilled the holes and screwed in the screws. Removed the tape and paper, removed the cowl, squeezed some thin CA in the screw holes.

Fitted the prop adaptor by first filing a flat spot on the motor axle, unscrewing the grubscrews, a dab of locktite on both of them, and then placing the adaptor on the axle making sure one grubscrew is right on top of the flat spot.

By now the CA from the screw holes had dried, so I screwed the cowl back in place.

I've got several props to try (including that cool 3 blade 10x7 one).

Next steps: aileron pushrods, tape the rudder and elevator servos on the fuse to see how she balances with the servos in the tail. Otherwise I will put them inside the fuse...
Last edited by Up&Away; Jul 26, 2010 at 08:52 AM.
Aug 13, 2010, 08:56 AM
The original Flying Pigs Sqd.
Up&Away's Avatar
Virtually ready for the maiden now. "It" was supposed to happen this morning, but family matters took over...

Anyway, that gives me time to watt test these props:
Aug 13, 2010, 09:38 AM
Registered User
Tony Oliver's Avatar
Shouldn't that be 'weight tests' ....

..or do we have to 'wait' for the watt test (what?)

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