Thread: Hirobo BBC Stork restoration project

Hello gents.

I have been given a really good example of a Hirobo BBC Stork. It was bought by my father-in-law in 1985 in Japan and built by my brother-in-law. He says he has flown it for about 5 hours without crashes, he used training gear though. The original landing gear is a 3-wheeled type, but this has been replaced with the more conventional landing gear. The reason for this is that the 3 wheeled type was to unstable and tip-overs happened too quickly. I also have all manuals, Radio Control Helicopter magazine from 1986 with a build review. It came with a Multiplex Commander transmitter, 7(9) channel receiver, Futuba rate gyro (proper spinning type).
It's not been flown for many many years, so it's well covered in grime and dirt.
I have started to dissassemble all major components and began cleaning and polishing. Sofar it's been a good few hours. All radio gear has been tested and it all works !!
I am going to sea for the next 3 weeks and lots of parts and engine (EX46VF-H) will come with me, so I can give it all a good service/reconditioning.
Here are a few photo's.
All your tips and advice is very very welcome !!
Joe of vrhc will be licking is fingers at this !!

DSCF2426.jpgDSCF2434.jpgDSCF2441.jpgDSCF2432.jpgDSCF2440.jpgDSCF2437.jpg

That's a 500 size heli in there just to compare seizes.

Cheers !!

Hey.

Good luck with the restoration, it will be nice helicopter afterwards as it was a good model back in its day. I well remember Dave Nieman demonstrating it at various shows and comps many years ago.

Keep us posted as you go along.
.

Good idea with the skids, took the trike gear off mine as it always wanted to tip over. Hope to see yours up and flying soon.

Joe

Nice looking Stork Joe...

...so when did ppl start to feel that it was a better idea to put the vertical fin on the other way up?

It was a 'fad' at the time as the eagle also had it but not the shuttle....

Joe

Hi gents.

Well, been cleaning the gyro/amplifier box, receiver, connectors, cables, switches. All degreased and small electrical spray onto the contacts where I find it needs it.
Totally dissasembled the engine today, liner, piston, piston ring all very good condition. New gaskets made for the muffler flanges, bearings cleaned, still running smooth. Clutch bell and shoe-assembly cleaning, spring still good, shoes still good. So no new parts needed here !! Amazing.......
Question for Joe: Do you use the spacers between bottom frame (actually the side frames) and the landing gear ? Some oval black plastic spacers used here, about 10 mm high/wide with long 3mm bolts/self-locking nuts. Don't see why I need them really ?

Cheers !!

look on the picture to the clue on the fin

Bell_206a_jetranger_g-bkzi_arp.jpg

The spacers are needed to located the landing legs below the level of the canopy otherwise the canopy will not fit without being 'butchered'; if missed out it also brings the tail down low to the ground, not good......

Joe

Hi folks.

I have been busy with the part of the frame that holds all the 5 servo's. Took out the old servo's, no make on them, just a 19.95 price sticker. Must have been pretty pricy at the time. All 5 are the same, no 'fast' tail servo. They were all fitted with the rubber grommets, except on the 2 left hand ones there was no bushing used. This caused the lugs to tear a little bit, also they didn't sit flush to the mounting holes, causing stress on the rest of the housing. Also the servo housing is held together with a clip arrangment on the sides, which have broken over time on nearly all servo's, causing the bottom cover to be lose. After cleaning and thorough inspection of the servo's I found that the gears are made of a good quality resin, no wear to be seen anywhere, all pots clean, circuit boards clean, electric motors in very good condition. So why not restore and use these as well, I thought !!
After cleaning the frame part that holds the servo's I started to think of a way to 'repair' the servo housings. I have used some good quality Ducktape, which I wrapped around the housing to keep the 3-piece housing together. That worked quite well.
I then installed the servo's into positions again, only using the 4 screws and 2 screw backplates per servo, just tighten them enough not to cause any further damage to the lugs. The rubber grommets and bushing were omitted/disgarded as they were to much damaged over time, and the lugs were just feeling a bit to weak to be stressed any further.
I then made up some Araldite Rapid 2-component glue and 'filled' up the gaps between the mounting holes in the frame and the servo lugs, covering the screws backplates too, so it all formed a nice solid joint-up weld. I have let it dry to a very hard weld over 2 days and I must say that the servo's are pretty much well stuck into position.
If I ever have to renew them I will definately need a chisel and sledge hammer to get them out LOL !!
I just hope that vibrations are not going to damage the servo's to quickly, so I will think of a way to dampen the whole servo's frame part arrangement..........or just take the plunge and wait and see.
The Multiplex Commander transmitter has had a good service to, all switches, sliders and pots have had a thorough clean with electrical spray. Everything has been tested and receiver, gyro and servo's are working good.
I can't upload any photo as I am onboard a ship and satellite data traffic is soooooo slow. Will take some detailed pictures later once I get home at the end of the month.

@Joe: what transmitter/receiver/gyro/servo's do you use Joe ? I have a Spectrum DX6i that I might use if all this fail at some time in future, but like to try the vintage stuff first of course.

Thanks !
Cheers !!

Hi Hans

It has full 'period' original equipment. Futaba FP-S130S (0.24 sec) servo's on all controls, FG-G154 mechanical gyro and FP-R107N 35 Meg receiver. I do use a modern T9CP transmitter in order to ease setting up and with the CAMPAC unit I have it has a large memory for about 250 helicopters.

I have only hovered this one so waiting for the gales to die down and I will get it up and away to see how it goes.

Joe

Threads like this really take me back.

Back in the 80's when we were all flying Shuttles the model we all really wanted was the Hirobo Hawk.
It's the one old school heli I've yet to see these days!

Ah takes me back, the Stork (purchased as a wreck in a box) was my first proper heli after the Morley's.
Within two tanks with the Stork I did my first loops and rolls:-)
I did have a Hawk after that too.

Cheers
Bob

Got the rotor head completely stripped yesterday. Proper cleaned and degreased all parts, then re-oiled the bearings for the blade holders, packed the thrust bearing with new grease. I noticed that the thrust bearings has got 2 different diameters of the holes that go onto the shaft, like the ones we use in todays blade holders ! Good job I measured them before I refitted them because they were fitted wrong, 2 small in one blade holders and 2 large in the other one. Feathering spindles in good condition, rubber flapping dampers little bit grease on them, to preserve them really, but they were like new. Don't know how tight the damper collar needs to be screwed but tightened them up equally. Gave the feathering shaft a good degrease inside the bolt hole before applying Loctite medium strength to the bolt that keeps the blade holder on the shaft. Center damper still in good condition, take notice to fit it back the right way, should slot into the 'curved' hole. All other pins that are needed to keep the center hub and feathering shafts into position were all cleaned a also a little bit greased to preserve them, but all were in good condition, not bend or corroded. Did CA-ed 2 small selftapping screws into the yoke were the caps go over the pins, just because the plastic in the holes was worn out by the screws, this worked just fine. Well, good job done here, blade holders spinning like new on their shafts, all rubber dampers checked, some new self-locking nuts for the blades and 'jesus' bolt 'found' in a cupboard.... It's funny to see that the feathering shafts actually sits under an angle, so the blades point upwards. Is this a charateristic for a flapping rotor head ? I have Dieter Schluters RC Helicopter book at home, will read up on this style rotor head. And what's the pitch range for the main blades btw ? Some negative like -2 ? Back to work now, rough sea, plenty wind......such fun.... O yeah, I might get a Shuttle for my next restoration project, there is one gathering dust somewhere that I know of.....but it's been crashed so need some spares for sure. But who cares, it's all good fun. Cheers for now !!

Hans

You adjust the collars to 'tune' the flapping of the head to suit the flying style; soft for easy general flying and tightened up hard for aerobatics. I would give yourself -6 degrees of pitch otherwise it will be difficult to make a fast decent and will compromise autorotation capability.

Joe

Hi all.

It's been very nice and warm the last few days and I have made some good progress. I met Joe 2 weeks ago, very nice gentlemen, I hope to see his collection of vintage heli's soon. We had a good hour onboard, talking shipping/engineering and heli's of course.
As said before, engine and radio/servo's all have been 'serviced' whilst at sea.
Spend a lot of hours this week cleaning/re-greasing/oiling all rotating parts, all levers, bearings and bearing bushes. A lot of old grease and grime removed ! Got a few very dirty rags......
Then assembly started.....That actually went quicker then expected. Or is it just me, once you start building the hours just 'fly' by, and you can't stop.
Well, see the pictures for yourself.
First two are from the clutch bell, which has quite a bit of axial play in upwards direction, it will actually touch the main gear. Is this going to be a problem ? I might make a spacer for in between the top bearing of the clutch bell and the bearing block for the extended part of the engine output shaft.

DSCF2470.jpg

The next pictures are just to show how far I got.
So...then it was time today of the big start up...
Filled the tank with some 10% nitro I still had from my RC Truck, it's old fuel but nothing wrong with it.
Tested the glowplug, still ok (OS 8) , starter motor working fine. Got myself a 12 V sealed 14Ah lead-acid battery for the powerpanel, fuelpump working just fine, glowstart working ok.
After the second attempt the engine kept running, but a bit too high rev's for idling, so clutch engaged but no harm done, was expecting the worst anyway. But no drama...it ran very very well, responding to the throttle pretty good. So well chuffed !!!
Sofar the only thing stopping me from continuing the build is a few stripped M3x10 panhead philips screws and a non-genuine M3x10 capscrew in the wash-out unit, which has damaged the plastic bearing bushes.
I have ordered these, and some clutch-shoes, form Karen Lee hobbies in Canada. They have quite a lot of original Hirobo parts for good prices.
Uploading the photo's is not working anymore...see next post.