Undercarriage

Once again the exchange rate had me hurting with the gear so I put it off for a long time. With a few exceptions, I made the parts myself or had them made at a local friendly engineer who thinks the idea of building a plane is very novel.

The oleos seemed like they would be one of the biggest expenses with the gear and it seemed like re-inventing the wheel to a degree. After asking around, Buzz Glade gave me the idea to use other oleos. I found some Socata oleos from a Rallye that were about the right size. Mine were second hand and very cheap. With the Kiwi dollar exchange I couldn’t say no. I hand some converters made up to make them as close to standard as possible.

Here are the bits for the U/C. I bought the top part and got the rest made. The axles are from Aircraft Spruce. The brackets are laser cut from a file I made with QuickCAD.

13 May 2001

A major hurdle for me was getting the aeroplane sitting on its feet.

It has a temporary wood side load strut to stop it collapsing. The load on these is very high actually so metal ones are a better idea.. I had a bit a bit of an ‘event’ due to these.. I wouldn’t do it again !

Here is the reraction housing installed. Actually I was just checking the fit of the nose gear drive shaft.

Notice the smaller universals.

Excuse the wiring mess.

20 June 2001

Finally..

After MUCH stuffing around

The gear…

WORKS !!! Hooray !

There are many stories about problems with the retraction system for Falcos. Some have the gear not extending to the full limit, requiring extra manual turns of the crank (This is due to the down limit switch not being installed in the correct place ie. there is a fix for this.)

 I’ve had a few people ask me how I made the retraction system. I got a bit of help from Buzz Glade on this bit.

I did buy a few parts but made a lot too. I purchased the motor and the housing. I had already bought the bearings which was a mistake since the housing comes with the bearings installed… never mind.

For the screw jacks I used a lot of standard parts. The parts are readilly available through either Nook industries in the USA or through an agent. In Aussie it is Motion Technologies.

The Part Numbers I used were.

1 X 11050 Right Hand screw (3′ long)

1 X 51050 Left Hand Screw (3′ Long)

4 X 20050 Right Hand Bronz/AC Nut

2 X 80050 Left Hand Bronz/AC Nut

Screw Jack Assy Tech details

The nuts themselves don’t fit inside the tube reuired for the Falco Jacks but it is a simple job to turn them down to the correct size. You don’t need to make the outside edge fancy since it will be brazed anyhow.

Bronz/AC nuts in their original form

You will also notice that the nuts are too short. This has a benefit of being able to use two nuts instead of one with a small gap to allow for a grease nipple to be inserted between them.

It is important to have the screw inserted in the nuts when brazing them into the jack tubes as it stops the nuts melting and collapsing into the tube. Use plenty of flux and clean them well when complete.

As for the screws… the ends need to be altered.. what I did was to uses a lot of filler rod and welded the ends to make a rough knob that was in excess of 1/2 inch diameter for the required length and then turned them down to the required 1/2 inch. If you miss this step then there will be very little material holding the screw in place when you drill and ream the taper pins.

The universal joints shown in the plans are MS20271-B12 variety (from Aircraft Spruce or Wicks) which require a spacer (Also in the plans) to fit the screws into the universals. It is also stated (Somewhere) that the load saftey margin is 9.5 times on the universals. I couldn’t see the point.. I used -B10’s which have the correct bore diameter that doesn’t require spacers and still have well over the normal 150% safety rating.

20 June 2001

The mitre gears and the top gear are standard parts.. I got mine from Spruce who were very slow but other people stock them. The plans have the details. They need a bit of machining to lighten them but nothing major. The only no-standard gear is the forward mitre gear for the nose gear. I had this made locally. I made the axles slightly longer and installed the gears first then cut the axles to size.. It makes the whole thing heaps easier and less critical

Vac Bagging

I don’t have a lot to add here other than the fact that if I was doing it all again I don’t think I would bother with main gear wheel doors.

I haven’t yet fitted my nose wheel bay doors since I haven’t been all that happy with them… I’m getting there with help from Ian Ferguson and Dave Thomas.

This is the main wheel doors being vacuum bagged. I’ve learnt a lot about fiberglass since all this but this did work out quite successfully.

 

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