airspeed indicator and flap torque tubes

[jeffreyhowell]

ac080400.jpg (516.62 KiB) Viewed 71418 times

I am building an S-90. I noticed in the POH the Vne is 204Kts. I called Darrell at Express Aircraft and he told me that is is supposed to be 230Kts. Witch is correct? I work at a aerospace company and know that flutter could become a big issue very fast. I am wondering what is the safety margin and at what speed was calculated for (204Kts or 230Kts)? I am also removing the flex disks between the flap actuator (center line) and the flap torque tubes. I am then replacing them with a universal joint. Does anybody know what type of linear actuator they used? Mine does not have a part number but it is plastic (if that makes a difference). how many pound actuator is it? I am trying to calculate max torque on the torque tubes. Also does anyone know where can I get small winglets like the one in the picture? Thanx Jeff

[kevin]

The linear actuator used in the 2000 was the convertible top motor for a volvo 2 seater convertible. About $300. I used a simple 150 lb capacity linear actuator like this http://www.ebay.com/itm/6-Inch-Linear-A ... Sw1XdUVSex from ebay. Pros- cheap and simple. Cons- not quite strong enough but strong enough. I will explain-
the book shows flap speeds of less than 100 mph. The 150 lb unit wont give more than half flaps over 90. Below 90 I can get down to full flaps as I slow down. It has built in current protection so it just kicks itself off at its limit for a second or 2, then when you turn final you can have full flaps.

The earlier models have it between the rear seats, the later models have it in the right wing root. I recommend the wing root, frees up a lot of floor space.

KA

[jeffreyhowell]

Thanks Kevin!

[LarryK]

Kevin, I am finally getting to that point, ran the wires for the Flap motor and am using a VPX pro for control, but am a bit stumped on how to set up the switch? Or what type to use, do you have a style of switch that works best? I flew the Cirrus recently and like there 1/2 and full flap switch, but can't quite figure out how they do it, (more thinking with a less distracted/fogged mind).

[jchisolm]

My wing is the original NLF (1989). I have the flap torque tubes from Larry. This set up has the outboard torque tube inboard of rib R, original flap p/p tube location. I'm having trouble visualizing how I'm going to be able to install or take the outboard section out of a closed wing. Just looking at it there does not seem to be enough space between ribs R and J to be able to manipulate the tube and get it out if needed for repair/maintenance.

Anyone have any pictures they could share of their setup. This is a CT with the original wing.

Thanks

[Johnwell]

Although I'd hate to 'break' the lower skin at that location and put another inspection hole there I can't see how else you could do any repairs there. The location is far away from the inspection hole between rib R and J to be feasible, I think.
Or...in case of a needed repair get a recip saw and take a deep breath....

[kevin]

A 4" hole saw makes a nice inspection plate cutter. And it fits back in the place it came out of.
I used a linear actuator with built in pot and hooked it to a microcomputer. Let me get my notes and I can tell you how to do it analog. Stay tuned. Email me if I take too long, been busy.

[kevin]

What kind of switch, slide toggle or rocker?