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Look Ma - No Flaps


BigPete
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Beautiful morning here in Echuca :thumb_up: - Drag out the Jabby, pre-flight and taxi for 17. Run up done A OK for go and just put in some take of flap and (@#$^) NO FLAPS. 068_angry.gif.cc43c1d4bb0cee77bfbafb87fd434239.gif

 

Nothing, Zilch, dead, silent. L o n g taxi back to the hanger. (sigh) 051_crying.gif.fe5d15edcc60afab3cc76b2638e7acf3.gif Off with the fascia, (well, I took out all the screws and moved it about 3 inches) Lots off wires 'n stuff in there. 031_loopy.gif.e6c12871a67563904dadc7a0d20945bf.gif

 

Anyway the short version is this:

 

found no loose wires, jiggled and poked around, but NO FLAPS. I'm going to replace the flap switch as it appears to be the culprit (after much poking with the multi meter). 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif

 

Can anyone tell me if the flap switch is a normal DPDT switch? Has anyone else had similiar problems with their flaps? (Working great 3 days ago)

 

:big_grin::big_grin:

 

regards

 

 

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Yes - circuit breakers ok. :thumb_up: Used more fuel (unleaded) in the car than I saved in Avgas just chasing around town looking for a switch. :yuk:

 

I'm assuming that the switch is a Double Pole, Double Throw switch with 6 contacts at the back. It needs to be spring loaded to center as this is the off position. 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif

 

I'm also assuming that one side is crossed over inside to give me a reversal of current (DC) to change the direction of the motor (flap).(I mean, why else would you have a switch with two ON positions?) If this switch is used with AC current then it would not matter. 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif

 

:big_grin::big_grin:

 

regards

 

 

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Pete

 

It is a DPDT switch.....and make sure you dont mess em up!

 

Not sure of what switch you have, when I installed ours (First J4/J2) and before Jabiru released it with the J160, I sourced my own switch. I also made a snubber and noise filter too!

 

Needs to be a heavy duty job, ours was a 250VAC, 10A rated unit.

 

Jaycar Electronics have a nice one and has not played up in about 630 hours of flying!

 

www.jaycar.com.au

 

Part number CAT. NO. SK0980

 

PS.... you can fly flapless you know!!!!;)

 

 

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Can anyone tell me if the flap switch is a normal DPDT switch?

Peter

 

 

 

Mine is not DPDT. Mine is more B-L-A-C-K-&-S-I-L-V-E-R.

 

 

 

I thought I had a photo of the back of mine all wired up, but couldn't find it on a 1st look so have attached a link to one of the front side which is sure to be no help at all.

 

 

 

http://www.recreationalflying.com/forum/attachment.php?attachmentid=3301&d=1191396877

 

 

 

However I believe that there is a copy of the wiring and connection instructions in the manual on the J website ..... or let me know and I'll email you a copy of that section of my Construction Manual for the 230.

 

 

 

Get it fixed by the Hopetoun Fly-in so that maybe we can finally say G'day.

 

 

 

Regards Geoff

 

 

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Thanks Guys - Yes I know I can fly without flaps, but I didn't know if loosing flaps was maybe just the start of a big electric meltdown. So I erred on the side of caution. I can fly the next day or the next etc etc.

 

I'll let you know how I go.....

 

regards

 

 

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That's funny Doug 006_laugh.gif.0f7b82c13a0ec29502c5fb56c616f069.gif006_laugh.gif.d4257c62d3c07cda468378b239946970.gif - It's just what I thought to myself as I took the long taxi (of shame?) back to the hanger. :confused:

 

:big_grin::big_grin:

 

regards

 

 

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Pete

 

It may not be the main switch, unless your multimeter has absolutely proven that to be the case. I was thinking it might be the limit switches that effectively limit how far up or down you can extend or retract the flaps.

 

The way the main dash switch is wired power will either come in to the center contacts (measure across the 2 center terminals) , or one set of end contacts (measure across either end set of 2 terminals). Either way with main power on it should be at one or the other, but not both. With the switch operated one way or the other which ever set of terminals had no power now should, with polarity changing depending on which way you toggle the switch. The switch is a center toggle DPDT switch and the cross over you allude to will be between the 2 sets of end contacts.

 

If that is what you find then move on to the flap actuator and start looking at the limit switches and then the motor.

 

Andy

 

 

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Thanks Andy - you may well be right. Until I read your post I thought it was the switch - some unusual readings on the multimeter until I matched it with what you said (in your post).

 

I will move onto the motor tomorrow.

 

regards

 

 

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Modest Pilot and others,

 

Quite correct, the reason I suggest the 250V 10 sitch is that its DC rating will exceed this by a fair amount and with the high inrush current (unlike an LED lamp) the switch will survive a lot longer if not indefinitely.

 

I would strongly suggest a snubber and filter across the switch, requires a suitable diode, capacitor and resistor, this will take the spikes and back EMF out of the system and reduce any noise you may get going into the DC system. You should get a local electronics guy to help you here!

 

As for switch ratings I found an article on the web that explains it quite well and here is what it says! There is some extra stuff you can pass over......

 

Any Carling Technologies' switch that has agency approvals will have its ratings stamped on its base. Carling Technologies switch ratings are listed by amperes, volts, and horsepower (when applicable). Electricity is the movement of electrons from one atom to another. The flow of electrons through an electrical conductor is called electrical current, which is measured in amperes or amps. The electrical pressure necessary to cause this movement is voltage. Voltage itself does not flow through conductors, but is the force that causes current to flow. Voltage is also called electrical potential, because if voltage is present in a conductor, there is potential for current flow.

 

Motors are rated in horsepower (HP) or fractions of horsepower (1/4, 1/3, 1/2, etc.) Mechanically, one horsepower (1HP) is equal to 33,000 pounds being moved 1 foot in 1 minute (or 33,000ft-lb/min). One horsepower (1HP) is also equal to 746 watts of electrical power.

 

The voltage rating is a function of a switch's ability to suppress the internal arc that occurs when a switch's contacts open. The voltage rating specified on Carling Technologies' switches represents the maximum voltage allowable for the switch to function properly at the rated current. The amp rating of a Carling switch is the maximum current in amperes the switch will carry continuously. So, in the example below the maximum amp rating for this switch at 250 volts AC (VAC) is 10 amps; the maximum amp rating at 125 volts AC for the same switch is 15 amps.

 

Switches that are going to be subjected to high-inrush inductive loads, such as an AC motor, will often be rated in horsepower in addition to volts and amps. This rating reflects the amount of current the switch contacts can handle at the moment the device is turned on. An AC motor will draw up to eight times its running current when first turned on or when held stationary while energized (stalled rotor). The switch in the example below would be rated for use with a 3/4HP motor at 125 through 250 volts AC.

 

Typical Carling Technologies' switch rating:

 

10A 250VAC

 

15A 125VAC

 

3/4HP 125-250VAC

 

AC/DC

 

Carling offers both AC (alternating current) and DC (direct current) switch voltage ratings. AC or alternating current is an electric current or voltage that reverses its direction of flow at regular intervals and has alternately positive and negative values, the average value of which over a period of time is zero. The number of times this value changes (or cycles) per second is it's frequency. Frequency is measured in Hertz (Hz). The more cycles per second, the higher the frequency. The electrical "grid" in North America is based on a very stable 60Hz frequency. Most European countries are based on a 50Hz frequency. All of Carling Technologies' AC voltage ratings are listed at 50/60Hz, and all Carling Technologies' agency approved switches will list specific AC voltage ratings.

 

DC or Direct Current is an electric current or voltage which may have pulsating characteristics, but which does not reverse direction. It's potential is always the same relative to ground, and it's polarity is either positive or negative. A battery is one example of a source of direct current.

 

A Carling AC rating is followed by "VAC", for example 125VAC is 125 volts AC. Carling AC/DC ratings are followed by "V" only, without the letters AC and DC following. For example a 125V rating would be read as 125 volts AC and 125 volts DC.

 

DC Rule of Thumb

 

For those switches that list an AC voltage rating only, the "DC Rule of Thumb" can be applied for determining the switch's maximum DC current rating. This "rule" states the highest amperage on the switch should perform satisfactorily up to 30 volts DC. For example, a switch which is rated at 10A 250VAC; 15A 125VAC; 3/4HP 125-250VAC, will be likely to perform satisfactorily at 15 amps up to 30 volts DC (VDC).

 

Types of Loads

 

An electric load is the amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy consuming equipment of the consumers. More simply put, a load is the piece of equipment you turn on and off.

 

Resistive loads primarily offer resistance to the flow of current. Examples of resistive loads include electric heaters, ranges, ovens, toasters, and irons. If the device is supposed to get hot and doesn't move, it's most likely a resistive load.

 

Inductive loads are usually devices that move and normally include electric magnets, like an electric motor. Examples of inductive loads include such things as power drills, electric mixers, fans, sewing machines, and vacuum cleaners. Transformers also produce inductive loads. High Inrush loads draw a higher amount of current or amperage when first turned on, compared to the amount of current required to continue running. An example of a high inrush load is a light bulb, which may draw 20 or more times its normal operating current when first turned on. This is often referred to as lamp load. Other examples of loads that have high inrush are switching power supplies (capacitive load) and motors (inductive load).

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Wow - Ya gotta luv these forums - Knowledge is power, and we've got plenty of it.

 

I'm on my way to the airport to tackle the flap motor itself - will keep you informed.

 

Thanks guys - fantastic.

 

:big_grin::big_grin:

 

regards

 

 

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Pete.. First flight of the day, we always do the preflight with the landing flap extended.. Checking for posative extention and retraction.. A guy had one flap retract on approach in a 160, the other one didn't retract, so u can imagine the party he had.. Just an idea, i think its GA standard to preflight with the flaps extended..(first flight)

 

cheers:thumb_up:

 

 

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Well - What a day!! :thumb_up:

 

Friend of mine flew over to give me a hand. keen.gif.9802fd8e381488e125cd8e26767cabb8.gif Tacho stopped working just before he landed. :yuk: Turned out to be a broken wire at the sensor (motor) end. Quick trip home to grab the soldering iron and some shrink wrap. Soon had it fixed. :thumb_up:

 

We then moved onto the club Jabiru, as its flaps had been reported to be "a bit intermitant" checked everything and all was OK. :thumb_up: Removed spats and checked/adjusted brakes. :)

 

After poking around yesterday with multimeter, I said to myself at the time, gee wouldn't it be great if Jabiru had placed a link somewhere in the cables for the flap motor. You know, something easy to get at to see if the power was getting through. i_dunno

 

Well, bless their socks they did :thumb_up: (and then hid it so well you had to be Sherlock to find it) or know where it was thumb_down (which my friend did). 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif This quickly established that it was the motor not working and the switch was OK. 011_clap.gif.c796ec930025ef6b94efb6b089d30b16.gif

 

Off with the flap motor (it sounds so easy doesn't it - well it wasn't) some hard to get at bolts slowed us down a little. Inside the flap motor shaft housing there are two micro switches, one at each end of the shaft. We very carefully sprayed the dickens out of them with electrical contact cleaner. (At 6.20 a small can we used about 2 bucks worth) :big_grin::big_grin::big_grin:

 

We then partialy re-assembled the unit and tested it - WORKING. 011_clap.gif.c796ec930025ef6b94efb6b089d30b16.gif Put it all back together and had a well earned cuppa. :)

 

And then I went flying........018_hug.gif.8f44196246785568c4ba31412287795a.gif018_hug.gif.0182e32b48b2df8aaf412ac8488cf68a.gif018_hug.gif.8f44196246785568c4ba31412287795a.gif

 

:big_grin::big_grin::big_grin:

 

PS. Many thanks to all that replied to my plight - 002_wave.gif.62d5c7a07e46b2ae47f4cd2e61a0c301.gif

 

:big_grin::big_grin:

 

regards

 

 

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Guest AusDarren

Congratulations on the satisfaction of sorting it out..

 

So are ya all set for the Winter Blues Weekend??

 

Several of us are comming up from MB. I'm in an Archer NBE

 

:-)

 

Regards,

 

AusDarren

 

 

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  • 2 weeks later...

Went flying again yesterday (Thursday). Just wandered around having fun. :thumb_up: Must do a few landings without flap I said to myself. But, first a couple with flaps just to "get in the grove". :)

 

So join downwind for 35, did my checks (as you do) called "...turning base for 35.." nose up, throttle back to 1800 rpm, left rudder in, flaps to 1st position...... 068_angry.gif.cc43c1d4bb0cee77bfbafb87fd434239.gif

 

Hmmmm, looks like I'm doing flapless landings as of NOW!. :yuk:

 

So I did 7 in a row - very high nose attitude, had to look out the side window, but no dramas. :thumb_up:

 

Today (Friday) out to the hanger, pull out the flap motor (with the use of a special tool to get at the hard to get to bolts) 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif and desolder the wires to the micro switch assembly and remove same from motor.

 

Over to the workbench and test switches (their are two) with micrometer - a zillion times - perfect. :yuk:068_angry.gif.cc43c1d4bb0cee77bfbafb87fd434239.gif:confused:051_crying.gif.fe5d15edcc60afab3cc76b2638e7acf3.gif:ah_oh:

 

Scratch head - question.gif.c2f6860684cbd9834a97934921df4bcb.gifquestion.gif.3fab79942766b9e477be0b131a0a3b3b.gif maybe switch "button" not being pressed in far enough inside flap motor housing. Made up some thin plastic shims to push switch out from mounting rail (less than half a millimeter). 040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif

 

Resolder wires, assemble motor and test - it's working with no load applied. Put everything back together in time to do 2 circuits before last light.

 

Works perfectly. We'll see....i_dunnoi_dunnoi_dunno

 

regards

 

:big_grin::big_grin::big_grin:

 

 

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Half flap.

 

One side down and the other up could be considered half flap ,.(joking) This is called assymmetric flap and is a pretty serious situation not covered in the design specification of our types of aircraft. There is no reason to believe that the aileron would counteract the roll resulting from it.( the flap) and further effects of rudder may help, if you put up with the big skid. Maintain and inspect the flap system and don't overspeed when flaps are extending/extended. If you suspect that the flap system is defective or jamming, land without flaps extended. If one side extends, limit the extension and consider retracting it. Nev..

 

 

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Yea, i got the story from a guy who knew the guy, so its second hand.. But apparently he just had enough ruddr and aileron to stop it flipping over.. Pretty scarry...don't know weather he tried to retract it or not...

 

I believe it was in an acft thats online at a bankstown school..

 

cheers..

 

 

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