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danielabernath

Well Known Member
I'm replacing the trim servo as someone pushed the NO PUSH NO PUSH trim on the stabalator and snapped off the screw on the servo.
I have now encountered this. Can you identify this and tell me what should be done next?
The new servo has bare wires and all are colored except TWO of them are white. An a&p told me that if you hook up the wrong white to the wrong white then it will be backwards (push up and the trim will go down) Anyway to do it right the first time?

Also,
1. how do I separate the old servo wires from this connections (to reuse the plugs coming from the aircraft)
2. are they shrink wrapped and have to be cut off and start from scratch with new connectors from the aircraft AND from the new servo.

Never did this before so your expertise is much appreciated.
24480611063_81212fb3ac_z.jpg
 
Just use a 9volt battery to test which white power wire drives the servo in which direction and label that wire accordingly.

Personally I'd ditch those connectors and replace the whole shoot'n match with a 9-pin Dsub connector.
 
Those are regular Faston terminals - Stein sells them as do thousands of other sources.

A DB9 would work here, or a Molex, or just about any other connector. If you use Faston terminals again, mark the wires with a Sharpie or something once you get them hooked back up and verify that the trim moves in the right direction.
 
There is a nice tidy upgrade available from Vans that replaces all those connectors with a single plug. It's on 'the list' about a dozen items from the top. '12 trim wire upgrade' is I think it is listed as. $7.00. Use a drill battery or similar to figure out which of the white wires is up and which is down.
There was a fairly recent discussion on the forum about the direction the anti servo (trim) tab should be moving. Use the search function to find it. Use the keyword 'trim tab' and you should finish up with more information than you need!:D
Hope this helps
Regards, DaveH
120485
 
white wires are the motor, reverse polarity for opposite direction, orange is power, green signal, blue ground, if using the Dynon for indication, the power is a 5 V feed from the Dynon EMS
 
daveyator said:
There is a nice tidy upgrade available from Vans that replaces all those connectors with a single plug. It's on 'the list' about a dozen items from the top. '12 trim wire upgrade' is I think it is listed as. $7.00.
Click to expand...

I tried to find a picture of that but I was unsuccessful. Can anyone post one?
 
Auburntsts said:
Personally I'd ditch those connectors and replace the whole shoot'n match with a 9-pin Dsub connector.
Click to expand...

I agree with using DB-9 connectors. Wire it up and test the trim direction. If it is backwards from what you need, then just pull both white wires from one connector and reverse them. Once you have the correct direction, label the white wires 1 and 2 on both sides of the DB9 and you will never have this problem again.

:cool:
 
Heh... I love it. "I'm going to show you how to properly strip wires"... and out comes the Bic lighter.
 
SMRacer said:
There is a SteinAir video showing how they suggest this connection.

https://www.youtube.com/watch?v=f8DCvBV2V4M&index=10&list=PLAzuY_lry21b9bd2h0MHqdp8lReIJ0XBw

Jim
RV4 N444JT
Click to expand...

I like to use clear heatshrink over the pins (& solder joints, too) so I can visually inspect to some degree without cutting open the joint.

To the OP: Stein's site might not show what you've got, but you can separate the connectors without cutting the cover. Those particular connectors are just fully insulated, so that when they're mated, there's no metallic conductor exposed.

Charlie
 
DaleB said:
Those are regular Faston terminals - Stein sells them as do thousands of other sources.

A DB9 would work here, or a Molex, or just about any other connector. If you use Faston terminals again, mark the wires with a Sharpie or something once you get them hooked back up and verify that the trim moves in the right direction.
Click to expand...

They aren't quite "regular" Fastons...notice they have a bump on the top and bottom of one side, and a matching shape on the other? You can't use a regular Faston without the appropriate opening on the "female" connector with one with the bumps on the "male" connector (but the other way will work).

I ran into this issue on a few items, but don't recall where I got the correct insulated terminals. I do agree about ditching them for servo wires and using a DB-9 connector or CPC.
 
Those are regular Faston terminals - Stein sells them as do thousands of other sources.

A DB9 would work here, or a Molex, or just about any other connector. If you use Faston terminals again, mark the wires with a Sharpie or something once you get them hooked back up and verify that the trim moves in the right direction.

I called Vans and am getting the new upgrade for the servo wires and tray (as suggested). They have no picture so when it comes in I'll photograph it and post it here.
I tried to reuse the old terminals by pulling them apart but the wires are 5 years old or so and were so brittle that a tiny wire just snapped. So I figured I go with Van's upgrade on the servo connector. They must know what they are doing in Aurora Oregon. Right?
 
Are you saying that you were pulling on the wires to separate the connectors? If so, don't do that (because it hurts when you do that).

Fast-ons are pretty snug when mating, and a lot tougher to separate, if they are working correctly. Two pairs of pliers, grabbing the shanks; fat screwdriver or other fulcrum between them, is the easiest way to separate them.
 
Never, ever, pull the wires to separate the connectors. Every time you do that, a unicorn stomps a kitten to death. It's considered bad form.
 
I was hoping to reuse the connectors coming from the aircraft but alas whilst in the field working on the project I erred.
I put plyers on the top connector and plyers on the bottom connector and pulled. The connection was firmly in place and the top plyer slipped and grabbed the wire while departing the connector and pulled out the wire from said upper connector.
So, I am at square one.
Home depot get the shrink wrap and small connectors revealed in the video.
Here is what the "new" and improved tray looks like for holding trim servo.
25054525411_a54033afb1_b.jpg
 
GalinHdz said:
I agree with using DB-9 connectors. Wire it up and test the trim direction. If it is backwards from what you need, then just pull both white wires from one connector and reverse them. Once you have the correct direction, label the white wires 1 and 2 on both sides of the DB9 and you will never have this problem again.

:cool:
Click to expand...

Yes on the DB connectors, but dump the body of the connectors.

Use the pins/sockets individually and cover each on with heatshrink. then add a larger heatshrink over the whole bundle to stiffen it up.
 
airguy said:
Never, ever, pull the wires to separate the connectors. Every time you do that, a unicorn stomps a kitten to death. It's considered bad form.
Click to expand...

I agree that it's bad form, but I didn't know about the unicorn thing ... good to know.

What happens if you use the wrong primer?
 
az_gila said:
Yes on the DB connectors, but dump the body of the connectors.

Use the pins/sockets individually and cover each on with heatshrink. then add a larger heatshrink over the whole bundle to stiffen it up.
Click to expand...

And you'll be cussing yourself the first time you have to pull the trim servo out for any reason. I've had mine out about 4 times already for various reasons, sure glad I had a DB9.

wjb said:
What happens if you use the wrong primer?
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It's worse - much worse. Rumor has it, it makes all your babies be born naked.
 
airguy said:
It's worse - much worse. Rumor has it, it makes all your babies be born naked.
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OMG .. both of my kids were born nekked! This is worse than I thought.

Though, I am not worried; Even though I walk through the dark valley (in IFR conditions), I will fear no evil, for I am building a tail dragger with a tip up canopy.

All is good. (and the kidz now have clothes)

Keep pounding!
 
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airguy said:
And you'll be cussing yourself the first time you have to pull the trim servo out for any reason. I've had mine out about 4 times already for various reasons, sure glad I had a DB9.
......
Click to expand...

The answer there is to use masking tape for all checkout purposes and only use the heatshrink when you know it's all working just before first flight. :)
 
danielabernath said:
25054525411_a54033afb1_b.jpg
Click to expand...

az_gila said:
Yes on the DB connectors, but dump the body of the connectors.

Use the pins/sockets individually and cover each on with heatshrink. then add a larger heatshrink over the whole bundle to stiffen it up.
Click to expand...

The part in the above image is intended to use a 6 pin micro molex plug. It mounts in the rectangular opening on the tab.

IMO, using individual wire connections for something as critical as pitch trim on a stabilator is not a good idea. It is providing opportunity for a mis-wire mistake to be made during maint.
The problems caused by the use of connectors are usually related to improper crimping of the pins, so bypassing the use of a connector body will not likely be of any benefit. The microfit connector used in this location has been extremely reliable and allows for easy disassembly for maint. with no risk of mis-wiring at reassembly.
 
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rvbuilder2002 said:
IMO, using individual wire connections for something as critical as pitch trim on a stabilator is not a good idea. It is providing opportunity for a mis-wire mistake to be made during maint.
Click to expand...

The critical wires here are the two white (power) wires which run the motor forward and backward. A simple solution, if one doesn't want to use connector bodies (as I didn't) but just heatshrink, is to "key" the two connectors after you figure out which wire is which...that is, on either side (harness or motor), us a male and a female pin (and vice-versa on the other side). No way to mis-mate them that way.
 
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