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Trim servo wiring

jferraro17

jferraro17

Opulence, I has it...
I'm in the process of reading AeroElectric Connection, but am also wanting to run some wires to the tail so I can rivet the aft top skin, so...

Can anyone tell me if they used 22 AWG for their Ray Allen elevator trim servo to stick run? A search--not very well worded I guess--turned up very little. I also saw one thread about a 5 wire Ray Allen bundle, but would like to avoid an order for now. Haven't thought about connections yet, but need to get the wire in. Is this an appropriate gauge for the current/distance?

Thanks-

Joe
 
I used 22 awg for the Ray Allen elevator and aileron trim servos in my -10.

Bob
RV-10 N442PM (flying)
 
Call Stein....buy the wire bundle.

Other places to buy it but I make these purchases from Stein whenever possible.....he needs the income....right Stein :D??
 
I used the Ray Allen 5 wire bundle. It is 26AWG. Total pain to work with. I would definately go with Stein's bundle. I got his for the AP and it is top notch. You can run your own bundle. It needs to be twisted.
 
We too really dislike the AWG 26 wire, so we stock the 5 conductor shielded wire in AWG24 instead...still small but you can actually work with it and still use normal tools/pins/connectors for it. It's not super cheap wire, but it's easy to work with.

Cheers,
Stein
 
EMC Problems

Just a heads up. Finished the wiring with Stein's 5 wire bundle and had an EMC problem on final check out. When ICOM was keyed indicator went dim and "jumped around" (I love technical terms). Fought it for nearly a week and talked to RA on several occasions. It is a RA problem that has some reports and no doubt it was EMI, I can tell you via E-mail if interested. Bottom line, shield the aft run with Steins 2 and a 3 wire shielded bundle and save the time. 5 wire shielded is not available from Stein or others in small lots. Wish it was. Don
 
CODon said:
Just a heads up. Finished the wiring with Stein's 5 wire bundle and had an EMC problem on final check out. When ICOM was keyed indicator went dim and "jumped around" (I love technical terms). Fought it for nearly a week and talked to RA on several occasions. It is a RA problem that has some reports and no doubt it was EMI, I can tell you via E-mail if interested. Bottom line, shield the aft run with Steins 2 and a 3 wire shielded bundle and save the time. 5 wire shielded is not available from Stein or others in small lots. Wish it was. Don
Click to expand...

Ummm....we do sell 5 wire shielded AWG24 by the foot...you can order a minumum of 1 foot, up to the 10,000 feet on the spool we buy it on (and any length in between). It's part number SA-445.

Just an FYI if you missed it.

Cheers,
Stein
 
Another Question

Since I've just run this wire through the tunnel to the rear, does this also affect different indicators? In other words, is the indicator the problem or the wiring. I'm using an EMS D-120 for indication and would rather "fix" it now than later, if needed.
 
PaulR said:
Since I've just run this wire through the tunnel to the rear, does this also affect different indicators? In other words, is the indicator the problem or the wiring. I'm using an EMS D-120 for indication and would rather "fix" it now than later, if needed.
Click to expand...

I have most often found that if (when?) you get flashing Ray Allen indicators when you transmit, this is more an indication that you have an antenna wire shielding issue somewhere that needs to be fixed. This is very common when people fire up their systems under construction for the first time, and start finding the places where connections aren't quite as good as they could be, or an unshielded antenna in the floor. My experience has been that most of the common devices used in our RV's live pretty well with the other devices when everything is installed properly.

Paul
 
I didn't find a SA-445 on SteinAir but I did find a SA-555. I think this is the correct product number ? So... clairify something for me. I would buy the wire and then a connector on the end of the wire and on the end of the trim servo wires, but hardwire it to the back of the trim servo switch and indicator. Right ?
 
Darren S said:
I didn't find a SA-445 on SteinAir but I did find a SA-555. I think this is the correct product number ? So... clairify something for me. I would buy the wire and then a connector on the end of the wire and on the end of the trim servo wires, but hardwire it to the back of the trim servo switch and indicator. Right ?
Click to expand...

That's right....again I fat fingered (or half fingered) it! it's SA-555.

Cheers,
Stein
 
Why not CAT5?

jferraro17 said:
I'm in the process of reading AeroElectric Connection, but am also wanting to run some wires to the tail so I can rivet the aft top skin, so...

Can anyone tell me if they used 22 AWG for their Ray Allen elevator trim servo to stick run? A search--not very well worded I guess--turned up very little. I also saw one thread about a 5 wire Ray Allen bundle, but would like to avoid an order for now. Haven't thought about connections yet, but need to get the wire in. Is this an appropriate gauge for the current/distance?

Thanks-

Joe
Click to expand...


Perhaps a bit late, but I'm just in the process of doing this now on my -6A project.

After reading Electric Bob's note on making a DB9 connector as small as possible, I came to the conclusion that I will be using CAT5 cable. The wire is 24AWG stranded, so no issues there, and the RJ45 connectors are light, solid, and lock into place w/o messing with screws. Finally, the installation is quite neat since all the wires are packaged up quite nicely.

Anyone see any reason to not go down this route?
 
I may be wrong on this, I wired my whole house with cat5 and I don't remember the wire being stranded.
 
jthocker said:
I may be wrong on this, I wired my whole house with cat5 and I don't remember the wire being stranded.
Click to expand...

CAT5 comes either stranded or solid; it's usually printed on the jacket (i.e. "24AWGSTR" is stranded cable). The stranded is preferable for this purpose I think.
 
ChiefPilot said:
CAT5 comes either stranded or solid; it's usually printed on the jacket (i.e. "24AWGSTR" is stranded cable). The stranded is preferable for this purpose I think.
Click to expand...

OK, I'm sold! There must be something wrong with this...... The ELT remote hooks up this way though.....Hmmmm!
 
Don't forget...

Hey Joe, while you're running wire to the tail, I thought I'd mention the deck underneath the vertical stab is a popular place to put mag compass sensors, so if you're sticking one of those in your plane and think you might locate it there, now would be a good time for that too (ask me how I know).
 
jthocker said:
OK, I'm sold! There must be something wrong with this...... The ELT remote hooks up this way though.....Hmmmm!
Click to expand...

Except...be careful on the ELT wires. They typically are a simple phone cord, but wired in crossover...meaning it's not straight through same wiring on each end. If you use something different (and many people do), make sure you wire it in crossed over, not straight.

Cheers,
Stein
 
Bill Wightman said:
Hey Joe, while you're running wire to the tail, I thought I'd mention the deck underneath the vertical stab is a popular place to put mag compass sensors, so if you're sticking one of those in your plane and think you might locate it there, now would be a good time for that too (ask me how I know).
Click to expand...


Hey Bill--

How ya been?

Never even thought of that location, guess there is less metal there than inside the aft skin or the wing ribs...thanks for the tip!

Now, if I just knew which avionics I was installing...:eek:


Joe


PS...I REALLY like the Cat 5 idea, now that I've got all the wires pulled and the skin cleco'd on :mad:
 
Yeah, the empennage deck is good also for accessability, with the fairing being right on top of it. The elevator control weldments are there, but don't adversely affect things (at least in our 8). The other area for the mag flux sensor is, like you said, inside the fuselage behind the baggage bulkhead. Either way, it requires wire back there. If you're gonna run anything other than steam gauges, you're going to need to plan for the flux sensor, I think.

I'm doing well, thx. Hope to have our 8 in the air before OSH. I'll be down to visit sometime later this year, so see ya then if not sooner!
 
Shielded or not? Elevator trim.

Folks,

Just running wires to the rear of the plane and I have on hand the recommended for Ray Allen installations WC2 5-WIRE TEFLON? INSTALLATION CABLE from ACS. I also have 24 gauge shielded 5-wire as well.

Is it necessary to use shielded wire here or is the "recommended" good enough?

Thanks


Don
 
It's only necessary to shield or twist the three position sensor wires. The motor wires can be run discretely. Connect the shield (if using shielded wire) at one end to ground and the three wires as recommended by RAC. Even though one of these wires is eventually connected to ground, treat it as a signal.

Cheers
 
vlittle said:
It's only necessary to shield or twist the three position sensor wires. The motor wires can be run discretely. Connect the shield (if using shielded wire) at one end to ground and the three wires as recommended by RAC. Even though one of these wires is eventually connected to ground, treat it as a signal.

Cheers
Click to expand...

Why?

The Ray Allen instructions don't seem to mention shielding...

http://www.rayallencompany.com/RACmedia/instructionsT2andT3.pdf


Are there other instructions around?
 
az_gila said:
Why?

The Ray Allen instructions don't seem to mention shielding...

http://www.rayallencompany.com/RACmedia/instructionsT2andT3.pdf


Are there other instructions around?
Click to expand...

Enough people have had problems with RACs trim displays acting up during radio transmissions that shielding the sensor wires makes sense. The underlying problem is that the position sensor is high impedance (up to 5K ohms.. the center of a 10K potentiometer).

This high impedance source, when connected to an unshielded wire is susceptible to picking up interference from noisy sources (RS-232 lines, antennas and so on). Normally, the electronics at the instrument end will filter the signal and reject the noise, but not always.

Early in my career, I designed SLICs (Subscriber Line Interface Circuits) on thick-film hybrid substrates. Despite careful layout, these devices were really good at demodulating the local A.M. radio stations so that we could hear the interference. The characteristic impedance of these lines was 600 ohms. The trim application is not the same, but the underlying principles are. The fix, in this case, was two 5pF capacitors fabricated with metal and dielectric on the hybrid circuit.

A similar case was found in my HR-II audio circuit. I have a Garmin Aera that uses a cable where the audio wires are bundled with RS-232 wires... all unshielded. The resulting audio noise was tolerable when the Aera was powered on, but when it was off the noise was much worse. When the Aera was off, the audio and data wires were unterminated (high impedance) and the RS-232 noise swamped the audio inputs. The fix? I used 10 ohm termination resistors to ground on the audio wires at the intercom end. The Aera can drive 8 ohm speakers, so this worked well.

It's just good practice for long runs of sensitive wiring to shield it. It's easy to do at installation, and a lot harder to do after the aircraft is complete and you have trouble.
 
vlittle said:
Enough people have had problems with RACs trim displays acting up during radio transmissions that shielding the sensor wires makes sense. The underlying problem is that the position sensor is high impedance (up to 5K ohms.. the center of a 10K potentiometer).

This high impedance source, when connected to an unshielded wire is susceptible to picking up interference from noisy sources (RS-232 lines, antennas and so on). Normally, the electronics at the instrument end will filter the signal and reject the noise, but not always.

Early in my career, I designed SLICs (Subscriber Line Interface Circuits) on thick-film hybrid substrates. Despite careful layout, these devices were really good at demodulating the local A.M. radio stations so that we could hear the interference. The characteristic impedance of these lines was 600 ohms. The trim application is not the same, but the underlying principles are. The fix, in this case, was two 5pF capacitors fabricated with metal and dielectric on the hybrid circuit.

A similar case was found in my HR-II audio circuit. I have a Garmin Aera that uses a cable where the audio wires are bundled with RS-232 wires... all unshielded. The resulting audio noise was tolerable when the Aera was powered on, but when it was off the noise was much worse. When the Aera was off, the audio and data wires were unterminated (high impedance) and the RS-232 noise swamped the audio inputs. The fix? I used 10 ohm termination resistors to ground on the audio wires at the intercom end. The Aera can drive 8 ohm speakers, so this worked well.

It's just good practice for long runs of sensitive wiring to shield it. It's easy to do at installation, and a lot harder to do after the aircraft is complete and you have trouble.
Click to expand...

Perhaps this Ironflight post on this thread from 4 years back is relevant?

http://www.vansairforce.com/community/showpost.php?p=393514&postcount=10
 
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