Can I use this actual aircraft potentiometer?

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jph
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Re: Can I use this actual aircraft potentiometer?

#41 Post by jph »

Yikes :shock:
Yes, that would make it slightly dysfunctional..

That is a sure sign of an aircraft sat in a breakers yard in a stack with the windows out. They probably removed the round instruments and left the rest to rot. A company NOT to buy from. Jeez. Animals.

It will probably clean up with wd40 and a cotton bud but apply no pressure to the wire wound coil that the wiper runs on. That is the variable resistor 'track'
The problem is in the bottom of the top image - slightly left of bottom centre. You can see a small gap in the track. That is why it only works in one direction and no continuity across the outer track pins. You can repair it by adding a tiny length of fuse wire. It is extremely delicate to do but basically you find fuse wire or wire strand that is just the right size to drop into place in the gap (just a straight piece of wire - not a coil). Locate in position with tweezers and tack solder one end with the solder mainly on the new wire. You can tin it first. do the same with the other end. Fixed. You need plenty of flu when you do it (if you do it) and clean all wd40 away with isopropyl alcohol first.
NOTE - (EDIT - I just saw your clean up image 0 if the track is intact then leave it as is providing the wiper contact isn't jumping over the issue - I still think there is a small gap but it is difficult to see - if there wasnt a gap you would have still had continuity across the outer terminals. You need to use Isopropyl alcohol on it now - very carefully) and inspect again.

EDIT 2 - ! - There IS a switch in the end housing that could be revealed by lifting in the 3 tabs visible on the lower image and lifting out the cover. It is operated by the tab on the wiper hitting the tab in the end housing. It is difficult to see at that angle. I have no idea why it is there. It is probably seized. or maybe the tabs have been deliberately misaligned so as not to operate ?? - again, why the wires ?

Joe - 50 misspent years spent working with radio equipment that would now be vintage but was reasonably 'state of the art' when I started. That kind of repair we did in the Military. It was standard practice using 'Nichrome' wire when the part wasn't available as in when at sea.
Joe. CISSP, MSc.

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jph
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Re: Can I use this actual aircraft potentiometer?

#42 Post by jph »

Oh, I meant to also mention that another way of cleaning shite like that is 'penetrating oil or fluid' - or, as it is known in the military - 'Diesel fuel' - seriously. Diesel is THE BEST.
Just soak the whole thing in Diesel overnight and then clean out with isopropyl alcohol (Rubbing alcohol I think the yanks call it) - You can also clean off the diesel with 'brake cleaner' or 'carb cleaner' . you can get a big spray tin of brake cleaner for a couple of dollars. Worth having in the shack.
You can also mix a small amount of vinegar with diesel and soak it overnight. Methylated spirits also work. Then clean with the alcohol or brake cleaner.
If you have corrosion on metal parts (Steel, plated and ferrous only!) then soak in neat vinegar overnight in a ziplock bag then drain and drop into boiling water for 30 seconds. It will remove corrosion and convert the previously corroded metal to a protective gun metal grey finish. Works superbly on old tools They end up like new. The new coating is ant rust as well. Use the Vinegar overnight and then in boiling water for any ferrous metal aircraft parts that may have corrosion.
But, I digress..
Last edited by jph on Sat Jun 25, 2022 6:14 pm, edited 1 time in total.
Joe. CISSP, MSc.

Kaellis991
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Re: Can I use this actual aircraft potentiometer?

#43 Post by Kaellis991 »

Joe,

I appreciate your help and the effort to write up the instructions for repairing these.
But I think with the corrosion I see and knowing that more than likely the other is not much better, I’m just going to replace them with those CTS pots.

The path of least resistance as they say. And since I’m not out to sea nor am I living on mars, I can just throw money at the problem.

It is very odd about the switch and the wires. Maybe I was mistaken about what I remember from flying the arrow IRL.
In the sim Arrow I don’t think there is a switch on that panel light dimmer. I’ll have to check again.

So much for trying to get these to work. If in better shape then they would have been the solution.
I may play around with trying to clean those up and see what I get for the effort.

In the meantime the more pressing issue is how to attach that switch panel to my cockpit panel. A work in progress.

Kirk

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jph
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Re: Can I use this actual aircraft potentiometer?

#44 Post by jph »

:D at least you have a better insight into how things like that work.
Looking at the switch it IS perfectly possible to have 'handed' switches so they may well me both supposed to operate. Luckily, it is a sim and you do not NEED to have a switch on the right one at all.
Look at all the fun you have had ;)
It passed my time whilst building 2 virtual machines on VMware 15.

How are you planning on laying out the instrument panel ?
Are you wanting the instruments (the round ones and moving ones) in the correct location in relation to the yoke as there are some cracking little display units that can be used on the lower instruments - and upper. Some amazing ones have just come on the market.
Joe. CISSP, MSc.

Kaellis991
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Re: Can I use this actual aircraft potentiometer?

#45 Post by Kaellis991 »

Joe,

I am just creating the bottom portion of a Piper arrow panel. The portion in the red box in the bottom image.
It’s way too expensive to do everything above that and I can’t really do everything on the lower portion.
For instance there is no room for the engine gauges on each side of the yoke. The fulcrum yoke is taking up all that space behind the panel. The climate control I don’t need and I am still debating the alternate air lever.

I will have my realsimgear gns530 as well as a transponder from flight illusions.
The rest of the instruments / gauges are on my monitor…

848A8523-A293-4238-8664-E2B1BC896975.jpeg
D623300A-C111-4B3F-83C5-B1D9E02CEE61.jpeg

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jph
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Re: Can I use this actual aircraft potentiometer?

#46 Post by jph »

Is that your actual panel in the upper image? .. if so I can sort the engine gauges.. I have a cunning plan . Just tell me the size of the gauge area each side, width and height.. dont worry about clearance behind.
Joe. CISSP, MSc.

Kaellis991
Posts: 581
Joined: Mon Sep 07, 2020 8:49 am

Re: Can I use this actual aircraft potentiometer?

#47 Post by Kaellis991 »

jph wrote: Sat Jun 25, 2022 8:19 pm Is that your actual panel in the upper image? .. if so I can sort the engine gauges.. I have a cunning plan . Just tell me the size of the gauge area each side, width and height.. dont worry about clearance behind.
Yep that is a picture of what I’ve been building over the last year.
I cant picture though what would work there that’s only 10.5mm deep. That’s just the thickness of my two panel layers right in front of the fulcrum box.
The slots on each side are 178mm x 25.5mm.
Left side is for oil pressure, oil temp and alt. Amps.
Right side of yoke is for left and right fuel tanks plus fuel pressure…
Frankly I was thinking of just creating decals that looked like the gauges.
C0ACA56F-1943-4C99-8084-61C27C096796.jpeg

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jph
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Re: Can I use this actual aircraft potentiometer?

#48 Post by jph »

This would probably work. VERY high resolution display (1920 x 480 pixels)
Size 219 x 54 visible. Very thin - and great price.

You just plug it into a PC with an HDMI cable. It is seen as a standard monitor. Drag and drop instruments onto it.
You can use a simple USB to HDMI converter is you havent got a spare Video output. USB HDMI converter only 8 euros)
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A couple of pics and the link. One each side would be very nice. Available in all sorts of sizes.
https://www.aliexpress.com/item/4001179 ... 7206%21rec
Wisecoco-8-8-Inch-IPS-LCD-Screen-1920-480-Aida64-Display-MIPI-40-Pins-HSD088IPW1-Micro.jpg_Q90.jpg
(5.5mm thick !!) and remember - these are just like a complete monitor - they simply plug into the PC via an HDMI cable. It doesnt matter if your PC has DVI HDMI or Displayport as you can get a simple converter for a few dollars. If no spare video port then use a USB3 to HDMI converter which provides a psuedo gpu output and works superbly. You can drive many monitors from a really cheap (100 dollar) PC that way.
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Others - but the above is slightly cheaper
HSD088IPW1A00-B00-8-8-inch-CPU-GPU-LCD-screen-aida64-Display-for-car-Rear-view.jpg
Sefdf05499bf5458688eb5c987d883a0bP.jpg
S907da7066a91488bbddd58605dbca459A.jpg
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link
https://www.aliexpress.com/item/3303812 ... 33f5bwYcjI
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Suitable USB to HDMI converter (These are excellent)
1080P-USB-3-0-to-HDMI-Compatible-Converter-Multi-Display-Graphic-Adapter-for-PC-Laptop-Projector.jpg_Q90.jpg
https://www.aliexpress.com/item/1005003 ... 1802uOt6Qo
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Do you have no plans to make the upper part also ? .
Joe. CISSP, MSc.

Kaellis991
Posts: 581
Joined: Mon Sep 07, 2020 8:49 am

Re: Can I use this actual aircraft potentiometer?

#49 Post by Kaellis991 »

Joe,

Never knew they could make a PC display that thin. I would have to cut a new slot in my 5.8mm thick plywood base layer. Not a big deal. My graphics card supports 4 monitors and all are taken up by my 3 main monitors and my realsimgear GNS530. Which BTW works the same. It’s just a small monitor onto which the gps window is dragged.

I will definitely need a converter. I’ll put that upgrade on my list.

There are no plans to do the upper part where I need the monitors for my daily work. My expenditures over the last year have been pushing the envelope as it is. Maybe if I retire some day and no longer have to work. But then I would have to win the lotto to make a complete sim.

The main reason for this cockpit build was to get as many physical controls as I could to get away from using the mouse in Xplane as much as possible. Since most of the controls that require the switching of toggles or the pushing and pulling of levers are located on the bottom half of the panel in this airplane, I get 90 percent of what I need. The only things on the upper part that need the physical turning of knobs are the altimeter, heading and VOR settings. I have a knobster that can handle that. My GPS, radios and transponder are taken care of with realsimgear and flight illusion.

Kirk

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jph
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Re: Can I use this actual aircraft potentiometer?

#50 Post by jph »

You are doing a cracking job Karl so keep it up.
Do you have the RPM etc wired up and working yet ?
Joe. CISSP, MSc.

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