Rudder wiring sanity check

[N4208T]

I need a sanity check.  It has nothing to do with the fact that I live in Minneapolis - St. Paul although that requires another one.

I converted a set of dual rudders and differential brakes to USB a while back.  They worked fine when I tested them so I moved on to other things.  When I subsequently installed them in the floor of the sim and kept going I made a mistake and did not test them right away.  When I did hook them up and tested them the brakes worked but the rudders did not.  I could not get them to work so I had to uninstall them and take the rudders apart again.  Figured something must have broken when I moved and installed them.

I could not find a short but these things are old so I completely replaced the wiring with new wire.  It's only a single 3 wire pot and some switches for the brakes.  Tested it, it worked.  Reinstalled it (not permanent wiring yet) and it worked.  So I moved on.

Yesterday I started routing some of the wiring to get it out of the way and make room for other things as I am now wiring the switches.  Tested the flight controls and everything works except the rudders.  Dead as a doornail.  Again I can find no short or loose wires (externally) and the bodnar board is fine.  Tried some different connector wires to no avail and even wired them to a Pokey with no change.

The ONLY thing that I can think of is that the pot, itself, must be bad and has finally worn out or shorted.  If I can find out what pot it is then hopefully I can just replace it.

So .. the sanity check.  Am I missing something?  Any suggestions before I tear this thing apart yet again?

Thanks for any help/suggestions you can provide.

Steve

[KyleH]

Get a multi-meter, disconnect the pot connections from the control board and measure the resistance between each of the pins. You should get full value between 2, and approx 1/2 between the wiper and either end when the rudders are neutral. Then also make sure the value at the wiper changes when you move the pedals.

[N4208T]

I did and I basically get nothing.  Actually, I put the meter across the wires since I cannot get to the pot without disassembling everything again but moving the rudders creates no deflection on the meter.

[KyleH]

Then looks like either the pot, a linkage to it or a wire connection.

[N4208T]

Thanks Kyle.  The wiring is new so I sure hope it is the pot.  If it is something in the linkage then the rudders may be toast.  But, since it was working I am betting on it being an old worn out pot (with my fingers firmly crossed)

Thanks again.

[jskibo]

Good time to upgrade to HAL sensors

[N4208T]

Perfect opportunity for me to ask .... because I was wondering anyway .... what is the advantage of HALL Effect sensors?  I think they are more precise than a pot or rotary encoder but do you want or need that for the rudders?

Also, since the pot is physically sensing the position of the rudder based on the movement of the mechanical pieces of the sim pedals, how do you get the sensor to attach to the mechanical part?  Do you still use a pot and wire the sensor to the pot?

Good idea and definitely interested so pardon my ignorance.  I had to replace a pot in the trim wheel of the throttle quadrant, too, but I would not mind "upgrading" with the HAL if I understood how.

Thx.

[jskibo]

Perfect opportunity for me to ask .... because I was wondering anyway .... what is the advantage of HALL Effect sensors?  I think they are more precise than a pot or rotary encoder but do you want or need that for the rudders?

Also, since the pot is physically sensing the position of the rudder based on the movement of the mechanical pieces of the sim pedals, how do you get the sensor to attach to the mechanical part?  Do you still use a pot and wire the sensor to the pot?

Good idea and definitely interested so pardon my ignorance.  I had to replace a pot in the trim wheel of the throttle quadrant, too, but I would not mind "upgrading" with the HAL if I understood how.

Thx.

A Pot has the physical wiper what ends up collecting, well crap, and will get spikey returns over time.  You can open them and clean them, but the spiking will come back.  On a HAL you don't have physical contact, so mo spiking.

It looks and mounts like a regular pot.  You just have to find one that works for the physical space you have.  These are similar to what I replaced in my TM Cougar Throttle.
https://www.midoriamerica.com/cotnactlesssingleturn/qp-2h/

[N4208T]

Thanks.  I will measure it but that looks like it would probably do the trick.  I did take the rudder pedals out again and I still cannot see any evidence of a bad wire so I really hope its got to be the pot.

Thanks John.

[Reco]

Hi

I'm keen on using halls on my project.
The ones in your link look good, silly question is I assume they still need a physical connection from the hall shaft to the control surface unlike the very small magnetic hall effect ones

Cheers

[jskibo]

Hi

I'm keen on using halls on my project.
The ones in your link look good, silly question is I assume they still need a physical connection from the hall shaft to the control surface unlike the very small magnetic hall effect ones

Cheers

It just replaces the pot and the same type nut is used to secure it on the shaft the way the pot was secured.  The's no extra magnets or anything external to the example posted.

[Reco]

Thanks for for the reply.  The vishay357 pots I'm using at the moment have GT2 pulleys attached to the shaft and they rotate on 6mm timming belt
Roughly how much are these hall pots

Cheers

Rhys

[N4208T]

I found this one on Amazon "Hall Effect Potentiometer Angle Encoder Sensor 360 Degree 6mm Shaft Analog 0-5v Output BY CALT FOR $38.  Not sure if that is good, bad, or middle of the road. 

I also looked at my setup again and found a cracked solder connection on one post so I may just repair that and see if that was the problem.  If it was, I think I will wire the internal wires to a Cat 5 or Cat 4 connector and then run a cable to the bodnar board connecting to another convertor to try and avoid stress damaging the wiring yet again.