[simpits-tech] PFC yoke conversion

[dabigboy at cox.net]

Just thought I would pass on one of the more interesting additions to my simulator. I scored myself a Jeppesen/PFC yoke on ebay for cheap (under $90 shipped.....something about "a bit of rust" and "unable to test" just scares other bidders away, hehehe!). It even included the avionics panel (!) which I really don't have any use for, though I may scavenge the rotary encoders out of it.

This unit was sold as part of Jeppesen's IFR training package back in the late 1990's, but is actually the standard PFC Mooney-styled yoke which is still being sold today. It even has a PFC serial # and data sticker on it. Upon opening the unit, I found there was actually no circuitry inside, all the buttons and axis were wired directly to a 15-pin gameport-style connector....PERFECT! :)

My plan was to mount the yoke behind my sim and extend the shaft. I was dismayed to find that the lovely solid aluminum PFC yoke is apparently glued/spot-welded onto the yoke shaft. I couldn't get it off, at least not without potentially damaging something else. But as it happens, I have a *better* yoke anyway, and the little hollow spot in the center of the PFC yoke just happened to be about the right size for the large yoke shaft I'd already come up with a while back.

Soooo.....after getting over the idea of taking a grinder to a $500+ professional yoke, I cut off the yoke arms and mounted my extended shaft with my fancy yoke on the end:

http://www.flickr.com/photos/alfamatt/6810610585/in/photostream

You `can also see the lovely engineering in this unit.....simply beautiful! I almost hate to put the cover back on. :) I started construction on the wooden frame that will eventually mount the sim to a full enclosure...for now it just provides stability and a place to mount the PFC yoke.

Here is a side view so you can see how it all goes together:

http://www.flickr.com/photos/alfamatt/6810610549/in/photostream

And here's the yoke outside of the sim, during test-fitting of the shaft extension....don't worry, the big ugly screw sticking out the top was temporary to hold the shaft in place:

http://www.flickr.com/photos/alfamatt/6810658719/

Finally, the finished product:

http://www.flickr.com/photos/alfamatt/6810610521/

The feel is EXCELLENT. There is enough force from the big springs that I worry about pulling the sim off the table during aggressive maneuvers (and it's quite heavy). I suppose it's about as good a yoke as you can get without going to something with active hydraulics. This is something I have been putting off for a while, but the sim had become essentially unflyable with my old homebrew yoke system. Not as much "fun" to work out as some of the more "cool" things (like converting the analog Gables nav/com head to talk to a Phidget....) but since the yoke is probably the one thing you use the most in flight, I felt it was pretty critical to get it right. And right it is! I had to run a couple new wires to connect the ground terminals of the pots, but since I won't be needing the PFC's connector for yoke buttons (they exit the yoke shaft further inside the sim), I had plenty of wires to spare for that. I am using Leo Bodnar's BU0386 to interface to the main PC, and the yoke performs flawlessly with that....full range, no perceivable jitter, nice linear output.

Next up: finishing the Gables analog nav/com conversion, and looking into those spherical mirrors that Gene has got me thinking about now...hummmmm!

Matt