Arc Navomatic components
 

Are the servos used with a 400 the same as those for a 400A or 400B? The later control units come up often on ebay, and I see there are still a few repair facilities out there that will refresh them. So I'm wondering if it would be feasible and practical for me to upgrade from my 400 to the A or b. I'm not sure but I think I would also need to upgrade the computer or amplifier, but would there be anything else I would need to consider?

When you find out let me know. I have 4 systems we changed out over the years that could be yours for the price of shipping and a hot dog lunch!

Well wait a minute there ... are we talking OMW or Nathan's?

Looks like I would need different servos and even wiring if I moved to the 400a.

Spoke with AP Central (in OK) earlier about changing the ARC to an A or B. Not only are the components separate, but it would be a field approval to convert as they were not offered in the Delta model (among others). Chances of success were described as "very low" even if I was up to the challenge.

Just spoke with Gulf Coast about giving in and exploring S-Tec. The prior models are no longer offered, and the ball park cost for a new 55x system all in is $43k. Sure wish I'd known the 30/40/50 systems were going offline sooner.

That leaves me squarely in the realm of fly-by-hand pilots--at least in IMC.

Congrats to S-Tec for pricing themselves out of an entire class of customers.

So where are we with that Garmin campaign?

Whaaa!
Guess I was asleep with life.
Wasn’t aware those autopilots were going out. Sure didn’t make the usual news routes. A check of their website confirms 30-40-50 autopilots gone. Really limits the options for alot of aircraft. Always had a below series 55x in mind as a backup plan…
Not anymore

https://www.portapilot.com/
 

https://www.portapilot.com/

Years ago, before GPS, we were on a friend's sailboat and it had this gadget looked like a shock absorber, . One end attached to the tiller and other the boat.

It would expand and contract to hold a basic constant heading.

This seems to be the GA version.

That all aside, the 337 is soooo table when trimmed......

Over the years I picked up servos and even Navomatic CPUs (and I use the term 'CPU' very loosely), to have enough bits and pieces. It's basically a collection of analog feedback 'chopper' circuits that ue pos/neg pulses to pass analog signals.

Eventually the CPU capacitors got snarky in the CPU so I pulled the whole thing and sent off to autopilots central for OH recert on their bench.

Arc Navomatic components
 

YankeeClipper.
I just spent about a year getting my 1965 straight 400 auto pilot operational. The avionics shop I used is Mayday in Grand Rapids Michigan, I had originally wanted to use Auto pilot Central, in Oklahoma. They told me they where no longer working on 400 auto pilots. Mayday rebuilt the computer, and bench checked the servos, and the control head, they told me the servos, computer, and control heads ARE ALL DIFFERENT PART NUMBERS EACH MANUFACTURE YEARS, AND YOU CANNOT UP GRADE 400 TO A 400A OR 400B! I had bad servos. I was very lucky to find a caring SOAPA member who had replaced his 400 to something newer and GAVE me his 400-FREE, I paid the shipping. By chance his servos were the correct part numbers and where in good condition which I used. All in I have about $10000 in, parts, maintenance, Avfuel traveling two times to Michigan, hotels, car rentals, to get my 400 auto pilot up and running. I figured that's much better than spending $30-40000 for a newer auto pilot, for an airplane I bought for $22,500!!
Hope this helps.
Regards, BILLS
'65 C337, Owner, pilot, and A&P

I'll give you $32,500 for it! :D

Arc Navomatic components
 

MSHAC
Well thanks, but that price wouldn't quite do it. Even with high time engines, although I'm installing an overhauled rear engine and new cylinders for the front I've got too much other improvements, ie new three color paint job, rear door removal kit, Garmin G5 AI and of course the overhauled 400 auto pilot. But thanks anyways !
Regards, BILLS

Hey Bill, how did you manage to get that big avatar photo of your plane uploaded to your profile? This site limits our avatars to 150 x 150 pixels, but yours is much larger and looks better. I WANT ONE TOO! :cool:

aircraft picture on web page?
 

MSHAC
Hey I don't really know!! I went back and forth in my personal profile reduced my pics several times and I too got the limited size quote. All I know is I edited the avatar, I think that's what it's call, and edited the picture. The next thing I know I see the oversized picture??? Sorry I'm not a computer geek.
Regards, and good luck.
BILLS