[amsat-bb] W5PGZ's continuing G5500 saga (bad news and good news)

[William P Gravett <wgravett@xxxxxxxx>]

Well, hope all you sat guys had a good Christmas and that Santa's reins
didn't foul your yagis.

I sent an earlier e-mail about my trepidations in getting the elevation
motor gearing assembly out to replace the elevation pot. I had to remove
the motor and gearing assembly to get more room to get at at  four "bolts
from hell". The motor/gearing ass mounts on a pretty stout steel plate
that is connected to the case by these skirted bolts. I was able to get
two off myself but the other two (requiring a hex head wrench) were in
there so tight, I rounded them out (yes!). I took the motor to a friend
of mine who is a pro mechanic (really good !) and he had 'em out in 20
minutes. He commented that 20 minutes for him to take two bolts out was a
,"long time" and it appeared to him that the manufacturer really didn't
want the rotor worked on by us average guys.
The way he got them loose was cutting a notch on the top rim and pounding
like you- know- what!!  At least in mine, the fine threads on all the
bolts look factory new ie little, if any corrosion. There was no evidence
of LOK-TITE being used on the bolts. I asked him what he thought about
using some lock washers under the bolts after I coat them with
anti-seize. He said thats what he would recommend. That way you don't
have to torque them down so tight.

So, I asked him if he would do the same for my az rotor since I read an
e-mail that said the situation was just as bad.. He said sure. I pulled
the az motor off, took the case off and what a difference. The az
feedback pot mounts on a little plastic assembly that is a piece of cake
to remove . There are two sets of bearings. They differ from the el motor
in that they aren't held in position by the races and they will fall out.
On one of the races, I was one bearing short. In general these bearings
appeared to be in slightly better condition after being exposed to
Houston wx for 1 1/2-2 years. The case inside and all other components
looked very good. I miked these bearings---would you believe larger than
the el bearings. I re-miked the el bearings just to be sure I hadn't
screwed up in reading it (I don't read a micrometer every day) . Here is
the data

AZ bearings=0.375"
EL bearings=0.310" ( in my earlier e-mail I got an el bearing that miked
out at 0.312")

The az plate transferring rotation force to the case is held in position
by some de tent posts plus screwed to the case by three 10 mm hex head
bolts with Phillips head fittings in the center of the bolt (Hallelujah!)
I used a 3/8 drive ratchet and six point 10mm socket and popped them
right out. There were lock washers under these bolts. Again, no evidence
of LOK-TITE and the threads were not corroded. 
Work on the motor/gearing assy and the start/run cap require that you get
to the back of the steel plate so you have to take these bolts out....but
if you have to replace limit switches or the az pot (same type as the el
pot and as far as I can tell, only available from Yaesu) they are easily
accessed.

The real "fly in the ointment" in changing out the el pot or the el limit
switches is getting the four bolts out on the el gear/motor assy plate
since these are in back of the plate. If you can do this easily , should
be a piece of cake. If you are having to use a lot of force and they
don't want to budge, save yourself some headaches and learn from my
experience---take it to a good mechanic or machine shop.

73

Happy New Year !!

Bill, W5PGZ

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