[R-390] Gear Train Guru Wanted

Sat, 3 Aug 2002 10:18:13 -0400

A few weeks after I obtained my first R-390a, I ordered a spare RF deck from
Fair Radio.  I understand that they have a few palletts of them, as rejects
from the depots.  They are complete, to include coils, racks, slugs,
transformers, etc.  I mean they are plug and play, except you have to find
the fault before it will work.  In my purchase the fault was only an
intermittent RF coil that ended up being caused by a malformed coil pin
socket.  No amount of bending or forming would remove the intermittent.  So
I simply removed it from the plastic holder (which destroyed the plastic)
and then it was easy to reform it.  I now only needed to remember to plug in
that individual pin from the bottom of the RF deck.  It works like new now.
I digress....

The point I wanted to make was that this RF deck is an excellent model to
compare to when disassembling and assembling your subject gear train.  And
it is only $40 from Fair Radio.  When I rebuilt my gear train, I used
Walters photos and dialog as a step by step guide to disassembly and
assembly.  But as good as Walters efforts are, 2D photos have limitations
that a 3D model does not have.  I have no doubt that the guys that did this
for a living referred to a 3D model, frequently, while learning their trade.
For the best and easiest rebuild, both methods together are superior to
either one by itself.

Jim Temple

----- Original Message -----
From: "Barry Hauser" <[email protected]>
To: "Walter Wilson" <[email protected]>; <[email protected]>
Sent: Saturday, August 03, 2002 9:43 AM
Subject: Re: [R-390] Gear Train Guru Wanted

> Hi Walter:
>
> The photo sequence and instructions on your site are terrific -- many
> thanks.  However, I see where you started to move from "baby steps" to
giant
> ones, no doubt owing to the web storage limits.  Later on, you go with
more
> of a verbal description.
>
> I just spent about 30 mins., so need to look over it more to see where to
> add intermediate steps.  Meanwhile, I humbly submit the following
> suggestions:
>
> 1.  Superimpose number labels on the gears that are about to be removed.
> Maybe I'm a dummy, but I had to flip back and forth between adjoining
photos
> a few times before I could spot what was coming off.  It might be a good
> idea to use the numbering scheme from the manual blowup.
>
> 2.  Use arrows in addition to "spotlight" highlighting.  In particular,
it's
> a bit difficult to make out the two gears that should not be meshed.
>
> 3.  Do a step by step reassembly sequence, not simply rely on the
"assembly
> is simply the reverse of dissasembly" approach.  Fact is, it's not, and
> that's where a lot of the vebiage comes in.  You can re-use most of the
> disassembly shots, but the key difference is this is where the
> synchronization takes place.  (Actually, the _assembly_ sequence is more
> important than the disassembly -- it's generally possible to take
something
> apart with little or no instructions, however, tradition has been the ol'
> "reverse of dissassembly" thing.)
>
> 4.  Maybe I didn't notice, but along the way I recalled some advice from
> various posts to the reflector.  For example, the split gears may have
> burred or chamfered over from wear such that they won't slip smoothly
> against each other -- which is easy to test with the gear sets out and the
> springs removed.  Someone had recommended (Nolan?) to lightly polish the
> mating surfaces with very fine grit abrasive - or maybe a wet stone?  May
> not be necessary in most cases, but this would be the time to fix them..
>
> 5.  I test printed everything in black & white on a 600 dpi laser printer,
> just to check if all the detail comes through.  Sometimes, even starting
> from excellent quality color, detail is lost when adjoining parts are of
> similar color or shade.  They print quite well in B&W -- the detail and
> contrast hold up.  Only thing I'd point out is the superimposed text about
> the two-gears-not-to-mesh is hard to read in B&W.  While the color
contrasts
> on screen, the shade is too close for B&W.  It's over a shadow, so yellow
> would work better when printed in B&W.
>
> 6.  It would be good to illustrate directly how to set up the intermittent
> gear, rather than refer to the manual -- so your creation can be a
> stand-alone.
>
> 7.  I strongly (but humbly ;-) suggest that you leave the disassembly be
for
> now, and start with the assembly sequence.  This will make it clearer as
to
> what additional shots are needed.  In many cases, photos can be the same
> between the assembly and disassembly sequences, so it won't be added
> storage, just an html photo link.  You probably have a lot of the photos
> already.
>
> 8.  I dunno -- might be better to break it up into pages with "next"
> buttons.  This would help control the pagination for printing purposes and
> it might make it easier for you to clone assembly from dissassembly pages
by
> doing a "save as" as a first step before editing.
>
> 9.  Now this one will illicit an involuntary ROTFL reaction in some
readers,
> but ... For a real gear-train-for-dummiies no-brainer approach, someone
> could put together a grid that prints out on, say 4 pages to be taped
> together which would have a place to lay down each part as they're
removed,
> with the corresponding reference number.  Many of the gears look different
> enough, some look similar and some may be the same/interchangable or maybe
> not, duhhhhhh.  Eventually, we could turn the R-390A into a true Heathkit
> experience. ;-).
>
> 10.  An emergency 24/7 hotline to call.  OK, I've gone too far.
>
> Great site, though.  Hope you use this in the spirit intended (everybody's
a
> critic, yadda yadda).  I posted my suggestions in case some one else has
> additional or alternative ideas.
>
> Barry
>
>
> ----- Original Message -----
> From: "Walter Wilson" <[email protected]>
> To: "Barry Hauser" <[email protected]>; <[email protected]>
> Sent: Saturday, August 03, 2002 7:31 AM
> Subject: Re: [R-390] Gear Train Guru Wanted
>
>
> > You may have seen the pictures I have posted on my website already.  I
> think
> > there are only eight shots taken during disassembly, but I've used these
> > pics a number of times when rebuilding gear trains, and they work well
for
> > me.  If you'd like more pics added to this sequence, give me some idea
of
> > where you'd like to see more details.  At one time, I was limiting the
> > number due to web space size restrictions, which is no longer an issue.
> > http://r-390a.us/gear_train_rebuild.htm
> >
> > Walter Wilson - KK4DF
> > http://r-390a.us
> > (REAL Radios: R-390A, R-390, T-368E, Ranger, Thunderbolt, KWM-2A)
> >
> > ----- Original Message -----
> > From: "Barry Hauser" <[email protected]>
> > To: <[email protected]>
> > Sent: Saturday, August 03, 2002 12:40 AM
> > Subject: Re: [R-390] Gear Train Guru Wanted
> >
> >
> > > OK Gang,
> > >
> > > Hate to be a wet blanket, but I have an on topic type post here I've
> been
> > > sittin' on.
> > >
> > > One area for improvement in the Y2K manual is in the gear train
> > department.
> > > What we still have there is that exploded line drawing with dotted
> zig-zag
> > > lines.  I don't know about you, but it doesn't really fill me with a
> whole
> > > lot of confidence to pursue a full teardown, cleaning and reassembly
> with
> > > that as a guide.
> > >
> > > Sooooo... it would be great if one of you geartrain experts with a
> decent
> > > digital camera would do a teardown/reassembly, stopping at each baby
> step
> > to
> > > snap a photo, so the rest of us can have a shot at it one of these
days.
> > It
> > > could use a little bit of narrative, but the pictures would do most of
> the
> > > talking.
> > >
> > > Any takers?  Who's gonna be the hero?
> > >
> > > Barry
> > >
> > >
> > > _______________________________________________
> > > R-390 mailing list
> > > [email protected]
> > > http://mailman.qth.net/mailman/listinfo/r-390
> > >
> >
> > _______________________________________________
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>
>
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