Folks:
Launched! With a creaking and groaning (the board's, not mine), I rolled my new 4x8 table on to its legs, and bingo! I had a table. A big clean 4x8 is a splendid thing, isn't it? Just stand there and imagine the possibilities.
The table is quite rigid, even with some minor flopping at the section joints. It has six legs, all diagonally braced to the benchwork with 1x2s. If I also put in some horizontal ties, the flopping would be completely gone, I think, but first I plan to try squaring off the sections so they can butt together without washers. I figure on removing the section bolts, then running the circular saw in, perhaps butted against a scrap-1x2 fence. Flopping notwithstanding, it's the sturdiest, steadiest table I've built to date, not counting those which were anchored to walls. Bump an end and it doesn't jiggle, it slides.
In general, the 2x4 L-girders don't seem to have huge advantages over a 1x4 grid, except that I was able to run all tabletop fasteners in from below, which may pay off handsomely when scenery is down. Stiffness improvements are marginal, thanks to the screwed- on top which masks them, but I intend to make a cookie cutter from this once I settle on a track plan, and then I might see something.
The final data, therefore, isn't in on the 2x4 L-girder grid, but I do think that I'll use a corner clamp and short 2x3-slice corner glue blocks in the future, instead of trying to make decent butt-joint corners.
The 3 x 4 angle legs, made from surplus 1 x 3s, however, are working wonderfully. They mount easily to elongated 2x3 corner blocks (glue and screws attach legs to blocks, blocks bolt into the frame for detachability). Of course these corner blocks are not glued, which is perhaps not the best plan for rigidity; the inconvienience of having projecting 2x3 spurs in knocked-down form made me leave the blocks on the legs, and they do strengthen them. The leg members are flush with the frame, which looks very good and allows the 1x2 diagonal braces to be mounted easily. The legs are also quite light and very rigid. As yet there are no height adjusters, but these are needed; I will add
2x3 blocks at the bottom to hold these. I'm not sure if I'll use T-nuts and carriage bolts, or casters with a locknut.With the table up, I quit benchwork for a while and dragged out my various troublesome DC power packs. This unfortunately included all of them:
-an MRC Railpower 1300, good control but wimpy, and with a bad reversing switch,
-an ancient MRC Ampack with rheostatic control and a nasty hum,
-an MRC Master Twinpak of uncertain vintage, made in Japan, and again with rheostatic control, and
-a battered KF variable-transformer pack with an over- heating selenium rectifier.
At this point the discovery was made that I had inadvertently made the table an optimal height for standing model-railroad repair. Not a good thing, really. I am going to have to build a second small workbench to draw off the inevitable clutter.
I am not sure where all this is going, except as a sort of journal of one man's descent into madness.
The madness really started when I decided to start with the MRC Rp1300. Of course it had tamper-proof screws, but that was nothing a cheapie screwdriver, notched with an oilstone, couldn't overcome. Inside, I found some surprising things:
-Practically nothing! The unit contains a transformer, a DPDT switch, and a PC board with a four-diode bridge, a disk thing which I assumed without looking to be a filter cap, a potentiometer, and a TIP142 Darlington transistor. Well, shoot, that ain't no TAT; course, I warn't 'spectin' none. I think I did expect something akin to a throttle-on-a-chip, but there's nothing wrong with a TIP142. It was just too surprisingly close to something I'd breadboard up with my mediocre electronics skills.
-Molded-in letters stating "PROPERTY OF MODEL RECTIFIER CORPORATION". Bwuh? They weren't reversed, so it wasn't meant for the die. The thing's bought and paid for; maybe I should hang up a SOLD sign.
Replacing the switch was a gory mess; my Radio Shack DPDTs wouldn't fit the board, so I ended up soldering a bunch of ugly wires, but it does work. I should have bent back the tabs and cleaned the switch, but by the time I realized that it was too late.
There must have been some overcurrent protector in there -- the pack clearly has one. Perhaps it was the standard MRC glass bulb, hidden behind the transformer? I didn't check. I was in too much of a hurry to cover up my half-assed workmanship. At least the unit works perfectly now.
Disassembling the other three units also revealed some odd things, and I finally understood why so many packs use a center tap and full-wave rectifier, not a bridge - one diode drop, instead of two. Perhaps this is elementary to the more skilled, but I am two steps past the waterwheel analogy (which is one step above two- sticks-make-fire). With this sort of rectifier it also seems easy to stick an SPST switch in series with one diode and get half-wave pulse dc.
Strange things I found:
-The Master Twinpak has selenium rectifiers? But it's so shiny and clean! How old is this thing, anyway? I would have thought the Ampack was older, and it has silicon diodes.
-The KF pack has some sort of black grease in the wirenuts that connect the xformer to the cord. Hmm. I wonder how many PCBs are in that. I think perhaps I will just cut them off, then use crimp wirenuts, or perhaps solder. I already removed the selenium cells;
6A silicon diodes are waiting for installation.After repairing the Rp1300, I was so pleased that, instead of going on to the others, I put down some track and tried some railroading. To this end, I dragged out some of my miscellaneous horrible 0-4-0 tank locomotives and did some cleaning and oiling. I seem to have a sick and twisted fascination with secondhand
0-4-0Ts.The four I took out were a Life-Like Dockside (old mechanism), Teakettle (remotored), Mantua Booster, and Lima Booster knockoff.
I continue to be impressed by Mantua engines. I wish I still had the ones I lost over the years due to carelessness or "not being into trains any more". The Booster was noisy at first, but with some oiling and wheel-cleaning, it smoothed out considerably. This is an old metal Booster, with the stock PM-1. I timed it on a short piece of flex track, using my Railpower 1300, and discovered it would crawl at
1 SMPH, albeit with a slight quiver. At 2 SMPH it was steady and smooth, except for a slight hitch, probably rod-bind, which I will have to hunt down.The Life-Like Teakettle, again, proved to be ast- onishingly good with its new motor. It's wonderful to watch it glide along, with that tape player motor so silent I swear I can hear the HO scale rods clank. The silence masks the fact that its minimum stable speed is actually just slightly higher than the Booster's; about
2 SMPH, with 3 SMPH being much smoother. There is no apparent bind, though there is some "boxing". The basic mechanism looks cheap, with coarse gears, but it works! I almost want to order another and try it out with a Jameco can motor.Neither of these, by the way, was achieved through use of pulse power, which my Rp1300 does not have.
The Lima and unmodified Dockside are...not quite so good. I will probably attempt to remotor the Dockside at some point, but the Lima will probably end up on the track-cleaning train or something. It has their goofy pancake motor.
That's the news from the Petrolia & Erie. I really don't like that name, already, but I haven't thought of a good replacement yet.
Cordially yours: Gerard P. President, a box of track and a gappy table.