Concor/Kato/Lifelike/Hudson 6-wheel tender truck upgrade

[mmagliaro]

Oh Max, did you get stuck with people flaking out on you?
That's really a shame, no good deed goes unpunished....
And I love this pickup idea, elegant!
Best, Otto

No no no!  I didn't mean that.  Actually, nearly everyone who said they wanted them ended up buying them,
so I did okay and didn't go broke.  And I still have some left, so I will eventually actually make some
money as the rest of it trickles out the door (he said trickles)

I just meant that these things are never going to allow me to quit
my day job.  I'm happy if I at least get back all the money I have to put up to make it happen.

And if I make
a little beyond that, well, hooray, I can buy train stuff with it, so everybody, including the hobby, wins.

[peteski]

I already checked with photo metals.  Yep, they can etch on .015" thick phosphor bronze.   Yay.

Um,  that might be a bit too thick (too stiff).  I would go with 0.010".  But then I also thought that your pipe hangers (while very useful) were a bit too thick (0.008 or 0.005" woudl have IMO been better).

[glakedylan]

wow Max!
I would certainly be interested in a small bunch of these
will have to recount my LL locomotives as I have sold some
and bought some others and not sure how many I have now
but this will be a super help in electrical contact from the
tender.
let me know how the etchings come out and if and when they
will be available.
thanks
Gary

[mmagliaro]

Um,  that might be a bit too thick (too stiff).  I would go with 0.010".  But then I also thought that your pipe hangers (while very useful) were a bit too thick (0.008 or 0.005" woudl have IMO been better).

The actual plates in the LL and Kato trucks are .015" thick and they fit into slots and/or holes in the top of the truck frame design for that thickness.  If I made them out of thinner metal, they would flop around.  Not good.
The long arms that reach out from the center and press on the wheels will be .015" thick, but they don't have to be
very wide.  Unlike my round wire, these will be flat wiper arms that are .015" wide, across the groove of the wheel they are riding in, but only .008 high, more like a flat wiper.  It's hard to know how perfectly it will work.  That's the chance you have to take if you want to make something like this (where "you" in this case is "Max").

But I think it will probably work.

My plan is to make a sheet that has both LL and ConCor style plates, in all their original glory, on there, and also
some with the springy thinned-out arms that will mimic what I'm doing with my wire.   That way, people can do whatever they want with these.   

[peteski]

When etching there are some constraints as far as what is the minimum width of the etched part as it relates to the material thickness.  IIRC, the minimum width of an etched item cannot be less than the thickness of the material.

[OldEastRR]

I bought one of the first LL Berks, no reason to have one, it just looked so pretty. It had only one tender truck p/U, and only one geared driver set. Figured no problem I'll order more contacts and wheels from the parts sheet. Unfortunately  that's just when Walthers bought LL. When I tried to call in and order my parts I got a long maniacal laugh then a click.
I had to forego the extra geared driver, but I used the tender contact plates to make a duplicate  set out of thin brass sheet. Yes, I wondered too why they designed the second truck to have contacts then never put them in.
But it never ran faster than 40 mph (or pulled anything) so I asked Max what I could do to fix it. He advised me to completely take it apart and check out everything, then reassemble it carefully. OK, I managed to do Step 1 but never got past that one. Now I have a large jewel box with a lot of very pretty Berk parts in it.
Seriously, did Walthers ever wind up stocking parts for this thing?

[peteski]

Now I have a large jewel box with a lot of very pretty Berk parts in it.
Seriously, did Walthers ever wind up stocking parts for this thing?

Walthers doesn't stock or sell replacement parts for any of their N scale locos.  They do have some models they cannibalize for parts and it if they have enough, and you ask them nicely, they will send you some spare parts. But that's all.

[dnhouston]

Excellent, and simple, upgrade.  Now I need to check all my tenders to see which ones can use this.  Thanks for the idea

[mmagliaro]

Peteski, it is true that you can't etch a feature any narrower than the depth of the material, because of undercut.

That is, by the time the acid eats all the way through .015" of material, it starts eating sideways and could destroy a strip feature that is supposed to be only .008" wide.  And some places will tell you that they flat-out refuse to etch anything whose artwork does not obey these rules.

But...  if you "game" it, you can do this.  The trick here will be to draw the contact fingers to be about .010", and then
hope that by the time the etch has gone all the way through, you lose only a couple of thou on your strips, so they end up at about .008".  Since their actual width isn't critical, as long as they "ain't too thick and they ain't too thin", it will work.

I had the same problem with the pipe hangers.  The holes are only .008 in diameter, but the metal was .010" thick.
So if I drew them at .008, then by the time it etched all the way through, the holes would be more like .010", and the rings around them might get completely eaten away.   So, we drew them to be more like .007", and it mostly worked.
That is, about 75% of the final 12" x 18" sheet had complete sets of good etched hangers on it.  The rest had some partial fill-ins or partially-open holes.

Photo Metals made it work by running some test plates through the etchant bath, and playing with the etchant temperature and timing until they got it just right.  I give them high marks for working with me on this.  They made
a part that some other places flat-out refused to make.

[mmagliaro]

Having said all that...

I may do the whole plate in .008" metal, but make it a 2-part assembly.  The second piece will also be on the same sheet and will consist only of the center section fo the plate.  So you could sandwich the two together with a little epoxy (or solder), and you would have a .016" thick center where it's needed, and thin .008" arms, and that would make the etching run easier.  A bit more work for the user to assemble a 2-piece plate, however.

[Chris333]

I don't know if an etched sheet would be as flexible as round drawn wire. Just sayin'.

[peteski]

Having said all that...

I may do the whole plate in .008" metal, but make it a 2-part assembly.  The second piece will also be on the same sheet and will consist only of the center section fo the plate.  So you could sandwich the two together with a little epoxy (or solder), and you would have a .016" thick center where it's needed, and thin .008" arms, and that would make the etching run easier.  A bit more work for the user to assemble a 2-piece plate, however.

I think that is a much better solution.  Maybe you could somehow etch it as a single piece which can be folded into correct shape (so some parts end up double thick).  No soldering or gluing required! 

[mmagliaro]

The fold is a great idea!  They can do half-etch, so I just need to put an extra center section as a mirror image
that flips down on a fold over the middle.  But I still think you would want to glue it.

Chris, as for the flexibility, remember, a square piece of phosphor bronze, that is .008" x .008", ought to
be about the same as a piece of .008" wire.  In fact, even if I used .015" stock, and the arms were .008 thick by .015" wide, they are only bending against the thin dimension, so it ought to be fine.

But if I do it as 2 layers, then the arms will be .008 x .008, which is probably best.

[Lemosteam]

You could design a Shapeways wire bending jig for the shape of the contact wire, and then half etch a groove for the wire to be soldered in.

[mmagliaro]

You could design a Shapeways wire bending jig for the shape of the contact wire, and then half etch a groove for the wire to be soldered in.

I thought about this.  But then it becomes a solder assembly job for the buyer.    Or I suppose I could bend a bunch of the
wires, solder them in, and sell the assembled unit.