My experience

I have purchased parts for custom work, and asked for replacements when needed, and Walthers has been very accommodating.  The caveat has been I have occasionally wanted a part that is back ordered or not stocked.

Milt

I would contact them and try.

Their P2k diesels are famous for cracked gears, and most of the people that I know of have just given up on Walthers having any of the gears available and have ordered Athearn parts instead to replace them.  I think they will sell the parts if they have them in stock, but I haven't heard of them stocking much in the way of spares for the P2k models. 

No on diaphagms

I found out after I had bought many Walthers Amfleet cars, that their later run  included separately molded diaphagms.  But when I asked if I could purchase a bunch to get my earlier purchases to match the later ones, it was No.

Walthers Parts

I have had excellent results dealing with Walthers and there parts department.  I had a few Walthers Bethgon Coal Porters that I changed the couplers out on, and in the process, I broke off a couple of the coupler pockets on the metal under frames.  Called walthers and they sent me new under frames free of charged!  I was extremely surprised that they didn't charge me for something that I broke!!!  With service like that, Walthers is high on my list of people to buy from.

Ken, I say give it a try!  

No luck

Well, I tried.  I e-mailed Walthers, asking about the drawbar.  I received a very friendly and apologetic response letting me know that they do have some parts in stock, but they are reserved for service and repair work, and not for sale.  I responded thanking them for their time and expressing my hope that they would consider selling parts in the future.

For now, It looks like I'm out of luck on this one.  It's a pity, too, because that is by far the best drawbar design I have ever seen.  I wonder if any of the DCC suppliers (I'm thinking of Soundtraxx or TCS, both of which make or sell a variety of connectors) would be interested in making something similar?  Hmmm...

How difficult would it be to scratch build a copy?

Ken, you have done some amazing work on steam engines that you have shared with us here.  What is there about that draw bar that keeps you from scratch building one?

I might try making one

Thanks for the compliment, Russ.  If it were just a drawbar, it would be fairly simple.  What makes the part so nice to me is that it's a combination drawbar and 6-pin (I think) plug.  The two halves snap together, and each half is screwed to the loco or tender.  Thus there are no wires visible between the engine and tender, no bulky connectors to fiddle with, and they are also semi-permanently coupled but still easily separated if needed.

Here's a photo of the tender half, from the TCS web site:

I was thinking about how I would make my own, and I think it may be possible.  TCS has already responded to my suggestion/request, saying that they have no plans to make anything like that at this time.  No real surprise, but I thought I'd ask.  I haven't contacted SoundTraxx.  If I were going to make my own, I would use a 6-pin JST connector and epoxy it to a styrene rectangular tube, with a hole in one end for a mounting screw.  The only question would be how well the JST connector would work as a drawbar - would it hold together or simply pull apart?  Given how hard some of them are to take apart, I think it could work.  I'm thinking I may have to give it a try.

I think I would use flat styrene & square section together.

I don't have one of those locos, so I had not seen what was so special about the draw bar.

I think I would make a flat draw bar out of .060 or .080 styrene, an weld the square section styrene tubing to it.  I would run the screw holes through each end of the flat stock to form the draw bar.  Then just run your wires through the tubing and let the plugs kind of float at each end.  The flat stock takes the load while the square tubing holds the wires in place.  There is no load on the plugs.

Elegant simplicity

The reason for transferring the load through the connector is that it allows the drawbar to be separated, disconnecting the engine and tender easily both electrically and mechanically at the same time.  Otherwise, you have to come up with a way of handling the mechanical and electrical connection separately, and that gets you right back where we are today.  I really like the elegant simplicity of the P2K design.

Given that the typical draft force of an HO scale locomotive in measured in ounces, I suspect that a common connector like the one below might do the job.  The styrene (not brass, just to avoid any potential shorting issues) would be to transfer the load from the model to the body of the connector, relieving any strain from the wires.  The weak point of these connectors seems to be the connection between the body and the wire, so relieving that should make it pretty sturdy.

I don't know it it will work, and I doubt I can make it as nice as the P2K part, but it might at least be worth some experimentation.  You start thinking about how to make this thing, and you realize just how much engineering work goes into designing our toys!  Suddenly $100 seems like a steal for a model that is an almost perfect miniature copy of a real locomotive, runs like a dream, and is fantastically well engineered.

Elegant simplicity

I would think a printed circuit board with 6 (more or less) traces (3 top, 3 bottom) in the shape you want with 2 connectors (one on both sides, think computer SATA type connector) then paint to order.

Needs a little more thought, but it seems like there should be something like this around already.

Good idea, Steve!

I like the circuit board idea, Steve.  I expect the challenge would be making the plastic female end so that it would securely connect to the circuit board.  Simple enough with an injection molding machine, but tricky without it.

drawbar

If you are talking about the oval piece left center, Soundtraxx sells them.

Quick-Disconnect harness assembly for separating locomotive from tender

Close, but no cigar

That's a different beast, unfortunately.  While you could certainly make the circuit board of the SoundTraxx part rotate easily enough, there is no provision for putting a strain on the other end - on the wires.  That's just an electrical connector, and would still need a mechanical drawbar to connect a locomotive and tender.

I don't have a good photo of the whole piece, but the Proto2000 part is actually a combination drawbar and connector, and both halves look very similar (aside from one being the male end, the other female).

How long are your trains going to be, Ken?

On the modular layout, my 2-10-2 typically pulls about 20 cars, and the weight of the train is significant.  I don't think a plug would hold things without a mechanical draw bar connection.  If you run shorter trains, it should not be a problem.

Testing needed

You bring up a good point, Russ.  Perhaps that's why those drawbars are only on the 0-6-0 and 0-8-0.  For me, I'll be running short trains so it might work on the main line as well.  I wonder if anybody has had one of those things pull apart on them?  They look pretty sturdy to me.

I think what may be needed is to test some connectors to determine how much force is needed to pull them apart.  It should be fairly easy to determine how much drawbar pull a locomotive can generate, and as long as the first exceeds the second, you're fine.