Help on an MTH 4-4-0 problem

Scott,
     The only things I can think of would be to shorten the pin or change the spring with a stiffer one.

Scott: Anything you put on it will wear off in time. You could try some electrical insulating compound like Glutaul (RED GLPT)I have used it many times, or some RTV in a very thin layer/coat. Jim M. should be able to help you with this if you ask him. Other wise your only option is like SSM suggests.

Scott,

 

This is not the first time we have heard of this issue. I just sent this post to Jeff Strank at MTH and asked him to let me know if they have a fix. I will let you know when I hear back.

 

Mike

Can you eliminate the dips in the track?

.....

Dennis

Replace metal pin with Nylon one. Go to local auto parts store look in the Help section for Nylon rivets find one with a center push pin about the same size as your metal pin. Pull the pin out of the rivet cut to length cut small grove for c-clip. Shorting solved.

I'm not sure that replacing the pin with a nylon one would work. On a locomotive with a wheelbase this short, the pilot wheels are most probably a part of the electrical pickup (Outer rails only.) and it probably would not run very well with only the spring to conduct the current.

 

One thing that springs to mind is that you could try covering the end of the pin with one of those little plastic (Delrin/P.T.F.E.?) self-adhesive replacement 'feet' for computer mice. These are thin, very hard wearing, and low-friction. You could probably find some at any local computer/gaming store.

Is the pin actually required?    I think I would glue a  home made  plastic cover  over the whole works, perhaps 1 inch by 2 . Something fairly thin that you can find around the house.

If you used a nylon pin, you can just connect a wire to the top of the truck and the frame if it's using them for track common.

 

I have one of these I converted to PS/2, but I've never had it bottom out on the track.

 

I am using RealTrax on my son's shelf layout. There are some dips (very slight ones) between some of the tracks. This is the only engine we had this issue on.  We have two other Railking 4-4-0's and we do not have the issue with the other engines.

Scott Smith

Makes you wonder what's different.  Have you compared the two to see why the others don't bottom out?

 

SSM's idea of a stiffer springs sounds pretty good.  Another thought, could you use a dremel grinding stone or file to take bit off the tip of the pin?

Along with this Proto 3 General. I have Railking Proto 1 and a Proto 2. The Proto 3 General is the only one of the 3 engines that has a spring. The Pre Proto 1 and the Proto 2 have a short rod that will not extend far enough to hit the third rail. Only on the new Proto 3 General will the connecting rod hit the track.

Scott Smith

Sounds like time for a modification!

 

I wonder if the older pilot would fit on the new locomotive?  I'd be somewhat surprised if the mechanical design changed all that much between the versions.

Scott, my originally conventional General 30-1120-0 has a rod just like your PS/3 picture.  However, when I compress the spring under it, the length isn't sufficient for it to protrude below the truck frame more than about 1/16".  It has no way of contacting the track, at least without breaking something.

 

It seems to have the same sliding track, I wonder if they just used the wrong length pin for the assembly?

 

Just a thought, but are you absolutely sure that it is the pin that's touching the centre rail? I was wondering if it might perhaps be the tip of the cow-catcher instead. 

Nicole,

I am sure it isn't the cow catcher. I can place electrical tape on covering the rod and it won't short out until the tape comes off.

Scott Smith

Thanks Scott. It just seems so strange that the pin should be log enough to hit the rail. I think that John is probably correct and that an incorrect length pin might have been fitted to your engine.

You could groove the opposite end of the pin with a dremel cut off wheel, and insert another c clip to lock it so it can only travel the same length of distance as the PS-1/2 engines.  Or call Midge and order the PS-1/2 version.  G

I figure that if it's the same as mine, the part should fit, sure looks the same.  The pin appears to be Part# IG-0000007 on my parts breakdown, it's only $.50 MSRP and listed as available on the parts order site.  It would be cheap to give it a try. 

 

Scott, if you want, I'll add it to my next MTH parts order.