7mm Richards P48 US Thread

[richard carr]

The third GP35 that I have is an overland model.





In many respects it is a better quality model, but it has an axlebox missing from one bogie and the nose doesn't sit properly against the front of the loco body. Its time to convert this to P48 and fix all the problems along the way.

It was easy enough to unscrew the chassis to get this.





Here's another problem, the motor is no longer fixed to the chassis at one end, in fact looking at the size of the holes and the small size of the retaining screws I'm surprised it ever was fixed to the chassis.








The bogie comes off nice and easy and in the middle photo you can see the missing axle box, I have obtained some spares but they are not an exact match, but near enough..

The gear boxes are helical and turn freely in either direction.

Plenty of work to do here to get this running nicely.

Richard

 

[Big Train James]

Richard,
Bill Davis at American Scale Models has all the old Overland parts, or at least what's left of them now. That happens to include a lot of drive and truck parts, so you might take a look at his site and see if anything there matches your trucks.

Jim

 

[richard carr]

Hi Jim

Thanks for that he does have the exact ones I need.

Richard

 

[richard carr]

SO the first thing is to get the chassis sorted out, by getting the motor fixed firmly to it.



I have added a trip of etch to the motor support and drilled some new holes that the screws only just pass through. I even soldered this etch to the motor mount. I then did a similar thing at the other end of the motor and screwed it down firmly to the chassis.




The next thing is strip the gear boxes to remove the axles.



Some really nice helical gears inside them.



The axles then drop out.

I have a set of Right O Way replacement wheels, but these are designed for 3mm axles, these are 4.5mm apparently later Overland models do use 3mm axles. So these all needed machining down to 3mm, a relatively simple job on the lathe but it does require accuracy to get a nice interference fit.

So here's the chassis all back together with P48 wheels.



I have fitted a temporary replacement axlebox, I have the correct ones from the source Jim suggested, but it will be well into next month before I can get them. This keeps everything in the right place for now.



Here you can see the new wheels with an old one for comparison, just a bit thinner !

Ideally the bogie needs narrowing a bit too, but that needs a new bolster, which would probably be best done with an etch, something to add to the list.

The chassis now runs well under DC, I just need to work out where to fit all the DCC bits and some speakers.

Richard

 

[Scale7JB]

Great stuff. Hopefully some track down soon!

JB.

 

[richard carr]

A bit more work has been done on the overland GP35, I drew up a support for the speaker and decoder and got Robin to print it for me.





Still quite a bit to do yet.

 

[richard carr]

Last week I was in Chicago and so brought a few things back with me, the first was a pair of Dash 8s, a 39B in SP livery and a 40B in BNSF livery.

The SP one was 2 rail but unpowered, which unfortunately means there is no electronics at all inside, so no lights, no speaker and no pickups. The BNSF one is powered so has front and rear headlights and ditch lights, but I'm not sure about the orange beacon. So I took one of the motors (and the central drive gear) from the BNSF loco and installed that in the SP loco, a relatively easy job, and at the same time changed the wheelsets to P48.




I was going to put the speaker in the fuel tank but although the tank is huge, so is the speaker and it doesn't fit



So the speaker is going to go in the side of the loco body



The speaker is screwed to the plastic card and then glued to the side of the body with MEK, it feels pretty solid today, now it has all dried



I also narrowed the bogie sides on the SP loco and added some picks for the insulated wheels



And this one is for Jordan



Another nice hopper car for the fleet. You can still see these running through Deshler on the ex B&O line running north South, the writing is fading and they look filthy.

 

[Big Train James]

I was going to put the speaker in the fuel tank but although the tank is huge, so is the speaker and it doesn't fit

Either the speaker or fuel tank, or both, needs to feel the gentle kiss of an end mill cutter. Wall thickness on the sides of the TB 1931 are between 70 and 80 thou each, and the mounting tabs are incidental. Photos of a machined speaker module can be found here in Mickoo's American modeling thread. I think we are taking the enclosure width down to 1.32", or 1.325", I'd have to check to verify, but 40 thou off both sides is safely doable.

If cutting the speaker enclosure, I'd recommend using a bigger cutter running a bit slower, as the plastic will heat up and gum up the flutes at higher rpm's. Use of a 2 flute cutter is also probably a good idea since the material is so soft. Lastly, bear in mind that the pc board appears to contain glass fibers, which will dull the cutter. We have milled everything else and then dressed the edge of the pc board with a file. Removing the edge of the board did not affect any continuity of traces to the solder pads.

Cuz you don't already have enough to do.....

 

[Yorkshire Dave]

So the speaker is going to go in the side of the loco body

I managed to mount two speakers in mine. A smaller one in the fuel tank (more suited to the higher frequencies) and a larger one in the body. The larger one was held in place by double sided sticky pads and one bolt into a bit of tube in turn bolted to the chassis.

 

[JimG]

If cutting the speaker enclosure, I'd recommend using a bigger cutter running a bit slower, as the plastic will heat up and gum up the flutes at higher rpm's. Use of a 2 flute cutter is also probably a good idea since the material is so soft.

i If you use a carbide cutter you should avoid the heating problem. I've machined a load of styrene over the last few years using carbide two blade slotting cutters with no problems at all.

Jim.

 

[Big Train James]

If you use a carbide cutter

Duly noted on the cutter, I'm not sure what type my guy has been using. Fortunately he's almost done with the eight speakers I had in my stash. I will say that the plastic used for the enclosures doesn't really behave like styrene at all, it's pretty tough. My first method for removing material was to hit the enclosure with an aggressive file. I didn't make much progress with that.

 

[Big Train James]

) and a larger one in the body

My only concern with the vertical orientation of the speaker is any degree of "directionality". I always see things with respect to bass woofers in things like TV surround sound systems that say the bass end of the spectrum emanates in all directions without regard to orientation. But I can't help but feel like there has to be some impact if the speaker is facing one way or another.

The other personal experience is that there isn't any way to to orient the speaker in my sw1500 other than flat, there's barely room to fit it in at all. So I don't have much choice in the matter for that application.

 

[Big Train James]

One other thing on the TB modules, if one is ever tight for space, consider the 1815 module instead of the 1931 module. The enclosures are the same size for all intents and purposes. However, the 1815 has a concave speaker cone while the 1931 is convex. There is a fair amount of space saved by using the 1815, especially if one takes the speaker excursion into account. Performance specifications are equivalent for both units.

The 1815 is pictured in the linked post in Mickoo's thread.

 

[Yorkshire Dave]

My only concern with the vertical orientation of the speaker is any degree of "directionality". I always see things with respect to bass woofers in things like TV surround sound systems that say the bass end of the spectrum emanates in all directions without regard to orientation. But I can't help but feel like there has to be some impact if the speaker is facing one way or another.

I haven't noticed any 'directionality' of the sound emanating from the speakers whether vertical or flat in locos. I'm sure some sound fitted HO locos had vertical speakers.

 

[Jordan]

And this one is for Jordan

View attachment 173181

Another nice hopper car for the fleet. You can still see these running through Deshler on the ex B&O line running north South, the writing is fading and they look filthy.

I used to have one of those, but got rid of it due to the awful molded grab irons & stirrups. I didn't need yet another "to do" project that would stand little chance of ever getting done....

 

[Yorkshire Dave]

I came across this short fillum I made after fitting both speakers in my Dash 8 40B . ESU Loksound L and two Tang Band speakers.

 

[Scale7JB]

Well that sounds pretty fantastic, is it a standard downloadable sound file?

Forgive my ignorance, what is SSW? Seen it many times on Cotton Belt locos, but never thought to ask..

JB.

 

[mickoo]

SSW

St. Louis Southwestern Company

 

[Yorkshire Dave]

Well that sounds pretty fantastic, is it a standard downloadable sound file?

Yes - download available from ESU.


St. Louis Southwestern acquired the Cotton Belt nickname as it ran through, you've guessed, cotton plantation country.

 

[richard carr]

JB

SSW was part of Southern Pacific, all locomotives from the 60s onwards were ordered by SP and they would be lettered either SP or Cotton Belt (or T&NO), all painted in the same livery.
So the Dash 8 39Bs were lettered SP and numbered 8000 to 8039 and the Dash 8 40Bs which followed a few months later were lettered Cotton Belt and Numbered 8040 to 8079
I've been reading my Joseph A Strapac books, great books just a shame the pictures aren't in colour.

Richard