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Korber roundhouse & Diamond Scale turntable repairs

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Posted by RR_Mel on Saturday, June 13, 2020 9:56 AM

tstage

 

Hmm The roundhouse stall is a bit short for your SF Northern???  Seems to fit the Rust-Oleum can well though...

 

Tom that’s why I kitbashed my Korber to 19” deep.

The walls look blue but they are actually light gray.

 



I actually made my Korber deeper for my SP Articulateds, a 18” long Cab Forward or Yellowstone AC-9 wouldn’t look good in a 15” roundhouse.



Mel



 
My Model Railroad  
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I'm beginning to realize that aging is not for wimps.
 

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Posted by tstage on Saturday, June 13, 2020 9:08 AM

railandsail

 

Hmm The roundhouse stall is a bit short for your SF Northern???  Seems to fit the Rust-Oleum can well though...

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by RR_Mel on Saturday, June 13, 2020 8:30 AM

When I was a teen (early 50s) I hung out at the El Paso SP Yard and their roundhouse was natural, red brick (dark red brick) inside.  The floor was painted concrete, dark gray.  Amazingly always very clean too.

I don’t remember ever seeing all the roundhouse stalls occupied, normally about a dozen GS-4s with an occasional AC-9 or two.  I don’t remember how many stalls, maybe 20.


Mel


 
My Model Railroad  
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

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Posted by railandsail on Saturday, June 13, 2020 7:46 AM

I had read back thru Dr Wayne's discussions on building his, and took ample notice that he taped the window openings up so as to not overspray the brick window sills.

(see I do learn from the forums...ha...ha)

I want to decide on the final color of that interior because I do NOT wish to have to re-tape those windows again.

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Posted by RR_Mel on Friday, June 12, 2020 8:51 PM

Looking good Brian



Mel



 
My Model Railroad  
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

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Posted by railandsail on Friday, June 12, 2020 8:32 PM

Color of the Interior?

I taped up all the window openings so the brick frames would not get recolored, then sprayed the interior with a primer coat. My question,..is my choice of color appropriate? Is it too dark?

Recall that I am considering leaving the roof off so my steam fleet displays well.

 

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Posted by railandsail on Friday, June 12, 2020 8:26 PM

Canopy Cement

Its been highly recommended that I use a product called canopy cement.

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Posted by railandsail on Friday, May 22, 2020 8:50 AM

Installing Windows?

I was very fortunate to be able to remove the window frames from my used roundhouse,...without damaging them. I'm not sure how they were originally put in, but it appeared to be just some sort of minimal tacking method.

So now I am looking for advice on the best way to re-install them once I finishing painting the interior walls, etc?

I assume I would use some sort of tacking method such as these
examples?

 

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Posted by railandsail on Friday, May 15, 2020 9:31 PM

Roundhouse Base Piece

 

I've mentioned building a base plate for my roundhouse structure before, but was unsure of what material I wanted to use. I settled on a thin sheet of metal I had laying around, and that happened to be painted black. I sought out a thin material so my incoming tracks would be practically the same level as all the other tracks around the turntable.

 

I intend to mount the tracks and the roundhouse structure all on the same base plate, so it can be lifted off the layout as one piece in order to add additional interior details at a later date, and to get it out of the way while finishing off the via-duct bridge behind it, and the city scene structures and backdrop.

I figured that the thin metal base plate could be made a stiffer by gluing both the tracks and the floor material to the metal base plate. The floor inside there needs to be level with the tops of the rails. The easiest way I could think of achieving that was to use a combination of 2 different material,...one about the height of the ties up to the molded on rail retainers, then a final layer of thin styrene to meet up with the rail tops. I chose some scrap masonite I had to build the first layer of 'floor' . In these photos you can see the 'between the track' masonite flooring.

 

 

The masonite is also relatively stiff on its own, and becomes more-so with fully glued to the base plate. Interestingly I discovered that PVC cement worked extremely well with gluing the masonite to the scratched up metal plate.

I then proceeded to glue up the wall structures of the roundhouse itself. For these operations I used a 5 minute epoxy as I worked my way around the perimeter section by section. The walls are joined to each other, but more importantly the are bonded to both the metal base plate AND the 1/8” tall edges of the masonite floor pieces.

 

 

BTW, I cut the metal base plate with a little extra oversize lip that helps with grabbing and lifting out.

Now I need to figure out how to arrange the electrically connections (detachable) to the tracks and the roundhouse interior itself ??

 

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Posted by RR_Mel on Friday, May 15, 2020 10:01 AM

railandsail

But didn't you have a more complicated slip ring(s) arrangement?

I was thinking a simple 'wiper lead' to the drive shaft from below for one of the rails, then the other rail would be fed from a wire to the tower on the bridge??

 

Yes, I built up a four contact slipring, it is for the bridge lighting and optical indexing.  The shaft and overhead power drop to the bridge are used for rail power.

You could use the pit rail and the shaft for rail power.  I didn’t on my CMR because for thirty years and several turntables I tried using the pit rail and everyone gave me problems.  The brass power drop to the bridge has never failed.

Mel



 
My Model Railroad  
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

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Posted by railandsail on Friday, May 15, 2020 9:32 AM

My Korber roundhouse project is coming along nicely, and I will post some pics soon.

But my one problem is those entrance arches and doors. Mine were warped. I tried an experiment using our FL sunlight. I placed those arches on a black piece of material, then under a pane of glass I had sitting around.

The arches all straighten out,...BUT I forgot to remove some of the doors that were still attached. They all warped BADLY.

Ed, do you have some doors I might have?? (oops, was that a korber model that you had?)

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Posted by railandsail on Friday, May 15, 2020 9:23 AM

But didn't you have a more complicated slip ring(s) arrangement?

I was thinking a simple 'wiper lead' to the drive shaft from below for one of the rails, then the other rail would be fed from a wire to the tower on the bridge??

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Posted by RR_Mel on Friday, May 15, 2020 9:12 AM

railandsail

 

 

That center shaft is solid metal,...why not just use it as one side of the circuit. Then use the top arch to power the other rail?

 

 

Brian

 

That’s the way I did it on my CMR turntable, it has worked perfect for 15 years.

 

 

 Mel

 

 

 

 

 

My Model Railroad  

 

Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

 

 

 

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Posted by railandsail on Friday, May 15, 2020 8:58 AM

This was my older 'drive box' from my Diamond Scale TT. I cut it off of the bottom of that pit floor, and sanded it level to mount on my new pit floor.

 

However I thought I might want a little extra height in there to both make getting at the set screws on the gears and bridge shaft a bit easier, AND to make the distance between the upper shaft bearing and the lower one a bit longer to help with any misalignment. So I fashioned a couple of 'PVC feet' (white feet) to space the drive box about 1/2" lower. (those feet also act as stiffeners to the pit floor plate)

 


(that's a plastic bottle under there to shelter the extra long drive shaft)

Used both epoxy cement and PVC cements to glue things together. Had to play around with getting that drive box and its spacer exactly positioned such that the bridge drive shaft was perfectly perpendicular and free to rotate the turntable bridge with NO friction.

Have not yet placed the gears back in the drive box yet.

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Posted by railandsail on Tuesday, May 12, 2020 12:26 AM

Yesterday I sorted out how I was going to mount the stock Diamond Scale drive box to the underside of my turntable pit. I'll post some pics tomorrow.

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Posted by railandsail on Tuesday, May 12, 2020 12:22 AM

gmpullman

My Diamond Scale 130 footer has a solid shaft through the center bearing. Difficult to run wire through. Therefore I use the ring rail for one side rail and the top arch powering the other rail. Haven't had any troubles in twenty-some years.

That center shaft is solid metal,...why not just use it as one side of the circuit. Then use the top arch to power the other rail?

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Posted by railandsail on Wednesday, May 6, 2020 8:41 AM

 

Connecting Drive Shaft to Turntable Bridge

 

As I have been rebuilding my Diamond Scale turntable, I've discovered an important feature they possess that should have applicability to turntables in general. The connection between the drive shaft and the bridge structure should NOT be a rigid one,...not an absolute rigid affair.

 

This is particularly clear as we consider larger/longer TT bridges. As our bridge decks become ever longer it becomes a problem to have them contact their pit rails at both ends simultaneously , while also being pushed up by their center drive shaft. We need to 'uncouple' this drive shaft's vertical motions, while still retaining its very positive rotation motions.

 

 

 

Diamond Scale accomplished this quite nicely by gluing a rectangular block of plastic onto the upper end of their drive shaft,.... then providing a slot in the underside of the the bridgedeck for this rectangular block to ride in. This uncouples the strictly rigid connection.

 


Here is the black piece of plastic stuck on the centering/rotation shaft,..and the slot in the bottom of the bridge deck into which it fits,..


 

 (btw, there is a crack across that hole where the center shaft fits. Mine developed that crack somewhere along the way, and I had to glue it back together.)

 

Here is that bridge deck partially set down on that black plastic block. You can see by these 2 photos that the bridge itself is free to dip either of its ends to meet the pit rails at either end,..

 

 

 

 

 

Yet the solid block of plastic keeps the bridge deck under absolute rotation control.

 

Another nice feature of this arrangement is that a person can lift the entire turntable bridge deck up and off the layout without have to remove the turntable assembly itself !!

 

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Posted by railandsail on Friday, May 1, 2020 8:19 AM

Centering Hole Correction

I was real upset with myself the other day when I found that my center hole was not centered properly.

At first I though I might just scarf in a new piece of that black PVC material into the center area of the pit, then locate and redrill a proper center hole. But first I thought I would try drilling out the larger FULL size hole needed for that brass bushing at the pit level, and relocating the center of that larger hole to its proper center. This was NOT acceptable, as it left that hole too large to properly retain the brass bushing in a snug, secure manner (oblong hole).

But it did led to another idea,...why not some sort of small thin metal plate glued to my pit floor that would snugly keep the brass bushing in its centered position. After all this upper brass bushing's primary job is keeping the turntable deck in a perfectly centered position. And since the brass bushing has a flange on its one end, it will fit perpendicular to that metal plate, that will in turn sit flat on the pit floor. So the turntable shaft will end up very perpendicular, particularly when the lower shaft bushing is located on center 2-3 inches under  that upper bushing.

That led me to a drilled out 'fender washer' to support that upper bushing.

Here are a few photos of that fender washer/bushing centering piece. The white ring inside the pit wall is 1/4" thick piece of PVC that will support the pit rail track. The pale white appearance over the whole pit area is piece of white tracing paper that was cut and laid in there to help locate the exact center in which to glue down that fender washer. Bushing sitting there (upside down) waiting to be installed.

 

 

When I cut out those pit rail foundation rings I ended up with some circular sections that matched the radius of my pit wall. I decided to add those scrapes onto the outside of my pit wall, as I need an additional 1/4" pad/spacer between the bottom surface of my plywood train deck and the base plate of my turntable pit.

(turntable drive shaft waiting to be installed)

 

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Posted by railandsail on Wednesday, April 29, 2020 6:51 PM

I screwed up! I'm not sure what I did wrong?

I made a wood block something like you suggested Mel, and I drilled the holes in it on my drill press. I actually started out with rather smaller drills so as to get a direct hole in the center hole I had made when I used the router to make my circular trench, then moved up 2 larger size drills to get to the size I would need for the bushing that guides the vertical shaft.

Just before I went to drill the largest size hole I would need I inserted the plain shaft and loosely connected by turntable bridge to it, WOW I'm not centered properly! I don't know how this happened !! It appears as though my center hole is off center by something like 1/16" to 3/32". Just don't know how this happened.

I have done some other measuring late this afternoon, and come up with several plans to correct this mistake,...tomorrow.

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Posted by RR_Mel on Wednesday, April 29, 2020 10:28 AM

I make a jig on my drill press.  A couple of small sections of Oak glued together, then drill the hole in the block with correct size drill on my drill press.  Attach the jig to the material you want to drill.  Two pieces of 1” Oak should give you pretty good bracing to drill a perfect hole with a hand drill.
 
For jigs that I use over and over I sleeve them with K&S brass tubing.
 
This jig is for drilling holes between the ties for IR detectors.
 
 
 
 
 
Perfect hole every time.
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by railandsail on Tuesday, April 28, 2020 6:55 PM

 

Perfectly Perpendicular Center Shaft

HELP
I need to drill a hole in the center of that floor to place the bearing (bushing) for the drive shaft. Ideally that shaft/hole should be perfectly square with the pit floor. Obviously I can NOT place it under a drill press, so what tool do I need to use to get that hole dead straight,...perpendicular??

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Posted by gmpullman on Monday, April 27, 2020 5:00 PM

railandsail
Did you ever get a chance to inspect that roundhouse?

I promise, I'll get to it tonight Embarrassed  Busy week!

Cheers, Ed

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Posted by railandsail on Monday, April 27, 2020 3:36 PM

New Turntable Pit
I spend a fair amount of time thinking about how I might construct a new pit for my turntable. The two primary pieces would be the pit floor itself, ...then the pit wall. One thing for sure I was NOT going to utilize plaster. So here is what I came up with.

 

 

 

Pit Floor:
Good grade ½” to 3/4” thick plywood was a top choice in my mind, painted to limit any moisture absorption.

I happen to have a nice square piece of 1/2” thick piece of black Sintra board (cellular PVC) I had collected up from the scraps being discarded by a local sign shop. Why not experiment with this first, .....then I can always return to the plywood alternative. I decided my pit wall was going to be 1/4” thick material, (cut from several different options), and bent into a circle to fit that round trench I was cutting into the floor.

I got out the router, installed a ¼” dia bit, and cut my 'trench' into the flat floor board.



Here I will note that I had 2 options,..cut that 'trench' (partial depth into the floor pit),..or just just cut all the way thru the pit floor piece forming an inner disc, and an outward retaining hole in that square floor piece of PVC. Either way, both methods would support my ¼” thick vertical pit wall.

 

Pit Wall:
I had another scrap piece of the black PVC that was 1/4” thick 9” wide, and about 5' long. I needed a strip of it about 1+3/8” wide, the full length, to bend around to form my 'pit wall'. At first I thought about cutting it with a saw, but on second thought why not use a sharp razor/ box cutter type device making multiple passes,...much cleaner operation.

 

That relatively thin strip of plastic would be flexible enough to bend into a radius to fit into my trench, but I wanted to trial run it several times, so several in and outs, plus final gluing. I figured it was going to be easier if the strip of pit wall material had somewhat of a 'natural bend'. I clamped it around my old pit wall casting, and got out my heat gun. Bravo, nice semi-permanent bend. Finally glued in place with PVC glue.

 


...test fitting

 


.....test fitting

 

 

Once all glued into the trench everything became quit rigid,, very happy with result.

Now I just have to cut some more of that 1/4” thick PVC (maybe the white stuff this time) to make a 'shelf' onto with to glue down the pit rail with its ties,...something like shown in the mock-up I did before I started the router cutting.


I can use the same router dimension plate to cut the hole in my main plywood deck that this turntable assembly fits into. That little black piece under the track sitting on the plywood there is a thin sheet of metal like that I am going to cut a much larger piece to make a base plate for my roundhouse,...so the roundhouse and its feeder tracks, pits, and raised floors will all be sitting on a common base plate that can easily removed from the layout to complete greater detail at a later date, and/or if I need to work on the viaduct and city scenes in the background. Interestingly the turntable bridge is also readily removable from the scene,...per the design of the Diamond Scale turntable itself.

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Posted by railandsail on Monday, April 27, 2020 3:33 PM

gmpullman

I'll try to get an email off to you as time permits.

Regards, Ed

Did you ever get a chance to inspect that roundhouse?

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Posted by gmpullman on Monday, April 20, 2020 7:21 PM

You don't necessarily have to go all the way to Hong Kong for a rotary switch.

https://www.amazon.com/Nxtop-knurled-11-Position-Selectable-Rotary/dp/B07DCKJZQ5/ref=sr_1_3?dchild=1&keywords=rotary+switch&qid=1587427508&sr=8-3

railandsail
DeOx sounds like a good idea. Are you saying you power the post lamps with a connection to track power,...DCC power??  

Yes,  These are the old 16V klunky-looking Walthers incandescent GOW lamps. I don't recall if I put a resistor in the circuit. I don't think I did. When I installed them there were very few LED lamps out there.

 IMG_5178_fix by Edmund, on Flickr

railandsail
I only have space for a 5 stall roundhouse (maybe 6). Can that one of yours be cut down fairly easy?

I'll look at it and see just how well I glued each stall together. It would certainly be easier to box-up If I split a few of the stalls apart.

 Roundhouse4 by Edmund, on Flickr

I'll try to get an email off to you as time permits.

 

Regards, Ed

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Posted by RR_Mel on Monday, April 20, 2020 1:23 PM

If your talking about my 23 position rotary switch, yes, last summer.
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by railandsail on Monday, April 20, 2020 12:14 PM

You purchased a single item from Hong Kong with no problems?

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Posted by RR_Mel on Monday, April 20, 2020 9:58 AM

I recently bought a new rotary switch for my turntable for better spacing.  My old one was 30° spacing and I didn’t like the 210° swing for 7 tracks so I bought a 23 position rotary switch with 15° spacing. 
 
 
 
Most rotary switches have an adjustable stop and I set mine at 7 positions.  The 105° swing from the inbound yard track to the track on the right of my roundhouse looks much better.
 
 
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by railandsail on Monday, April 20, 2020 8:51 AM

doctorwayne

There is no roundhouse at Lowbanks, but several tracks coming off the turntable and a couple, turnout-connected, all controlled via the rotary switch. 

There's also a separate ON/OFF switch and a direction switch for the turntable rails....very low-tech, but all easy to do.

Wayne

 

Sort of what I had in mind,...two questions,...
1) Are rotary switches still available? I thought they were 'old school'.
 
2) Does this mean you need to remember if the turntable is turned 180 degrees as to matching its polarity with that of the 'powered tracks' connected to the turntable,...MEMORY required to hit the polarity switch??
 
This was suggested on another forum, but I am unsure as to whether it would work 'automatically' in this situation,..
The rails on the turntable itself at one point will be reversed as you turn it. I use a DCC Specialties PSX-AR auto reverser on the turntable tracks. Track buss to the auto reverser-auto reverser to the turntable track. No issues and works just fine.

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