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Roundhouse and Turntable

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Roundhouse and Turntable
Posted by brakeman321 on Tuesday, February 22, 2011 10:17 PM

      Hello I'm new to fourms so bear with me please

    I have a fleischman round house 9 stall @ 7.5degrees Kit # 6476 . I'm trying to install it on our layout along with a walthers 90ft. Turntable . Having problems getting the tracks to line up with the roundhouse. Can any one help with this? How far back does the TT need to be from the center to the roundhouse.    Any Help would be greatly appreciated.

                           Thanks in advance

                          brakeman321

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Posted by Svein on Wednesday, February 23, 2011 2:40 AM

I don't have the roundhouse you mention, but if you measure the track center distance in the door openings, you should be able to calculate the exact distance to the turntable center with the following formula:

sin 3.75 = X / Y (where X is half the track center distance, and Y is the distance from turntable center to door opening)

Let's assume you've measured the track center distance to 60mm. Then the calculation goes like this:

sin 3.75 = 30 / Y

y = 30 / sin 3.75

y = 30 / 0.065403129230143066815315558775175

y = 458.69364896035535088169922863849 or 459mm from turntable center to roundhouse doors.

Anybody please correct me if I'm wrong, I haven't done this in a while...

Regards, Svein

 

H0 Peco C75, MRC Prodigy Advance, NSB (Norges Statsbaner / Norwegian State Railways) in the 50's

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Posted by Paulus Jas on Wednesday, February 23, 2011 7:07 AM

hi

Svein your math is correct, though i do not understand the question. It could be done easily on the layout, with a little bit of tinkering. It might be a different probelm.....are the angles of the turntable and the roundhouse the very same?

Paul

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Posted by Svein on Wednesday, February 23, 2011 7:41 AM

The Walthers turntable looks identical to the Heljan turntable which I have, and if so every track position is programmed individually. However, if the turntable has fixed indexing with different angles than the roundhouse, that may be his problem.

Regards, Svein

H0 Peco C75, MRC Prodigy Advance, NSB (Norges Statsbaner / Norwegian State Railways) in the 50's

My photo albums:
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Posted by bogp40 on Wednesday, February 23, 2011 9:15 AM

Svein

The Walthers turntable looks identical to the Heljan turntable which I have, and if so every track position is programmed individually. However, if the turntable has fixed indexing with different angles than the roundhouse, that may be his problem.

Regards, Svein

If this is the case and the fixed index angles don't match, could the indexing be eliminated and control turntable by momentary toggle for the roundhouse track alignment?  Then roundhouse position can be set by stall radians to turntable center as usual.

Modeling B&O- Chessie  Bob K. 

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Posted by Svein on Wednesday, February 23, 2011 11:01 AM

bogp40

If this is the case and the fixed index angles don't match, could the indexing be eliminated and control turntable by momentary toggle for the roundhouse track alignment?  Then roundhouse position can be set by stall radians to turntable center as usual.

I don't know how the fixed indexing works or if it can be eliminated, maybe some others with experience can chime in here? If the indexing can be eliminated, a momentary toggle to control the turntable is indeed an option, provided of course that the bridge position is clearly visible from the operators point of view.

Another option is to keep the fixed indexing, but slightly curve the two outer tracks to match the angle of the roundhouse stalls. This of course only applies for a 3-stall roundhouse, with a 9-stall roundhouse as the OP had (three kits?) this might prove to be difficult.

Regards, Svein

 

H0 Peco C75, MRC Prodigy Advance, NSB (Norges Statsbaner / Norwegian State Railways) in the 50's

My photo albums:
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Posted by dehusman on Wednesday, February 23, 2011 11:02 AM

It should be about 7.63 times whatever the door spacing is (in whatever units you are using). 

If the door spacing is 2" then it will be 15.25 in from the door to the center of the turntable.

If the door spacing is 50 mm, then it will be 381 mm from the door to the center of the turntable.

If the door spacing is 15 HO scale feet, then it will be 114.5 HO scale feet from the door to the center of the turntable.

Dave H. Painted side goes up.

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Posted by brakeman321 on Wednesday, February 23, 2011 11:08 AM

Thank you for your information. However, there is a slight problem with it.  The formula works very well in placing the tracks correctly for the center stall and the two end stalls.   The problem though is that there isn't enough room for tracks coming from the other 6 stalls that are spaced between the ends and center. 

Prototypically, did the tracks curve between the turntables and roundhouses or did they cross one another?   (ie: one rail from one track coming out of a stall would cross the track of another stall close to the turntable.) 

If the turntable is moved closer to the roundhouse, there isn't a straight run from the stalls to the turnable which won't work.

Do you know of any type of book or literature about roundhouses and turntables?  I just don't know what the heck I'm doing and I would really like to do this correctly. 

Thanks again for the help and time with this.

Brakeman 321

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Posted by Svein on Wednesday, February 23, 2011 11:23 AM

brakeman321

Thank you for your information. However, there is a slight problem with it.  The formula works very well in placing the tracks correctly for the center stall and the two end stalls.   The problem though is that there isn't enough room for tracks coming from the other 6 stalls that are spaced between the ends and center. 

Prototypically, did the tracks curve between the turntables and roundhouses or did they cross one another?   (ie: one rail from one track coming out of a stall would cross the track of another stall close to the turntable.) 

If the turntable is moved closer to the roundhouse, there isn't a straight run from the stalls to the turnable which won't work.

Do you know of any type of book or literature about roundhouses and turntables?  I just don't know what the heck I'm doing and I would really like to do this correctly. 

Thanks again for the help and time with this.

Brakeman 321

Not enough room around the turntable edge you mean? That wouldn't surprise me, 7.5 degrees between stalls is a very shallow angle. You need to cut the ties off the tracks near the turntable edge. It's not uncommon for rails to cross each other close to the turntable edge if the angle between the roundhouse stalls demand it.

Regards, Svein

edit: Turntables come in different sizes, but their center is allways the same in relation to the roundhouse. A large turntable would have no problem placing all your tracks around the edge, since the edge is further away from the center.

 

H0 Peco C75, MRC Prodigy Advance, NSB (Norges Statsbaner / Norwegian State Railways) in the 50's

My photo albums:
http://home.tertitten.com/svam1940/fotoalbum/
http://foto.mjf.no/main.php?g2_itemId=5809

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