Heljan 89121 Turntable Quality Issue

[Flunter]

Hi.

 

I've recently purchased and installed a second-hand (but unused) Heljan 89121 turntable that has a couple of quality issues.

 

Firstly, there's a slight twist in the deck causing just 3 wheels to be in contact with the track.

Second, the centre of the bowl is ever so slightly high, giving an almost rocking motion to the deck. If a loco is off-centre and sat at the non-driven end of the deck, motion is very juddery.

 

Has anyone overcome such issues, and if so, how?

 

Thanks in advance.

 

Phil.

[MG 7305]

I have 2 Heljan 89121 turntables and they both reliable and great assets to the layout.  Here are a few pointers:

 

1.  The well has a lot of screws to hold it down to the baseboard and you can play tunes with them to to level it up.  It just requires accurate drilling of the holes.

 

2.  Thin shims under the rails running onto the well are one solution as are shims between the well and the baseboard (the obverse of point 1 above).

 

3.  Yes, the bridge can rock in certain locations but if the locomotive is centred or biased to be over the drive there will be no issue with locomotives getting on or off the bridge.  Just run onto the bridge very slowly, exactly as per the prototype.

 

3.  You should note that the the turntable is created around code 83 track.  Although developed and made by Heljan (they have assured me this is so) it is clear that the Walthers labelled US version is a big market.  So I have shimmed code 75 where appropriate and use code 83 on my hidden 'table in the middle of my fiddle yard, it makes setting everything up much easier.

 

4.  Use 2 straight tracksettas, one at each end of the bridge, if you are intending to have tracks over half or more of the 'table and align both roads simultaneously.  Indeed use one when installing every road, even if a single one, they give an accuracy in alignment which is a must.  I align the roads to the bridge rather the other way round which may be counter intuitive.  36 roads around one table and 12 the other cannot be wrong.

 

5.  When installing the roads do not push the track pins fully in to start with.  You may need to make micro adjustments to achieve reliable working.  I use a model with the dodgiest pony truck for trials as well as a more fixed wheel base vehicle.

 

6.  The turntable in HO is 90', in OO it is 78' 7 1/2".

 

Good luck.

Edited June 6, 2022 by MG 7305
Adding final point.

[Free At Last]

The only criticism I have with mine and I have read of others with the same problem is that it doesn't re-align with through track when rotated 180°. For that reason I only have entry and exit roads on one side.

 

[MG 7305]

7 hours ago, Free At Last said:

it doesn't re-align with through track when rotated 180°.

Ahha.  That is why I recommend that roads are aligned to the bridge.  The bridge is a fixed element in the equation if you see what I mean, at least the centre is and therefore the ends.  So my order of batting is:

 

Choose site of turntable pit.

Cut out, drill holes, and place pit in hole.

Test and adjust.  But keep in mind that it is best to adjust roads rather than the turntable.  Any adjustment to the turntable will affect more than a single road.

Align roads.  As I previously stated, use tracksettas and align the roads to the bridge.  The bridge and its rotation are the fixed elements, yes, really.  Test each step and test again until perfect, it is a slow business.

Do not ballast until a full cycle of temperature and humidity has passed, these things move.

 

I have 2 of these turntables installed, one with 18 pairs of roads and the other with 6.  Each pair being two roads 180 degrees  opposed and every road works when the bridge is rotated 180 degrees and locomotives can run from one road, across the bridge and onto the opposite road whichever way the bridge is aligned between the two.  It can be done.

[Free At Last]

8 hours ago, MG 7305 said:

Ahha.  That is why I recommend that roads are aligned to the bridge. 

I did align both ends of the track with the bridge but then when the bridge is rotated 180° only one end can be lined up. If I re-align the other end to the bridge again then when the bridge is rotated 180° both ends again do not line up.

Quote

The bridge is a fixed element in the equation if you see what I mean, at least the centre is and therefore the ends.

This seems to be where the problem lies. I think the centre is slightly off.

Other posters on this subject have not realised that their turntable was also out until looked at closer.

 

 

Edited June 7, 2022 by Free At Last