Peco N turntable, motor drive mounting

[phlyfifer]

Hopefully a few will read all of this before loosing the wil to go on !

 

I have an N layout with a PECO motorised turntable. The motor gearbox is one of the standard after market offerings. I have never been happy that the turntable bridge is turning as freely and "non-wobbly" as it should.

I have reed switches, mounted in the turntable well, operated by a magnet mounted under the bridge and operating a relay stop start system. Repeatability of track alignment is an issue.

 

I decided today that I would unballast the tracks in/out of the turntable and re-align the "ends". This prompted me to look pull the bridge off the drive and look at the centrality/verticality of the shaft up thro the well hole. Needless to say it was not central and who knows re verticality.

 

I remember reading an article in one of the mags re installing a turntable drive and it simply said mount the motor/gearbox on a convenient cross member with a block of wood screwed to it -- Aye Right !!

 

When I originally mounted the motor drive, the base board was on its side and suspect this is the start of some of the problems. The drive shaft is only partially engaged in the bridge as the motor gearbox was mounted first.

 

I have been thinking about what might be the best way to mount the drive to give a reasonable degree of centrality/verticality but am looking for feedback by anybody who has got a good method and forgive me if some of you think some of it is too obvious to be worth mentioning..

 

My curent thoughts are :-

 

To get the least wobble on the bridge the drive shaft needs to be pushed as far into the bridge mounting as possible. How do you achieve that and get just enough pressure on the polarity reversing pins when the drive is mounted but be able to keep the bridge clear of the sub miniature reed switches located in the "corner" of the well wall --- once the motor is mounted?

 

To get the bridge central in the well i.e. clearance all the way round when the bridge turns is an obvious requirement --how is that achieved when the motor/gearbox is simply being screwed to a lump of wood ?

 

 

Method for critique/ Complete critiscism.

 

Offer the drive shaft up through the turntable well ---- motor/gearbox not mounted to anything.

Push the bridge onto the shaft as far as it will go.

Lower the bridge into the well until it settles on the bottom of the well.

The motor/gearbox is still just hanging below the turntable/baseboard.

 

Pack card between each end of the bridge to keep it central.

Under the base board, turn the motor/gearbox until the mounting face is parallel to where a mounting block can be located.

Fix a mounting block but leave it 3mm? clear of the gearbox.

Drill through the gearbox mounting holes into the mounting block.

Put set screws through the gbox and fit 3?mm packers onto the screws as they are pushed through the mounting block, finger tighten the set screws/nuts.

 

Remove the centralising packing and test run the bridge to see if it runs around --odds on it will stutter.

 

Pull the bridge off the shaft and check how central the shaft is up through the hole. Adjust the 3mm packers to get it central. Use an extension tube on the shaft to check and adjust verticality by slackening the screws and jiggling the motor gearbox side to side using the clearnce in the mounting holes.

 

Refit the brige and try again !!!!!!

 

Better fool proof method ??????