Model Railway Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
60 Posts
I have installed the Peco OO turntable with the Frizinghall motor kit. There have been other threads about this combination but not mentioning this particular problem as far as I am aware.
The motor is driven from the same Gaugemaster controller as the track, via a DPDT centre-off switch
It works (subject to installing the polarity switch) but the rotation is not smooth; the turntable judders. The worm is not jammed against the large gear:





so I can't see why this is happening.
The one design fault I find is that having cemented the securing collar underneath, one can not get to the central spindle for maintenance or adjustment.
Can anyone advise? Thanks. Colin
 

·
Registered
Joined
·
68 Posts
This is no help at all, but I have exactly the same problem. It seems to work more smoothly in one direction than the other.
 

·
Administrator
Joined
·
9,844 Posts
Wild guess - one or both of the shafts is flexing?

David
 

·
Premium Member
Joined
·
4,854 Posts
Hi Colin.

This is a problem which can occur if BOTH ends of BOTH drive shaftes are not properly supported and aligned.

The best way to do this is to make two 'U' shaped brackets which will fix up to the underside of the baseboard and solder or braze a brass collar into each of them that the shafts can turn in. The brackets need to be made from quite rigid steel which will not, itself, flex under the torque from the motor and the collars need to be quite a close fit on the shafts.
 

·
In depth idiot
Joined
·
7,675 Posts
Expat's suggestion is a good enginering practise approach and will solve the problem. What you could also do is:

Take the worm wheel off the shaft and evaluate how freely the table turns under finger power. As assembled mine needed PTFE lube on the carrier wheel axles and plastic compatible grease on the table shaft before it turned really freely, particularly when carrying my heavier locos (500 - 750g).

Take the gearbox off, turn through 90 degrees so that the worm shaft is much closer to the underside of the turntable, reattach gearbox as close as possible to turntable shaft while clearing worm wheel, fit worm wheel to mesh.

That shortens the working lengths of the shafts (less length to flex) hopefully reduces the driving force required (less force flexing the shafts) and may be enough to deliver the required improvement.

The first time I saw one of these kits, the user had attached the gearbox to the underside of the turntable pit. Not only could you hear every meshing tooth, (the pit base acting as an efficient loudspeaker diaphragm) but by attaching a small piece of shiny metal to the pit base and directing a light at it while the motor was running, the turntable pit could be seen to be flexing in time with the audible 'wow-wow' of the drive and perceptibly pulsing table motion.
 

·
Registered
Joined
·
60 Posts
Discussion Starter · #7 ·
A medical problem held up completion. Eventually I did shorten both the drive/worm spindle and the main vertical TT spindle. Then I reprinted the brick-work on thinner paper and replaced it! I also applied a (hopefully) plastics-friendly grease TF2 by Weldtite to the worm and cog to take up some more of the movement. It all helped quite a lot but there is a little residual jerkiness.
 

·
Premium Member
Joined
·
450 Posts
I dont like the look of this set up at all,from an engineering point of view the mesh is far to coarse,and the shafts far to long,every vibration in the mechanism will reverbarate through the bottom of the turn table as mentioned before,I chucked mine in the spare's box in the end and built one out of meccano using drive belts quiet as a mouse,if you want to keep it,everything that the previous lads have said must be done,and then go and get from a auto centre some door skin deadening sheet,(anti vibration ) and stick it to the bottom of the turntable,it will take most of the noise out of the system
 

·
Premium Member
Joined
·
17 Posts
I had the same problems and in the end gave up after a lot of work.I then purchased a direct drive kit from Signal Box Model Railways which works very well.
Chris.
 
1 - 9 of 9 Posts
Top