Sudden slow down with my Triumph A-B

[briankeith]

My Triumph A/B is one of my weekly players - strong quiet running motor. I always keep it clean (Lid on when not being used) and oiled. Last night while playing it for a friend the record (perfect record) would suddenly slow down to almost a complete stop unless I lifted up the small carriage lever ever so slightly then it would play at normal speed. I have never made any adjustments as it always plays several cylinders perfectly on one full wind. I'm baffled - the belt (new) is not slipping, the feed nut is clean and the reproducer is rebuilt with new stylus. Any thoughts?

[FellowCollector]

If the belt tension is correct and you have wound the Triumph mainsprings sufficiently to play what you want to play and lifting the carriage resumes play at normal speed then I would recommend looking at (and adjusting) the feed nut tension on the feed screw. If 2/4 minute gearing has been added to your Triumph A/B then I would also suggest looking at the clutch assembly and assure that the feed screw rotation is not slipping during play.

Doug

[PeterF]

Before making any mechanical adjustments to something that was running fine, I always think through what could have logically changed since the last known good condition.

The two variables here are lubrication and the record itself. Temperature can also be a factor, although most houses don't fluctuate too widely - but was it a cold day?

A mechanical adjustment would merely compensate, maybe, for changes in those variables, and only to some limit. Doing so is masking the real cause though.

Why not try a few other records, especially any that you recall playing well on that machine previously? And if all records produce the same behavior, maybe try doing a little cleanup and re-lubrication on the rotating as well as sliding parts and see how you make out, before altering adjustments. Be especially sure to re-oil the governor pads and shaft.

[briankeith]

Thanks - no adjustments made, I will re-clean and re-lube the machine again tonight. All records I tested last evening still slow down. Belt is not slipping (new) and I even switched reproducers.

[Fonotone]

You should also check the rubber wheel on the belt tensioner and confirm -- when you raise the tensioner's spring arm from the pulley -- that it's spinning freely. The wheel has a tendency to attract ambient gunk, and if enough gunk gets caked on the axle, the wheel will start to drag. If the drag is significant enough, the drive belt will not be able to overcome it and the machine will slow down or even stop. This problem is more common on an Edison Standard, which has a smaller motor and considerably less torque -- but I've encountered it on larger machines too.

--Grant