Page 13 of 15

Posted: 07 Jan 2009 14:43
by pivot
Hey MuZak,

I note that you have a Merrill motor on the table now. Has that motor become noisy or have some other flaw?

The Merrill is, after all, just a worked over Hurst. IF you have noise have you tried just reoiling the bushing and replacing the capacitor?

Posted: 07 Jan 2009 20:44
by MuZak
Hey there Kevin...

Thanks for the helpful analysis and suggestions!

The situation is this...
The Merrill/Hurst motor has a bent spindle.
It got bent while trying to remove the pulley, which
had gone on crooked.

Long story.
Maybe I'll post the long story one day since its kinda humorous.
In a tragic sort of way...

Basically it goes like this:
Mr Merrill told me over the phone way back when I first
did the mod... to use superglue to mount pulley to spindle.
I'm certain he'd said that. Would never have occured to me.
The reason for the phone call, was that the replacement
pulley that came with the motor part of the mod, was
way to big to fit on the spindle.
Dramatically so.
The original pulley had 2 small cuts so it could be closed
down on the spindle, but the replacement didn't.
It wouldn't close down (crimp) to fit the spindle,
so I phoned for advice.

Trouble was... it went on crooked.
The table was unusable till I figured out how to get
the crooked pulley off.
After many attempts with everything I could think of,
including letting a copious amount of super-glue remover
sit in the "basin" for several weeks....
it finally occured to me to use a puller.
I found a great one, perfect sizes for the job, at a model
railroad supply house.
It worked like a charm... came off in one second.
If only I'd thought of it sooner.
I can tell anyone who may have need where to get one.
Cheap too.

Bottom line... all the prior attempts at removing the pulley
had obviously bent the spindle in the process.

It wobbles pretty badly... and I've used it that way for
some time, but I've managed to adjust it out with suspension
adjustment.
While its not audible... its FAR from ideal, and replacing
the motor is a key reason for the total re-do of the table.

Hurst offers no replacement parts... just complete motors.
I tried that route first.

Obviously I would like to start out with a motor spec'd
at least to the same level as what is in there now.
Ie: with the Merrill mod done.

Anyway, I now have in my hands, a brand new Hurst.
Now, its about making the most of it.
I plan to disassemble the Merrill/Hurst after the table
is up and running again, to see if any repair is posible.
Maybe its possible to straighten the spindle or something
like that.
Don't want to experiment till I have a working table again.

I can't be 100% certain that its a bent spindle.
It could be that the bushing is cocked or some such.
Its just not possible to know without taking it apart,
and I've no idea if it'll go back together, much less if its
possible to effect a repair.
Worth a try later on though, since it might just need
a variation of the Merrill-mod technique to put it right.
We'll see.

Meanwhile, I'd like to do to the new Hurst whatever is
possible/feasible/worthwhile to improve it before
installing it.

I'm wondering about using clay instead of caulk in the
basin thingy..
It would have a tad more mass, and be easier to clean
up when upgrading to the co-polymer pulley I'd think.

Anyway, thanks again for the suggestions.
Greg

Posted: 07 Jan 2009 22:41
by Alec124c41
Greg, you beat me to it. This thread gave me the idea to try some plasticene/ modeling clay in my pulley.
BTW, I have posted my method of straightening the pulley shaft on my Thorens:
https://www.vinylengine.com/turntable_f ... ght=#86712

Alec

Posted: 07 Jan 2009 23:12
by MuZak
GMTA Alec, GMTA...

Although, it does appear that GMs also have a tendency
to bend pulley shafts too... :roll:

Plz DO let us know how the clay experiment works out,
since mine will be out of comish for a while!

Thanks sooo much for the thread on straightening!
I'm going to read it right now.

Greg

Cap values?

Posted: 31 Jan 2009 07:04
by MuZak
Well... I've spent much of the evening re-reading
the entire thread from the begining. Lol..
Very interesting indeed, but.....

I still don't know, definitively, what is the BEST cap value
to use for the Hurst 3001-001!

Is it the .47?
The .1 that comes with it?
Does using the Sprague "Orange-Drop" (in .47) really
make an improvement???
Will it kill the motor prematurely??

What about the start cap value?
I DO have a loud pop from the spkrs when turning the
motor on... even with the volume all the way down!

I'd really like to add a start cap, but what value?
Particularly if not using the cap that comes with the motor.

Have these been answered to a certainty?

Posted: 31 Jan 2009 12:59
by ddarch
Hi,

Personally, I only replace with original values. That's just me because I like to be conservative, figuring there was a reason AR and Hurst chose the values they did.

That said, I'd love to see someone approach this sysytematically and take some real data after installing various values with the presently manufactured Hurst AND the original. Any one who would undertake that in a methodical way would be doing all of us a great service.

DAve

Posted: 03 Feb 2009 04:45
by MuZak
Hi Dave..

As always, thanks!

I too tend to be conservative with these things.
Particularly in the absence of certain knowledge
that something is better (and safe).

However, what corporations choose for mass-market
products is not nescessarily always optimal for
the purpose... and our purpose isn't nescessarily
theirs.

Just to make an arbitrary example;
What if optimal for performance were .152mfd
but those would have to be custom made with
a large minumum order.
That might translate to several dollars more per
unit, which might price that unit above the competitor's
unit.
The corp decides that .1mfd is "good enough".

I also have to wonder, in the case of the Hurst,
if their choice assumes certain motor-load conditions.
And if so, what load is that.
Or, is that even a factor in the choice.

I too would love to see someone approach this
sysytematically
and resolve this once and for all.
I have neither the knowledge or means to do
so, unfortunately.
IIRC, Eric did so to some extent.
Both in a thread here I can no longer find, and
for the stuff he sells from his www page.
The info is there in that thread, if you can find it.

Of late, I've been re-examining the 'geddon clone
type of thing.
It really does make sense in a lot of ways.
Not so much in terms of cap values, but in general
as a power supply box.

If you leave the (whatever value) caps in the
turntable... its really just a huge transformer
in an outboard box.
Trafos have an inherently high degree of regulation.
That translates into speed regulation for an AC
synch motor.
One can also use a stepdown trafo, rather than
just an isolation trafo.
Stepping down whatever comes out of the wall
to a constant 110V, which is much better.
That combined with line isolation should make
a big improvement.

I've been thinking of adding some FILTER capacitance
"in the box" along with the trafo.
But implimented to smooth the waveform,
like used in power amps to smooth ripple.
Perhaps even with inductors to make a filter.
(LC-network)
A very narrow bandpass filter.
Ie: 59 to 61 hz.
That'd give you a fairly clean 60hz @ 110V
near sinewave I should think.

Perhaps not as deluxe as a fancy VPI type box,
with its sine generators and class A amps, etc..
but close enough for most of us, at a FAR lower
price, and DIY-able.

Probably not put out all the RF the crystal oscillators
and all that stuff in the fancy boxes must also.

Seems to me it would also mitigate the importance
of small motor-run cap differences too.

Just thinking aloud...
Maybe someone with greater knowledge will
pickup the baton....

Greg

PS: Dave.. do you happen to know the value
of the stock motor START cap offhand?
I've forgotten and it would be easier if you
(or someone else) could just tell me, rather than
having to go hunt it down.

Posted: 06 Mar 2009 16:51
by coax man
Hurst's website is buggy, but I found this motor on an industrial supply site that looks pretty promising for cheap. Unless someone has experience with it or advice suggesting it's a bad choice, I'll give it a try and offer some feedback.

http://www.grainger.com/Grainger/items/3WY73

Posted: 06 Mar 2009 17:20
by gkimeng
coax man wrote:Hurst's website is buggy, but I found this motor on an industrial supply site that looks pretty promising for cheap. Unless someone has experience with it or advice suggesting it's a bad choice, I'll give it a try and offer some feedback.

http://www.grainger.com/Grainger/items/3WY73
The shaft on this one is too small for the motor pulley on a single-motor AR table.

There are two motor types used in AR tables. 600RPM with a 2mm shaft used in the older two motor tables, and 300RPM with a 3mm shaft used in single motor tables.

Annoyingly, Grainger carries a 600RPM Hurst with a 3mm shaft and this 300RPM Hurst with a 2mm shaft.

Posted: 06 Mar 2009 19:12
by gkimeng
Being single phase, what would you power it with? how would direction be set? If i'm not mistaken, single phase motors have brushes to power the rotor instead of an induced field of 3 phase.....If it is brushed, it would make a horrible noise......like driving the TT with an electric drill.
Just my thoughts/questions
These are 4-wire motors, and I think they'd use caps just like the originals. But yes, they do appear to have brushes. One would need to be pretty hard up for a motor.

Posted: 15 Jun 2009 12:04
by ddarch
bump

Posted: 16 Jun 2009 04:09
by MuZak
Ouch!

Posted: 16 Jun 2009 05:06
by MuZak
OUCH?!?!?!?!?! ouch what?
The bump!
Hit me right in my achin lombago.

(and notified me via email that "a reply has been posted to
a thread you are following")
(so I hurried to log on... salivating to discover what
new breakthru had occured)

New Hurst website www.hurst-motors.com

Posted: 25 Aug 2009 17:37
by AB9JK
Hurst has an improved website http://www.hurst-motors.com

Re: New Hurst website www.hurst-motors.com

Posted: 25 Aug 2009 18:34
by pivot
AB9JK wrote:Hurst has an improved website http://www.hurst-motors.com
Interesting - anybody given thought to the 24 volt 3001-003 and DIY a Speed-Box-like clone?

Easier/cheaper I would think to cob up a smooth power supply for a 24 volt vs. a 115 volt motor. Just thinking in print.

Would a stock Speed-Box (16 volt) work wit a 24 volt motor??