As part of my "getting to know you better" plan with my Smithy 3-in-1 combo
machine, I was using a dial test indicator to see how accurate the spindle
mount on the lathe is. There seems to be a 0.001" wobble. I've checked the
face of the spindle, the inner tapered part (it's a D1-4 spindle), and
finally I put a dead center in the spindle and checked that. I see the same
1 thou. wobble everywhere. Is this typical? Seems like, even if I mount
between centers, the end near the lathe spindle is going to be slightly
out-of-round.

I don't notice any play in the spindle (I can't move it side-to-side or
up-and-down by pushing against it....and I've verified it isn't moving when
I do this by looking at the dial indicator)....however, ever since I've had
the machine the spindle bearings have made a little rattling noise. I don't
really see how a bad spindle bearing could cause the wobble. It looks to me
like the spindle is simply mounted slightly off center.

....or maybe I'm just being too picky?

Todd Rearick

PrecisionMachinist sez:

Ya gotta trade in thet Smithey fer a Monarch EE if you wanna qualify as
"picky"....

Yeah, true enough. But be prepared to get really picky when you re-build an
old clapped-out 10 EE. Chances of finding a used 10 EE in good condition
are slim to none. Or, you could drop close to 90K for a new one. Otherwise
you can figure on having to do a great deal of work on an old 10 EE. A
friend is restoring one. I have helped him with problems in the electrical
drive section. A daunting task indeed. He spent close to $500 for one new
tube.

Bob Swinney

"Todd Rearick" wrote in message
news:i%e6b.45287$Zw4.45200@lakeread03...
As part of my "getting to know you better" plan with my Smithy 3-in-1
combo
machine, I was using a dial test indicator to see how accurate the spindle
mount on the lathe is. There seems to be a 0.001" wobble. I've checked
the
face of the spindle, the inner tapered part (it's a D1-4 spindle), and
finally I put a dead center in the spindle and checked that. I see the
same
1 thou. wobble everywhere. Is this typical? Seems like, even if I mount
between centers, the end near the lathe spindle is going to be slightly
out-of-round.

I don't notice any play in the spindle (I can't move it side-to-side or
up-and-down by pushing against it....and I've verified it isn't moving
when
I do this by looking at the dial indicator)....however, ever since I've
had
the machine the spindle bearings have made a little rattling noise. I
don't
really see how a bad spindle bearing could cause the wobble. It looks to
me
like the spindle is simply mounted slightly off center.

...or maybe I'm just being too picky?

Todd Rearick

It could be they used the wrong class of spindle bearings. I know this guy
who saved a few dollars on his 16" Hendy lathe. He bought cheaper class of
bearings for the spindle. From then on he had .002 run out.

Richard W.

Todd Rearick wrote:

As part of my "getting to know you better" plan with my Smithy 3-in-1 combo
machine, I was using a dial test indicator to see how accurate the spindle
mount on the lathe is. There seems to be a 0.001" wobble. I've checked the
face of the spindle, the inner tapered part (it's a D1-4 spindle), and
finally I put a dead center in the spindle and checked that. I see the same
1 thou. wobble everywhere. Is this typical? Seems like, even if I mount
between centers, the end near the lathe spindle is going to be slightly
out-of-round.

I don't notice any play in the spindle (I can't move it side-to-side or
up-and-down by pushing against it....and I've verified it isn't moving when
I do this by looking at the dial indicator)....however, ever since I've had
the machine the spindle bearings have made a little rattling noise. I don't
really see how a bad spindle bearing could cause the wobble. It looks to me
like the spindle is simply mounted slightly off center.

So Todd, you're thinking it's impossible for "them" to make a bearing that isn't
perfect? Just because bearings are supposed to be manufactured with miniscule
runouts doesn't mean someone can't have a bad day and make a sloppy one. (Or
maybe a whole bunch of them.)

If you do use a 3-jaw chuck, as another poster has said you'll be lucky to clamp
the stock within a thou of running perfectly anyway, but parts turned on the end
of that stock will be OK as long as you don't unchuck the stock before they are
completed.

If you have to unchuck and rechuck, it can help a bit are to mark the stock and
the chuck so you can replace the stock in the same angular relationship to the
chuck.

Also, find the "master" pinion on your chuck, the one which when tightened,
providuces the least runout of a round test bar close to the size of the part
you're chucking, and always use that same pinion for the final scrunching down
of the chuck.



...or maybe I'm just being too picky?

Methinks you just may be, for more parts than not.


Todd Rearick

Jeff (Who's had to learn how to get the best he can out of what he's got.)
--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can smile when things are going wrong, you've thought of someone to
blame it on."

Todd Rearick wrote:

mount on the lathe is. There seems to be a 0.001" wobble.

Have you contacted Smithy? What did they say?

Ted

"PrecisionMachinist" wrote in message
...

Ya gotta trade in thet Smithey fer a Monarch EE if you wanna qualify as
"picky"....


Yeah....I'm only picky to the extent that it remains within my relatively
tight budget.

Todd

"Ted Edwards" wrote in message
...

Have you contacted Smithy? What did they say?

Ted


Not yet. I just noticed it Friday night...I'll have to call them monday
morning.

Todd

He spent close to $500 for one new tube.


Must have been a C16J.

About $800 from its current manufacturer, Richardson Electronics. About double
that from Monarch.

A tube drive Monarch has two of these thyratrons.

1250 volt PIV SCRs would be another 30 years in coming to market.

Todd Rearick wrote:

"Ted Edwards" wrote in message
...

Have you contacted Smithy? What did they say?

Not yet. I just noticed it Friday night...I'll have to call them monday
morning.

I was changing chucks on my Smithy today and recalled this thread so I
measured the runouts on my spindle. My chucks are held on with three
screws. There are two registration surfaces - one radial, one axial. I
measured the total indicated runouts with a Starrett DTI reading tenths
(0.0001"). The radial TIR was 0.0002", the axial 0.0003". I was
surprised, actually. This is on a ten year old Smithy AT-300 that has
seen hard use (but not abuse) for a home shop machine.

Ted

Ted Edwards wrote in message ...

Have you contacted Smithy? What did they say?

Ted

I'm quite impressed. I just contacted Smithy, and they are going to
send a replacement spindle, plus a few extra parts I will need as part
of the replacement and instructions on how to swap it out (hopefully
not written in chingrish). Not bad service...

Todd