vinyl recorder with precision motor

[marcy108]

hi everyone.

i'm VR T560 user.
i bought precision motor and plate one month ago.

at first,the two worked very fine.
but i'm having problem today.

My groove is mixed 2 type shallow and wide with precision motor.
Playback stylus jump at shallow groove....

the things following are confirmed.

---if i don't use motor,problem doesn't come.

---problem happen in only outer of 12".in inner of disc,it's no problem.

---weight setting 15g is nomal.when i set weight 20g,problem get bigger.when i set weight 7g,the problem doesn't occurs.but groove is too shallow.no good.

i can't figure what's happen...can someone know it?
any help would be appreciated!

best regard,

[marcy108]

This is the problem groove...

[Snug Music]

hey mary...
what I see is that the grooves run into each other! the width does not there .. try it with a larger groove width!
the deeper you cut, the narrower the grooves.
change the wideness, which should help!

Best regards
Scotty


no, I have made a mistake !!!
I'm unfortunately a very long time awake!
the Groove is too shallow .. (too little weight!).
Since you must increase the weight!
there is something wrong in the setup!

[marcy108]

thank you for reply.

>the Groove is too shallow .. (too little weight!).
>Since you must increase the weight!
>there is something wrong in the setup!

if i increase the weight,problem get bigger....
groove disappeared...even shallow groove.
next picture show it...

[marcy108]

Like this..

[Snug Music]

hey marcy..

Uhhh..., what the f ...? That's hard! I just do not know what this could be. hmm ??
Try to set times with Steve from myshank.com communicate, because something is wrong with your machine.
I will make myself even at times clever.
Is not normal!

THATS A NIGHTMARE!!!

[Gridlock]

Wobbely platter.

[Snug Music]

Wobbely platter.

I agree!
Head suspension, and so on .... all control times properly.
marcy trying times (if you have or can get!) to test a prezisions dial indicator to the Platter on imbalance!

best regards
Scotty

[Gridlock]

My presto platter wobbels unless you engage the motor at a certain point on the circumference the previous owner thankfully marked with sharpie. I have examined the bearings and metal on metal points and have no clue why it does that

[SueDenim]

Hi Marcy,

Firstly, using the adjustment tool, recalibrate the precision plate to make sure that it is as flat as it can be; i.e. within tolerance on the meter.

Next, whilst you are cutting:
- check that the dashpot plunger isn't anywhere near the limit of travel; especially make sure it never hits the bottom of the cylinder
- check to see if the suction tube is binding/catching on anything
- check to make sure that the audio cables which run into the cutting head aren't tight; they should be loose at all times

One more thing; the viscosity of the oil in the dashpot may be too high and isn't allowing the cutting head & stylus to track any slight warps in the blank.

If I think of anything else I'll let you know.
Best of luck!

[marcy108]

thank you very much for showing many point!

hi Gridlock
>Wobbely platter.
yes,i also agree it.but i still can't find how to improve it...
at moment all i can do is plate setting.

this is plate setting.can you figure any mistake?
https://www.youtube.com/watch?v=LmpbGGyWMgM


hi SueDenim
>Firstly, using the adjustment tool, recalibrate the precision plate to make sure that it is as flat as it can be; i.e. within tolerance on the meter.

can you check above video?

>- check that the dashpot plunger isn't anywhere near the limit of travel; especially make sure it never hits the bottom of the cylinder

yes,i'm not sure but around dashpot is suspected.
but i can't find where is the point..
can you find from my photo?

cable and suction is ok.


just in case,this is precision motor setting.i think this is right setting.
https://www.youtube.com/watch?v=wUjGa3PeiBQ

thank you everybody.
i appreciate your continued support!

[marcy108]

sorry my photo had side way.this is right photo.

[SueDenim]

Hi again Marcy,

In the video of the precision plate, it appears to be within tolerance, although I cannot see the scale on the meter in enough detail to be absolutely sure.

Please look at the areas highlighted in the image below.
YELLOW:
This is the dashpot which contains a plunger inside the cylinder.
At the moment the plunger is hard to see as it is on the very bottom of the cylinder because the photo was taken whilst you weren't cutting.
When you are making a cut, the plunger will rise up the cylinder to be somewhere near the middle.
Whilst cutting, check to make sure that the plunger never makes contact with either the bottom or the sides of the cylinder.

RED:
Check that this pivot connection is completely free to move and isn't binding.

BLUE:
Whilst cutting, check that these audio cables aren't tight.

IMG_8702.JPG

[SueDenim]

Something else just occurred to me...
- Set the overhead motor speed to be fairly high (e.g. around 40-60)
- Manually wind the cutting head to the start position for a 12"
- Without dropping the head, stylus heat or vacuum, switch the overhead motor on and listen carefully to the noise it makes
- Let it run at least a couple of minutes

As the cutting head is driven across the blank, is there any point where the noise from the overhead motor gearbox changes dramatically?
For example, does it sound as though it's slowing or binding??

[marcy108]

hi SueDenim.
thank you very much for your kind reply.

>When you are making a cut, the plunger will rise up the cylinder to be somewhere near the middle.

this is photo that when stylus is down.
i don't think plunger don't rise up to somewhere near the middle.
what do you say?

>RED:
>Check that this pivot connection is completely free to move and isn't binding.

can you say setting of this video is completely free?
https://www.youtube.com/watch?v=5iKZ3MH_J0k

>BLUE:
>Whilst cutting, check that these audio cables aren't tight.
yes,cables always aren't tight.

Something else just occurred to me...
- Set the overhead motor speed to be fairly high (e.g. around 40-60)
- Manually wind the cutting head to the start position for a 12"
- Without dropping the head, stylus heat or vacuum, switch the overhead motor on and listen carefully to the noise it makes
- Let it run at least a couple of minutes

As the cutting head is driven across the blank, is there any point where the noise from the overhead motor gearbox changes dramatically?
For example, does it sound as though it's slowing or binding??

i'm done this process.
i always can listen motor gearbox noise.
but it's not change dramatically...

thank you for your continued support.

[marcy108]

dashpot when stylus is down.

[SueDenim]

Hi Marcy,

The pivot connection in your video looks correct, so no problem there I don't think.

Perhaps I was going a bit far when I said that the dashpot plunger would rise to around the middle of the cylinder.
It really all depends upon how you have the suspension set up (height, angle, counterweight etc.)

However, the goal of what I'm trying to discover here is whether or not the plunger is hitting the bottom of the cylinder during a cut.
In order to confirm this 100%, I would suggest that you increase the plunger height using the top wheel and setting nut.
You will probably need to adjust the height a little when you do this and also readjust the counterbalance for correct weight (15g).

[marcy108]

Hi SueDenim.
Thank you very much for your quick checking.
I appreciate to you.

I change setting in many ways.
It looks bit far ease up when I don't set weight.
But once I set weight 45/15g, plunger rise up is not change before...


>whether or not the plunger is hitting the bottom of the cylinder during a cut.

Please let me comfirm.
not hitting is good?

However how can I check it hitting or not?
Because I think bottom of cylinder is always hided,right?

> I would suggest that you increase the plunger height using the top wheel and setting nut.

Is this nut?

[marcy108]

I could rase up plunger around middle of cylinder.
I couldn't move nut.too tight..
I could see bottom of plunger don't hit cylinder when I during cut.

But the problem still keep on occurring ...

My plate setting is still wrong??
I uploaded new video.
You can see tool dial.
https://youtu.be/OdoO2aj9jKk

[SueDenim]

Hi Marcy,

From the results of your testing, I think we can also rule out the dashpot as being the root cause of the problem.
And, yes, the plunger hitting the bottom of the dashpot cylinder whilst cutting is not good and something to avoid.

Your new video of the precision plate measurement looks like its within tolerance to me - I certainly cut with a similar amount of variation without encountering the problems you are having.
So, I'm afraid that this leaves us back at square one I've gone through every basic check I could think of for calibrating the VR.

The fact remains however that something is causing your cutting head suspension to not track the vertical variations in the blank's surface correctly.
These variations will be in the blank itself and also the small deviations in the precision plate as it rotates.

You say that this problem is restricted to the outer diameters of a 12". If you examine the groove under a microscope from the outer diameter towards to centre, does the problem suddenly stop or do the variations in groove depth gradually become less extreme?