Vinyl Recorder dashpot

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DJ2000
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Vinyl Recorder dashpot

Post: # 56186Unread post DJ2000
Fri Jul 10, 2020 3:21 pm

Hi there,

been having issues lately with missing grooves (vertical tracking) on the outside edge of 10 and 12inch, been through all sorts but think have ruled it down to an issue with the dashpot now their is one thing thats always bugged me should the lid to the dashpot with the butterfly screw be screwed all the way tight? mines always had a big gap between it, its a second hand system and always been like this have attached a photo for ref
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DJ2000
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Re: Vinyl Recorder dashpot

Post: # 56187Unread post DJ2000
Fri Jul 10, 2020 4:28 pm

thought would add this photo is taken with the head up and not down

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Discomo
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Re: Vinyl Recorder dashpot

Post: # 56188Unread post Discomo
Sat Jul 11, 2020 12:05 am

Set the weight of the dashpot higher. 12g minimum. This will solve the issue with the missing grooves.

The opening of the dashpot is no problem.

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SueDenim
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Re: Vinyl Recorder dashpot

Post: # 56190Unread post SueDenim
Sat Jul 11, 2020 4:51 am

Discomo wrote:
Sat Jul 11, 2020 12:05 am
Set the weight of the dashpot higher. 12g minimum.
So does this mean we should decrease the tension in the dashpot spring a little?

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PMST
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Re: Vinyl Recorder dashpot

Post: # 56191Unread post PMST
Sat Jul 11, 2020 5:46 am

With the head up there should not be a big gap like that, it should be fairly flush, as that means there is constantly tension in your spring which over time will slacken it

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Discomo
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Re: Vinyl Recorder dashpot

Post: # 56192Unread post Discomo
Sat Jul 11, 2020 5:57 am

SueDenim wrote:
Sat Jul 11, 2020 4:51 am
Discomo wrote:
Sat Jul 11, 2020 12:05 am
Set the weight of the dashpot higher. 12g minimum.
So does this mean we should decrease the tension in the dashpot spring a little?
Well, it works for me if I have it at 12... When set lighter I have the same problem with the vanishing grooves. If I have it at 15 I have another problem-the Technics 1210 hasn't got enough torque. Of course when you have an SP-10 you don't have this problem. But maybe it differs per recordplayer and you can set the dashpot heavier on your recordplayer.

That said, I'm still looking for an SP-10 (mkII). If anyone has one, send me a pm please

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Discomo
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Re: Vinyl Recorder dashpot

Post: # 56193Unread post Discomo
Sat Jul 11, 2020 6:01 am

PMST wrote:
Sat Jul 11, 2020 5:46 am
With the head up there should not be a big gap like that, it should be fairly flush, as that means there is constantly tension in your spring which over time will slacken it
I think you're right. I missed the last message and thought it was with the cuttinghead down.

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DJ2000
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Re: Vinyl Recorder dashpot

Post: # 56197Unread post DJ2000
Sat Jul 11, 2020 7:18 am

Hi All,

ok so adjusted the dashpot so it does not have a big gap when head up but dailing it to get to 15/20grams it stretch again back weight is 45gram have uploaded a video for ref any ideas?

https://www.dropbox.com/s/y1iphslt8vnhfb4/20200711_120633.mp4?dl=0

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PMST
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Re: Vinyl Recorder dashpot

Post: # 56198Unread post PMST
Sat Jul 11, 2020 8:49 am

In the video the record is spinning whilst measuring and changing weights, you definitely should do this with the record not spinning, otherwise you won't be able to set the 45g weight from the back without potentially breaking something. Readings won't be accurate either.

So from the top, i would start again with calibration, the order MyShank advises is good to follow: https://www.myshank.com/en/content/6-faq

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PMST
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Re: Vinyl Recorder dashpot

Post: # 56199Unread post PMST
Sat Jul 11, 2020 8:53 am

Also not sure how the measurements are being taken in the video, you seem to be changing the black knob and head weight while the head is being suspended by the scales?

The weight measurement is taken when head is down, and lifted, and the measurement is taken from when the stylus first leaves the blank, so nothing should be getting changed while the head is suspended by the scales

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PMST
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Re: Vinyl Recorder dashpot

Post: # 56200Unread post PMST
Sat Jul 11, 2020 9:14 am

Just re watched the video, the problem is the readings are being taken wrong, that is going to be the issue for you, the head shouldn't be suspended at all whilst anything is being changed, all changes to the black knob should be made whilst head is up, no suspended by the scales. Best to go from the start, follow the my shank guidelines and then take the measurements so that the head is down, and then lift with the scales slowly, the reading is taken the moment the stylus leaves the blank, nothing more

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DJ2000
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Re: Vinyl Recorder dashpot

Post: # 56202Unread post DJ2000
Sat Jul 11, 2020 2:44 pm

Hi PMST,

ah thanks for the info, have redone the calibration like you said I have always done it by having it to the right of the platter and lift the head and adjust it, had the machine for two years as well hah, you learn something new everyday! :) btw in the video the head was away from the blank and platter its done in the deadspace on the right so you cant damage the cutter

have put the precision platter back on and dti gauge that up and re done the weights, fingers crossed now the missing grooves issue is sorted cut a 12inch and 33rpm and no groove break. looks like it was partly cause by the dashpot yet to try cut a 12in at 45rpm that would be a good test!

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PMST
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Re: Vinyl Recorder dashpot

Post: # 56206Unread post PMST
Sun Jul 12, 2020 1:41 am

When taking weights you want the head to be lowered onto the record, not the dead space otherwise its impossible to take a reading, the weight will be from when the stylus leaves the blank, so doing it off the side makes this impossible, try that and see how you get on

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