Can Anybody Tell Me Whats Going On Here? (Pics Included)

[sgreiner1011]

Hi All,

I have been cutting (not embossing) for a few weeks with a Sapphire cutting stylus on my Presto K10. I am cutting 45RPM singles. The type of records I am cutting are these---> https://www.ebay.com/itm/7-Large-Hole-Blank-Vinyl-Records-QTY-of-10/253054296263?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

The pictures below show what I am ending up with. The sound of the record could be better. Has anyone ever seen the grooves look like this after cutting? It looks like my needle is bouncing up and down or something. They look like waves. In the first pic, the part of the record between the red lines does not have any sound on it. Its just silent and dead with no sound. Then after the red lines the sound starts to play. Inside the green circles is what I am talking about (waves). Since the "waves" extend into the dead part, I am thinking this has something to do with my cutting head/needle rather than the actual recording? Is the needle dull do you think? Please help. Thanks!!

[descent]

Hello, I have the same result sometimes. The problem is coming only from the blank disc.

[Jccc]

its kinda hard to tell from the picture.

What does it sound like when the play back needle plays those spots?

If it starts to skip then I would think that you have the recording levels too high and the grooves are clashing.

Also have you tried cutting other records? Does it always happen in the same spot with different records?

is the feedscrew firmly in place and not loose or wobbly?

[Kris D]

It looks like you have a flat spot on the drive idler that is causing the spoke pattern. You can have them rebuilt at Terry’s rubber rollers. Does the pattern also appear at 33 or 78?

Best,
Kris

[sgreiner1011]

Hello, I have the same result sometimes. The problem is coming only from the blank disc.

So do you think its just the way the blank discs are made? Basically once the record is cut, you can see the inside?

What does it sound like when the play back needle plays those spots?

If it starts to skip then I would think that you have the recording levels too high and the grooves are clashing.

Also have you tried cutting other records? Does it always happen in the same spot with different records?

is the feedscrew firmly in place and not loose or wobbly?

I cant really hear it unless I really listen hard. There is a bit of distortion every now and then, but it does not coincide with those spokes. I just hope I am using the right needle to cut Virgin PVC from eBay ---> https://www.ebay.com/itm/7-Large-Hole-Blank-Vinyl-Records-QTY-of-10/253054296263?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It happens on all records I am cutting. They always look the same and are always the same length apart. I have only tried one kind of Virgin PVC so far. I haven't tried any other medium.

Feedscrew is perfect and so is the puck.

It looks like you have a flat spot on the drive idler that is causing the spoke pattern. You can have them rebuilt at Terry’s rubber rollers. Does the pattern also appear at 33 or 78?

I am not familiar with what is called a drive idler? Where is that on a presto K10? Everything on my Presto seems in great condition except for the rubber tire. That could be replaced but I don't think its in that bad of shape.

I have not tried recording at 33 or 78... Maybe I should give that a try.

[piaptk]

Your k10 has a rubber belt around the platter, not an idler. The belt may be cracked or bumpy. Very common issue withk10 and k8.

If the blank is too thin, (like a picnic plate), this could be an issue as well, but unlikely with recordblanks.com blanks.

You should also make sure that your needle is straight up and down and perfectly perpendicular to the blank when looking at it head on. A leaning needle can cause something like that as well.

[punkrock]

Maybe it has some relation to this topic I posted years ago:

https://www.lathetrolls.com/viewtopic.php?f=1&t=4856&p=32728#p32728

[sgreiner1011]

Maybe it has some relation to this topic I posted years ago:

Do you mean turntable wobble? Mine wobbles if I press on one side of the platter without it turning. But only a very very slight bit, like 100um or something. I'll look into that more.

Your k10 has a rubber belt around the platter, not an idler. The belt may be cracked or bumpy. Very common issue withk10 and k8.

If the blank is too thin, (like a picnic plate), this could be an issue as well, but unlikely with recordblanks.com blanks.

You should also make sure that your needle is straight up and down and perfectly perpendicular to the blank when looking at it head on. A leaning needle can cause something like that as well.

The belt is extremely smooth and looks brand new. Its very quiet too. I did have to adjust the needle perpendicular when I first got it. Its perfect now. I also have the cutting head at the recommended 5 degree angle that is in the instructions.

It just seems like my needle is bouncing up and down ever so slightly but in a very consistent way. What force should I have that cutting head at? I have a tool that can measure such force. I cannot find any info on what force the cutting needle should be at. I do know the groove strands (looks like hair when cutting) are supposed to have a certain look to them according to the instrcutions, but at this point I am kind of winging it.

[descent]

Try one by one 3 steps:

1. Try another blanks (Myshank or better [if you have the opportunity] Sourie's vinylrecorder-stuff)

2. Setup in a better way the cutterhead's counterweight, (smooth move).

3. Setup the turntable's flatness. Other trolls explained allready.


Send us update!

[tragwag]

do you use a suction tube? If my suction tube is touching the cutter head at all (due to an uneven blank), it'll bounce the head during the cut.

[sgreiner1011]

Try one by one 3 steps:

1. Try another blanks (Myshank or better [if you have the opportunity] Sourie's vinylrecorder-stuff)

2. Setup in a better way the cutterhead's counterweight, (smooth move).

3. Setup the turntable's flatness. Other trolls explained allready.

I think I am going to try other blanks as well as another needle. I have a lot going on all at once. I will post back with details after I get everything I need. Thanks!

do you use a suction tube? If my suction tube is touching the cutter head at all (due to an uneven blank), it'll bounce the head during the cut.

I don't use any suction. I use a soft brush to clean up the waste. I don't think its the brush as I am not that consistent with the strokes. I don't think there is any way I could even try to get the "waves" as consistent as they are.

I am starting to believe its my sapphire needle. A lot of people are saying I cannot use a sapphire on PVC. All of a sudden the tip broke after using it ~10 times on 45 singles as I share in another post. The problem I have is that I do not know how old that sapphire is so I cannot tell if it broke prematurely. My sapphire used to cut PVC really well and it was really quiet. Since a lot of people are telling me I cannot cut PVC with that sapphire, I will change needles. You guys know best. I'm just a newbie. I think I am going to try a diamond.