Too Hot! getting the disc temperature right/swarf dropping

[nikc]

Hello,

To get my vinyl blank a good temperature for diamond cutting I use stylus heating (a little) and heat the disc up with a hot lamp.
To get a cut where it has good "high end" frequencies , a bright and not dull sound, it helps to get the disc up to about 35 degrees (95 Fahrenheit) or more .
But at this temperature the swarf drops and sticks to the vinyl. So I go down a bit to about 32, where the sound it not quite as good.
Using a infrared thermometer BTW

I have increased humidity too (as that helps static apparently).

Does anyone else have this problem? What temperature do you use?
Is using the lamp wrong?
Should i be focusing on the static?

Any idea?

Thank you

Nik

[SueDenim]

It sounds like you're working though the problem logically which is a good thing!
My next area to question is your vacuum suction as it can cause all kinds of issues if not strong and consistant.
What type of vacuum are you using?

[nikc]

Hi Sue
Thanks for getting back. Good question.
I am using an old pump that was used for cleaning out car air conditioning. Made by General Electric, but the label has since fallen off. Its quite big and does seem powerful, but perhaps it is old..It makes alot of noise. i am searching for it on the internet. so will send a link when i can find it. My ebay purchase history only goes back 3 years.

BTW my swarf usually drops as soon the stylus first makes contact. I wonder if this is unusual

Thanks

Nik

[SueDenim]

In my experience, the initial swarf pickup by the suction is one of the most critical parts.
Once you have it running through to the swarf jar it usually takes a drop in suction, increase in static or blank warp to upset it.

I used to use an old pump too and it was fine for months... then I began to have all kinds of swarf drops.
No amount of increased suction from this pump helped the issue.
Eventually I bought a fairly new side channel blower and haven't had the problem since! Even though the newer blower doesn't produce the same pressure as my old pump, it's enough and much more consistent.

With a side channel blower (as the name suggests) it can both suck and blow. Using it to blow allowed me to highlight leakages in my vacuum system (e.g. pipes, connections etc.) and eliminated them... usually with gaffer tape!

[nikc]

Thanks I have been looking at Side Channel Blowers (after reading your post). It be good to be able to get the disc hotter and have no swarf drop. By the noise mine makes and the leaking oil, Its going to completely go soon.

[nikc]

BTW what do you use as a filter on your swarf jar in you have one,? I am using some hessian type material to stop the swarf going into the pump.

[tragwag]

sounds like a static problem to me, do you use an anti static fluid?
you should treat the disc with something before cutting, even as simple as a few oz of water with 3-4 drops of dish soap in it

[nikc]

Hi tragwag. Yes I have used staticide in the past and now turtle wax which makes lots of difference . But yes it still could be static. I was looking online at a static meter type thing and they were £100 which I thought was alot just to prove/disprove something once. I think increasing the humidity helps but it's hard to tell.

Thanks
Nik

[tragwag]

right on. here in FL it's a big deal when it drops below 40% humidity my chip drops right away.
sometimes I even spray really lightly onto the disc with dropped chip, and it picks back up.
on more troublesome days I'll spray anti-static and let it sit on the disc for a while before cutting

[ObiKutnobi]

Just a thought, are you u lowering the stylus VERY VERY carefully and slowly. If you drop a stylus too quick it will cut a deep initial groove that can often prove too much to be picked up by the suction.

[nikc]

Hi ObiKutnobi, Perhaps I am not; it IS doing it at that initial point. Thank you, that is something good to know about. I will try this out. I have before thought of modifying so it has a smooth lowering.

[nikc]

right on. here in FL it's a big deal when it drops below 40% humidity my chip drops right away.
sometimes I even spray really lightly onto the disc with dropped chip, and it picks back up.
on more troublesome days I'll spray anti-static and let it sit on the disc for a while before cutting

That's interesting to know; when it was dropping once it was about 27%. And seemed better when its over 40%. It seems to vary alot in London, but perhaps that is Normal.
Its hard to tell without more testing what are the factors that is making it drop.

I bought a little humidifier but it doesn't make much different in the reading. Putting the shower on next door for a while make alot more of a difference.

[Discomo]

Nice! Another static topic, of which we trolls are so fond of.

Currently the humidity is so low, I cant get it up anymore (the humidity that is) so I’m currently cutting in a tent.
Yes. A plastic coverage over my VR and a humidifier inside.
Believe it or not, its the only way it works atm. So far for a professional set up.

[Discomo]

The type of swarf can also point you in the direction of the cause.

Curly swarf means your stylus weight is too light.
The suction can’t get a grip on the swarf and it (the swarf) takes the path of least resistance which means sticking to the blank. You can put an entire bucket of anti static over yr blank, it won’t solve the real problem: swarf which is too light. Think a stylus weight which is less than 7g. You’re good between 12-15g, possibly higher under yr circumstances.

[nikc]

Ah wow. I have seen differences in the swarf from time to time. So it could be that. I am having good result ls with cutting myshank blanks at 25-27 degrees. Not as hot as before. And using my new pump and also fixed up the swarf jar so has no leaks. I think the wieght is about 12 grams. But it's hard to measure on my old MSS lath e. As you have to have the arm lifted a bit to get the jewelers scales under. And the angle effects the weight. But not too much. I will have a think to get a correct measurement.

Thanks
Nik