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Originally posted by quddha DJTJ is right. I touch the platter all the time, still works 100%. why? because the motor is electromagnetic. Nothing is in direct contact, as opposed to gears and stuff, so nothing can be physically worn out if you touch the platter. touching the platter is 100% safe on my technics. it does NOT hurt the motor.

Exactly. The thing that makes the platter turn is just an electromeagnetic field. The only thing that happens when you slow down the platter is that you create a small inductive current in the motor opposing the direction that the motor is trying to push the platter in. This is only the same thing that happens when you press the start/stop button. (trust me on this, I got an A at A Level Physics. I know what I'm talking about.) There is no actual physical contact with the motor or any parts of it.

on some cheap direct drive tables, cant you stop the motor if you touch it a little too strong??? b/c i have had times where i use my friends gemini pt2000 and i kept touching the motor and the platter almost stopped on me.(well, it didnt but it felt like it was going to) .... so is that where the amount of torque a table has comes in? because the more torque you have the stronger/durable the platter??

You guys are all confused. Obviously everyone touches the platter. But the manner in which you touch it is important. Just look at the dots! If you cue up a song and they slow down, it means that you are applying pressure to the platter. Suddenly, it becomes harder to turn at the same speed. "Mr. physics" should know this. I'm not saying that this will break your table if the dots move a bit. But the bottom line is that it isn't good for the table. Why do you think we use slipmats to mix? ...so we don't put any pressure on the platter when we spin the record.

"There is no actual physical contact with the motor or any parts of it." Umm... so? Usually, when I try to argue a point, I don't just throw in random, irrelevant information, because I find that that this doesn't prove my point.

If you are so confident in your theories, turn on your tables and push as hard down as you possibly can. Better yet, get something really heavy and leave it on your table while its spinning overnight. Don't cry to me when it doesn't work as good...

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Originally posted by Michael Russo Suddenly, it becomes harder to turn at the same speed

You are totally wrong! The "drive" of a direct drive turntable doesn't "push" any harder!! Why? Because all it does is to create a magnetic field, and this field is what you work against when touching the platter. Not the turntable drive itself. You will have to place an elephant on top of there to actually hurt the TT. DJTJ and others have made this perfectly clear a number of times. No offense, but is it really so hard to understand? Ask any pro about this.

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Why do you think we use slipmats to mix? ...so we don't put any pressure on the platter when we spin the record.

They're there so that the magnetic field can get the record up to normal speed faster when you let go of the record when cuing. It's reduced friction, not pressure we're talking about. But that really has nothing to do with this topic, so if this sounds weird, just forget about it.

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Originally posted by zapper You are totally wrong! The "drive" of a direct drive turntable doesn't "push" any harder!! Why? Because all it does is to create a magnetic field, and this field is what you work against when touching the platter.

Correct. The motor is not "smart", all it does is convert the incoming AC signal into an electromagnetic field, by way of a number of coils. If you take the platter off, you can see them. There are 12, I believe. The fixed magnet on the underside of the platter just moves as a result of the changing magnetic field caused by the coils. The only actual physical contact between the platter and the rest of the deck is where the platter sits on the spindle in the middle.

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You will have to place an elephant on top of there to actually hurt the TT.

You can try this if you want, it won't hurt the motor iteslf, I can't guarantee the rest of the turntable will be OK though!

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They're [the slipmats] there so that the magnetic field can get the record up to normal speed faster when you let go of the record when cuing.

Yep. If you think about it, if you stop the motor (which doesn't hurt it by the way ), once you let go of it, it's going to take a little bit of time to get back up to speed. This will ruin your mix if you have to wait this split second. You can't have instant acceleration from 0 rpm to 33 or 45 rpm. So, the slipmat reduces the friction between the platter and the record to prevent the platter from stopping.

--- Why do you think we use slipmats to mix? ...so we don't put any pressure on the platter when we spin the record.


any of you guys ever take physics? F=MA basic equation.
Force is a constant. that means if your stop the platter and then let it go it will accelerate slow. If however you only stop the record and the slip mat, M is far less and acceleration is quicker. give it a shot, take a record that isnt warped. stop the platter, then let go. next just stop the record and let go. which ones faster? The slip mat creates enough friction so that the record will not resist the forces of acceleration by itself, but when you add forces by hand the mat slides and sliding friction has less force than static friction, this allows for easy scratching.. etc etc, i could go on for hours.

dazzed

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"to be intoxicated is to feel sophisticated but not be able to say it"

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Originally posted by Michael Russo If you are so confident in your theories, turn on your tables and push as hard down as you possibly can. Better yet, get something really heavy and leave it on your table while its spinning overnight. Don't cry to me when it doesn't work as good...

That would just damage the platter if anything :P

If I turn on my motor, and stop the platter with my hand, with the motor still running, and leave it there overnight, and did this everyday for a month, it will still work just as well as when i bought it.

Have you heard any stories of anyone damaging there turntable motor because they slowed down the platter with it running?

quote:

Originally posted by Michael Russo If you are so confident in your theories, turn on your tables and push as hard down as you possibly can. Better yet, get something really heavy and leave it on your table while its spinning overnight. Don't cry to me when it doesn't work as good...

Yes the manner and power in which you hold the platter does matter...

But no idiot holds the platter down with 10 times the force needed to stop it. What you have said above is stupid because no one with a mental head takes a seat on their platter to cue it up. Additional force against the platter will stuff up internal parts, but with the amount of evergy normal people use to hold the platter, its just not enough to destroy anything on the TT.

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Damn all this is getting too technical for ma little brain.. I can't believe physics and the F=ma equation made its way in here. I feel like I'm having some sort of school tutorial lesson here; spare me!

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Melodic Progressive.

Better than sex.

okay people, i'm really convinced!
it won't hurt anything. many thanks to all of you!!

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Originally posted by Great Outdoors Damn all this is getting too technical for ma little brain.. I can't believe physics and the F=ma equation made its way in here. I feel like I'm having some sort of school tutorial lesson here; spare me!

next I will do a lession on the integration of the shape of the platter in respect to metal density, to calculate the true rotational inertia of the platter.

woohoo physics

haha

dazzed

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"to be intoxicated is to feel sophisticated but not be able to say it"

I always use the record to slow it down, because that gives me a better feeling than the platter

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Latest mixes: http://soundcloud.com/rhorjus