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Author Topic: Technics 1500 brake pad check and clean  (Read 2845 times)

Offline analogfan

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Technics 1500 brake pad check and clean
« on: February 21, 2011, 01:31:30 PM »
Hello all,

I have cleaned the brake drums - I want to check my break pads.  It looks like there are two possibilities:

1. Back and top cover removed, unscrew the three phillips head screws holding the motor and carefully remove it through the top or move it to the side.  I am hoping the motor has a connector for the wiring.

2. Remove the runout bearing assembly at the rear, pull the C-clip on the end of the shaft at the rear and remove spindle/rotor assembly from the front.

clean the pads with a q-tip lightly with a naptha based cleaner (but don't soak the adhesive - I did read this on the forum I believe).

Are brake pads available from somewhere?

Sorry if this is on the forum somewhere - if it is, I could not find it.

Thank you, Bob Edwards

Offline ironbut

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Re: Technics 1500 brake pad check and clean
« Reply #1 on: February 21, 2011, 04:05:36 PM »
Hi Bob,

I think it is on the forum somewhere but there's so many freakin RS1500 posts, good luck on finding it!

The way I service my brakes is to remove the reel motor. Pulling the motor apart isn't that easy with it mounted and should be done with it completely out of the machine.
There is a multi pin connector for each motor on the vertical circuit board just to the left of the take-up reel motor. They're the big ones on the top and the bottom. Unfortunately, since the supply reel motor is also connected there, the wiring harness come from the far side and goes behind the transformer which makes it a pain to detach.

When you just want to service the brakes, cut a few of the cable ties to give yourself some slack (you'll need just a few inches) and pull the cable from the square cable organizers on each side. Since I do lots of work in there, I took the time to separate the different harnesses and cable tie them together in bundles rather than one or two big ones that you have to pull apart every time.
It's also a good idea to take out the little circuit board to the right of the take up reel (with the fuse on it) since it's totally in the way.

Loosen the three motor screws then remove the bottom 2. Technics was nice enough to countersink these so they shouldn't fall out when totally loosened. When you loosen the top screw you should be able to pull the motor into the machine without the screw falling out. Be very careful not to put any strain on the little circuit board that sticks out of the bottom of the motor or the wires that are attached to it.
I balance the motor on top of that vertical circuit board on the take up side and the power supply board on the supply side.
When doing this, be careful not to mar the black brake rotor. I thinks that's some kind of enamel so it's not super tough.

Once the motors are out of the way, you can get to the brake pads through the front very easily.
I know that Doc likes to use a Scotch brite pad on the felt pads and I usually use a light sandpaper. Try and avoid using a solvent any stronger than alcohol since, like you said, you don't want to loosen the felt.
I don't think that the felt is anything special. You can buy a ton of it at a fabric store for cheap. It's also pretty thin so don't think that if it's thicker, that it'll work better.
One thing to bear in mind is that IMHO, the spec's for the brake force that in the service manual is too darn high. When those numbers are adhered to, it's a bear to pull tape off of the reels when you're threading a reel. The RS1500 does most of it's braking dynamically with the reel motors and the brakes only engage at the very last second of stopping the machine. So having high braking force doesn't really yield significantly quicker braking times. I think it's much more important to have the braking nice and even. I also think that the lighter braking forces give you more wiggle room between the two.
You'll also find that the braking force will change as they get even the slightest amount of wear and contamination which is unavoidable. So you'll probably need to adjust them after a few hours of use.
 Don't spend a lifetime working on them or loose any sleep worrying about them. Take it from me, you can!
If they seem to be working OK, (stopping the reels without weird noises or tape slack) you might want to move on to more pressing issues.
steve koto
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Offline analogfan

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Re: Technics 1500 brake pad check and clean
« Reply #2 on: February 21, 2011, 08:31:31 PM »
Wow Steve!  What a great reply.  I was totally intimidated by the reel motors & brakes.  Thank you for demystifying it for me!

This is a great forum!  Thank you again, I will post the outcome of the project.

Regards, Bob Edwards