The Secret Society of Lathe Trolls

Hi,

Next time you have things apart, post a picture. There may well be a difference.

Mark

Hi, You might have a tolerance issue between the bottom white pulley and the platter. The shaft of the white pulley has a key slot that engages the platter. The metal center pin is also keyed and should be a bit shorter than the surface of the white pulley. When you add the keyed overhead pulley and...

Hi, The reason for cutting inside out was to make the transition from a multiple disc performance seamless for broadcast. If you start cutting inside, you have lower fidelity. As you move to the outer diameters, the fidelity improves. When you reach the end of the side, the next disc starts its reco...

Hi Daniel,

Just in case you don't have this document. See the attached pdf. It seems to have quite a bit of info. Looks to me that they spec 75ma as the bias point if I am reading correctly. See page 7.
Mark

Hi,

Here is a version with an extra hole on the side of the pivot. Due to the pivot hole, I could only fit one setscrew on this side. I think it should work out fine.

Hi, If you are using the full RIAA recording curve, you will get very bad results. The low frequencies will be over boosted and you will have wildly large excursions. You need to develop an EQ curve that works with your open loop head design. The published RIAA curve assumes your head is flat vs. ve...

Hi, Looks like it turned out nicely! I've attached a pdf of the schematic for my amp. I am using an off the shelf amplifier board with a TI TPA3118 chip. Its a 50 Watt unit. You can get instantaneous peaks up to 100 Watts. There are several sources for these boards. Here is one: https://www.amazon.c...

Hey Thomas,

Nice work! I knew you would dive right in and get that sorted.

Mark

Hi Thomas, I'm glad you found this helpful. If you need some help sorting this out, feel free to ask. Based on your abilities, I'm sure you will be able to dive in. The Arduino timers are a bit complicated, but they can be made to operate in several different modes. The Nano and Uno have very few ti...

Hi Thomas, A better approach to doing the phase control is to use an unused hardware timer setup to cause an software interrupt after it reaches the required delay time. In the interrupt handler, you fire off the triac with a short pulse and then do any setup the for the next line cycle or half cycl...

Hi, Glad you find that useful. Yes, you should be able to do the standard build and start with an embossing stylus as long as the stylus holder is designed for the standard Presto long or short shank. One nice thing is that if you wear out a cutting stylus, you can turn it around backwards and it be...

Hi, You don't really get good stereo separation via embossing. The reason why is not totally clear. The theory is that the embossed grooves tend to be U shaped and this makes the playback stylus ride in the bottom of the groove. I'm not 100% sold on this explanation and I think more work could be do...

Forget #2. Look for a pro machine in bad shape and restore if you have the technical chops. To start from scratch and expect to equal a machine of that caliber in a reasonable timeframe and budget is not realistic.

That looks really nice!

Hi, We are getting somewhere. The spec for the motor I could find on line was not complete, but it indicates is a 2A, 3.2V winding. That should be able to provide plenty of torque with a 12 Vdc or better driver supply. In fact, I would say its vast overkill. 1080 RPM is pretty fast due to the large ...

Hi,

That driver might be ok. Its not a full micro step drive, but at 32 pulses per step, it might not be too noisy. What is the model number of the stepper motor are you using? What is the motor rpm you need to reach 45 rpm platter speed?
Can you upload the Arduino code you are running?

Mark

Hi, What RPM are you needing to run the steppers at? What size and spec motor are you using? What are you using as a driver and what voltage are you powering the driver with. If you can afford a full on servo, that would be best, but if this is a hobby build, you should be able to get decent perform...

Hi, I am embossing here. You can flip the Gakken/Teenage stylus 180 degrees and it works fine as an embosser. You get much longer life in this mode. I decided to make the new version of the head and arm so that you can use a standard Pesto short shank stylus instead of the Gakken/Teenage stylus. The...

Hi, Glad you find this stuff useful. I do all my printing here. The price for a FDM machine is so low these days, that it would pay for itself pretty quickly. Even the resin printers are low in cost. They are just a mess to deal with due to the chemicals. The potential issue sending them out is how ...

Hi,

Thanks for posting that!

Mark