The Secret Society of Lathe Trolls

Hi, I would stay away from Rochelle salt. Its hydroscopic and has a finite lifetime. That was what was available back in the day. You should be able to source a proper PZT element that will sub for the crystal. You might take a look at the elements uses in grill igniters. They should be of a large e...

Hi Everyone, I've been working on a new cutting arm and head design and I thought I'd share it here. New Cutting Arm Low Res.jpg This is a complete replacement for the existing arm with several new features. 1. Allows for a head tilt angle adjustment for cutting or embossing. 2. Adds ability to adju...

Hi, I upgraded my motor to a small stepper. It now has plenty of torque and the speed is stable. The larger platter stl is attached. I had to do some machining to get it to run true. I made a special sanding disc that made that easy, but you would need a metal lathe to fabricate it. You may get luck...

Hi, I think that its marginal due to the construction of the bearings used and the fact that things are not so stiff. I printed a 6.5" platter to provide a better base for the blank, but you still run up against the deflection of the platter at the outer radius of the 7". If you drop the down weight...

Wow! That's pretty impressive. Maybe the world record (pun intended) for largest diameter locked groove!

Mark

Hi, I've attached stl's for two new parts I created. The pulley is a dual LPI design so you can switch between about 85 and 100 LPI by moving the round belt between the two diameters on the pulley. This should be printed with a resin printer for best results. The second part is a simple anti-backlas...

Hey, That looks nicely done! I checked and Dayton has a smaller exciter that has a 9mm voice coil vs. 13mm that I used. One drawback is that its BL product is about 1/2 of the 13mm driver. That might be made up for since you will be using 2 drivers. Also, the Gakken head design has about a 3:1 mecha...

Hi, I don't see why not, but if you are embossing, the stereo separation is vey low. I heard some theories on why that is so (e.g. U shaped grooves vs. V shaped), but I've never dug into it to see if that is really true or if could be improved. It would be a challenge to get the size and weight redu...

Hi,

Just grabbed them. Shoot me a private message with your email and I'll send them over.

Mark

Hi Everybody, Thomas, thanks for the kind words. The work you are doing is incredible. I'm following your progress. Looking forward to seeing the finished lathe. It was brought to my attention, that I left out one of the STL files for the actuator. The zip attached here has the correct set of 3 file...

Hi, Now that we can do 7" cuts, I wanted to see if I could increase the LPI from what I measure as about 89 to 120. I have modeled and resin printed a replacement pulley that does that. This gives you about a 35% increase in cut time possible. For the NAB standard 45 rpm 7",the start of audio is at ...

Hi Again, Now that I have the 7" adaptor, I was finding that operating the small button on the rack was difficult. So I came up with an extension to allow me to press the button with the blank installed. I've attached some Fusion renders, a photo of the device in place and the STL files. If you prin...

Hi, I was Inspired by skwoz821's 7" mod and came up with my own. In this version, you do not need to make or change change the rack. Just remove the two small screws that hold the head slide and bolt my all in one head mount in its place. It seems to have plenty of clearance for a standard 7" 45 and...

Hi,

I just had a thought. You are looking at the idler with the platter off and assuming that it is not hitting the motor. I'm wondering if this is because the idler is not in contact with the platter edge. Have you tried re-installing the platter to see if the mech is working as designed?

Mark

Printed your parts out Mark and have managed some pretty good cuts using a 50w and 100w amp, many thanks for the stl's. I've started working on making a larger version to cut 7" blanks. I've attached a sample and a pic of the many iterations of gear track til I figured out the dimensions correctly ...

Hi, I have a DP2000 here that I got some years ago for around $40 at a junk store. Needed some cosmetic work, but runs fine. I just did a very unscientific finger test against my SL1200Mk2 and I would say it has less available torque. So, probably not a great candidate. I've never poked at the elect...

The motor looks pretty well centered in its opening. So, I would look at the speed change mech. You may have to remove it to see what is going on. I can see from the underside photo, that the arm seems to be hitting the end of the curved slot on the baseplate. That seems suspect.

Mark

Hi, Is it possible you have the motor rotated from its correct position? It looks pretty symmetrical and could be mounted in one of 3 ways. Remove the motor and make sure that the idler makes contact on the bench. The arm that the idler swings on could be bent or hitting something. Hope that gets yo...

Glad you got this sorted out. I think you did the right things to troubleshoot the issue. I've found that there is not an across the board correct downforce number that works. There are so many variables that you need to find the operating weight by trial and error. Too little weight and and you don...

Hi, That should be no problem for a modern solid state amp. It would be more of an issue if the head was much lower than 8 ohms. The only side effect will be that you will develop less power to the head than the amp is capable of. For example, an amp rated for 100 Watts into 8 ohms will only deliver...