The Secret Society of Lathe Trolls

Hi megrimm I have so many projects going on in parallel, so this particular one is stalled at the moment. You can see in my earlier posts that I tried to do some embossing. It kind of worked, but I have to make a new platter. The platter I used was something I found in the scrap bin. It is not solid...

It's not done yet, and may end up a complete fiasco, but as I say; "failure is always an option". You always gain something from it

After working with some other projects ( incl this ) I have gained some more time for this. I have assembled a simple heating unit consisting of a modified heat gun (brought out separate leads for the fan to be able to control the heating elements separately), a solid state relay, an IR temperature ...

Hiya Did some measurements on the surface today. The surface roughness of the blank area of an original disc was 0,05 Ra (very low indeed!), 0,89 Rz. I used a surface grinder to remove the old tracks, and finished with a 500 grain paper. Measured the surface roughness and got 0,34 Ra, 3,4 Rz. hardne...

My first plan was to use fixed depth but then I realized that many people got good results with floating suspension. I believe the surface roughness would have a bigger impact on sound quality if using floating suspension, but I will give it a try. Regarding heating; I just made some quick tests, bu...

it should be noted that original 78 discs have pumice added to the mixture to wear the stylus as you play the disc, this prevents the stylus from wearing the groove. one needle, one play. the playback stylus must be changed every time you play another disc, or the same disc for that matter. this is...

You have the equivalent of a impedance transformer given the fact that large speaker travel results in smaller stylus movement. So the speaker will less mechanical load than the stylus point. That might be a good thing. I'm sure you'll have no problem playing with all of the mechanical and electric...

I guess frequencies above 5kHz will not be interesting. I will also have the option to slow everything down. I could go half speed or even slower if that would be a benefit. The actual arm has a mass of 3 grams, but since it pivots around a point the effective mass will be lower than that. I don't t...

Did some more CAD:ing today. I may be able to cut out most of the parts next weekend!
Do you think there is a need for angle adjustment of the cutting stylus?
I am also not very sure about what amplitude of the stylus would be suitable.

Well, I believe even the "factory made" shellac records did not last very long. I don't really have any experience my own on this, but did not these records wear out much quicker than modern vinyl records? Maybe I should add that HiFi is not really main focus here. Of course, it's good if it sounds ...

Regarding the balanced output from DAC to amp. The current setup was a really quick and dirty test, but it seems to work well. I am honestly not too sure about all the functions of the WM8741. It seems to have internal filtering, but I guess there should also be an external anti-aliasing filter befo...

latetrolls002.jpg latetrolls006.jpg This is the result: DSCF4216.JPG For moving the cutter head I'll use a small linear drive unit with ball screw and a DC servo that I had laying around. Since the records are very hard I need to heat them up when cutting. I tried with my hot air rework station and...

Hiya Joined this forum mainly for this project. I have already introduced myself here , so let's get straight to the topic. I have an old hand cranker which I really love. Unfortunately, getting hold of good old 78RPM records is not too easy and I also came to think; "wouldn't it be very nice to be ...

Here is a pic of the drive electronics for the stepper motor: DSCF4213.JPG Regarding balancing of the platter; both the hub and the platter itself are CNC machined so they are very symmetric. I have not done any balancing after that, and I honestly do not think that is necessary. When it comes to vi...

Markrob: I'm running the stepper in open loop. I use a microcontroller to generate two sine waves using its PWM outputs, and an analogue amplifier driver the motor. Regaring the cotton drive "belt". I tried several different materials. Nylon fishing line. FireLine fishing line. Some kind of rubber s...

Hi there So, now I'm registered at yet another forum. Thought I should say hello before I start writing about my current project. I'd say my interests are quite diverse, and covering science, motors, engineering, electronics, mechanics, hifi and of course music! Listing all my previous projects woul...