I WILL cut records playable on a Victrola, or die trying!

[sdt9030]

Hi Everyone! My name is Steve (not THAT Steve) and I've just plunged head first into the hobby of record cutting. As an introduction, I am a PhD research physicist at 3M Company in Minnesota, and have recently become obsessed with the physics behind making and playing records (especially on my old manual Victrola). My ultimate goal at this point is to be able to create records playeble on the Victrola, although I understand this is a big undertaking. I've been lurking on the forums for a little while and feel like I've learned enough to get started. I just bought an old-but-functional Presto K8 and have started getting my feet wet with it.

I am hoping to bring my knowledge of Materials Science to the problem of finding the right recording material to enable cutting a record on my K-8. I've only had my lathe for a couple of weeks, but have managed to cut a record that is playable on an electric turntable. I'm quite pleased with it, especially as it is only my second real attempt. Lots of background hiss, but other than that it sounds pretty good to me.

From here, I plan to make a silicone mold of the record and then create an epoxy copy that will hopefully be hard enough to survive the Victrola. I've ordered a Fiber Needle cutting tool so that I can try bamboo needles, in case I need something softer than steel even with the epoxy. Ultimately I want to find a material with two cure states: a soft one for cutting, and then a hard state for playing on the Victrola. I'll keep you posted as to my progress.

[piaptk]

You can cut Victrola playable records (without the molding process) using Farmer John's Tungsten embossing needles (tell him you want them "old style" for the wide groove) with a lot of weight on polycarbonate. Poly is hard, but I've never actually tried to wear one out, so not really sure exactly how long they last, but a while, I'd imagine...

[sdt9030]

I'm surprised that embossing can produce a "Victrolable" record! Good to know! I assumed that an actual "cut" track would be necessary. I will most definitely try that approach out!

As I noted, my ultimate goal is to try to identify a polymer that can can have two different levels of hardness depending on preparation, so that you can cut at one hardness and then crosslink the polymer to a much harder state for playback. I know some materials that can do this, but they may well not have the two hardness states needed. One of the advantages of working at an entire company of adhesive and polymer chemists is that there's is probably someone I know who knows what I need to know!

[sdt9030]

Oh, and did I read in an article about you somewhere that you used to live in Olympia? Because that's where I grew up!

[piaptk]

I'm surprised that embossing can produce a "Victrolable" record! Good to know! I assumed that an actual "cut" track would be necessary. I will most definitely try that approach out!

You just have to use a lot of weight.

[fredbissnette]

i use a up to 500g and tungsten on lexan and i can play them at 78 no prob

as a rule tho i cut at 33 with the audio slowed down to play back at 78 and the fidelity is much better

cheers

[piaptk]

as a rule tho i cut at 33 with the audio slowed down to play back at 78 and the fidelity is much better

cheers

This. You will get much better tracking as well, because the stylus can dig in better at the slower speed.

[sdt9030]

A sincere thanks for all the helpful suggestions so far! Being able to take advantage of the vast experience on this forum is the only reason I even CONSIDERED trying this project!

Having no easy access to cactus thorns, I tried playing one of my shellac records using a simple wooden toothpick last night (as I had seen on YouTube) and was pleasantly surprised by how nice the sound was! The wood does an excellent job of filtering the high frequency noise/hiss. I am going to try triangular bamboo needles out as soon as the set I ordered from Ebay arrives.

I've only just started my research into a polymer system that could have two different defined hardnesses depending on it's cure state. Still trying to nail down exactly what the hardness of a shellac record is. I may need to build an indentation tester and just measure it myself. For the "cutting state" hardness, I am thinking of something in the range of vinyl or maybe a little softer. It actually seems to me that ductility is probably a better characteristic to specify for the pre-cut state, since getting a clean cut is important. Fortunately, my wife's job is primarily centered on micromachining, so she's a great resource!

Recording at 33 and 1/3 to get a deeper cut sounds like a really sensible idea! I'll try playing around with that tomorrow!

Oh, and if anyone has a good reference mentioning the Shore hardness of an old shellac record, I would be most grateful to be pointed in the right direction.

[socialroots]

Im.sure ive read somewhere from an old post about the shellac thing,as i remembered it was something about abrassives being in the shellac formulas inorder to make needles the needles wear down instead of the record grooves,hence having to change the needle out after each play. im sure the victorolaguy has quite a bit of info as he specializes in those old hand cranked machines.by the way im in no way an expert or have alot of experience in the area where your interests are at,but i do remember in the yrs past there has deffinitely been posts about the subject of shellac 78,s,formula wise i think mossboss even knows the formulas of the past .
Maximum respect,
Patrick

[tragwag]

I've done it a few times on my Vinyl Recorder with increased depth, it comes out pretty good!
there are some fibre/cactus needles on Ebay but they're sold in sets which can be a little pricey.

[piaptk]

These are nice too:

https://www.ebay.com/itm/351941289333

[dmills]

On the surface hardness thing, I don't have numbers but the thought occurs that if someone has access to the gear required (Not trivial!), Parylene coating has some options that put down a layer north of 80 Rockwell hardness, and the process should be compatible with records....

Problem is the gear is not trivial, and it only really becomes reasonable when you can fill that chamber with things to coat.

Not one for home use, but possibly interesting for a one off experiment if someone has industrial access to a machine.

Just a thought.

Regards, Dan.