Lathe from scrap

[Kaferlago]

Hey trolls,

I spent most of my life playing with vinyl, one thing I never tried is to make my own so why not.
Because I'm cheap, like challenges and usually have no idea what I'm doing, I'll try to make my own using scrap parts I have laying around.
Between work and family and a million other hobbies I don't have much free time, the plan is to just get the bare minimum understanding of how the process works and learn during the journey.
I started to design in CAD but that was taking too much time and just starting cutting metal. I don't have a 3D printer, I'm old style manual subtractive material material hobby machinist.

I'm currently building the first iteration of the cutting head using two 2" midrange drivers, the table is a old JVC DD that I altered to mimic DJ TT dimensions, I don't believe it will have the torque needed but maybe I can reuse the bearing and platter for some Frankenstein contraption... let's see once I get there.

[kugelblitz]

I'm curious to see how far you get with this.
I've seen quite a few people starting out with the cutterhead, but it's actually one of the last parts you need. Building an overhead that brings the head slowly but surely (and very leveled) to the center is perhaps the first challenge.
good luck!

[Kaferlago]

I made some progress, @kugelblitz I try to work in parallel with the cutter head and the X axis, I'm using a hobby lathe/mill so I try to optimize the build depending on the machine configuration.
The X bridge is done but has flaws maybe good enough for a proof of concept, will post a picture.

The cutter head is progressing, I decided to attach the cone as close as possible to the voice coil to avoid cone deflections. The cutter is 2mm tungsten for now.
Cutter heating in in the plan. i need to figure out the torque tube attachment.

Any suggestions or comment?

IMG_2013.JPEG

[Kaferlago]

I'm puzzled, what the angle should be between the pushrods and the cutter, I made a couple of torque tubes. Ona the 90° and the other 72°

And here is a picture of the x axis, it's made out of an old printer shafts, the screw is just a section of a commercial threaded rod, very wobbly. I could probably turn a screw between centers to make it decent but it the cutter head works I may just invest in a linear rail. we'll see.

[Logrythmic]

Hi, the build looks really solid so far. How do you plan to drive the Speakers? Do you have an Amp or are you planning to build your own amp or something?
Im also interested in building my own Lathe sometime in the future. That's why i was curious about it. Thanks.

[Kaferlago]

Hi,

maybe I need to give you a background so you can understand my build, I don't need a lathe, I'm not working in the music industry and I'm not planning to set up a record production. I will be satisfied even to just cut one decent 12".

I want to see how far I can make it with recycled/repurposed materials, I have a couple of consumer grade amplifiers ~100Wch in storage that I used over the years. That will be the starting point.
Those will need to be serviced I'm sure, but I have no intention to build audio electronics, there is plenty out there and fairly cheap. If I have to invest time I will on expensive or non commercially available parts (or things I have fun building).
I'll probably need to sort out the cutter head transport and platter drive electronics but other than that no mess around with PCBs is in the plan.
I want to keep it simple for now and eventually upgrade the parts I cant develop further due to lack of time or capability.
There is a lot of knowledge in this forum but it's scattered all over the place and at times is too simple or too technical to me, I'm building mine in a modular and adjustable fashion so I can experiment with different solutions.

[Kaferlago]

Here some progress to the cutting head.
I also tossed my diy axis and bought a linear rail instead.

What will be a good cutting bit geometry to sharpen the business end to?

[Kaferlago]

It's winter again and time to restart, this is where I'm at the moment. Everything is surprisingly square considering my skills and tools.
I'll try stepping the motor now.

[kugelblitz]

Looking good, you're a long way there!
Is the y axis a part of a photo enlarger?
Make sure to use a silent stepper driver (like a TMC2209) to step the motor.

[Kaferlago]

Hi kugelblitz,

yes the y axis comes from the picture camera world, but it's a "focus rail". It's used in conjunction with macro lenses, to shift the focus plane by sliding the camera in and out.
It's a cheap rail I had, I thought may be useful to be able to adjust the height of the cutting head until I figure out the geometry.

I have a TB6600 stepper driver, not sure if it's silent, I mean the thing is noisy but not sure if that ok or not. The quieter setting is at 1,2A 3600 Pulses. Even though it's a small motor it has plenty of torque. I might decouple the leadscrew with belts and pulleys to limit the vibrations at later time.

I'm using Vinyl Burn software from Dave to test the movements, it works enough to do some checks but I can't find the correct configuration in the arduino sketch. Any Idea what can be used instead?

[Kaferlago]

Here is where I am at the moment.
It does move and scratch the plastic but the platter motor has zero torque and I'm sure the cutter geometry and cutting angle is totally wrong.
I'll look in my assortment of salvaged motors and see what I can come up with.

[Semar]

You're on the way