Lockdown turntable and lathe - a DIY project

[pentlandsound]

Hi - yes, I'm afraid I drew these diagrams initially for my own benefit, so the drawing conventions are a bit non-standard! The green 10K component is a 10 kilohm potentiometer (three-pin variable resistor). The one I used was a small square box occupying 3x2 pin spaces on the board, although it only has three pins, orientated vertically in this diagram. Its outer two pins are connected to 5V and GND, the output at the centre pin controlling the contrast of the LCD.

Note also that the circuit as shown in the diagram is built on stripboard, with the copper strips on the back running left-to-right. The red X's show where the strips have to be broken.

Hope this helps, and good luck with your build!

David

[imisanthropeofficial]

Thanks so much for your help! I'll keep y'all posted on my progress

[alex rex]

Hi,
Great project. I just scrolled down and it looks quite interesting.
I will try to dive more into your project and read along.

I am currently also building a lathe in a box from scratch.
may you like to follow along my process as well

[imisanthropeofficial]

Got another electronics noob question. On the linear rail control board, there are power connectors for the Arduino and the LCD display. The LCD display has connections for power but also for Clock, Latch, and Data. Where would those three signals come from? Also, doesn't the power for the Arduino come from the USB unless I choose to use a separate 5v power supply?

[imisanthropeofficial]

I found an earlier post about the LCD display inputs coming from the Arduino. I'll have to do that after work at some point and let you know if I have any other questions.

[imisanthropeofficial]

Since this is my first time using an Arduino, I must ask - what output pins from the Arduino would I use to supply power to the linear rail controller since the 5v and ground pins are used for the LCD panel?

[imisanthropeofficial]

I followed the schematic, and I get it now. Took me a bit to realize the pins in the lower left corner have 5v and ground from the Arduino (USB) that goes to the LCD 5v and ground pins. May test this after the holidays - been busy.

[GreatSoulSounds]

Hi all - I am newby and have been building this lathe over the past couple of months - I have decided to jump straight into cutting and set up everything so needless to say at 8 degrees - any hints on weight people are running at or should I continue to increase until grooves are roughly 0.8mm wide - also is this done when silent?

[spinnertownblanks]

Hi all - I am newby and have been building this lathe over the past couple of months - I have decided to jump straight into cutting and set up everything so needless to say at 8 degrees - any hints on weight people are running at or should I continue to increase until grooves are roughly 0.8mm wide - also is this done when silent?

If measuring the groove width you want 0.05mm to 0.07mm (50 to 70 microns). Best off doing it with a unmodulated groove (silent groove), your microscope will do the job nicely judging by previous videos

[GreatSoulSounds]

Awesome I’m heading in the right direction - slight delay as
I took the tip off the diamond today installing a vacuum tube 🫣

[imisanthropeofficial]

So I got it built and electronics connected, but for some reason I'm not getting the 24v or 5v power. I used strip board and built the circuits as close as possible to the instructions. My guess is my soldering sucks. Any suggestions?

[GreatSoulSounds]

I’m back up and running however playback sound was super quiet and I could not get it to increase so I have taken my cutter head apart to remove the 3m tape off the coin exciters - the “torsion” bar is really solid should it move freely before a glue to back to the coin exciters

[GreatSoulSounds]

Video

[GreatSoulSounds]

“Torsion” tube I think it all may be too solid? Should i try to rebuild the boomerang part out of a coke can?

[davidferguson]

Hi pentlandsound /David,

First of all thanks so much for this thread, your instructions PDF, and for making the CAD files available. I don't think I'd even be attempting this if this great info wasn't out there!

I have a question about the dashpot and damping side of your build. It seems to be the most expensive part that can't be found second hand, or cheaper alternatives be found. Or at least that I can find for searching on ebay/aliexpress/etc. (Although I realise that "expensive" is very relative with record lathes and equipment!).

In your instructions you mention If using a swarf tube or dashpot - which to me implies that the dashpot part is optional? I just wanted to ask if you can clarify that a bit - is this something that is optional (but probably recommended to improve performance, especially on blanks that may not be perfectly flat)? Or is it optional, but-you-really-should-use-it-otherwise-your-cuts-will-be-bad?

Many thanks,
David

[kugelblitz]

I have a question about the dashpot and damping side of your build. It seems to be the most expensive part that can't be found second hand, or cheaper alternatives be found. Or at least that I can find for searching on ebay/aliexpress/etc. (Although I realise that "expensive" is very relative with record lathes and equipment!).

Hi, i made a small 3d printed oil dashpot for my build of David's lathe.

DSC00529.jpeg

dash_3d.png

It sits on a small printed hinge that can be screwed to an unused slot in Dave's design,
The dashpot bracket is also adjusted: since my pot uses oil instead of air i had to flip it, otherwise it would leak.

The design isn't perfect, the plunger is supposed to take a OD16mm CS2mm O-ring but i had to trim down the o ring for it to run smoothly, and fitting a brass insert in the bottom of the hinge is a bit fiddely, so i ended up glueing the hinge in the slot for extra support, but now that it is mounted on the lathe it does it's dampening job nicely.

I'll attach the STL's here.
Print any part that is in contact with the oil in PET-G

On the subject of the more expensive parts in David's design, i'm also busy with an alternative z-stage

zaxisnl.png

But that one still has a couple of growing pains, i just sent it back to the printer with some adjustments.

Both of these parts have the advantage that they don't break the bank...

[pentlandsound]

Hi, if you're using the lathe purely for embossing (rather than cutting) then the dashpot is (possibly) not required. I included one in my design to cater for a later move to cutting: because the downforce on a cutting stylus is only one-quarter to one-third of that used for embossing, the whole arrangement is much more sensitive. The secondary reason for including the dashpot was to minimise the risk of crash-landings when lowering the stylus for action, but that was really for my own benefit as I am incredibly clumsy

I'm very pleased to note the new designs for a 3D-printed oil dashpot and Z-stage, from kugelblitz above - the Airpot I found was expensive (£135 - dearer than the embossing stylus) and so printing your own makes a great deal of sense!

David

[grooveguy]

You know, guys, I was on the point of asking about the utility of a dashpot in the first place. Pentlandsound hit the nail on the head, in that a dashpot will indeed prevent crash-landings, but is otherwise somewhat useless today. Historically, and this is covered in Oliver Read's The Recording and Reproduction of Sound, a cutterhead could go into vertical oscillations when 'excited' by the compliance of the cutting stylus within the lacquer disc coating, primarily at high groove speeds (sort-of analogous to a bow on a violin string). This was sometimes a problem with 78s, especially 12" ones, and toward the outside diameter of 16" radio transcriptions. Both instances were 'wide groove' recordings, and when microgroove techniques came along, much less lacquer was stripped out of the groove, greatly reducing this tendency, operators then removing the messy, oil-filled dashpots. By the way, an 'airpot,' or non-oil dashpot, has a characteristic opposite to the oil-filled one, in that small vertical movements of the head (oscillations and other 'perturbations') are not damped much at all because the air must be compressed before it acts as a cushion. Oil, on the other hand, resists the movement of the dashpot 'piston' in a more linear manner. An airpot is ideal to mitigate the crash-landings that we've all experienced, but a lowering cam with the right contour should do the same thing. My first 'pro' lathe, an RCA-73A came with a sealed dashpot (arrow in photo), which I kept for a while, but ultimately removed with no noticeable change in operation. I never opened the dashpot, but it felt like a piston centered in a cylinder between two springs. And it did resist being shaken quickly!

73A.jpg

[PhilFW]

Hello.
My name is Todor (from Bulgaria) and a friend of mine asked me to help him with the "Arduino" part for this vinyl recorder project. I'm done with all the wiring. Actually I'm running A4988 driver instead of TCM2208 (I hardwired MS3 for the A4988 and changed the Arduino routine setHStepperMS for the steps) and I use buttons for the end positions. The motor is running well in "Forward_wind"/"Back_wind", but I have an issue on "Recoding". The motor is running for a second and then stops, starts again and stops again and so on. It seems to me that this is no "normal" situation. Do you have any suggestion what can be the problem/solution ?

Best regards
Todor

Hi Todor

Maybe check the motor power supply is adequate. I had this problem and upped my motor power to 12V then everything was smooth.

[kugelblitz]

Here are some parts i made for my version of this lathe, in addition to the dashpot i posted before.

DSC00577.JPG

I'm working on a design and build doc, heavily inspired by david's and knop's projects, specifically destined for artist run workshops to build a simple and relatively cheap embossing set up.

Here are some parts that might interest other people building this project:

A 3d-printed z-axis:

zaxis.png

DSC00565.JPG

DSC00567.JPG

DSC00568.JPG

DSC00570.JPG

Harware i used:
2x LWL7B rails
36x m3 inserts (Length 4mm, M3(OD4mm))
8x m2.5 inserts (Length 2mm M2.5 (OD3.5mm), )
4x m5 inserts (length 5mm(!),(OD 8mm))
2x thumbscrew (M3, 8mm)
1x knob 5mm hole
1x leadscrew T5 (Picth 1mm lead 4mm, 100mm)
1x leadscrewnut T5 (Picth 1mm Lead 4mm)
2x KFL05 pillow block
2x 5mm collars with setscrew
a series of m3, m2.5 and m5 screws...

Note that i don't think this z-axis fits in combination with the airpot david suggests, it should be used with the 3d printed parts for a dashpot i posted before

A mount for the head with adjustable rake angle:

headmount.png

Hardware i used:
M3, 65mm screw and wingnut
3mm rod

A heatlamp fixture that attaches to the main frame, no standoff needed,
The thumbscrews are completly optional and really only decorative, also i'm not 100% sure the pla lamp holder will not eventually just melt from the heat of the lamp, but so far so good.:

lightfix.png

Hardware i used:
2x m5 inserts
2x m5 thumbscrew, 12mm
2x 6mm rod 300mm
4x 6mm collars with setscrew