Lockdown turntable and lathe - a DIY project

[Fattcamp]

Thanks for the info! You guys are quick and spot on! Dave, that looks awesome! Hoping I can get those kinds of results. This is basically my upgrade from a Teenage Engineering Record Factory, which I love but am hoping to improve on sound quality and be able to cut or emboss larger media. I even experimented on x-rays and am pretty impressed with the results.

Just to keep in line as much as possible with the lathe plans, I ordered the Tectonics from the sole eBay seller. Once I have to order more exciters, I'll go with the Dayton Audio 4 ohm. It may be a month or two (or longer) before I have everything I need, but I have all the main parts except for the exciters, v-slot rails, and the electronics. This will be my first time using a breadboard since the mid 90s (and I didn't do well in that class), but I understand electronics a bit better now than I did then. Wish me luck - I will update you all on my progress.

Yeah it takes a bit to get everything together for sure. I had tons of orders and made quite a few trips to local hardware stores to get what I could locally as well. Just when I thought I had everything, there was always something else needed!

I had some stuff from awhile back but had to order most of it. I used to build guitar fx pedals and synth modules. I dabbled with copper clad etching using negative transparencies, developer fluid, ferric chloride and all that. Nasty stuff but super rewarding once I dremel'd the remaining copper traces, populated the boards and actually patched in the modules.

Fast forward about 20 years and here we are! Just stick with it and you'll succeed just like I (and many others) have! The build requires patience can definitely take some time depending on skill level but it's totally worth it. Building it was just as fun as using it in my experience (with the odd frustration here and there of course!). I'm rooting for you!

Dave

[Alex112233]

Hello, guys! Currently I'm engeneering this record lathe too but I have some ongoing questions. I think photoes in different angles (rear view and left and right views) could help me

[Alex112233]

Hello, guys! I started assembling, the difficulty is that I can't get many of the parts from the instructions.

THK linear slide, model KR2001, pitch 1mm replaced with a Chinese analogue also with a pitch of 1 mm
1 x Sigma Koki Z-axis linear slide, model TSD-403RL replaced with a Chinese analogue
Some technical holes were moved.
So far, there is a big difficulty with replacing the Airpot, there is no way to buy it. For now, I am looking at FESTO ADN-20-10-A-P-A.
I will send a report when possible.

[url=https://flic.kr/p/2qHcMu4]

[pentlandsound]

Hi all - in response to the people who have requested extra photographs of my lathe, here are several, taken from various angles:

IMG_20250128_114705038.jpg

IMG_20250128_114644223.jpg

IMG_20250128_114633175.jpg

IMG_20250128_114625082.jpg

IMG_20250128_114611895.jpg

IMG_20250128_114607990.jpg

IMG_20250128_114545932.jpg

IMG_20250128_114532796.jpg

Hope these are of some use!

David

[grooveguy]

Good work, David. A couple of questions, if I may...
1. Is the counterweight the only means of adjusting depth of cut? Are youe cutting, or embossing only? (Just wondering about the total mass of the head and counterweight and how it affects the resonance period of the suspension; that is, ability to follow warped blanks.)
2. Is that a stepper motor driving the turntable, and what is that belt? (I started with a stepper but it was too noisy; changed to a BLDC motor, a smaller drive pulley and using a flat belt.)
I applaud your use of a belt between the leadscrew stepper and the screw.

Thanks,
Jim

[Alex112233]

Hello everyone. The work is going slowly so far, because all the parts are in the process of ordering. The status is in the photo, a question arose. Ordering a needle from Embossing stylus, Presto short-shank is expensive for me because of the delivery, what is better to take for a replacement? Or is it possible to send a photo of the game in good quality, I will try to make it on the machine.

David, thanks for the photos you sent earlier.

[pentlandsound]

Hi Jim - in answer to your queries:
1 - yes, I'm embossing just now, and the counterweight is carefully set so that the total downforce on the Presto stylus is about 40 g as recommended by the manufacturer. (I have - briefly - attempted cutting, on PETG with a diamond, but I don't yet have a swarf removal system in place.)
2 - yes, it's a stepper motor, nothing special at all, just a cheap NEMA-17 from Wantai. The driver is a TMC2209 controlled by PWM pulses from an Arduino. The TMC2209 is capable of quite fine microstepping so that the movement is tolerably smooth. The motor is also mechanically isolated, as far as practicable, by several sets of anti-vibration mounts and damping, including parts of a cut-up tea towel! The belt is actually a neoprene O-ring, ID 325 mm - these are available online in all sorts of sizes, and cost pennies each. Platter is from a scrapped Lenco-75.
3 - the leadscrew belt was originally a timing belt, but the engaging/disenganging of the teeth on belt and gears created noise, so I switched to simple round pulleys and another O-ring, which works fine. I've embossed grooves up to 15 lines/mm (380 lines/in) without any problems.

David

[grooveguy]

David, that answers it all. The lathe I'm currently building sports a toothed timing belt to drive the lead screw, but I'll have to evaluate and maybe rethink this. My initial inclination was to use a round belt, and that may well prove the better option after all. Thanks for the quick answers! -Jim

[pentlandsound]

Correction: the belts I used were nitrile, not neoprene.

David

[Thelatheofus]

Cheers for the info about the pulley and belt. I've had a really hard time sourcing pulleys and belts that don't have teeth. In europe I can only find nice U shaped or band pulleys on professionnal websites that only sell to companies. I remember Knop used multiple rubber bands as belts, it's less noisy than teethed belts, but it feels fiddly.

Right now I'm using a 3d printer pulley and belt with teeth, the pulley attached to the motor is 3x smaller than the one attached to the lead screw. The friction or motor noise is barely audible, it's only present when I do the faster lead out grooves. I'm getting a bit less than 40dB difference between the noise floor and my signal on PETG. I think that not using heating affect the noise more than my stepper motor atm. But definately I'll try to upgrade to your belt and pulley setup when I can get my hands on proper pulleys.

[grooveguy]

Guys, I found a couple of sources for O-ring type pulleys, one US source is McMaster-Carr:
https://www.mcmaster.com/products/pulleys/chain-and-belt-pulleys~/round-belt-pulleys-6/
...and another is ServoCity.com:
https://www.servocity.com/o-ring-belts-pulleys/
The second also features belts of various sizes, mostly metric. For belting, I've had great success with eBelting.com for both flat and round custom-size, welded belts. No real bargains, of course, but I wonder if a 3D-printed pulley could be fine-tuned on a lathe to acceptable noise standards? (I have no 3D experience myself, although my day-job company does it all the time for prototyping and odds & ends.)

[tragwag]

Hey guys,

This post is overdue, but here's my first build! A lockdown lathe in it's current state with a Stanton STR8.150 turntable for embossing. I must have lucked out with the platter on it as I don't appear to have any noticeable issues. I stayed as close as possible to David's build in every way and it works great!

I'm currently troubleshooting a whistling issue on the outer portion of 12" PC blanks specifically, but I'll know soon enough if it's on my end of something with the stylus and can then troubleshoot from there. There are no issues with smaller media though. As mentioned prior, I still haven't figured out why my photointerrupters aren't working yet, but I've been just using the transport controls and my eyes for now.

There's still plenty to do and upgrade. Lasers for calibration, better heat lamp/source and probably 1000 other things but this is ground zero. I'll eventually want to be able to cut slower than 33-1/3 but for now I'm utilizing the 33-for-45 method to squeeze in a bit more top end. I may look into cutting down the road, but the goal was always embossing and I'm happy with the results given the known limitations of embossing and the materials I'm working with.

I joined the forum in Jan '24 and was hellbent on completing this build, and managed to get it functional back in Sept! This was entirely done in my spare time outside of my day job and navigating life with my wife & 2 young kids. They also think it's pretty cool! I am grateful for the endless knowledge, support & talent here on the forum. A huge thank you to David for putting this build together and everyone on the forum for lending an ear to allow a noob like myself achieve his first functional build. This was really just a fun project for myself, but I plan on working with local artists for small runs for merch booths and things like that.

Here's a few pics of the build. I haven't enclosed any of the electronics yet. I actually like the exposed spaghetti mess but it'll get cleaned up at some point. I've got a breadboard there mainly for the LCD display to live on and to troubleshoot the photointerrupter problem using the handy-dandy dupont connectors. If anyone has any questions that's attempting the build or whatever, I'm happy to share my experiences, sources for parts etc... I'm in Canada for what it's worth.

I'll add some audio soon, but just wanted to show you guys my rats-nest in all it's glory!

Dave


PXL_20241030_000704617.MP.jpg
PXL_20240919_045146395.jpg
PXL_20240919_045156039.jpg
PXL_20240919_045211086.MP.jpg
PXL_20240919_045235341.jpg
PXL_20240923_194417759.jpg
PXL_20241012_065006435.jpg
PXL_20241030_011812831.MP.jpg
PXL_20241029_051030635.jpg

This is fantastic work, congrats on it!
It's likely just a photo angle thing - but it looks like your cutting stylus isn't aligned with the center pin?
That could certainly be causing the whistling you're hearing on the larger diameter discs, if you haven't solved that particular issue yet.

[Fattcamp]

Hey Guys,

It's been a minute. I still haven't bounced any recent audio from my lathe here but I'll try and do so soon to let you guys know how it sounds.

Hello, guys! I started assembling, the difficulty is that I can't get many of the parts from the instructions.

THK linear slide, model KR2001, pitch 1mm replaced with a Chinese analogue also with a pitch of 1 mm
1 x Sigma Koki Z-axis linear slide, model TSD-403RL replaced with a Chinese analogue
Some technical holes were moved.
So far, there is a big difficulty with replacing the Airpot, there is no way to buy it. For now, I am looking at FESTO ADN-20-10-A-P-A.
I will send a report when possible.

Alex112233,

Awesome job getting going on the build! I know you're already well on your way past some of this but thought I'd chime in even though I'm late the party:

• THK linear slide, model KR2001: I purchased mine through the same ebay store as Dave for what it's worth https://www.ebay.com/itm/255769483219

• 1 x Sigma Koki Z-axis linear slide, model TSD-403RL: I found these crazy expensive and gambled with a used one off AliExpress. Shipped surprisingly fast and worked great. Had to go with the left-handed model.

• Airpot push/pull dashpot, model 2KS160A2.0NF: I'm in Canada and I basically just looked up the main Airpot Dashpot Website, checked for Canadian distributors and ended up getting it through CPI Automation.

Hello everyone. The work is going slowly so far, because all the parts are in the process of ordering. The status is in the photo, a question arose. Ordering a needle from Embossing stylus, Presto short-shank is expensive for me because of the delivery, what is better to take for a replacement? Or is it possible to send a photo of the game in good quality, I will try to make it on the machine.

David, thanks for the photos you sent earlier.

As with the rest of the build, I too went with the recommended Presto short-shank. I started with Tungsten and quickly upgraded to Mike's embossing stylus and it seems to be the way to go. I can't suggest an alternative, but let me know if you are looking for anything specific photo-wise of the stylus or lathe. I know David already provided a bunch.

Dave

[Fattcamp]

Hey guys,

This post is overdue, but here's my first build! A lockdown lathe in it's current state with a Stanton STR8.150 turntable for embossing. I must have lucked out with the platter on it as I don't appear to have any noticeable issues. I stayed as close as possible to David's build in every way and it works great!

I'm currently troubleshooting a whistling issue on the outer portion of 12" PC blanks specifically, but I'll know soon enough if it's on my end of something with the stylus and can then troubleshoot from there. There are no issues with smaller media though. As mentioned prior, I still haven't figured out why my photointerrupters aren't working yet, but I've been just using the transport controls and my eyes for now.

There's still plenty to do and upgrade. Lasers for calibration, better heat lamp/source and probably 1000 other things but this is ground zero. I'll eventually want to be able to cut slower than 33-1/3 but for now I'm utilizing the 33-for-45 method to squeeze in a bit more top end. I may look into cutting down the road, but the goal was always embossing and I'm happy with the results given the known limitations of embossing and the materials I'm working with.

I joined the forum in Jan '24 and was hellbent on completing this build, and managed to get it functional back in Sept! This was entirely done in my spare time outside of my day job and navigating life with my wife & 2 young kids. They also think it's pretty cool! I am grateful for the endless knowledge, support & talent here on the forum. A huge thank you to David for putting this build together and everyone on the forum for lending an ear to allow a noob like myself achieve his first functional build. This was really just a fun project for myself, but I plan on working with local artists for small runs for merch booths and things like that.

Here's a few pics of the build. I haven't enclosed any of the electronics yet. I actually like the exposed spaghetti mess but it'll get cleaned up at some point. I've got a breadboard there mainly for the LCD display to live on and to troubleshoot the photointerrupter problem using the handy-dandy dupont connectors. If anyone has any questions that's attempting the build or whatever, I'm happy to share my experiences, sources for parts etc... I'm in Canada for what it's worth.

I'll add some audio soon, but just wanted to show you guys my rats-nest in all it's glory!

Dave


PXL_20241030_000704617.MP.jpg
PXL_20240919_045146395.jpg
PXL_20240919_045156039.jpg
PXL_20240919_045211086.MP.jpg
PXL_20240919_045235341.jpg
PXL_20240923_194417759.jpg
PXL_20241012_065006435.jpg
PXL_20241030_011812831.MP.jpg
PXL_20241029_051030635.jpg

This is fantastic work, congrats on it!
It's likely just a photo angle thing - but it looks like your cutting stylus isn't aligned with the center pin?
That could certainly be causing the whistling you're hearing on the larger diameter discs, if you haven't solved that particular issue yet.

Thanks tragwag! The main whistling issue seemed to be a bit of an anomaly with my first embossing stylus. It was swapped out and seems to be resolved for the most part. It's still possibly to get a hint of a whistle/screech but nothing like before.

What do you mean about the stylus not aligned with the center pin? It's possibly the camera angle/picture, but I still don't think the stylus is 100% perfectly straight. I can now emboss on 12" blank outer edges cutting at 33-1/3 though. I haven't played with 45 RPM embossing since previous whistling sounds as it was most noticeable at that speed.

I find I'm mainly pitching down audio and cutting at 33-1/3 for 45 RPM playback to increase fidelity a bit on the top end, or just cutting at 33-1/3 for playback at 33-1/3 in order to fit more material on a single disc. It's a trade-off with fidelity and material costs (LP vs 2xLP etc...)

Good work, David. A couple of questions, if I may...
1. Is the counterweight the only means of adjusting depth of cut? Are youe cutting, or embossing only? (Just wondering about the total mass of the head and counterweight and how it affects the resonance period of the suspension; that is, ability to follow warped blanks.)
2. Is that a stepper motor driving the turntable, and what is that belt? (I started with a stepper but it was too noisy; changed to a BLDC motor, a smaller drive pulley and using a flat belt.)
I applaud your use of a belt between the leadscrew stepper and the screw.

Thanks,
Jim

grooveguy, specifically regarding your question on the counterweight/suspension to pentlandsound, I've run into some slightly warped blanks and it can definitely show on playback. I got the same dashpot as Dave but I'm sort of embarrassed to say I don't really understand how to properly use it. I get that it's just a screw on the top but I find as you increase dampening, it takes time for the full 40g of weight recommended for the specific embossing stylus.

Perhaps someone can break down how an airpot on this build can overcome audible artifacts of slightly warped blanks (embossing stylus moving up and down while in use). I find it less an issue once moving inwards but definitely noticeable on the outer half or so of 12" blanks depending on the severity/location of the warp.

Dave

[grooveguy]

The dashpot on a recording lathe has historically been hydraulic, based on the viscosity of oil, rather than a pneumatic 'airpot.' The action of the two is really quite different. Airpots are fine for screen doors and mechanical assemblies that require a slow action for large perturbations, but they are only marginally effective for very low-amplitude ones . Air is compressible, so nothing much happens until the piston travels far enough in the cylinder to create some pressure against it, at which point it slows down. Remember, as you let go of a screen door it quickly closes about halfway and then slows down, often after a couple of cycles of oscillation... essentially 'bouncing' off the compressed air.

An oil-filled dashpot, on the other hand, creates uniform resistance throughout its travel, even if it's just a small fraction of an inch. I don't pretend to fully understand the fluid dynamics, but have had experience with oil dashpots on both Presto and RCA disc recorders. Their primary utility was back in the day of 78s, where the cutting process, with a high groove speed, could set up vertical oscillation of the cutterhead. Even with wide-groove recordings the dashpot got a workout only at the outer diameter of 16" transcriptions. I never experienced vertical oscillations cutting with a microgroove stylus, and embossing should not pose a problem in this regard at all.

Many trolls will be familiar with the oil dashpot on the 6N and other Presto models. The oil-filled cylinder rode with the head, and a 'piston' made up of a couple of washers dipped into the cylinder and was supported by the fixed overhead mechanism. The RCA lathe I owned had a sealed dashpot that rode next to the head, but with no coupling to the internal piston. In that case the piston was just a mass supported between two springs, submerged in, and coupled by, the oil. It resisted quick motion but was oblivious to the once-around period of the turntable. Here's a snapshot (from about 50 years ago!) of the RCA 73-A lathe I had at the time. The arrow points to the 'passive' dashpot.

73A.jpg

Typically, cutterheads are lowered onto the spinning disc with a cam arrangement that drops the head slowly, although I can see an operator's appreciation of being able to just put the head in free-fall and have it slowly settle onto the blank through the auspices of an airpot. In his book The Recording and Reproduction of Sound, Oliver Read does address the advantages of a dashpot, from a 1940's point of reference.

[Fattcamp]

Thanks for the detailed info on that. Perhaps the airpot on David's design is mainly for the initial needle-drop, which it definitely will do. I perhaps assumed it's for more than just that and for constant use while embossing, but maybe pentlandsound is able to confirm/deny that. Either way, oil-filled sounds like the way to go for a future build.

I've been very happy with the sounds I'm getting from this lathe once calibrated, but I have to ensure the blanks are flat. When I had some back and forth with Mike regarding his embossing stylus, he mentioned using thin double-sided tape for any warped areas but in my case doesn't work well since I'm heating up the blanks.. not to mention needing a better platter mat that's completely flat to tape to. I've tried purchasing the nice hudson hi-fi silicone platter mat off amazon but it's come warped each time and had to return. Currently using my old Technics one but has large "teeth" preventing taping properly.

Dave

[grooveguy]

Fattcamp: As far as a turntable mat goes, I've always used either 1/16-inch sheet cork, which is a bit fragile, or the 'rubberized' equivalent, also 1/16 thick, generally intended for DIY gaskets for automotive purposes. The rubberized stuff, often associated with the brand name 'Permatex,' is tough and has a very flat surface. It glues down nicely with 3M "77" spray adhesive. The only caveat is that it's flexible, of course, and might not do well for covering consumer playback turntables that have large holes (for lifting the turntable or checking belts, etc.). Recording turntables want to be solid, and I've even used 'JB Weld' (epoxy) to fill unwanted holes in the platter. You don't want a thick, squishy turntable mat, especially for embossing, and this material, as thin as it is, won't allow the blank disc to deform under the weight required for embossing. This is the stuff I use as sold on Amazon:
https://www.amazon.com/Cork-rubber-gasket-material-16-inch/dp/B0987HC9MG/ref=sr_1_14?
The 18-inch width works for turntables up to 16", but may be bigger than you need. There are other Amazon listings for 12" widths at lower prices, just make sure it's thin material to ensure a firm surface for your blank to sit on.

[GreatSoulSounds]

i am just starting out on my first build and parts are starting to come in!! Can anyone recommend a replacement for the Tectonic TEAX-19C01-8 which will fit the same - they seem to be out of stock everywhere?

[grooveguy]

Hey, GreatSoul, the Tectonic appears to be very similar to the Dayton DAEX19CT-4. I've attached the datasheet for both. Compare these and, if you think the Daytons might be made to work, I have a spare pair of them here I could let go real cheap, although the Daytons are pretty inexpensive to begin with. The difference in impedance should not be a problem at all; in fact, the 4Ω Daytons might prove easier to drive with modern, Class-D amps.

[hondajan]

Hello here from Denmark.
I am new here and trying to make a record cutter like David`s in ALUMIDE from I.materialise but they do not allow the measurement of the Torque tube 18deg.The minimum from them is 6mm. 6mm.28mm and David`s is 5,3mm.5.3mm. 25mm . Hope someone can help me thanks.

Best regards Jan Madsen Denmark