KNOP lathe DIY build

[Xertz]

Another question. What materials did you use for the cutterhead? You probably mentioned them all, but I didn't see everything when I skimmed through all of the posts.

[Xertz]

Sorry I have so many questions! I'm a noob to all of this stuff so i'm totally confused. When I opened up the cutterhead in Sketch Up it looked like this: https://drive.google.com/file/d/1i5yZxl0f5D46bzKJhzvq2o8yzkuzJxUv/view?usp=sharing. Was this odd design intentional, or is the file corrupted or something? If anyone could give me a hint to why this is happening that would be much appreciated.

[soeffingodly]

Sorry I have so many questions! I'm a noob to all of this stuff so i'm totally confused. When I opened up the cutterhead in Sketch Up it looked like this: https://drive.google.com/file/d/1i5yZxl0f5D46bzKJhzvq2o8yzkuzJxUv/view?usp=sharing. Was this odd design intentional, or is the file corrupted or something? If anyone could give me a hint to why this is happening that would be much appreciated.

Pretty sure that appears correct in terms of design.

The head is being 3D printed but I am not sure which type of 3D printer or what type of material it uses. [there are different 3D printer plastics] I'd just aim, shoot and see what happens! That is what I am doing. [I know my buddies 3D printer isn't top shelf but it will be nice to get started with something...]

[Xertz]

Really? What are all of the things sticking into the cutter head? Are those the "Spirol inserts" KNOP talks about?

[audiosteam]

If I remember well they used SLS printing. Materials for the latest versions are Alumide for the body and Aluminium for the spring and the torque tube.
Spirol is a brand making threaded inserts, you can get many types.
What you see inside the head when you're opening the file are the springs and the tubes. It's common to gather several ojects together for efficiency. They are connected with links that you'll break to separate the stuff. Think about those plastic toys that you need to break from a frame the first time you unbox em.
https://imaterialise.helpjuice.com/ have top info to digest before jumping in

[Xertz]

That makes sense now. Thank you for explaining.

[Xertz]

After I actually looked over the 3D model another time, I have new questions (sorry!). What is this spring are you talking about? Is it just another name for the torque tubes? If so, I don't see any in the model/do I need to design them myself?

[audiosteam]

V- shaped leaf spring.

these two threads will help you getting an overview
https://www.lathetrolls.com/viewtopic.php?f=15&t=5371
https://www.lathetrolls.com/viewtopic.php?f=15&t=5249

and that page

http://www.aardvarkmastering.com/westrex.htm

[Xertz]

Nice. I think I understand now.

[KNOP]

Hello everyone,

Kind of took a summer break with the record cutting, but made a new version suspension.

Improved the bearing hinge, added a mount for a suction tube, and made a better lifting mechanism.
Still need to test it, if everything works out I'll post the files.

IMG_20180917_091539.jpg

IMG_20180917_091547.jpg

IMG_20180917_091559.jpg

[karig13]

looks good! I've been reading this thread and I am eager to start a new project inspired by this in the next months.. We only have one record cutter in my country as is (T560 probably, I can't be bothered to deal with some german dude regularly) and I want to be the second one with such equipment I have access to a SLS printer though! Would probably get blanks and stylus from myshanks..

any chance of a very basic tutorial/collection of tips/updated .skp files/etc to help me save time and avoid mistakes (even though there are going to be plenty probably)?

[KNOP]

Hi Karig13,

I am still working on some refinements and other stuff, almost there. I plan to get upload all the files and info, maybe sell some kits or something for the interested.

[audiosteam]

@ Karig13
"dealing with some German dude regularly" is totally ok for me. Dealing with Souri can be complicated.
What's your country?

[soeffingodly]

Hi Karig13,

I am still working on some refinements and other stuff, almost there. I plan to get upload all the files and info, maybe sell some kits or something for the interested.

I may be interested. For kicks I had my buddy print me one of your heads on his 3D printer but it's a "home/lower grade" model and it didn't necessarily translate. It came out better than expected but still would need to print it on a better more "professional" rig.

[KNOP]

Wow that's quite amazing how it came out since I really did not design for the geometric constraints of FDM printing.
It's meant to print on SLS or MJF printers. Those prints are really not so expensive anymore.
Anyhow I've made a hackaday project page where I will put all the latest 3D files and info on the project.

Here's the link:

https://hackaday.io/project/162739-knop-record-lathe-stereo-cutterhead

[DoKo]

Hey KNOP,

I just wanted to say what an amazing work and it is really inspiring !
Im a newbie and trying to build a lathe myself, that really help a lot !

I wanted to ask how do you input the sound to the drivers? what equipment and programs do you use?

*somehow it is impossible to download the skp files in the Hackaday site .

Thank you very much, waiting for more updates

[KNOP]

@DoKo

For the .skp files right click - save link as should do the trick.?
For signal path you can find a lot of examples on the forum.
Basically you correct the sound using an EQ to get a 'flat' response, get it to a high power amp and into the cutterhead (put at least some fuses between cutterhead and amp).

Got the new suspension 3D model online as well. Prints all the parts as one piece. Bit fiddly to set up but works fine.

IMG_20181213_193806.jpg

nested.png

[elmood]

Hey folks,

Long time lurker here. (years) I began a lathe design a few years ago and then moved and lost access to a makerspace / machine shop.

Knop's project has renewed my interest seeing how much excellent progress he made with only access to mail-order printed parts! I've studied the photos and 3D models and have a few questions, some for Knop and some that probably others could help with:

• I've tried signing up to the Myshank site to see pricing on cutters and blanks but to no avail... my email goes unanswered. Does anyone have other suggestions of where to buy this stuff?
• I'm hoping to cut vinyl... having read all the topics about motor torque, etc. I'm trying to figure out which turntable to use. The usual suggestion of the SP-10 is not very practical in 2018 it seems as they are going for insane prices. The Stanton ST-1500 seems strong enough other than perhaps the need to machine the platter to remove runout. Access to real 1200s is easy. But from most of the discussion I can't figure out if some cutting types (lacquer, polycarbonate, vinyl) need different torques. If I were to make something similar to the Knop machine, what would be suggested for reliable performance doing 12" vinyl blanks?
• Are there any design guidelines for cutting angles of the head, where to put the pivot point for raising the head, attaching the dashpot, how much weight on the cutter, etc.? I'm very skilled in 3D design and would likely use the Knop design as a reference and draw up my own version that I better understand. I prefer to go back to standards and best practice documents on design when possible to make sure I understand the theory.
• Has anyone made DIY cutterheads with feedback and is it worth it? I emailed Flo from the Caruso project but so far get no response... for a few $K I would probably just buy his head if it's still available. Does anyone know the current status on it? Or how about another head recommendation either to buy or build? I would consider spending up to a few grand on a proven / working cutterhead and build the rest of the machine and electronics myself.

Thanks for your help!

[KNOP]

Knop's project has renewed my interest seeing how much excellent progress he made with only access to mail-order printed parts! I've studied the photos and 3D models and have a few questions, some for Knop and some that probably others could help with:

I've tried signing up to the Myshank site to see pricing on cutters and blanks but to no avail... my email goes unanswered. Does anyone have other suggestions of where to buy this stuff?
I'm hoping to cut vinyl... having read all the topics about motor torque, etc. I'm trying to figure out which turntable to use. The usual suggestion of the SP-10 is not very practical in 2018 it seems as they are going for insane prices. The Stanton ST-1500 seems strong enough other than perhaps the need to machine the platter to remove runout. Access to real 1200s is easy. But from most of the discussion I can't figure out if some cutting types (lacquer, polycarbonate, vinyl) need different torques. If I were to make something similar to the Knop machine, what would be suggested for reliable performance doing 12" vinyl blanks?

Well the only affordable current turntables with enough are the so called "Super OEM" DJ turntables. They can be found dirt cheap 2nd hand (150 euros should do the trick) but have 2 significant downsides for cutting purposes (they are in general pretty shitty turntables) namely the runout as you indicated (tried to minimise the influence by setting the pivot point pretty far from the stylus (about 90mm) so the cutting angle does not change much when the record goes up and down slightly. Second is the really horrible transformers they put into those turntables, which make for a 100/120Hz very audible rumble. Only way is to remove the transfo from the turntable body. I'm in the process of building a custom built turntable using a high end Project platter and a belt driven BDLC drive using software cogging compensation. Which should have a LOT of torque and a flat platter but the noise floor and torque ripple (WOW/Flutter) is still a mystery until a prototype is built.
I dont think the material you cut into will have a lot of effect on the needed torque. But if you were embossing you would need a lot more torque. (lots of downforce on the stylus)



Are there any design guidelines for cutting angles of the head, where to put the pivot point for raising the head, attaching the dashpot, how much weight on the cutter, etc.? I'm very skilled in 3D design and would likely use the Knop design as a reference and draw up my own version that I better understand. I prefer to go back to standards and best practice documents on design when possible to make sure I understand the theory.

For downforce I use about 10 grams. For pivot point and dashpot attachment I just made something and it seemed to work out good from the start.


Has anyone made DIY cutterheads with feedback and is it worth it? I emailed Flo from the Caruso project but so far get no response... for a few $K I would probably just buy his head if it's still available. Does anyone know the current status on it? Or how about another head recommendation either to buy or build? I would consider spending up to a few grand on a proven / working cutterhead and build the rest of the machine and electronics myself.

Making a DIY feedback cutterhead will probably be a really expensive and time consuming affair. Making one for yourself would not save you any money I think. But would be pretty cool.

[Ciuens]

Knop's project has renewed my interest seeing how much excellent progress he made with only access to mail-order printed parts! I've studied the photos and 3D models and have a few questions, some for Knop and some that probably others could help with:

I've tried signing up to the Myshank site to see pricing on cutters and blanks but to no avail... my email goes unanswered. Does anyone have other suggestions of where to buy this stuff?



I'm hoping to cut vinyl... having read all the topics about motor torque, etc. I'm trying to figure out which turntable to use. The usual suggestion of the SP-10 is not very practical in 2018 it seems as they are going for insane prices. The Stanton ST-1500 seems strong enough other than perhaps the need to machine the platter to remove runout. Access to real 1200s is easy. But from most of the discussion I can't figure out if some cutting types (lacquer, polycarbonate, vinyl) need different torques. If I were to make something similar to the Knop machine, what would be suggested for reliable performance doing 12" vinyl blanks?



Well the only affordable current turntables with enough are the so called "Super OEM" DJ turntables. They can be found dirt cheap 2nd hand (150 euros should do the trick) but have 2 significant downsides for cutting purposes (they are in general pretty shitty turntables) namely the runout as you indicated (tried to minimise the influence by setting the pivot point pretty far from the stylus (about 90mm) so the cutting angle does not change much when the record goes up and down slightly. Second is the really horrible transformers they put into those turntables, which make for a 100/120Hz very audible rumble. Only way is to remove the transfo from the turntable body. I'm in the process of building a custom built turntable using a high end Project platter and a belt driven BDLC drive using software cogging compensation. Which should have a LOT of torque and a flat platter but the noise floor and torque ripple (WOW/Flutter) is still a mystery until a prototype is built.
I dont think the material you cut into will have a lot of effect on the needed torque. But if you were embossing you would need a lot more torque. (lots of downforce on the stylus)



Are there any design guidelines for cutting angles of the head, where to put the pivot point for raising the head, attaching the dashpot, how much weight on the cutter, etc.? I'm very skilled in 3D design and would likely use the Knop design as a reference and draw up my own version that I better understand. I prefer to go back to standards and best practice documents on design when possible to make sure I understand the theory.

For downforce I use about 10 grams. For pivot point and dashpot attachment I just made something and it seemed to work out good from the start.


Has anyone made DIY cutterheads with feedback and is it worth it? I emailed Flo from the Caruso project but so far get no response... for a few $K I would probably just buy his head if it's still available. Does anyone know the current status on it? Or how about another head recommendation either to buy or build? I would consider spending up to a few grand on a proven / working cutterhead and build the rest of the machine and electronics myself.





Making a DIY feedback cutterhead will probably be a really expensive and time consuming affair. Making one for yourself would not save you any money I think. But would be pretty cool.

You need to be more specific, what do you need? Blanks? stylus?Lathe?CutterHead?
I believe that as your project is still in the early stages, you can opt for a Super OEM with no problems like Stanton or Numark TTX
I do cutting heads with feedback, the level of complexity and development is high, but the quality of the cut is also high.
Development involves a lot of trial and error, successes and failures (more failures than successes), the cost is high and the learning curve is slow, but if you do, you will succeed.

Some tips: You can use PETG blanks, they are softer than polycarbonate and PVC.
Replace your rods with metal, the response at high frequencies is better.
Always use a dashpot to avoid overloading, smoothing the cut or engraving.

Cheers

Ciuens Silva

ZEZ Cutters