DIY Mono lathe - advice required

[stoneley]

Thanks for adding me to the group.
I have enjoyed reading all the information you have shared here.
Some friends create and record their own music for their own pleasure.
Given our age, vinyl is the de facto medium and they have had some professionally lathe cut.
They would now like to try to do this for themselves, to complete the creative process.
I have an engineering background and they have asked if I could “build” them a lo-fi mono lathe.
After studying all the wonderful projects on here, I think I could create a traverse mechanism using a DIY CNC X axis controller by Arduino, with a pivoting recording arm.
However there are two areas I do not fully understand and was wondering if anyone could shed some light or give some guidance, apologies if I have missed the information I am seeking in existing posts.
Firstly I have seen designs for cutting heads using speakers to drive the cutting needle via a pivot mechanism. I could try this method, but looking at info on original mono cutting heads it seems they used a horseshoe magnet with a coil in the field to excite a pivoting needle mechanism passing through the coils, is this correct? With the availability of strong Alnico magnets, I was wondering if I could re-create an old style head, is this possible? What gauge wire, number turns or resistance would the coil need? Any other thoughts or design ideas?
Secondly how is the depth of cut controlled? Is this purely by controlling the weight on the cutting head, if so any values to use? Or if it is done by an alternate method, such as manual screw feed, please could someone enlighten me?
Is there anything else I need to consider, am I being too adventurous?
Any assistance would be greatly appreciated, thanks in advance.

[ilium]

After studying all the wonderful projects on here, I think I could create a traverse mechanism using a DIY CNC X axis controller by Arduino, with a pivoting recording arm.

Can't say I have seen any DIY projects taking that approach over the more standard linear method.

Secondly how is the depth of cut controlled? Is this purely by controlling the weight on the cutting head, if so any values to use? Or if it is done by an alternate method, such as manual screw feed, please could someone enlighten me?

I believe it is mostly by weight.. I think the reason why is because unless the recording surface is extremely flat you need the stylus to ride on it.

[ilium]

BTW I've told that 14grams is appropriate downward pressure for a Presto 6n but have not tested it yet

[stoneley]

Thanks for the feedback ilium