Feel free to tell me this is a very silly idea, but could there be traction in photolithograthy for making records.
My notion is to use a photoresist coated metal plate (off the shelf electronic PCB material?), with a laser as the head (405nm near UV might work and it is cheap, even better a blue ray recording head assembly has voice coil motors that were originally used for tracking but can re position the beam over a +-100um zone at audio rates, they also have a VCM for focus with typically a 1mm range AND they contain the optics to produce a <1um spot if we really wanted it for some reason.
Develop, leaving bare copper where the beam hit, then either etch (if trying to make a playable record) or electroplate to make a negative?
DMM done different!
There is an INTERESTING article from ACS Sensors here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066758/pdf/se8b00340.pdf That has an attached PDF giving the driving details for these things.
A fun variant would be to do the output onto high resolution lithograthic film at maybe 2:1 size and then optically reduce the resulting 'mask' to make the record.
Just a silly idea.
Daft thought, but photolithograthy?
Moderators: piaptk, tragwag, Steve E., Aussie0zborn
Re: Daft thought, but photolithograthy?
Hi,
Interesting, but how do you create a V groove using that method?
Are you think of doing this is real time?
The thickest PCB material I've used is 3oz copper (about 3 mil thick). That seems too thin.
Mark
Interesting, but how do you create a V groove using that method?
Are you think of doing this is real time?
The thickest PCB material I've used is 3oz copper (about 3 mil thick). That seems too thin.
Mark
Re: Daft thought, but photolithograthy?
1oz/sq foot copper is ~35um thickness (about 1.4 mil), but we probably don't want to etch all the way thru, we are not trying to create a circuit here! Nominal microgrove is 1.1 mil so 1 oz copper would just about work in mono, 2oz would definitely work (from that perspective at least)!
The V grove is going to come down to being careful with the etch, but it might be possible if the etchant conditions favour leaving stale etchant in the corners, this I think is probably where the experimentation is required.
I was planning to run the thing in realtime, (Obviously develop and etch are later), but I sort of wonder if litho film photoplotting service could make a mask from a data file (file would be one effing huge gerber file, but maybe, just maybe), if that worked you could produce the data from the audio purely in software... <Googles> seems that a modern photoplotter manages 5um spot size, but it is a pixel grid so not easily suitable.
It is a fun notion.
The V grove is going to come down to being careful with the etch, but it might be possible if the etchant conditions favour leaving stale etchant in the corners, this I think is probably where the experimentation is required.
I was planning to run the thing in realtime, (Obviously develop and etch are later), but I sort of wonder if litho film photoplotting service could make a mask from a data file (file would be one effing huge gerber file, but maybe, just maybe), if that worked you could produce the data from the audio purely in software... <Googles> seems that a modern photoplotter manages 5um spot size, but it is a pixel grid so not easily suitable.
It is a fun notion.
Re: Daft thought, but photolithograthy?
Hi,
I don't think the Gerber format has enough resolution. You need to create details in the range of a few hundred nm to equal what a mechanical cutting system does.
If you do this in real time using a VCM, then you are back to the physics of a cutter head. Not sure what the moving mass of a laser system would be.
Are you planning on stereo? If so then you have to etch each wall of the V groove based on the left and right audio.
Still waiting to see if the guy touting the HD vinyl process ever gets to the finish line.
https://hdvinyl.org/
Mark
I don't think the Gerber format has enough resolution. You need to create details in the range of a few hundred nm to equal what a mechanical cutting system does.
If you do this in real time using a VCM, then you are back to the physics of a cutter head. Not sure what the moving mass of a laser system would be.
Are you planning on stereo? If so then you have to etch each wall of the V groove based on the left and right audio.
Still waiting to see if the guy touting the HD vinyl process ever gets to the finish line.
https://hdvinyl.org/
Mark
Re: Daft thought, but photolithograthy?
Gerber technically has as much resolution as you are prepared to give it digits, but it is not the ideal format for this by any means (Probably no worse then G code, but <shudder>).
I know the literature implies stereo is one channel cut into each wall, but is that actually quite true? Seems to me the geometry is really closer to M/S where M is radial modulation and S is depth modulation.
If so, then assuming the chemistry gives a reasonable groove geometry (NOT a given!), then M is a case of driving the tracking VCM, while S is varying the spot size by playing with the focusing coil?
Might have to order a few replacement playstation laser heads and build me some electronics.
Regards, Dan.
I know the literature implies stereo is one channel cut into each wall, but is that actually quite true? Seems to me the geometry is really closer to M/S where M is radial modulation and S is depth modulation.
If so, then assuming the chemistry gives a reasonable groove geometry (NOT a given!), then M is a case of driving the tracking VCM, while S is varying the spot size by playing with the focusing coil?
Might have to order a few replacement playstation laser heads and build me some electronics.
Regards, Dan.
Re: Daft thought, but photolithograthy?
Hi,
Yes its true. Each channel is modulated normal to the 45 degree wall of the groove. Most stereo cutters have the drivers at 45 degrees from normal (90 degrees between them).
You can translate from M/S to 45/45 by sum and difference of the M and S signals. L+R = M and L-R = S or M+S = 2L and M-S = 2R. If both walls have the same signal (L+R), you end up with vertical motion. Lateral motion results if the left wall motion is in the opposite polarity with respect to the right (L-R). To maintain compatibility with mono records, One of the the two drivers is fed with a reverse polarity signal so that you if you feed L+R into the cutter, you have (L-R) or lateral motion.
Mark
Yes its true. Each channel is modulated normal to the 45 degree wall of the groove. Most stereo cutters have the drivers at 45 degrees from normal (90 degrees between them).
You can translate from M/S to 45/45 by sum and difference of the M and S signals. L+R = M and L-R = S or M+S = 2L and M-S = 2R. If both walls have the same signal (L+R), you end up with vertical motion. Lateral motion results if the left wall motion is in the opposite polarity with respect to the right (L-R). To maintain compatibility with mono records, One of the the two drivers is fed with a reverse polarity signal so that you if you feed L+R into the cutter, you have (L-R) or lateral motion.
Mark
Re: Daft thought, but photolithograthy?
Emile Berliner has done it already