The JE-98D

[jjwharris]

This is the product of about 3 years of experimentations and failings. - I ended up opening a small record store with some friends a couple of years ago and the idea was always that I would design and build a self-service embossing lathe for it. After many revisions this is the first machine I've decided is sort of fit for that - the 98D is for 98% done, as in, there's still more to do - and there always is. But I'm pretty happy with it!

These forums have been pretty integral to my progress.

The platter is driven with a servo and frequency generator - pretty much what Bryan has done with his Fairchild restoration, except with a belt. I've messaged Bryan asking for help with the servo and frequency generator and he was very forthcoming and helpful, so thanks Bryan!

the embossing stylus I'm using is based off EposLabs New Embossing Stylus,

EQing is done by an ADAU1701 miniDSP (thanks to grooveguy for his post on an inexpensive cutting head!)

Carriage is (obviously) heavily borrowed from the Little Elephant Records lathe, except with a few differences, namely the rails being pyramid shaped, I experimented with linear rails, but didn't like the multiple contact points of ballbearings.

Both the lift and carriage steppers are controlled with TMC2130s, theres no noticeable noise, but I've a suspicion that may change when I attach a diamond.

Platter is a 13" 12.5mm waterjet cut steel plate - I'll come back to this

shaft is aluminium through two bearings (for radial load) and sits on a single ball bearing on a steel plate for axial load.

current protection comes from a cheap arduino 'donut' current sensor - I don't like it, it works, but I'm always afraid it won't work, so I've got a 'backup' fuse wire in the back.

The VU meter displays current, and has a reset button when the protection is tripped.

it has a input jack in the front to plug a phone/laptop into, this goes to an ADAU1701 which does all the EQing

It's got three buttons;

setup - you press this once you've loaded a blank, the carriage moves over and detects the blank size with an IR sensor
start/stop - this starts and stops the carriage movement
reset - this resets the current protection.

it's 'fixed pitch' at the moment, set to 192LPI, but changing that is just changing the code.

The biggest issue is there is a slight wow/flutter, but it's only slightly noticeable and will be fixed in the next revision - the waterjet cutting didn't leave me with a true circle, and the entry point has made a bit of a bump. Also the pulley I turned is attached with a threaded rod - again, this will be fixed later.

The most surprising thing is that these (quite major) deficiencies have a much smaller effect on wow and flutter than I imagined.

I'll put a video up soon of what I'm up to, but here's a photo and a sample. I'm getting another guy to EQ the head as sound engineering isn't my strong point.

Again, thanks, and I hope I haven't forgotten anyone!

[rsimms3]

Tell us about the drive belt, I've considered running my 5D in a similar manner.

[jjwharris]

It was recommended and fitted by a local engineer I was doing some work for - it's a rubber and plastic mesh, with a heat welded join. I know another local guy is just gluing his together for playback machines.

There's a crown machined into the pulley so it stays on the platter, but it seems to run well.

The biggest issue I had with the servo motor was noise, I used a ihss57 integrated servo, but I had to turn the microstepping way way up high to get rid of the noise, and in the end I ended up making a fairly thick isolation mounting plate made from three layers of foam, nuts, washers and rubber cement.

[Estrada]

Hey, this looks great - really impressive build. What’s the name of your record shop? I’ll stop by next time I’m in your neck of the woods. I’m assuming you are in Christchurch as I saw a video of your first lathe that RDU had made?

[jjwharris]

Hey thanks Estrada, that video is a great reminder of where I've started from.

The record shop is called Ride On Super Sound and we're in the shop above Smash Palace on High Street...which I guess makes us the tallest record store in New Zealand?

[basplin]

This is really impressive, nice job! If I lived in NZ, I'd definitely come check this out in person!

[pennstate913]

Would you be up to share the stl's for the 3d printed parts?

[jjwharris]

Hi Pennstate!

Not at the moment...There's a few things that I've since worked around and my model management has been somewhat subpar!

I'm happy to explain some of the design decisions with you if you're interested.

The linear rails are just 25mm L shaped extrusion - the pieces that fit over them do have ridges printed into them which help them slide. The rest is clamping pressure. I'm hoping for a redesign this year, except it's quite the overhaul. The carriage/headholder has changed a fair bit too - currently I'm using an aluminum skeleton in a similar shape for most of them, I've got a semi-prototype carriage which I prefer which uses ball bearings as the pivot point, and has the tilt/height and distance to spindle all adjustable.

That initial model did end up having issues with resonance - the entire 3d printed carriage ended up oscillating up and down as it approached the 10" mark of a 12" record!
My fix was to print the carriage as a shell and fill it with epoxy and sand, which took care of it. The epoxy tended to warp the plastic as it cured though.