Sillitoe Lathes

[dimi751]

Very nice James ! Looking forward to the update

[Sillitoe]

Variable depth proof of concept, extreme settings so you can see the movement.


You can hear the vibration of the coil, this won't be an issue when cutting because the changes in current won't be anywhere near as severe.
It looks like this electromagnet will have the perfect range with the proper settings, we shall see...

I'll be saluting 2015 by sacrificing a 40 hour old Shank diamond in order to dial this thing in...

Cheers
James

[dimi751]

Ha ha good bye diamond it was nice knowing you !

Nice work as usual Sillitoe, what's telling the head to not go down too far ?
Is it some sort of micro switch or sensor ?

Merry Xmas and happy new year too u

Dimi

[Sillitoe]

Hi dimi, cheers.

In the video the head is obviously going down waaaaaay too far...
The goal is a variable magnetic field with no contact points so as to maintain "fluid" motion of the head.

The maximum depth is determined by the amount of current going to the electromagnet and the overall height of the suspension box.
You can limit the current directly at the power supply or with de facto software settings.
You can also finely adjust the suspension box to a desired height.

So it is basically the user settings which ensure that the head doesn't go down too far... A little risky at first for this poor diamond

Happy new year!
James

[Sillitoe]

... A little risky at first for this poor diamond

Just thought that I'd point out that I mean this unlucky diamond, Shank sells very awesome products!!!

[dimi751]

I know dude I understood what you meant, myshank gear rocks totally agree.

[analoghifi]

James excellent Job once again man! Looking Great mate!

Ive got my cutterhead waiting for this lathe man, so cant wait till its all done!

I bet you are having a blast innovating and making breakthroughs everyday! Id have to say well done and hats off !

Kev

[recordboy]

Hello

I've just been becoming active on here again after a long time.

the progress here is VERY exciting!!!

Fantasic work.

Look amazing too!!!

Cheers

[Sillitoe]

Cheers Kev, I can't wait to see your Ortofon on one of these lathes mate!

Thanks recordboy, I appreciate it.

Variable depth is working and the stylus is still fine!!!
The vibration you can hear in that last video was actually the pwm signal that was driving the electromagnet, that is sorted.

I've just received some very nice ammeters, one for the electromagnet and a couple of ac for the cutterhead, now I'll be able to push the volume.
I need to get a nice microscope so I can make groove measurements in order to calibrate the depth and pitch system properly.

I've changed the ratio of the pitch motor pulleys and now have a range from 450 to 5 LPI at 33.3rpm.
Analog pitch motor control is now repeatable as I'm using a stepped attenuator (mastering version ). The pitch is still switchable to digital control via Ableton or simple arduino code.

I've changed the head suspension spring mechanism and its height is now adjustable in 0.01mm increments (allows for precise adjustment for heads of different weights- dunno about a Westrex though haha...).
The vacuum tube under the suspension box is also height adjustable in 0.01mm increments of a 10mm total.

So all functions I wanted are now working.
The machine is in skeletal form at the moment so I still don't wanna make a video just yet... (secrets ).
Measurements, cad drawings and machining are next.

Cheers James.

[sakuszi]

it works great! now do almost all wood, I have no professional machines, is using a hacksaw and a portable drill. Nice is your lathe recorder that's something you have recorded?

[Sillitoe]

Thanks Sakuszi,
Here's a cut from mid december, pushing the highs to break the 0.5A fast blow fuses. 7cm/sec 1kHz tone is a bit wobbly cos of the brush swarf pickup...

https://soundcloud.com/sillitoe/arent-so-smart-at-all-7cmsec-05amp-fast-blown

[Sillitoe]

Little vid showing digital and analog head drop and pitch control.

I've started to cut with my variable pitch system, it has developed from those previous primitive videos. Max for Live enables seemingly infinite possibilities.
I've shown the pulley spinning with exaggerated automated variable pitch- when it turns very slowly during the "digital" part of the video, you can see the led on the arduino blinking with the changing signal.
The pitch is obviously also manually controllable via the midi controller, you can map controls for base pitch etc...

The head drop actuator does not transmit any noise to the recording during drop and lift.

Most of the changes I need to make now are just cosmetic.
The suspension box won't be the length of the one shown here.
The wiring will be cleaned up, the control panel will change and might get housed in a small console...

I will add a simple disc diameter measurement scale.

My cuts are sounding better and better, but the accuracy will increase once the production model parts are precision machined.
I've made this with a cannibalistic sliding compound mitre saw, small drill press and hand tools.
I don't think I've done the Caruso any real justice yet.

I'm hoping to shoot a video showing a fully automated cut of a multiple locked grooves, (scratch/ sample record) once I have set up a vacuum pump.

(The tune in the video isn't a cut, classic BOC).

Cheers
James

[dimi751]

Just awesome James really nice work !

[MEGAMIKE]

Great work james

[Sillitoe]

Cheers fellas!!!

[sakuszi]

hi,
Your machine is very solid! You'll certainly had fantastic results with record cut! I'm sure! I did burner caliper and somehow record [badly at the moment and on CD] I am not happy with their recordings, but I'm working on it.
I think your project is one of the best! Very good engine Technics, professional head, metal structure so it should be done, I can only dream ..... I am curiously waiting for the effects of your work record. It is for me a great school, learning. Thanks for sharing of knowledge!

[Sillitoe]

Hi Sakuszi!
I learnt the fundamentals by reading the forum and joining the dots, people have shared an amazing amount...

I think your cuts sound very good for a diy head on cd!
Keep going!!!

Cheers
James

[Sillitoe]

Locked grooves at 33.3rpm with automated head drop/ lift and pitch.
You can see that the pulley turns while the head is lifted in order to space the grooves.

When the head drops it takes exactly 1.8 seconds to make contact with the disk surface, so that makes setup very easy.

Now I really need to setup a vacuum!
(The sound in the video is straight from my speakers to the camera).

Big shout out to Dr Dub for the awesome educational video!!!
https://www.youtube.com/watch?v=ky8FMZu7YKc&list=WL&index=61

Cheers
James

[sakuszi]

you need to slow the rate of descent head, easy to break a knife DOWN , on German films head is lowered slowly to the plate, but is raised quickly UP

[Sillitoe]

Hi Sakuszi,

This is a new Australian lathe, not an old German one!

The head drop is perfect!
It lowers quickly with the last couple of mm being damped to a very slow rate.
Once the suspension is set correctly it seems difficult to damage a stylus with this machine.

I am still yet to damage one...

Cheers
James