DIY Cartridge?

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DIY Cartridge

Hi dnsey

I've done it. Took me 5 years though! Moving coils are easier to make than mm's. You can do it if you have a workbench of sorts, a good quality vice fitted with aluminium or nylon jaws, some files, a fine saw and basic power tools, 10x magnification, steady hands, good eyesight and lots of patience. To measure your work you also need a twin channel 'scope to 35mHz, test records, a volt meter and various other bits & pieces. A better way to do it though, is with a lathe and a milling machine. Membership of an experimental engineering society will also help.

Just do it!

bulgin
 
Hi dnsey

bulgin? Heheheee! From my Leak stuff of course. I've got plenty of pics - alu carts, wood carts but I've not tried to post pics here as my photo software goes into oscillation if I try posting pics to boards. Anywhere else is OK If you're keen to see, try http://www.rpm-audio.co.uk or http://www.blueangelaudio.com. The pics at the latter is very much out of date though. They look a lot better now.

Cheers & have a fine weekend. Sun for a change here in Cape Town but rain again tomorrow. Just committed sacrilege by painting my Quad 405 with auto paint basecoat/clearcoat gunmetal (not the gold sinks in the friont though).

bulgin
 
Looks like a superb piece of work:cool: Way out of my league.
How many prototypes did you have to make before coming up with a good 'un?
I'm very impressed that you can accurately reproduce it using hand production methods!

Have a great one yourself - it's a bit cooler here today after a couple of weeks of record-breaking temps:redhot:
 
Thanks, dnsey!

I'm a bit embarrassed at the pics. The guys in the UK have some - I don't know why they don't use them as the cart looks much better now.

Prototypes? Sacksful. They all worked but once you start you can't stop. KK reviewed it in 02/05 in HFN. I hear it is going to get some award or other from the US in 09/06. I have a day job too. All work was done at night until the small hours.

Now, what are you waiting for? Any monkey can make a cart.

bulgin
 
Ex-Moderator
Joined 2003
Hello bulgin, OK, so I've got a lathe and a mill, so I can easily make the gross parts. Neodymium magnets are readily available too. But the fiddly bits are the diamond, the cantilever, the coil assembly and the suspension. Merely assembling them will need a decent microscope, let alone making them. Any tips?
 
No experience (*), but I have been thinking about this for a while, plus some discussions with cartridge manufacturers.

The smoothest way to start is probable taking apart commercial
MCs and modifying aspects of their build. For instance, disassemble a DL-103 and build a nice metal body around it. Or take its suspension apart and then try to rebuild it, while observing the resultant changes in sound. Perhaps the easiest cartridge to try this with is the Benz Ace.

Stylus/cantilever assemblies can be bought. Wound coils, I think, too. Perhaps even complete stylus/cantilever/coil combinations.

Bulgin,

please give my regards to Rodney G. We fondly remember dinner with him and Ruth during our 1998 trip to SA.


Werner


(* The only thing I ever dared was glueing a metal top plate with threaded mounting holes to a DL-103.)
 
Hi EC8010 @ Werner

Errmm, this is getting ahum...interesting! Lathes and milling machines are part of the equation. These machines have to be set up for great accuracy eg to be able to drill dead centre a 0.3mm hole into a little cylinder of 0,5mm. Milling machines too, setup as close to total accuracy as possible, otherwise you'll be making devices chewing groove walls or only capable of playing 'One note Sambas'.

A great number of specialised cutters are also required - some specially ground ones to your own specs too.

I have the same stereoscope as shown in the earlier pic in this thread but rarely use it. My specs get in the way.

Stylus/cantilever assemblies can be bought but suspensions and damping materials are usually not 'off the shelf'.

A supply of magnets to your own specifications can be outsourced too, but it is still better and less hassle to machine your own, for which more special tools are required.

Also be prepared to get acquainted with all kinds of other disciplines like chemistry for anodising, metallurgy for body parts and other bits, rubber technology for damping materials, acoustics for measuring the device you are making and so on.

As you progress along the long road of making needles, you will also have to devise 10 or more jigs for repeating the same dimensions of your design with great accuracy (unless you go to CNC).

Taking other carts apart (and reassembling/repairing them) certainly would be a way to acquire knowledge but how do you determine the direction of coilwindings on an armature? How would you make an armature core (a sliver of iron or whatever under 1.75mm square x 0.3mm thick and with a hole absolutely dead centre)?

Then, once you have everything sorted and you wish to go 'commercial' with your clone, somewhere in the fruit of your labours should be some kind of innovation or a new 'angle' at solving a certain problem. There are so many famous cart makers - each with their own traditions, manufacturing secrets and solutions - how can you compete with them if you've made yet another variation on the same theme?

Humans are innovative and resourceful. If you are a member of this board you already have sufficient interest in audio matters to give it a go.

@ Werner, I shall certainly give Rodney G. your regards & best wishes. Rodney has had a connection with the cart from the beginning as he supplies my packaging materials.

Regards all

bulgin
 
Ex-Moderator
Joined 2003
Completely barking.

Hmmm. I fear that drilling a 0.3mm hole down the centre of a 0.5mm rod may be beyond my lathe even if I spend some time tweaking it. Something to thing about, though. I've always fancied the idea of an electrostatic cartridge...
 
Hi EC8010

Easy does it. A good Britishmade chuck (Eclipse/Jacobs) in your tailstock to hold the drillbit - the very same chuck is used by doctors for sawing bones - and an accurate pinchuck in the three-jaw to hold whatever you're drilling and bob's yer uncle.

Btw, look at SOLIDSTATE to see how stupid I really am with some things. Still learning, though.

Also, one cannot do these things unless you have friends. My fishing pal helped me with the setups on the lathe an milling machine. During the time of making it accurate, we came to a stage where there was only a very small error. After sinking a fair amount of beer in sorrow at the error, we found it - a tiny seepage of lathe paint had entered two mating surfaces on the tailstock assembly when the lathe was assembled at the factory.

bulgin
 
Ex-Moderator
Joined 2003
Hello bulgin, I have an Eclipse pin chuck (I use it for drilling PCBs), and the tailstock chuck is a Jacobs. Trouble is, I'm certain the bed is not perfectly aligned with the headstock but I don't know how to determine the error and correct it. I have a dial gauge.
 
Hi EC

Setting up of machine tools is not really my subject. We used dial guages, and a finger clock and took almost an entire Saturday to get everything OK. My lathe is ancient (a Myford) but solid and well-looked after. The mill is a geared head Maximat. I'm sure on DIY would be someone with all the knowledge you need.

The friend who helped me, is a tool and die maker - so good that he now runs a heavy machinery (train engines) refurbishing workshop.

The problem with cart. making is total disbelief from people when you say something must be deadcentre and tolerances must be impossibly tight.

If these requirements cannot be met, the result is there for all to see and hear - wrong tracking angle, cart pointing in the wrong direction, insufficient body clearance and other horrors.

Regards

bulgin
 
Lathe adjusting for small drills

The countercenter of a lathe can easily adjusted, turn an axle with center, then adjust the alignment until the axle is cylindrical, not conical. Some countercenters can be adjusted in height too. And with a fine chuck it should be possible to drill small holes then.

I once wanted to rebuild a MC Ortofon with broken cantilever, but discovered the suspension of the cantilever was made of pianowire and this had some recessing diameters, not easy to remake. A fine clockmakers lathe can do the job.

I was lucky i managed to repair a Benz Gold MC, the cantilever was bent, and its playing again! I repaired it without any tools, just only with my fingernails. (I got this Benz from another member)
 
Goeie dag, Tubee

Yup, I bet you saved yourself some money here.

Here is a better way to make a temporary or permanent repair to a bust cantilever.

1) Take an old but good quality jewellers tweezer. Turn on you lathe a small cylinder of +- 1.5mm dia from nickel or phosphor bronze or even stailess steel. Drill right through it with a 0.6mm drillbit.

If the redundant tweezer has very sharp tips, grind a bit off so that the ends are +- 2 or 3mm wide.

2) Now silver solder this little tube you made between the two tweezer tips so that the ends are both fixed to the tube..

3) Now, take a jewellers saw and saw lengthwise through the tube so that the tweezer jaws once more become separated.
You now have a modifified tweezer with a small half-tube at either end.

4) carefully smooth all sharp ends to the tube with fine waterpaper and give it a final polish with some metalpolishing compound.

That's it. You now have a custommade cantilever straightening tool. If the cantilever is bent, carefully position the halftube tweezer jaws around the cantilever an 'massage' the bend until it is straight again.

I thought of this a few years ago as I got tired of people bringing me bent needles.

bulgin
 
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