Project progress report

Whenever I make something I'm usually asked to explain the "how's and why's". Usually I end up polluting another thread...so I made a thread for this purpose.

The latest project is a tool for winding big inductors.


The pics can be found at www.briangt.com/gallery/magura

Magura

I just realized that I forgot to put a lighter in the photos for size comparation. The tools are 200mm/8" diameter.

Magura

Just added photos of the just made copper heatspreaders/- heatsink mounts. There are 24 of them at approx. 1kg. a piece.

http://www.briangt.com/gallery/magura/PICT0061

Machined to fit the round box for the ZV7 project.

Magura

Machined a pair of aluminum inductor mounting brackets, for 2.2mH air core inductors for the PSU.

This should result in a solid mount and excellent heat transfer to the chassis, which is more or less just one big heatsink.

Added a couple of pics to the gallery.

http://www.briangt.com/gallery/magura/PICT0079

http://www.briangt.com/gallery/magura/PICT0080

Magura

Now the time came for a little progress in the 40 step attenuator project.

http://www.briangt.com/gallery/album05

Further description to come.

Magura

Theese contact plates have been machined of 3mm double sided PCB. The outer circle of contacts will be 3mm, the inner circle will be 2.5mm. Outside diameter is 85mm, the center hole is 36mm, to accomodate a 20mm axle and the mount for the spring/-slider assembly.

The whole this is to be mounted in an aluminum cylinder, which is stack-able, in order to allow for an unlimited number of decks.

Magura

Machined the bolts and nuts for mounting the heatsinks on the ZV7 project. I forgot to make a photo of the wrenches made for the bolts and nuts...but they do exist

http://www.briangt.com/gallery/album01

Also got round to machining the housing of the attenuator switch, will post photos later (left the ithems in the workshop).

Got the silver for the switch today as well...around 300 grams of it exactly enough for 9 poles of 40 steps.


Magura

DIY 40 step attenuator, update.

Got around to finishing up the housing for the 40 step attenuator switch today.

Everything is to be assembled with M3 bolts. A pair of deep groove ball bearings will keep it running smoothly.

Now the silver contacts and the sliders is all thats left....should be a walk in the park from here ...and the spindle naturally...

A couple of pics, oily fingerprints and all

http://www.briangt.com/gallery/magura-40stepattenuator


Magura

pinkmouse said:

So, are those grooves milled into your inductor brackets actually matched to the windings of the coils?

Click to expand...

Yes, it seemed to be the easy way to get good contact for the sake of heat transfer.

I tend to choose milling over turning for the sake of convenience, might as well go all the way then, and take any advantage possible.

Magura

Added a couple of pics of an inductor winding tool and the inductors wound on it.

The inductors are made for an x-over for a friend of mine, they are 1.9mm magnet wire, 2.7mH.

Magura

I just realized that I forgot to post the link for the pics....that link just might make it a little more interesting

http://www.briangt.com/gallery/album02

Magura

Just finished the 600+ solder joints to mount the silver contact pins, what a nightmare

http://www.briangt.com/gallery/magura-40stepattenuator/PICT0002

http://www.briangt.com/gallery/magura-40stepattenuator/PICT0006

Anyway, I hope to machine the sliders during this weekend, and to have a working 40 position, 9 deck switch, sometime next weekend. Depending how much trouble I'll have finding the required values of the resistors.


Magura

Devil_H@ck said:

Why do you need a 9 deck switch?

Click to expand...

The first 8 are obvious I guess The 9th is for position indication, as each position will have a led.

I figured that would be a good indicator when using the remote to control the volume.

Magura

Re: Contacts

kamskoma said:

Hi Magura,

Where do you find the silver contacts? is it possible to find gold contacts or a alloy with gold as main part.

Kamskoma

Click to expand...

The silver contacts are made of 935 silver wire, as you most likely know it's a silver/ copper alloy. Since the switch will be sealed, there is little point in using gold, as far as I remember it silver is one of the best switch contact materials, and can't be bettered significantly by any material. What have to be kept in mind is also that there is more than 250grams of silver in those contacts, which set me back 130 euro....I don't even want to think about the price if it had been gold

I have bought the wire through a jeweller, as they get it much cheaper from the wholesales than we do.

Magura

Got pics???

Magura