Carving tool for pcb's

Would you have loved it $400 worth?

If I could have talked my boss into it :-). Along with what I was doing we hand cut a moderate number of foam rubber and viton sheet gaskets so I would have had a shot at it, but probably not. We had dies made for higher volume gaskets and had those custom punched but there were a few low volume items we still did the old way. Besides, I'm guessing John's toy budget is different from mine.

I get along with a Dremel and some x-axto knives, with occasional help from a drill press and a shear and sandpaper and, rarely, an old Bridgeport mill and a band saw. Normal shop stuff.

We have a Tormach but it has to be programmed so isn't for casual use.

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Cursitor Doom wrote in news:q8tenp$50f$ snipped-for-privacy@dont-email.me:

Normal stuff? You guys never heard of resist and etchant?

That's a lot of hassle. Slow and dirty and messy. Bad resolution, bad registration, just two layers, no vias.

We had one of those pcb milling machines for a while, but it was too much hassle too. Got rid of it.

There are lots of cheap quick-turn pcb shops now. For a non-trivial prototype, lay out a proper 4-layer board with 5 mil features and real vias and solder mask and silk, and do something else for a week until it arrives.

Anyone know the name for the profile of cintride/sintered nitride/"diamond" dremmel-type bits. The small reverse cone on the active end, I find most useful for tidy pcb-track deletions? . Not in every pack of "diamond" bits, unfortunately. Another useful type is , assuming I don't break it along the way. I save any 0.5mm thick simple grinding discs , worn by use cutting into steel sheet usually, so instead of being 15mm diameter, only about 6mm or so diameter

N_Cook wrote in news:q8uqta$c9k$ snipped-for-privacy@dont-email.me:

The tiny "concrete saw" composistion and form are called "cut off wheels" More ideal to use a brand new one than the smaller diameter used ones. That will keep the heat generated on the cutting edge down.

The reverse cone shaped bits are not cutoff wheels, but I don't know what they are called.

NT

The reverse-cone ones don't skitter across the copper surface, like the "edge" end of a cylinder type or ball type often do, presumably because its more of a cutting angle at the base of the cone.

snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

I was referring to the .5 mm 'gringing disc' you mentioned.

If it is indeed a small grinding wheel you describe, the 'cut-off' wheel works far better. That is all I was talking about. And I mentioned that using the thing after its diameter has been reduced produces more heat at the work site than the larger diameter.

Someone else brought that up.

If you use the sub-min spherical ones embedded with diamond dust, they don't 'grab' the surface. These accessories usually come as part of a selection and are dirt cheap and definitely worth having:

I use carbide dental burrs. The diamond dust things are awful.

One carbide burr lasts many months hacking FR4.

For whatever reason, they do work better. But regardless what burr you use, the best thing you can do its run at an extremely high RPM with very light force. The air turbine dentist drills run half a million RPM, and feel like you're using a tiny paintbrush to brush away dust. Not enough bite to create drag. Totally different experience from a Dremel.

Milling copperclad by hand, I found it very difficult to control cut depth with a disk; it tends to hop around. Slicing clear through the board is tacky.

A carbide dental burr with a rice-shaped end seems to be best.

John Larkin wrote in news: snipped-for-privacy@4ax.com:

Being so mumbly fingered that you slice clear through the board is an indicator that someone else should be doing it.

There are CNC type gantry setups for mounting a dremel tool allowing the operator to have digitized x y control of the tool.

Both moving head and moving bed types. Also types which evolved into homespun 3-D printer cages. x y & z.

If there were suitable polymer based conductor media, one could 3-D print circuit connections.

build something like this :)

Lasse Langwadt Christensen wrote in news: snipped-for-privacy@googlegroups.com:

Yep... That's the ticket.

We need to make chocolate circuit chips. Just keep them away from your dog.