How about mounting the dremmel to a pipe and then using a smaller vertical pipe or dowel as a guide? It will take up less space an not pivot.

Gio

Posted at 6:28 pm on Jul 22nd, 2008 by diy audio projects

@1: I don’t know, the four bar linkage looks really stable, and the movement is going to be pretty precise with minimal effort. Using pipe, you’d need two guides to get rotational stability, then you have to make sure they’re parallel or you get binding, and you also have to make the sleeves tight enough to be accurate but loose enough to slide. Obviously using a vertical guide is better if you have the time and tools to do it right, but the hardware store hinges and scrap wood get you something 90% as good for about 10% of the effort.

Posted at 6:43 pm on Jul 22nd, 2008 by garrett

the rotation comes from the hinges distance. If the hinges are exactly the same distance apart, then there wouldn’t be any rotation. The 4 angles need to make a (perfect) rectangle or a complimentary rhombus. Also, I think that extending the length of one of the boards on the pivot might provide a place for a couter-balance which might be simpler than a spring. Frickin spring math is insane…

Posted at 8:58 pm on Jul 22nd, 2008 by fred

Milescraft makes a pretty nice dremel drillpress that can be had for around $30 on amazon. works pretty good for drilling PCBs in my experience.

Posted at 12:48 am on Jul 23rd, 2008 by taco

“Frickin spring math is insane…”

F=kx…
yeah man hooke’s law is totally insane!

Posted at 2:00 am on Jul 23rd, 2008 by userjjb

I suspend my Dremel from the ceiling with a bungee cord, about an eighth of an inch above the PCB which has a couple layers of cardboard behind it.

Holes can be drilled with only a couple fingers of one hand on the Dremel, and I can drill several holes without repositioning the board because the bit can move over about a square inch without becoming too far off vertical.

Posted at 8:07 am on Jul 23rd, 2008 by Bill

Ok smartass. F=-kx isn’t too tough, but he still needs to “apply” the math. how many coils per inch? What material? How long to heat it? What temp?

Posted at 9:11 am on Jul 23rd, 2008 by fred

A simple 7-bar linkage (1 ‘bar’ being the drill, another the base stand) would provide completely linear motion (though you’d probably need two of them to prevent twisting, given that the linkage would not be flat).

Posted at 12:52 pm on Jul 23rd, 2008 by EdZ

http://www.instructables.com/id/$30-High-Speed-PCB-Drill-Press/

Built this a while ago; it’s probably more much more stable (only bits I’ve broken so far were when I pushed the bit WAY too deep into the material, and when I accidentally got my glove caught in the way–drills PCBs [almost] like butter) and it’s cheaper, provided that you already have a compressor and the tools to make it.

Posted at 11:40 am on Jul 24th, 2008 by threepointone

I’ve always found drill presses hard to use. You need to align the drill bit with the hole with your naked eye, which is time consuming and usually approximative. The method I use is to have a very small drill that I can hold in the palm of my hand, and drill freely. This method is very fast. The drawback is that you need a steady hand, and drill bits do break once in a while, but much less often than I need to change them because of abrasion.

Posted at 6:20 pm on Jul 24th, 2008 by vic