Dremel "WorkStation" ?

[philba]

Philba! I looked up your bargain milling/lathing tools:

http://www.sherline.com/

Can you mill the copper off a PCB with that thing? No etching?
I see there are CNC upgrade kits for it including software and computer if you need it.

I probably could mill a pcb with a CNC conversion but I'm not a fan of milled PCBs. With AP and a heated bath, etching is a snap.

I'm not sure I want to CNC convert the sherline as it isn't that powerful. Also, it has a very small chuck (1/4", iirc) so the choice of mill ends is limited. When I move up to a bigger machine (still small), I'll sell the sherline setup - I think I could get enough to pay for the CNC conversion.

[FOB]

Hi there,

Sounds interesting. Wow, several hundred boards? What was that for, to back the article?

The article was for an auto shut-off for a soldering iron. I got tired of burning up tips because I got called away from the bench for extended periods. I showed it to the Ham club at a meeting, and several people wanted to build one. I went to a T-shirt shop and had the guy make me a silkscreen for the PC boards then printed up 100 boards..... we etched, .....drilled, .....plated, .....and cleaned.....we had construction night for 6 weeks during the winter months and most of the guys got them done. Then somebody suggested submitting it to 73 mag and they published it in Aug 1988 issue. The finished board is about 3"x5" which I asked $8.00 for post paid. Counting the mail orders, and sales at hamfests, I ended up screen printing and selling/giving away about 350 more. The whole project took 8 months 100 pages of manuscript typed on a commodore 64.....11 pictures, 1-schematic, 2 layout diagrams, the pc layout, and a parts list that you could get at radio shack, they paid $75.00 and I knew I would not be doing that again soon.
Getting back to the dremel drill press....I would indent the holes with a scratch awl then put the board on the drill plate and hold it loosely enough for the bit to center the hole before applying pressure then hold it firm with my finger till the hole was completed. It seems sloppy, but you soon develop a rhythm.....each board had over 100 holes, and there were between 400 and 500 boards total. I don't think I have any of the boards left, but I can send anyone interested a copy of the article for an S.A.S.E.

[MrAl]

Hi again,


I checked out the mills and the cheapest one would be somewhat over 300 dollars US, and i dont
really want to go that high.

Anyone here ever design/build their own mini drill press for precision drilling?

[jm]

I have the Dremel rig. It is only usefull for casual stuff. I have a 100$ Ryobi manual drillpress (made in China) which works OK. The main issue is MASS. The thing has to be made of heavy enough metal to be stable and stiff. The Ryobi weighs more than 40 lb.

[MrAl]

I have the Dremel rig. It is only usefull for casual stuff. I have a 100$ Ryobi manual drillpress (made in China) which works OK. The main issue is MASS. The thing has to be made of heavy enough metal to be stable and stiff. The Ryobi weighs more than 40 lb.

Hi jm,


Did you ever use it to drill copper clad fiberglass PC boards using carbide bits?

[philba]

One other problem with drill presses is that they don't have high enough rpms.

Al, I'd look at the DIY CNC crowd. There are a number of plans that use angle iron and roller blade bearings to build sliding platforms. Bascially, you would just build the vertical. You'd use a dremel in one of the those. I've been thinking of building a foot operated drilling set up. Probably won't but it would really speed up drilling as it frees your hands to position the board.

You might want to look at some of the smaller routers (like for dry wall) as they have a little bit better build quality than a dremel.

[MrAl]

Hi philba,

Yes that sounds like a good idea. I was thinking of rigging something up just to drill holes with.
As far as the dremel though, i dont mind using the one i have. I like the bigger one too though.

[Lenp]

Hi guys,
I have an older, probably made in the 50's Atlas drill press with a 1/2" chuck. It is all cast iron, weighs a ton and has near zero chuck runout. I use resharpened cabide biits and rarely break one unless I do something dumb like move the board before the bit clears. The bits easily center on the pad center and usually I'll get thousands of holes before the bit starts to cut poorly. The point is that small carbide bits simply will not tolerate lateral flexing so chuck stability and runout is the key to success.

I have looked at many import presses and these tin lizzies do not stack up anywhere near this old veteran. Check out surplus suppliers and local schools for their dust collector specials. Mine came from a closing school at zero cost. I refurbished it about 30 years ago and tear it down every few years to clean and repack the quill bearings just to keep it running smoothly. This press uses a 6 step pulley system, so it's a nusiance to change speeds. In the near future I expect to install a VFD to give the ultimate in speed control.

I sure hope this this Atlas press lasts forever!

Len

[MrAl]

Hi Len,


Well you are one of the lucky ones here then

I looked at a few on the web and not really sure what i would be getting anyway since i cant
see it before i pay for it, which is against my personal policy for buying big things like that.
Some of them do look nice though.

I'll have to suffer through my little boards i guess with the hand drill or the shaky drill press
for now, or else ask you to make another board or two in the future

BTW, what kind of motor does your current drill press have?
Horsepower, voltage, speed, anything else you care to add, and does it have brushes?
The reason i ask is because it may be very economical for you to build your own
speed control if the motor has brushes. I've designed several types in the past
one of which handled a rather large grinder. The main cost is in the triac, which
can run about 10 dollars but that's almost the entire cost of the whole thing.
20 bucks would probably do it for the parts.

[CeaSaR]

Hi MrAl,

My old drill press is a table top mount that uses twin 3-step pulleys, probably similar to LenP's.
When I bought it off of my old boss (RIP), it didn't have a motor. I happened to have an old
Sump Pump motor lying around, and it really puts the bits through their paces. On high speed,
it will drill through 1/4" plate steel using standard high speed steel bits.

The motor mount is home made, using carved mounting blocks on a hinged board, strapped
down with a very large stainless steel screw-type hose clamp, tensioned with a heavy spring.

CeaSaR

[Robert Reed]

MrAl
In the past presses I have owned ranged from 1/2 - 1 HP. My current press is 3/4 HP. They all had adequate power even for the most demanding tasks. My current press is a floor mount weighing in at 250 Lbs. The machine has no vibration due to its heft, but the spindle still has enough runout to cause locating problems with small bits. For cicuit board machining, I dont think that weight or power are issues, but rather that all important runout (or should I say the lack of it). I have to beleive that a small bench mount unit with a 1/4 HP motor would fill the bill as long as it was quality machined. Machining tolerance is the key here and also what you pay for!

[Lenp]

By the way...
I also have a vintage Unimat SL lathe that converts easily to a drill press. It works great for those "small as a hair" drill bits!
Len