widening brass pinion for microscope?

Yeah, that was one of the books in our library.

Other important ones were Dick Moore's books about the jig borer and the jig grinder, which referenced the earlier faceplate methods; charging diamond points; and so on.

Well, hand drill would be hard. You could go in steps; #21 is .1590" or

4.04mm; 3mm is around #31, so one way would be to use a bunch of intermediate drills that shave very little in each step.

If you have a lathe, I'd use a 4-jaw chuck, indicate on the existing hole, and bore it out.

BTW, are you sure it's not metric 4mm?

Cool. (DLed a copy.)

Thanks to all, but what I ended up doing was borrowing a neighbour's drill press. I took two pieces of oak scrap, but them together tightly in a drill press vice, and then drilled a hole at the seam just slightly smaller than the pinion diameter. I then unclamped, inserted the pinion, tightened, checked alignment with a bit of the same size as the bore first, then carefully oiled the pinion area and proceeded drilling out to #21 drill bit size at highest drill speed setting. The result ended up great and the pinion works like a charm. My biggest concern was the pinion itself; upon arrival, it wasn't as thick as I anticipated and I had concerns about drilling the bore out to a larger size. With perfect alignment of the press, it turned out to be a non-issue, but there's no way I could have done this by hand I don't think.

All this experience has me thinking that I need to get a drill press. Problem is that I don't have a lot of money (I'm retired on fixed income), and I don't have the space for a regular sized press. I've tried the hand drill to press half plastic jigs in the past, but they could never do something like I did with the neighbour's press. Is there a small, accurate and less costly press available anywhere at US retailers? I was eyeballing a currently for sale $69 Harbor Freight unit that could even be acquired for around $55 or so with an online coupon, but it had bad reviews so decided not to. My neighbour says his press was around $200. Unfortunately, too costly for me and too large. I would appreciate any suggestions.

thanks again, Bill

You could look for a hobby milling machine that its owner outgrew. This gives an idea of what's available new at the lowest cost end:

Without trying it my guess is that a machine that lightweight might be adequate to mill or drill (slowly) plastic, aluminum and perhaps brass, but probably not steel. I wouldn't expect good accuracy from it without careful testing, and filing or shimming the joints.

Personally I like to see and try before I buy, which is why I don't own a Sherline lathe or mill. I need to cut threads in up to 1" steel rod.

You can get a pretty good idea of how square the spindle is to the table by chucking a paper clip bent to an L shape, finding the high spot where the outer tip grazes the table or barely drags a small piece of paper, turning the spindle half way around and gauging the clearance with sheet(s) of paper. Stiffer wire and feeler gauges would be better, but I tend to stumble onto good deals unexpectedly and have to make do with office supplies. I keep a 4" dial caliper in the car just in case.

--jsw

Me too .

I've used the button jig method to transfer hole spacings to within a few ten-thousandths. I put one dowel pin in the first hole and chucked a second in the mill collet, then moved the buttons on them into light contact.

--jsw

Here's the hard copy:

I snapped up nearly all of Lindsay's technology offerings.

--jsw

My buddy, Glenn, keeps reminding me that "Metal isn't wood, and you can't get away with a 1/16" tolerance." for some reason.

Well you can, if you don't mind living in the 1700's.

Yay! See folks, he didn't need excessive precision for this job.

Not sure about new. I'd shop used for two reasons if possible. Old stuff is better, and no doubt an old taiwanese drill press is made better than a new chinese one. Used is cheaper too. Just try before you buy. I've seen real bad play on some stuff at the pawn shop.

I bought some dogs before I knew what to look for.

So I took a night school machining class and used it to fix them, and gain experience on a good lathe, mill, bandsaw and surface grinder.

--jsw

The 15" clausing drill press project was sort along those lines. It cost about as much to fix up as it cost in the first place, but the defect it had was peculiar and I learned quite a bit in the process. I still need to tear the rest apart to check the variable speed sheaves and overaul the motor. It's completely usable now though. I filed and stoned the table so the vise floats around nicely now.

He apparently never had to work with Bongossi or some such...

I would set it up about the same way, then drill with a #22 and use

to finish ream to 4mm.

Might have 10 bucks in the entire job.