Should I screw around with it or leave it alone?

I wish any of my drill presses were that tight. 1" deep into Al? How big is that #85? What alloy? What speed? What lube? I don't see anything out of whack here.

You might consider removing the chuck from the arbor and measuring run out on the arbor. If the arbor also is removable from a morse taper spindle as was referenced in the other thread you can remove it and measure run out at the actual spindle. Then you'll know where the run out is coming from and have a better chance of reducing it vs. blindly replacing parts like the chuck that may not be part of the problem.

Certainly the run out you measured seems to be in a quite acceptable range for a normal drill press. Your application with the micro drills is really one for a precision high speed drill press, not a regular one. You might take a look at the Micromark site, they have a few small high speed drill presses that might be better suited for the micro bits.

Pete C.

Sure, the bit was flexing a tiny bit, hole straight, all as it should be ..

Almost certainly something wrong with the bit geometry, almost certainly your speed way way too slow for tiny carbide drill in aluminum unless your drill press actually runs at like 6000 rpm. Again, probably normal, just don't use tiny carbide bits on aluminum, run HSS, and learn about proper speeds.

If a machinist took it off and replaced it then the likelihood would be near zero, as a taper is a very clever mount indeed. It just has to be clean & burr free inside and out. Run your quill out until you see the holes at the back end of the taper, insert the appropriate drift pin (should have come with your DP, if you don't have it, cobble up a wedge or use a plier handle or something) and pop out the chuck and arbor, and then you can directly indicate on the spindle. Do not be afraid to remove your chuck, just learn about taper tooling and how to remove and insert tapered tooling correctly and you will be fine.

Your runout is excellent. It isn't the problem. Use HSS bits, new ones if you need to, and run them as fast as your machine will go, and feed gently. Be careful as the bits break through, they tend to grab, and also brass parts especially like to lift up the drill helix and helicopter so be real careful.

Not the problem.

Not the problem.

GWE

According to Norm Dresner :

O.K. HSS bends to deal with minor runout.

Solid carbide bits are *very* brittle. The slightest sideways shift, or runout, or too aggressive a feed (all of which are likely using that small a drill bit on a standard sized drill press) can lead to breaking it. And, as has already been mentioned, you need a much faster spindle speed for those tiny drills.

But enough to snap a tiny solid carbide bit, even though a HSS one will likely survive.

It is unlikely -- unless someone *carefully* assembled a chuck with runout to an arbor with runout to at least partially cancel the runout. Given the source of the chuck and (likely) the arbor, that is possible, but not too likely.

Get a sensitive drill press for that purpose, and don't try to make a standard 1/2" drill press serve a function for which it was not designed.

Not too likely.

It depends on the measured runout of the Morse taper hole in the spindle.

You *could* simply get a smaller chuck with an appropriate arbor (I would suggest an Albrecht 0-1/8" (0-3mm) chuck.) And swap arbors and chucks when you need to hold smaller drill bits. But this still will not provide you with the spindle speed needed to work with such small drill bits.

So -- look into getting a sensitive drill press. It will work far better for the task, and keep the big drill press for the larger holes.

How far from the edge do you need to drill these tiny holes? IIRC, my sensitive drill press is good for perhaps 2-1/2" from the edge. But, another model of the machine (Cameron Micro Precision) will drill holes much more distant from the edge.

Here is the URL for the company:

and the one which is shown on that page with the model number 164 is essentially mine. It can be lifted by a single hand. (Mine is too old to have the belt guard shown on top, but otherwise the same.

The MD-70 (found on their "manual micro drill presses" page) is the one which can reach to the center of larger workpieces, if that is what you need.

The prices are frightening. The one which I have appears to now be at $584.00 (It was about $150.00 back in 1973 or so.) So you may wish to play the eBay game to find one which is affordable.

Good Luck, DoN.

measurement

Two problems here. One------and I'm assuming you really mean you're drilling with a #85 drill-------in order to power that drill properly, you'd have to be spinning it well in excess of 30,000 RPM, so your chance of success is very small.

Carbide is not forgiving of misalignment. If you could see deflection in the tip, it had to be at least .003" TIR, a huge amount as compared to the drill diameter. That you drilled as deeply as you did before the drill broke is the surprise. Drills the likes of those you described should be run dead true and fast unless you expect to break them routinely.

As far as I'm concerned, for a drill press, yours is acceptable. You're just expecting too much from it. Virtually none of the typical drill presses have the feel, precision or speed for drilling with miniature drills.

Harold

Who makes this drill press, and how large is it? How fast does the spindle turn?

For drilling small holes like that you need to have something like a Dumore senstive high speed drill press. The chuck is mounted directly on the motor shaft, and the motor is typically a universal brush type. I run mine off a simple variac at work. Spindle speeds around 10K rpm are typical.

You are very unlikely to get a large drill press chuck (here I am thinking the JT2 is probably for chucks about 1/4 inch capacity or so) to run true enough to accept drills no. 80 in size.

I use HSS drills in that range to drill in brass an polymers all the time, the speeds sound excessive but work out what rpm you need to get a no. 80 drill running at to get a reasonable sfpm number for, say, brass.

Jim

As far as my #85 drill experiment is concerned, everyone is right that the speed I was using was much too slow. Over the last few years I've left the DP set to the lowest speed it can go - 860 RPM -- which has never given me any problem with HSS drills in wood and brass (and occasionally steel) and even a few hundred holes in PC boards with carbide drills in the #70's and #60's. But this was my first attempt at using a micro bit and it's clearly a failure. At least now I have some ideas why.

NOW ... For most "precision" work I've done, I have a drill press adapter for a Dremel tool which I've used with good success drilling in all types of materials. But I have an electronic speed control which will run it from a pace almost slow enough to watch it turning around up to 30,000 RPM which is what everybody's been recommending for tiny carbide jobs. Since I leave one Dremel tool permanently in the stand, I should measure the runout of that setup. If it's low enough, it'll probably suffice for everything I need to do. If not, I'll seriously consider buying one of the "sensitive" machines that have been recommended.

What I didn't make clear before is that the really precision stuff I need to do is on tiny things. The chuck to column dimension of the Dremel stand is

1-5/8" and that's pretty much been adequate for everything I've thrown on it. The smallest drill I've used in it is a #80 HSS and I should try the smaller carbide drills after I measure the runout.

| >

| | I wish any of my drill presses were that tight. 1" deep into Al? How big | is that #85? What alloy? What speed? What lube? I don't see anything out | of whack here.

Tom. Sorry if you misread what I wrote. I said one-tenth inch. Certainly now way I'd gotten 1" deep because the drill bit flutes aren't anywhere near that long.

Norm

I drilled a couple holes the other day, to .5 depth, just to see if I could do it, using a.01 drill.

I was using my double headed Signourney drill press. Drilled full depth just fine at 14,000 rpm and Fast!

Ive got some #77s in carbide Ill try today. Carefully..very carefully

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3