Drilling Very Small Holes

[lkrestorer]

My question is: What is the best way to hold (very) small drill bits when drilling? I had been using an old sensitive drill feed device with a miniature Jacobs chuck. It will close down to 0" and hold up to 1/8" bits. It is worn out and has developed way too much wobble (it was a "pre-owned" Ebay purchase). I bought a new Chinese keyless chuck and arbor from a well-known supplier (no need to throw rocks at them because I have bought other very good items from them). The chuck could not be tightened adequately without using pliers - and it's supposed to be a keyless chuck. I sent it back and they replaced it with another that is equally as bad. The bits will randomly either push back in the chuck or grab in the material being drilled and spin in the chuck. This makes it very hard to be accurate especially when drilling to a specific depth.

I don't have the resources to jump to an Albrecht version as they are over $400 but I need something that will hold these small bits tightly. I have been looking at possibly getting a few ER-11 collets and a chuck for them. Would this be a viable solution? What are you other people using out there?

I'm running this in a Grizzly "Bridgeport clone" that uses R8 collets. The other idea I was tossing around was using small pin vises mounted in the R8 collets. I have some of those but my fear is that there would be a great deal of runout.

I would like something simple that would run true and not cost me an arm and a leg. Any good ideas?

 

[rklopp]

I drilled holes as small as 0.15 mm (0.006") by holding the drill, which has an enlarged shank, in an ER-16 collet chuck. I don't have ER-11. The main keys to success were to use a calculated power feed rate and to limit the drilling depth to not more than about 1xD. My mill has separate VFDs on the feed motor and spindle motor, so it was an easy matter to lower the feed rate below the normally lowest speed given the feed variator. The calculated feed rate was D/64 per revolution. That rule of thumb works for 0.006" drills and 2" drills (of the two-flute twist variety).

 

[Longboy]

Get yourself a pin vice with a metal straight shank and chuck it up in the Jacobs.

 

[rklopp]

Get yourself a pin vice with a metal straight shank and chuck it up in the Jacobs.

I have yet to find a decent pin vise with low enough runout. The Starrett ones with straight shanks are just not up to par.

 

[MRA]

I use a pin chuck. Eclipse ones over here, but much the same as Starrett I suppose. Perhaps you have been unlucky, or perhaps I am not very choosy. Some have knurled shanks - perhaps it would help to polish that off, but I never have.

 

[Longboy]

I have yet to find a decent pin vise with low enough runout. The Starrett ones with straight shanks are just not up to par.

The best I've done with the mini mill/lathe chucks is about a #50 drill for carb needle and seat.

 

[krypto]

What size drills are you talking about?

Since I found out about them, I've been using the 1/8" shank solid carbide drills commonly used for drilling circuit boards. They easily drilled any metal I've tried. You can get the metric ones from China from .1mm to 3mm in .1mm increments pretty cheap. They don't bend much, which is good and bad, so it's best to have spares.

 

[kiwi2]

Hi,
You can get sets of small drills with 1/8" shanks such as these:
https://www.aliexpress.com/item/100...00021779100698!sea&curPageLogUid=L0168esC3VFvStandard chucks work fine for these.
Regards,
Alan

 

[gunna]

........... They don't bend much, which is good and bad, so it's best to have spares.........

For 'much' read 'not at all'. Carbide drills do not bend, but otherwise they are very good.
Ian.

 

[kwoodhands]

I tried a pin vice but the runout was too much. Tried a few different things but none were satisfactory. Then I made a holder, 1/2" diameter CRS 4" long. Turned it down slightly so it would be concentric. Bored a 1/4" x 3/8" hole for a wood dowel.
Bored on the lathe with the pin vice into the wood dowel and same drill drill used for the work.
I used a # 50 drill for a starter drill . Then the small drill in the pin vice in the tailstock chuck. Bored 1/4" deep.
Pushed the tiny drill into the dowel using a pair of pliers.
One drop of glue on the base of the dowel to hold the drill from spinning.
This was not perfect but was satisfactory.
A hint for drills that are bent , drill into a scrap hardwood block several times. The drill will heat up and straighten out . This works for drills 3/16" and smaller. The smallest drill I have done this was a #51 drill. The larger the drill the more times the drill is run into the scrap until straight. Usually a drill 1/16" takes about 3/4 passes.until straight.

 

[Steamchick]

I find that the best pin chuck I have only goes down to 0.4mm (0.0016"). as anything smaller can slip in use. I has to be held in a standard tailstock chuck, or with a centre in the back centre-drilled depression. Not easy to use. But my precision drill chuck copes easily with the 1/8" shank carbide drills (from China - cheap enough... 10 for £3). To start them I use a "dremel" style sharp pointed tapered drill/reamer thing. Just the tiniest dot of a centre is all that is needed for the 0.2mm drills to make good gas jets. But be careful not to push the drill too hard or fast. That breaks them quicker than is desirable. I usually get at least 3 holes in brass before the edge goes off or I break a drill-bit.
K2

 

[Ken I]

I've posted this before...

High speed drilling, sensitive drills?

These are what I use for very small holes :-

The upper one uses a DC motor, Dremmel collets or chuck (5/16" 40 ME thread) - the whole thing floats in that it is free to rotate and slide in the MT3 shank. It uses a Mabuchi motor running off a DC power supply, all the mechanical bits are home made - I scavenged the chuck end of an old Dremmel accessory.
You hold it and feed by hand - this gives you "feel" for the torque - I keep the other hand on the on/off switch.

The lower one is a similar sliding pin chuck that I use held in a conventional tailstock chuck in the lathe - again you feed it manually and you can feel the torque - if the drill snatches, you just simply let go and it spins harmlessly. Obviously it doesn't work for the mill - apart from using it for M3 or smaller thread tapping by hand.

The motorised unit works on my mill or lathe - on the lathe you can rotate the part as well as in gun drilling which is suppose to held keep it running true.

I use a spotting drill rather than a centre drill to make the start point.

Regards, Ken I

 

[Steamchick]

Good stuff Ken. I finally developed a process for setting the tailstock chuck accurately so very gently feeding with that works well.
But I have a motor and stuff to make a tailstock drilling machine if ever I need to.
A good idea!
K2

 

[stanstocker]

I used to drill quite a few small holes while still restoring clocks and watches. Fortunately most of the time it was in the end of a shaft / arbor, so the work was spinning in the lathe and the drill bit was hand held in a pin vise and allowed to advance into the work. When I had to do a small hole in a mill and no sufficiently concentric tool holding was at hand, a blank faced piece of rod was held in the lathe and drilled to make a larger shank. Once a shank of 1/8 or larger was loctited to the drill, existing tool holding options could be used. Having the work spinning tends to deliver a nice straight hole.

In the lathe, straight flute solid carbide drills gave the best results, while in a mill the chip extraction provided by a twist drill is beneficial. Frequent removal of the drill to clear chips is a must, particularly when drilling to 4X the drill diameter or greater. Typically when repivotting a clock arbor the depth is 5X the drill diameter or more.

Naturally the official answer would be to purchase an Albrecht 15J0 and a matching arbor, or a nice clean Cameron precision drill press, but those options will leave at least a moderately sized smoking crater in your wallet or credit card...

 

[len1042]

My question is: What is the best way to hold (very) small drill bits when drilling? I had been using an old sensitive drill feed device with a miniature Jacobs chuck. It will close down to 0" and hold up to 1/8" bits. It is worn out and has developed way too much wobble (it was a "pre-owned" Ebay purchase). I bought a new Chinese keyless chuck and arbor from a well-known supplier (no need to throw rocks at them because I have bought other very good items from them). The chuck could not be tightened adequately without using pliers - and it's supposed to be a keyless chuck. I sent it back and they replaced it with another that is equally as bad. The bits will randomly either push back in the chuck or grab in the material being drilled and spin in the chuck. This makes it very hard to be accurate especially when drilling to a specific depth.

I don't have the resources to jump to an Albrecht version as they are over $400 but I need something that will hold these small bits tightly. I have been looking at possibly getting a few ER-11 collets and a chuck for them. Would this be a viable solution? What are you other people using out there?

I'm running this in a Grizzly "Bridgeport clone" that uses R8 collets. The other idea I was tossing around was using small pin vises mounted in the R8 collets. I have some of those but my fear is that there would be a great deal of runout.

I would like something simple that would run true and not cost me an arm and a leg. Any good ideas?

I know what you are talking about in regards to the crappy low cost small keyless chucks. They do not tighten very well and I sometimes have to resort to using a set of pliers to tighten them enough.

 

[lkrestorer]

I stand here with my tail between my legs after reading some of these responses. My idea of "very small" drill bits is #50 and it sounds like you folks look at those as monsters. I looked at the 1/8" shank micro drills in the post by kiwi2 and that is really small. I have gone down into the #70 area but that doesn't happen very often.

Looking at those little carbide bits my first thought is that there must be a reason they sell them all in quantities. It seems like a carbide bit of those sizes would be very susceptible to breaking - then you find another piece of metal and start over.

Back to my original question. For the "huge" bits I'm using I'm leaning more toward the ER-11 collet idea. I don't have any ER collets yet but they should be quite good at gripping a "normal" twist drill bit and providing minimal runout.

I guess I'm just wondering if there are any downsides to to this method - other than needing to change collets to handle different sizes. Yes, I was looking for the convenience of a keyless chuck but I am retired and could manage to find the few minutes needed to change collets. In my dream world (where I do most of my planning) I was even thinking of attempting to design a spring loaded sliding device with a collet chuck like the "sensitive drill feeds" use.

I do my mill work on a large machine with a VFD for the speed and a DRO for positioning. Therefore I don't have any problem with repeatability or rigidity in my setups. I use this means for my tapping, too. Some time ago I bought tap handles with a boss on their tops that fit a guide block that mounts in a R8 collet ( ENCO used to sell them) so lining up to drill and then tap a small hole can be quite easy.

Just looking for a real good way to hold these bits, thank you.

 

[lkrestorer]

len1042,
I splurged on a 1/2" Albrecht chuck a few years ago and it is a dream to use. This little one was just over $100 and I was expecting similar quality. Just got a dose of disappointment instead. Using pliers on (what was supposed to be) a precision tool just doesn't sit right with me. The Chinese do make some nice things, but............................................

 

[olympic]

I just use this little thing I found at a yard sale.

 

[krypto]

Back to my original question. For the "huge" bits I'm using I'm leaning more toward the ER-11 collet idea. I don't have any ER collets yet but they should be quite good at gripping a "normal" twist drill bit and providing minimal runout.

Yes, holding drill bits is one thing collets are good at.

Here's an ER-11 collet on an extension shaft held by an Albrecht 1/2" chuck. This setup was purchased for drilling in tight spaces as shown.

The problem is that I bought a really cheap (~$30) ER11 collet set thinking that would be "good enough" for this purpose. Wrong, they are TOTAL *****! They were good enough for drilling mounting holes as shown and that's about it. At some point I'm going to get a decent set from either Shars ($150) or Maritool ($250) that's worth owning. Get a metric set in .5 mm increments, that way you can hold the continuous range of .019 to .275 inches (#76-17/64) as each ER collet has a wide grip range.

 

[willie lochhead]

I have a Cameron Micro drill with Albrecht chuck listed on the For Sale section of this website. Make an offer if you are interested.