# High speed drilling, sensitive drills?



## WisJim (Feb 26, 2021)

What do folks do for drilling very small holes in various metals?  The higher speeds specified for small bits aren't usually in the range of available speeds for the average drill press, and drill presses made for those speeds (maybe 10,000 rpm and up) are expensive.  I'm not sure if the run out on my older Craftsman drill press is small enough to make it worth adapting the drill for the higher speeds needed.  What do you do when drilling very small holes that need to be positioned accurately?


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## HennieL (Feb 26, 2021)

Hi WisJim,
I don't think you NEED the very high speeds recommended for industry. In fact, I do a lot of drilling into titanium and into high alloy and normal high carbon tool steel (annealed, of course), and even into 300 series stainless (303, 304 and 316) whilst making pocket knives - making holes to tap for 0-80UNF screws, and that's pretty small . I use both HSS-Co and solid tungsten drills, and only run them at around 2000RPM on my little mill/drill... have only broken 4 of these small drills in the last 3 years... I do use a good quality soluble oil cutting fluid on all my drilling, and "black magic" tapping compound on the taps.
I suspect a bigger risk/problem will be that these small drills break just as the drill exits the hole. This is normally as a result of play in the drill press spindle, and can be largely eliminated by adding two coil springs to keep the chuck/spindle in tension even as the drill passes through the hole. I will have to post a sketch if this is not clear and if you cannot find anything on the 'net - just give me a shout.

Hope this helps.
HennieL


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## jack620 (Mar 3, 2021)

I have one of these: proxxon
I made a holder to mount it on my lathe toolpost for cross-drilling holes. It's extremely smooth and has very little runout. Eventually I will buy the drill stand for it for drilling holes in circuit boards, etc.

I also have one of these: Sensitive Drill Feed | 1/8" Keyless Drill Chuck - LittleMachineShop.com

It allows a more delicate touch when drilling with very small drill bits on a lathe or pedestal drill.


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## RM-MN (Mar 3, 2021)

The high speed listed for small drills is more of a maximum for the fasted drilling.  If making the hole in the least amount of time is critical you want a fast drill.  Slower works pretty well.  One of the downsides of the slower drilling is that the bit may not evacuate chips as well so peck drilling becomes more of a necessity.  Get the bit into the material just a little, then back out to clear chips.  Failing to do this can fill the drill flutes and jam the bit and the small bits break very easily.  I have proof.


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## Steamchick (Mar 4, 2021)

I make gas jets and find drilling 0.25mm  (about 0.10") a bit of a pain on my lathe. The biggest problem is striking a centre to start the drill. If off centre by even a "thou" or 2. the drill will cut a large hole and/or just break. So I have about 3 holes per drill before the edge goes and I expect a break. And only 1 in 3 jet holes is "on size" - the others just save me making larger jets.
My latest idea is to use a "broken" drill - with maybe 0.5~1mm of drill bit left attached to the 3mm shank... and use this to strike the centre - as regular centre drills etc. are just bigger (on the blunt end before the cutting edge at the flutes!) than the holes I'm drilling. When I have a centre (maybe only a few thou deep) that I like, I then drill with the proper drill bit. But I am unsure of speed. My lathe is currently set to go to 1600rpm, but I drill at around 800rpm as this seems to be OK... I'm only drilling through about 3mm of brass to make the jet so don't need to "Peck" at it - although when I have tried to drill deeper even pecking doesn't get me past the 5mm depth before a breakage. Feeding the tailstock is very difficult - "old" muscles sometimes don't work perfectly. - Too fast and the drill breaks. The lathe is far too large to have any sensitivity so I can feel the drill pressure. Maybe I need a sensitive drill chuck? Does it need a special adapter for a no 2 Morse taper?
Any suggestions to help me improve?
Thanks,
K2


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## Jules (Mar 4, 2021)

Steamchick, have you tried PCB drills ?
They are usually very short and have 3.2mm shanks. 
A sensitive drill chuck will also help no end. 
I would also try using a very small carbide stubby drill to give you a centre. They are very ridged and should cut at the correct angle to start your small bits.


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## Steamchick (Mar 4, 2021)

I'm using drills with a 3.2mm shank. The 0.25mm. bit is only about 10mm long. A centre-drill would need the central web to be less than 0.25mm. thick. I'll stick with the 'broken 0.25 drills" for centring until I can find a super small centre drill.
I just don't know what speed I should be using? Or how to get better control? I'll try and find out more about the Sensitive Drill chuck..
K2
Thanks.


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## Jules (Mar 4, 2021)

Steamchick, 
You can easily make a sensitive drilling tool. 
I would get an MT2 blank with a short stub. Drill and ream to 10mm. 
Make a disc approx 40mm dia x 8mm and drill out 10mm. 
Drill and tap for a locking grub screw and then knurl the outside. 
Then lock that onto an ER11 parallel shank collet holder. 
Put the drill into the ER11 collet and the MT2 in your tailstock. The collet holder should slide smoothly into the tailstock. 
Just hold the knurled disc and feed in your drill. 
Take care of the chuck. (Much better with a collet)


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## Steamchick (Mar 4, 2021)

Thanks! That is the tip of the week!
K2


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## Richard Hed (Mar 4, 2021)

Steamchick said:


> I make gas jets and find drilling 0.25mm  (about 0.10") a bit of a pain on my lathe. The biggest problem is striking a centre to start the drill. If off centre by even a "thou" or 2. the drill will cut a large hole and/or just break. So I have about 3 holes per drill before the edge goes and I expect a break. And only 1 in 3 jet holes is "on size" - the others just save me making larger jets.
> My latest idea is to use a "broken" drill - with maybe 0.5~1mm of drill bit left attached to the 3mm shank... and use this to strike the centre - as regular centre drills etc. are just bigger (on the blunt end before the cutting edge at the flutes!) than the holes I'm drilling. When I have a centre (maybe only a few thou deep) that I like, I then drill with the proper drill bit. But I am unsure of speed. My lathe is currently set to go to 1600rpm, but I drill at around 800rpm as this seems to be OK... I'm only drilling through about 3mm of brass to make the jet so don't need to "Peck" at it - although when I have tried to drill deeper even pecking doesn't get me past the 5mm depth before a breakage. Feeding the tailstock is very difficult - "old" muscles sometimes don't work perfectly. - Too fast and the drill breaks. The lathe is far too large to have any sensitivity so I can feel the drill pressure. Maybe I need a sensitive drill chuck? Does it need a special adapter for a no 2 Morse taper?
> Any suggestions to help me improve?
> Thanks,
> K2


Let me be sure that I understand you.  You say you are drilling a .25mm hole with a lathe?  your lathe is a toy lathe?  I would thimpfk even a toy lathe would be too clumsy to try this with.  I would thimpfk a dremel type tool would be needed.  You could set that up in your lathe but to use the lathe itself would be like hunting mosquitos with a 500lb bomb.  A dremel style tool, (I thimpfk), would give you far more control over a tiny operation like this.  Is there any other possibilities?  a local water jet? Laser? acid etching?  EDM?  If you have a small enough hole, (as you do), you might be able to construct a tiny EDM machine particulalry since you have only a few mm to go thru.


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## geo (Mar 4, 2021)

Steamchick said:


> I make gas jets and find drilling 0.25mm  (about 0.10") a bit of a pain on my lathe. The biggest problem is striking a centre to start the drill. If off centre by even a "thou" or 2. the drill will cut a large hole and/or just break. So I have about 3 holes per drill before the edge goes and I expect a break. And only 1 in 3 jet holes is "on size" - the others just save me making larger jets.
> My latest idea is to use a "broken" drill - with maybe 0.5~1mm of drill bit left attached to the 3mm shank... and use this to strike the centre - as regular centre drills etc. are just bigger (on the blunt end before the cutting edge at the flutes!) than the holes I'm drilling. When I have a centre (maybe only a few thou deep) that I like, I then drill with the proper drill bit. But I am unsure of speed. My lathe is currently set to go to 1600rpm, but I drill at around 800rpm as this seems to be OK... I'm only drilling through about 3mm of brass to make the jet so don't need to "Peck" at it - although when I have tried to drill deeper even pecking doesn't get me past the 5mm depth before a breakage. Feeding the tailstock is very difficult - "old" muscles sometimes don't work perfectly. - Too fast and the drill breaks. The lathe is far too large to have any sensitivity so I can feel the drill pressure. Maybe I need a sensitive drill chuck? Does it need a special adapter for a no 2 Morse taper?
> Any suggestions to help me improve?
> Thanks,
> K2


I have 1 .8 and .5 mm centre drills they are not expensive and very good joe pieczynski on you tube does a good sensitive drill feed


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## Ken I (Mar 5, 2021)

WisJim,
            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 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


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## Drawfiler (Mar 5, 2021)

For lathe work I use a pin chuck. You put the shaft into the normal tailstock Chuck just loose enough to turn, almost as though the shaft is running in a bearing, you then get the lathe going and feed the pin Chuck forward by gently holding it between your two forefingers with the rest of your hands holding the tailstock Chuck, if the dill jams or bends, the pin Chuck will turn between your fingers.


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## MRA (Mar 5, 2021)

I do some volunteering at a place which collects industrial engines (Anson Engine Museum), amongst which are many diesels.  We have a display case containing some photos and a drill bit with a small shank, out the end of which protrudes the bit itself which looks like a hair - how the **** they formed and sharpened it, I don't know.  I think it came from Gardners.  Attached is a label hand-written in ancient copperplate, saying something like 'this bit was used to drill 14,245 injectors for type 'xx' engine.  It is now undersize, but may be used for type 'yy' engine'.  

The photos show the rig - much like your ideas above, but on a small cast iron bed about a foot long on top of a bench with a strong light immediately above, operator sat next to it, and driven by pulleys and a round belt to get the speed.

I regularly break bits up to about 1/8".  I've even sheared an M10 tap, once


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## Steamchick (Mar 5, 2021)

Richard, Ken 1 'n all. Thanks. Being fair, I have probably only made a couple of dozen jets all told. The 6" (Chinese) lathe is more accurate than my Unimat SL. (Which I guess must date from 1960s or earlier?). The Unimat must be at least 1 diameter off-centre for the 0.25mm drills. And trying to align the headstock with the tail-stock  tells me the Unimat lathe just isn't true after a long life. I have had best results on the 6" lathe by threading the jet, drilling the "gas-side" 1mm dia for all bar 3mm of length - then parting-off. Reverse the jet in the chuck, face then strike a centre for the 0.25mm drill and do the drilling with tail-stock chuck holding the drill. On the Unimat, I have to swap the chuck and tail-stock (drill-chuck) so the drill is rotating, as I just can't find a true centre the conventional route with the drill in the tail-stock. - Through the magnifying glass you can see the drill bending as it wobbles off-centre. If I get a hole it is somewhere around 0.27~0.28mm I guess (smaller than my 0.30mm drills). I buy sets of 10 drills of [email protected] for £2.50, so cheap enough, and I have a dozen or so shanks from broken drills - some with a mm or 2mm of drill left unbroken. I use these to strike the centre now, as nothing else is small enough in my collection of centre drills and spot-drills. When I get a true centre, the jet gives a gas flame exactly the same size as a commercial jet (cost £3.). I'm just a sucker for making it myself, rather than buying "mass-produced stuff at 10 times the cost". When commercially practical - I buy! - Then spend my time making the more unique stuff.
I would just like advice on the best speed for drilling? The drills are so femur that high speed definitely doesn't work for me. I seem to do best at 800rpm... but when you talk about it you seem to be at Dremmel high speeds of over 10,000rpm? (If I read you correctly?). When I tried that the drill bit simply broke-off the shank "to meet its maker".  Glad I was wearing glasses! Perhaps you are drilling >0.5mm when the drills are strong enough for the speed? When I have tried simply holding drills with a steadied chuck that has less than a 70% chance of success, as my hands are not "stiff" enough. You can't feel the snatch - there isn't enough torque on such a small drill. But you can feel the drilling pressure, holding the chuck lightly 'tween finger and thumb mostly supported by the tail-stock, but without the taper jammed... (like Drawfiler's method). - I don't need pin chucks (mine are not accurate enough anyway) as the drill shanks are 3.2mm dia. I'll make a tail-stock sliding holder for a small chuck I have, and try that. It really does need the alignment from the larger lathe, but with the feel I guess I'll achieve with the sliding chuck arrangement? - I'm much like MRA with my hand skills, so need the machine to compensate! (Breaking 10mm taps is easy for me! - For hand tapping, my Push and Pull are not in-sinc most of the time!  ).
Cheers lads! If I achieve more than 1 in 3 true jets I'll let you know... or if I ever reach more than 5 true holes with 1 drill-bit. My real challenge will be to buy some 0.2mm drills...
Did someone recount the tale that after WW2 the Americans sent the British a tube with a machined-hole that was smaller than anything supposedly available? - So the British sent it back with a tube inside it? Here's the latest! - Smallest 'test tube' scoops world record

At work, we needed oil-spray bars for valve cam lubrication (400,000/year)... 0.5mm holes specified. The Japanese had very clever checking devices an cameras to check for broken drills, blocked or badly drilled holes, etc. and a 5% part reject rate. To make these in the UK I specified Laser drilling - 100% OK parts - and cheaper! (High capital cost recuperated in months).

I'll try not to stress you with my "simple" queries again!
K2


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## goldstar31 (Mar 5, 2021)

Ken
          The holes in holes dates back to the Japanese- and the Tyne which built Japananese battleships.

My eyesight is more than rough but drilling holes correctly on a round object demands a milled surface PRIOR to attemps at drilling.   Here were go again,  but I hit problems at the age of 14/15 trying to drill reheat holes in a baby athodyd jet engine   ex Aerodeller and Cpl Henwood.   The metering was made on an old pre-war Myford.
Skipping( he jis joking at 90),  I wood then make up tiny D bits that the local  nurse had made(. Vickers Armstrongs and Metal Box yet agai) to release trapped blood in  crushed finger nails.

You and I discussed a possible workshop  from an even old bloke and  he was a Geoege Daniels and George Thomas fan.  Both were also wath,akers and it took Daniels a year to make a wrist watch.
Contraast this  to me haggling over a £10 Rolex diving watch in the Ladies Market in HongKong.

So my thoughts of an ancient old git is to buy a set of turns with a set of 6mm collets.  Shut the door on the metal butchery department here and  start thinking about watchmaking.

Incidentally, this 10 milllie Pultra 10 had a microscope!  More words of dismay but the chairman of the British Horological Society of old- has an empty shop in in Byker.   OK he does Mason's time[ieces from time to time(!) but he is maintaining instruments for the NHS.
Damn, another bloody Quorn e-mail but  if you had on ----- say no more

Cheers


N


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## Steamchick (Mar 5, 2021)

Thanks for that Norman. I bought the Unimat SL 20 years ago for small stuff. Just my luck the lathe I bought isn't so good. (It has been well used and is worn).
I have ordered a different pin vice with multiple collet and a shaft to run in a hole I'll ream in a tapered sleeve in the tailstock. Maybe it will work? Not sure I can make that quality of precision. 
Keep well,
K2


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## goldstar31 (Mar 5, 2021)

When Noah and I were  lads, I had a SL and r ecall the late Rex Tingey( he was. same age as me)  did some overhauls and put in   silver steel bed bars and I recall the gibs were plastic.  FYI and I ithen  had a  mk3/4 clone= which I recentltly( ?????) sold.   Vagely, I have Making the Most of the Unimat on file somewhere.  Thonkiing of Quorns, I recall someone using the little  motor as ubit for a sort of Quorn.
My Mk3/4 had ER14 collets. I think.

Off topic( really OFF0 the Quorn  guys are prattling on about  microscopes and eye aids. Bright set of enthusiasts.  How I got in is a mystery of science.

This 6" Chinese lathe has  made me curios.   I had no idea abut one. Details please, of you can.
Meantime, I have just driven myself nuts on  rebuilding my garden shredder and am off to run a  series of tailstock tests  until a couple of us are going to devour a remaing half bottle of Scotch.


Cheers everyone and stay safe

Norman


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## DickG (Mar 5, 2021)

Steamchick said:


> I'm using drills with a 3.2mm shank. The 0.25mm. bit is only about 10mm long. A centre-drill would need the central web to be less than 0.25mm. thick. I'll stick with the 'broken 0.25 drills" for centring until I can find a super small centre drill.
> I just don't know what speed I should be using? Or how to get better control? I'll try and find out more about the Sensitive Drill chuck..
> K2
> Thanks.


I often need to drill a 0.010” dia hole in silver steel. This is for the anvils used in my “Graskop” Rivet Tool. I do have an advantage in that I can use the tool to centre pop the blank anvil. I can drill with  very small drills in my Myford S7. This has a rack feed tailstock and a 1HP 3-phase motor. I wind the VFD up to 100 Hz to get the spindle turning at around 5k RPM. However, I prefer to use my small  Pultra as the spindle turns at around 8k RPM, still a bit slow for a 0.010” drill. The Pultra has a lever feed tailstock so peck drilling is easy.
I do have some ‘micro’ centre drills for starting in a plain bit of material.


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## mecanotrain (Mar 5, 2021)

salut les copains,
Voici un appareil pour multiplier la vitesse d'une broche:








						Multiplicateurs de vitesse | Meca Diffusion
					

Méca Diffusion et PIBOMULTI ont développé des multiplicateurs de vitesse pour le perçage, fraisage, taraudage et rectifiage.




					mecadiffusion.com


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## olympic (Mar 5, 2021)

For tiny holes I use a Cameron precision drill press with PCB carbide drills. 






						Cameron Model 214 Table Top Drill Press - Cameron Micro Drill Presses
					

The Cameron 214 Micro Precision Table Top Drill Press with sealed DC Motor, Variable Speed Control and interchangeable spindle assembly.




					cameronmicrodrillpress.com
				




Found one, complete with a cabinet containing a couple of hundred drills, at a yard sale for cheap-cheap, and wouldn't be without it now. It turns at up to 30000 RPM.

Here it is "as found" at the sale:


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## Steamchick (Mar 5, 2021)

Thanks Dick G and Merci Roger! - I'll have to wind-up the speed of the lathe a lot! It only does 3000rpm tops! Or somehow make the Unimat SL align at some point between headstock and tailstock.... I can wind that up to >9000rpm. (Mainshaft bearings and non-standard brush motor get very noisy then!). Not sure at what speed it destroys itself though.
Today I ordered a new drill arbour (MT2 to JT0) as the existying one (MT1 to JT0) for my small ROHTI drill chuck is about 0.3 mm off true centre, maybe because I have to use an MT1 to MT2 sleeve?  But this afternoon I used my 10mm tailstock drill chuck holding a broken 0.25 drill to strike a centre for a 0.3mm drill.  I needed to reclaim a jet on a Butane blow-lamp I am re-building. That blow-lamp has a "pre-heating" tube to prevent flare-up - and it is good in very cold weather, because I can invert the canister to flood the burner with wet butane and that way can still get full flame size when otherwise I would lose a lot of heating power. Works fine until -4 degrees C  when the last of the butane pressure fades into liquid. (I stop then as the "family jewels" dissapear at sub-zero temperatures - I reckon you need them to play with pressurised gas burners!).
K2


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## Steamchick (Mar 5, 2021)

goldstar31 said:


> When Noah and I were  lads, I had a SL and r ecall the late Rex Tingey( he was. same age as me)  did some overhauls and put in   silver steel bed bars and I recall the gibs were plastic.  FYI and I ithen  had a  mk3/4 clone= which I recentltly( ?????) sold.   Vagely, I have Making the Most of the Unimat on file somewhere.
> My Mk3/4 had ER14 collets. I think.
> This 6" Chinese lathe has  made me curios.   I had no idea abut one. Details please, of you can.
> Meantime, I have just driven myself nuts on  rebuilding my garden shredder and am off to run a  series of tailstock tests  until a couple of us are going to devour a remaing half bottle of Scotch.
> ...


Hi Norman. My 6" lathe is a Chesters model DB7VS. - Maybe that is a 7" lathe?





Ken


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## goldstar31 (Mar 5, 2021)

Thanks Ken.



I think that I have  much the same- i..e. an An Axminster C4 with power crossfeed.

Not a bad lathe.  I paid £350 for mine,,   Giggles!

 Enjoy it


Take care

Norman


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## IanN (Mar 6, 2021)

Steamchick said:


> I make gas jets and find drilling 0.25mm  (about 0.10") a bit of a pain on my lathe. The biggest problem is striking a centre to start the drill. If off centre by even a "thou" or 2. the drill will cut a large hole and/or just break. So I have about 3 holes per drill before the edge goes and I expect a break. And only 1 in 3 jet holes is "on size" - the others just save me making larger jets.
> My latest idea is to use a "broken" drill - with maybe 0.5~1mm of drill bit left attached to the 3mm shank... and use this to strike the centre - as regular centre drills etc. are just bigger (on the blunt end before the cutting edge at the flutes!) than the holes I'm drilling. When I have a centre (maybe only a few thou deep) that I like, I then drill with the proper drill bit. But I am unsure of speed. My lathe is currently set to go to 1600rpm, but I drill at around 800rpm as this seems to be OK... I'm only drilling through about 3mm of brass to make the jet so don't need to "Peck" at it - although when I have tried to drill deeper even pecking doesn't get me past the 5mm depth before a breakage. Feeding the tailstock is very difficult - "old" muscles sometimes don't work perfectly. - Too fast and the drill breaks. The lathe is far too large to have any sensitivity so I can feel the drill pressure. Maybe I need a sensitive drill chuck? Does it need a special adapter for a no 2 Morse taper?
> Any suggestions to help me improve?
> Thanks,
> K2



Hi,
I’ve come to this thread a bit late and in quickly reading through I may have missed a reply that already covers what I’m about to type, so sorry if I’m repeating stuff

I drill small holes in the lathe using the method I videoed in the YouTube clips below

The vids were made as part of a discussion I had in another forum about drilling small, deep holes

It includes discussion of a short, ”heavy duty” graver I use only for “catching a centre” on a full size lathe (as opposed to a watchmakers graver)

The hole shown was 0.5mm diameter and 12mm deep

The graver


Catching a centre


Drilling the hole


Finished hole


The videos include a background “cameo appearance” of the workshop cat and the little kid from next door who always seems to come round when he hears noises from the workshop - sorry for these distractions

Ian


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## Steamchick (Mar 6, 2021)

Thanks Ian,
I have tried using a graver - well a tool ground as such. - but without the handle and good steady found it a bit difficult to pick-up the centre. But seeing your video I'll give it another try. Although I am having reasonable success with the "broken" 0.25 drill as a centre drill at the moment. About 1mm of 0.25 drill is stiff enough and fine enough to centre - providing the tool is a thou or so high and completely cleans the face when facing the material.
I Must get a file handle and make a proper graver!
Thanks - good videos!
Ken


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## goldstar31 (Mar 6, 2021)

Ken
          Probably there was little or nothing wrong with the graver except for the ability to hone it properly.
Lying about on my work desk is an assortment is an adornment  of 'stones and diamond pastes  which are progressively getting finer and finer until they  reach  the white Arkansas sone. There is a finer one again  but that is the black variety  but my late wife left me her white one used for  her surgery.
Now I am waiting for my bit of the frozen North East to warm up a bit  so that I can take that tiny whisker off a test bar to really ascertain  and better the measurement yesterday when I got a mirror finish with my tooling and   I had other things to do that were more pressing than changing the Diamond  cutting tool on the top slide for  a tool room dial mike in tenths. I was within a TIR range of + &_ half a tenth( by eye)
As for tool honing,  I need crudely made jigs because my eyesight is non exitent in one eye and split vision in the other- even wearing surgeons binoculars.
Most of it is simply attitude of mind but correct and not gimcrack purchases seem necessary.

I think that the remark of the late Martin Cleeve is still apt and that was 'barely perceptible swarf' from his 'half a Myford Ml7"

Meantime- Brest Wishes for your future success

Norman


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## L98fiero (Mar 6, 2021)

mecanotrain said:


> salut les copains,
> Voici un appareil pour multiplier la vitesse d'une broche:
> 
> 
> ...


The biggest problem with those multipliers is most will cost more than your lathe or mill, there are though other options like a DIY multiplier using belts but you still have the issue of the weight of the spindle and little sensitivity. I suppose the idea of a floating chuck could be incorporated as jack620 [post #3] suggested. 
Personally I have a 17,000 rpm Dumore variable speed drill but I've had to modify the feed mechanism that lifts the table with a knob.  Sensitive Drill Press | Dumore Series 16


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## IanN (Mar 6, 2021)

Steamchick said:


> Thanks Ian,
> I have tried using a graver - well a tool ground as such. - but without the handle and good steady found it a bit difficult to pick-up the centre. But seeing your video I'll give it another try. Although I am having reasonable success with the "broken" 0.25 drill as a centre drill at the moment. About 1mm of 0.25 drill is stiff enough and fine enough to centre - providing the tool is a thou or so high and completely cleans the face when facing the material.
> I Must get a file handle and make a proper graver!
> Thanks - good videos!
> Ken



Hi Ken,

As Norman pointed out, there is nothing special about the graver.  The only reason I have the strange looking tool in the video is that I am also involved with horology (and use "normal sized" gravers in pursuit of that hobby) but my watch and clock work takes place in the house and horological tools never venture outside to the workshop.

The "one inch of tool steel hammered in to a file handle" is used in the "big" workshop for the sole purpose of catching centres and putting a tiny chamfer on the ends of freshly faced bar to remove the sharp edge - not for any serious hand turning.

It also finds a use for all those little stubs of tool steel that are too small to use in a tool holder but too big to throw away and which you keep in a little tobacco tin because "they will be useful one day"

It is a handy tool, easy to make and costs nothing (my favourite price) - everyone has little tool ends and the odd old file handle lying round somewhere in the shop

Ian


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## traction engine (Mar 6, 2021)

As soon as a drill goes far enough off center, it will break; hence the use of a center drill.  However, at these diameters, the pilot must not have a flat bottom or the drill will wander around against it and break. Seems to me (and I've no experience doing this) that an impression such as a sharp center punch leaves would work. The impression has to be on center so you would have to make this tool for use in the same chuck/collet as is used for the drill.
As for speed, again I haven't bothered to work it out, but you are into the 10,000 rpm and more range. If your speed is anywhere near correct and you run on center, the feed rate is next. It must be sufficient that the drill cuts its way through and not "wear" its way. At this size, you can only tell this by the swarf and this is where the sensitive feed comes in. Good luck!
The smallest drills I use (rarely) are #80 (0.013") which I do on my old used Emco combo lathe/mill. Fortunately, I've never broken one so maybe I'm just lucky. I will say though that I've been machining for more than 50 years and have always paid great attention to what doesn't work and why. 
Having said all this, my luck will change!
Have fun, work safely.


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## Richard Hed (Mar 6, 2021)

traction engine said:


> As soon as a drill goes far enough off center, it will break; hence the use of a center drill.  However, at these diameters, the pilot must not have a flat bottom or the drill will wander around against it and break. Seems to me (and I've no experience doing this) that an impression such as a sharp center punch leaves would work. The impression has to be on center so you would have to make this tool for use in the same chuck/collet as is used for the drill.
> As for speed, again I haven't bothered to work it out, but you are into the 10,000 rpm and more range. If your speed is anywhere near correct and you run on center, the feed rate is next. It must be sufficient that the drill cuts its way through and not "wear" its way. At this size, you can only tell this by the swarf and this is where the sensitive feed comes in. Good luck!
> The smallest drills I use (rarely) are #80 (0.013") which I do on my old used Emco combo lathe/mill. Fortunately, I've never broken one so maybe I'm just lucky. I will say though that I've been machining for more than 50 years and have always paid great attention to what doesn't work and why.
> Having said all this, my luck will change!
> Have fun, work safely.


There are 1/8th" center drills, which can be used to just put a dimple on the piece.  This will center it perfectly fine.


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## SmithDoor (Mar 6, 2021)

I would use a dremel or a Fordham flex shaft. Dremel is around up to  30,000 rpm , Fordham is up to 15,000 rpm. 

Most drill press will go up to 3,600 rpm. 
But you can convert a drill press to 10,000 rpm, by changing the spindle pulley to steel pulley and using a 1/4" v-belt. You may need to replace the spindle bearings too.

Dave 



WisJim said:


> What do folks do for drilling very small holes in various metals?  The higher speeds specified for small bits aren't usually in the range of available speeds for the average drill press, and drill presses made for those speeds (maybe 10,000 rpm and up) are expensive.  I'm not sure if the run out on my older Craftsman drill press is small enough to make it worth adapting the drill for the higher speeds needed.  What do you do when drilling very small holes that need to be positioned accurately?


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## DickG (Mar 7, 2021)

SmithDoor said:


> I would use a dremel or a Fordham flex shaft. Dremel is around up to  30,000 rpm , Fordham is up to 15,000 rpm.
> 
> Most drill press will go up to 3,600 rpm.
> But you can convert a drill press to 10,000 rpm, by changing the spindle pulley to steel pulley and using a 1/4" v-belt. You may need to replace the spindle bearings too.
> ...


O


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## Steamchick (Mar 7, 2021)

Thanks all for advice. I shall experiment further as I need more jets for the burners I make. Now awaiting some bits from  [email protected]
K2


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## DickG (Mar 7, 2021)

As I have an electronics background I often need to drill 0.8mm holes in PCBs. As an aside a 1mm drill to me is big! Many years ago I set out to build  a Quorn. This involved a series of tools to build tools to build tools. One of these was a tapping & staking tool and I also made the precision drill attachment for it. I use this to drill small holes. A ‘proper’ PCB drill will give you the high speeds needed for small drills and probably will be a lower cost and better option than a Dremel in a Dremel drill stand.


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## goldstar31 (Mar 7, 2021)

I too have a Mark1 Quorn and like Dick made  a Drilling and staking tool. Mine was to the castings and design form Geo Thomas's  Workshop Techniques.  Another example of  hard going with none of this blethering and simply buckling down and not  wanting to re0-invent the wheel. 
But before the  arrival of the Mark2 castings, I got a fabricated one, cheaply meade with  scrap metal and a  small stick welder and the guy didn't ha ve an internet or one of those confounded gadgets.
It simply was cheap, not quite nasty and Worked until something better or prettier ccame along.
More rently,  I was chasing a motor for the Quorn in my earlier remarks and   found tht the motor was attached to yet again a fabricated  Stent Mark 1 tool and cutter grinder.   It was all the pricelly sum of £100 and I think thst I got a few more bits. I've forgottn but I greatly admire the two gentlemen.
Both Thomas's books are priced around the £30 mark.  I have  and still have great joy building  stuff from them and LEARNING!
 Why does anyone want to  improve on a guy that has already collected a heap of engraved cups.

My thoughts- and I think that I am  right

Norman


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## Steamchick (Mar 13, 2021)

Latest... I have now fitted the new drill chuck arbour to my little RHome chuck (5mm). It aligns perfectly! not the -.003" off-set that was causing broken drills and oversized holes. Sometimes the factory bought stuff beats the home-made...  The manufacturers have the money to "get-it right".
But not always!
I bought some centre drills (from China: "what do you expect?" I hear you mutter, and chuckle?) which were branded ... Of 6, 2 were perfect, 2 had a single end that was OK, and 2 were so obviously scrap that I didn't bother wasting time even trying to re-sharpen the tips. So of 12 ends - probably all bought as scrap from the manufacturers, I got 6 usable ends... OK. That's what I did expect. Cheap at that! (I got a full refund as that's what the internet traders do...). That makes 3 orders of free scrap in about 15 years of buying stuff on-line... I can live with that.
K2


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## Steamchick (Mar 17, 2021)

Next problem - maybe with the obvious solution that I have missed?
I am OK drilling 0.25mm and 0.30mm holes as the drills have 3.2mm shanks - great for collets or the ROHM chuck (down to 0.5mm maybe?).
But today I want to make some 0.35, 0.40 and 0.45 jets - so I have an age-old problem of to to accurately hold these? The pin-chucks I own only go down to - you guessed? - 0.5mm. And anyway, they have knurled outside and are NOT precision for aligning in the lathe when I hold them in a precision tail-stock chuck. I'm calling it precision, as it hold the 0.3mm drills just fine - on centre every time. Know any good watch maker's web sites for tools? - Maybe with proper pin-chucks true to 0.3mm?
I'm going into the freezing cold garage to start with a 0.30mm drill and opening it out by holding the larger 0.35mm drill somehow... But a good tool should do the trick - it's just I don't trust all the cheap stuff called "precision" that isn't!
K2


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## goldstar31 (Mar 17, 2021)

Between gardening and messing about with my Potts vertical mill attachment, I priced the Universal Pillar tool kit from Henigwaykits - and tool a seep breathe at the prices. I didn't get to the price of the little motor which is also needed to drive the drilling attachment because  I nearly fainted with the  prices of the two little Jacobs chucks recommended.

 The pair are around £120.


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## BaronJ (Mar 17, 2021)

Hi Guys,

Tracey Tools do a very nice 1/4" inch capacity Rohm drill chuck that will hold a 1 mm drill and is very accurate and quite inexpensive. Though I do use solid carbide PCB drills in it that have 3.2 mm (1/8" inch) shanks.


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## goldstar31 (Mar 17, 2021)

BaronJ said:


> Hi Guys,
> 
> Tracey Tools do a very nice 1/4" inch capacity Rohm drill chuck that will hold a 1 mm drill and is very accurate and quite inexpensive. Though I do use solid carbide PCB drills in it that have 3.2 mm (1/8" inch) shanks.


I bought a couple of so called Rohm chucks from them recently ad was told that   -- they are not .
I've had to overhaul my Boxford  ( Tenths of a thous) and simply awaiting getting my own readings from them.

I'm getting rattling fits and I know that it isn't the tailstock.
More anon  as they say!


Norman


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## BaronJ (Mar 17, 2021)

Hi Norman, Guys,

I've held mine a time or two in the lathe chuck soft jaws with a 3.2 mm carbide drill and not been able to see any run out with a 1/2 thou test indicator.  Certainly no more than noise from rotating the chuck.

I did make a threaded mandrel but by the time you have cut the threads and screwed it on you have at least a couple of thou there. When I get the time I will turn the mandrel down with the chuck in the soft jaws. That should get rid of the run out, at least I hope it should.


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## BaronJ (Mar 17, 2021)

goldstar31 said:


> I bought a couple of so called Rohm chucks from them recently ad was told that   -- they are not .
> I've had to overhaul my Boxford  ( Tenths of a thous) and simply awaiting getting my own readings from them.
> 
> I'm getting rattling fits and I know that it isn't the tailstock.
> ...



Hi Norman,

I have found, particularly with smaller drills, that the more pressure you apply with the tail stock the bigger the drilled hole.  Even though the cutting faces have been ground to be identical.

It can make the difference between a press fit and a loose fit !


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## goldstar31 (Mar 17, 2021)

BaronJ said:


> Hi Norman,
> 
> I have found, particularly with smaller drills, that the more pressure you apply with the tail stock the bigger the drilled hole.  Even though the cutting faces have been ground to be identical.
> 
> It can make the difference between a press fit and a loose fit !




Thank you for invaluable advice

Norman


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## goldstar31 (Mar 17, 2021)

goldstar31 said:


> Thank you for invaluable advice
> 
> Norman



It suggests that I drill amost on size with a cleanup to take the final whisker off and see


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## BaronJ (Mar 17, 2021)

goldstar31 said:


> It suggests that I drill almost on size with a cleanup to take the final whisker off and see



Part of the issue is that the drill bends ever so slightly under pressure.  It is worse if the drill is blunt and even worse if the drill is cutting off center.

This is why if you want a dead on size, for say a dowel pin, you drill under size and then you ream the hole.  Even then with a reamer you can make that cut over size.

Now we wait and see how many turn up to tell me its rubbish !


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## goldstar31 (Mar 17, 2021)

Hi John

No argument from me! I'm going to do a test drill as I said and if it still proves oversize, I'm , I'll drill undersize and  use a micrometer boring head for the last cut to size. 

So my thanks

N


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## IanN (Mar 18, 2021)

Steamchick said:


> Next problem - maybe with the obvious solution that I have missed?
> I am OK drilling 0.25mm and 0.30mm holes as the drills have 3.2mm shanks - great for collets or the ROHM chuck (down to 0.5mm maybe?).
> But today I want to make some 0.35, 0.40 and 0.45 jets - so I have an age-old problem of to to accurately hold these? The pin-chucks I own only go down to - you guessed? - 0.5mm. And anyway, they have knurled outside and are NOT precision for aligning in the lathe when I hold them in a precision tail-stock chuck. I'm calling it precision, as it hold the 0.3mm drills just fine - on centre every time. Know any good watch maker's web sites for tools? - Maybe with proper pin-chucks true to 0.3mm?
> I'm going into the freezing cold garage to start with a 0.30mm drill and opening it out by holding the larger 0.35mm drill somehow... But a good tool should do the trick - it's just I don't trust all the cheap stuff called "precision" that isn't!
> K2



Hi

Get a good pinvice - it will grip close to zero diameter

Then drill by hand in the lathe as I described in my previous post - no need for precision drilling machines, no need for high speeds.

Watchmakers have been using this method for over three hundred years

Ian


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## GrahamJTaylor49 (Mar 18, 2021)

Seeing the conversations concerning very small drills and the difficulty in using them, one of my clients manufactures
air bearing spindles. These are used for drilling holes as small as 0.005" and run at speeds as fast as 80-100,000 rpm.
I have no idea of the cost but might be worth having a look at.


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## goldstar31 (Mar 18, 2021)

GrahamJTaylor49 said:


> Seeing the conversations concerning very small drills and the difficulty in using them, one of my clients manufactures
> air bearing spindles. These are used for drilling holes as small as 0.005" and run at speeds as fast as 80-100,000 rpm.
> I have no idea of the cost but might be worth having a look at.


Sounds very similar to dentistry- and as my late wife and my daughter folloeed this employment, I'll 'keep my mouth shut'

Mumble, mumble

Norman


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## L98fiero (Mar 18, 2021)

Deleted


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## Richard Hed (Mar 19, 2021)

There is always the possibility of getting a laser drill, don't know about the efficacy of this, but it WOULD be very straight.  Also, EDM might be a possibility but I understand that takes quite a while to do.


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