High speed drilling, sensitive drills?

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olympic

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


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

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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
 

Steamchick

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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.
Cheers everyone and stay safe
Norman
Hi Norman. My 6" lathe is a Chesters model DB7VS. - Maybe that is a 7" lathe?
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Ken
 

goldstar31

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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
 

IanN

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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
 

Steamchick

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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
 

goldstar31

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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
 

L98fiero

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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
 

IanN

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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
 

traction engine

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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.
 

Richard Hed

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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.
 

SmithDoor

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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

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?
 

DickG

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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
O
 

Steamchick

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Thanks all for advice. I shall experiment further as I need more jets for the burners I make. Now awaiting some bits from E$@y...
K2
 

DickG

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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.
 

goldstar31

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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
 

Steamchick

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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
 

Steamchick

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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
 

goldstar31

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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:(.
 

BaronJ

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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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