# Miniature Burr?

N

#### N Cook

Jan 1, 1970
0
Where there is a different footprint for a replacement item and you have to
pierce the pcb, in slightly different positions to the original, to push
pins through.
At the moment I use a small drill bit in a dremmel and use the fluted part
of the drill but its more melting by friction than cutting. I tried grinding
notches around a sewing needle but that did not work. Any ideas ?

J

#### James Sweet

Jan 1, 1970
0
N Cook said:
Where there is a different footprint for a replacement item and you have
to
pierce the pcb, in slightly different positions to the original, to push
pins through.
At the moment I use a small drill bit in a dremmel and use the fluted part
of the drill but its more melting by friction than cutting. I tried
grinding
notches around a sewing needle but that did not work. Any ideas ?

It depends on what sort of cut needs to be done. I've used a jewelers
screwdriver at times to enlarge a hole, or small drill bits in a drill
press. If the hole needs to be a bit larger, a hand drill will usually
suffice.

R

#### Ron(UK)

Jan 1, 1970
0
N said:
Where there is a different footprint for a replacement item and you have to
pierce the pcb, in slightly different positions to the original, to push
pins through.
At the moment I use a small drill bit in a dremmel and use the fluted part
of the drill but its more melting by friction than cutting. I tried grinding
notches around a sewing needle but that did not work. Any ideas ?

http://www.watchclocktools.co.uk/shop/

Ron(UK)

D

#### Dave Plowman (News)

Jan 1, 1970
0
Where there is a different footprint for a replacement item and you have
to pierce the pcb, in slightly different positions to the original, to
push pins through. At the moment I use a small drill bit in a dremmel
and use the fluted part of the drill but its more melting by friction
than cutting. I tried grinding notches around a sewing needle but that
did not work. Any ideas ?

I'm not quite sure what you mean - pretty well all components can have
the leads bent. If the holes are too far out to allow this a new one
would be required so drill it in the normal way - or just enlarge the
existing one with a suitable size drill?

'Normal' drills of this size have to be pretty soft for hand held use in
a dremel etc so I have a rather nice but ancient small pillar drill
bought off Ebay which uses collet tungsten types - expensive but very
hard so ideal for drilling new PCBs. But far too brittle for handheld
use.

N

#### N Cook

Jan 1, 1970
0
Dave Plowman (News) said:
I'm not quite sure what you mean - pretty well all components can have
the leads bent. If the holes are too far out to allow this a new one
would be required so drill it in the normal way - or just enlarge the
existing one with a suitable size drill?

'Normal' drills of this size have to be pretty soft for hand held use in
a dremel etc so I have a rather nice but ancient small pillar drill
bought off Ebay which uses collet tungsten types - expensive but very
hard so ideal for drilling new PCBs. But far too brittle for handheld
use.

--
*You sound reasonable......time to up my medication

Dave Plowman [email protected] London SW
To e-mail, change noise into sound.

It seems its bur and not burr.
In the case yeaterday ultra-miniature pcb mount toggle switch with thick
pins, not bendable, to go on a populated board. Footprint of 6 pins on
slightly larger , in terms of centre spacings than the original, so cannot ,
without making a jig , drill new holes. The drill would drop into the
original hole. So a matter of short radial slots out to the replacement
positions. Enlarging the existing holes would require filling with glue or
something for structural integrity , after soldering.

M

#### [email protected]

Jan 1, 1970
0
Dave Plowman (News) said:
It seems its bur and not burr.
In the case yeaterday ultra-miniature pcb mount toggle switch with thick
pins, not bendable, to go on a populated board. Footprint of 6 pins on
slightly larger , in terms of centre spacings than the original, so cannot ,
without making a jig , drill new holes. The drill would drop into the
original hole. So a matter of short radial slots out to the replacement
positions. Enlarging the existing holes would require filling with glue or
something for structural integrity , after soldering.

It sounds like youre choosing the toughst option. Why cant you bend &
extend the pins to reach the existing holes? OIr cut off the pins that
dont go and solder equipment wire to them and take them round the pcb?
Glue the switch to the pcb etc?

NT

W

#### Warren Weber

Jan 1, 1970
0
N Cook said:
Where there is a different footprint for a replacement item and you have
to
pierce the pcb, in slightly different positions to the original, to push
pins through.
At the moment I use a small drill bit in a dremmel and use the fluted part
of the drill but its more melting by friction than cutting. I tried
grinding
notches around a sewing needle but that did not work. Any ideas ?
I use dental burr's in my dremal. W W

M

#### Mike Berger

Jan 1, 1970
0
Not to mention, it's rare to have enough real estate to safely
chop up a board like that. And if it's multi-layer you're

J

#### jakdedert

Jan 1, 1970
0
It sounds like youre choosing the toughst option. Why cant you bend &
extend the pins to reach the existing holes? OIr cut off the pins that
dont go and solder equipment wire to them and take them round the pcb?
Glue the switch to the pcb etc?

NT
I also have questions, but appreciate that I'm not there and have to
depend on the description given. For instance, the solution given
(short radial slots) seems the best answer, and I wonder why they would
require filling; but if it is the best answer, then what is the question?

FWIW, I'd probably use a Dremel cutoff wheel which had been 'turned
down' to a nib from use. These constantly get smaller as they cut hard
materials (like metal) until they are barely larger than the arbor onto
which they are mounted. At that size, it might be possible to make the
slots he describes.

jak

S

#### Smitty Two

Jan 1, 1970
0
N Cook said:
Where there is a different footprint for a replacement item and you have to
pierce the pcb, in slightly different positions to the original, to push
pins through.
At the moment I use a small drill bit in a dremmel and use the fluted part
of the drill but its more melting by friction than cutting. I tried grinding
notches around a sewing needle but that did not work. Any ideas ?

Drill flutes aren't cutters. And a dremel's RPM is too high for most
drilling. If you want a new hole, use a hand held pin vise to hold the
miniature drill bit, and twist it by hand. Or, use an electric or air
drill at a lower RPM than the dremel.

To move a hole slightly by making it oval or oblong, get a small end
mill instead of the drill bit. End mill flutes ARE designed for cutting.

J

#### Jim Yanik

Jan 1, 1970
0
Drill flutes aren't cutters. And a dremel's RPM is too high for most
drilling. If you want a new hole, use a hand held pin vise to hold the
miniature drill bit, and twist it by hand. Or, use an electric or air
drill at a lower RPM than the dremel.

To move a hole slightly by making it oval or oblong, get a small end
mill instead of the drill bit. End mill flutes ARE designed for
cutting.

you can make a variable speed controller by using a incandescent lamp
dimmer and a dual outlet mounted in a junction box.I made one side of the
dual outlet full 120VAC,and the other variable.It works fine for slowing a
Dremel.
you could also use it to reduce power to an uncontrolled soldering iron.

I buy carbide bits at Skycraft Surplus,they also side cut.

B

#### Baron

Jan 1, 1970
0
N Cook inscribed thus:
Where there is a different footprint for a replacement item and you
have to pierce the pcb, in slightly different positions to the
original, to push pins through.
At the moment I use a small drill bit in a dremmel and use the
fluted part of the drill but its more melting by friction than
cutting. I tried grinding notches around a sewing needle but that
did not work. Any ideas ?

Have you tried dental burrs. You can get them in .3mm with 3mm shank !

S

#### Spehro Pefhany

Jan 1, 1970
0
Where there is a different footprint for a replacement item and you have to
pierce the pcb, in slightly different positions to the original, to push
pins through.
At the moment I use a small drill bit in a dremmel and use the fluted part
of the drill but its more melting by friction than cutting. I tried grinding
notches around a sewing needle but that did not work. Any ideas ?

You want an "end mill". If you get a solid carbide type it will snap
off easily in such a small size. If you get a high-speed steel type it
will dull quickly with the abrasive PCB material. The second option is
the more attractive, but you might have trouble finding a small
diameter HSS end mill with a 1/8" shank to fit a Dremel collet (most
seem to be 3/16").

Best regards,
Spehro Pefhany

M

#### Michael Kennedy

Jan 1, 1970
0
Jim Yanik said:
you can make a variable speed controller by using a incandescent lamp
dimmer and a dual outlet mounted in a junction box.I made one side of the
dual outlet full 120VAC,and the other variable.It works fine for slowing a
Dremel.
you could also use it to reduce power to an uncontrolled soldering iron.

I buy carbide bits at Skycraft Surplus,they also side cut.

--

Skycraft you say? Great Store. You must be in the Central Florida area as
well.

- Mike

N

#### N Cook

Jan 1, 1970
0
Anyone familiar with tension files, for hacksaws/coping saws
eg
http://www.buckandryan.co.uk/product.php/section//sn/VIT250005
I'd never heard the term , I cannot find the diameter of this stuff on any
site.
Anyone know what the name is for that centride or carbide embedded cutting
wire that I seem to remember can be found in camping/oudoor pursuit shops.?
Just for the material, if the right sort of diameter would require any ends
snipped off to pass through the pcb and two chucks or something for holding
the ends

M

#### Michael A. Terrell

Jan 1, 1970
0
Jim said:
you can make a variable speed controller by using a incandescent lamp
dimmer and a dual outlet mounted in a junction box.I made one side of the
dual outlet full 120VAC,and the other variable.It works fine for slowing a
Dremel.
you could also use it to reduce power to an uncontrolled soldering iron.

I buy carbide bits at Skycraft Surplus,they also side cut.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=36252

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

W

#### Warren Weber

Jan 1, 1970
0
Spehro Pefhany said:
You want an "end mill". If you get a solid carbide type it will snap
off easily in such a small size. If you get a high-speed steel type it
will dull quickly with the abrasive PCB material. The second option is
the more attractive, but you might have trouble finding a small
diameter HSS end mill with a 1/8" shank to fit a Dremel collet (most
seem to be 3/16").

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
[email protected] Info for manufacturers:
http://www.trexon.com
http://www.speff.com

My Dremal has variable speed and Dremal has many collet sizes. One that fits
dental drill bits that cut through and on the sides. W W

J

#### Jim Yanik

Jan 1, 1970
0

I have a Harbor Freight store a block away from me,and Skycraft about 15
miles away!

The carbide bits are $1 apiece at Skycraft for specific sizes,or you can buy random assortments,IIRC,10/$5.

M

#### Michael A. Terrell

Jan 1, 1970
0
Jim said:
I have a Harbor Freight store a block away from me,and Skycraft about 15
miles away!

The carbide bits are $1 apiece at Skycraft for specific sizes,or you can buy random assortments,IIRC,10/$5.

The Harbor freight kit is a nice assortment for people to get started
with, then you can buy replacements for whatever you break at places
like Skycraft.

I have a Harbor Freight 20 minutes away, but Skycraft is over two
hours away, which is beyond my usual driving distance. At current gas
prices, I could buy several kits at Harbor Freight, throw ay over half
the burrs, and still come out ahead.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

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