Homebrew PCBs

Hi,
  Well, I'm getting rather sick of my Expo Reliant breaking drill bits. The
chuck seems to be quite badly worn, and the bearings are utterly fried (not
that they were any good to begin with. I'd hazard a guess that the drill bit
really shouldn't look as if it's vibrating...
  Anyway, long story short, I'm after a new PCB drill. I've come up with a
shortlist of three:
  1) Dremel MultiPro. Saw it in B&Q for \ufffd35, looks like a nice drill.
     15kRPM-33kRPM, two-speed (IIRC), mains powered. Couldn't find any
     suitable stands for it - with a bit of luck it might fit the stand I've
     already got.. with a little modification that is.

  2) Expo (www.expotools.com) Zircon. \ufffd40 including transformer and accessory
     kit. Build quality looks a little suspect, but it will fit the stand
     I've already got.
     
  3) Minicraft MB1012 "High Precision" (see www.shesto.co.uk). 18,000RPM. \ufffd38
     for the drill, plus another \ufffd55 for the speed controller, then another
     \ufffd39 for the stand. Hideously expensive for what it is IMO.

  What PCB drills are you guys using? Anyone got any recommendations?

Later.
-- 
Phil.                              | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB,
philpem@...              | ViewFinder, 10BaseT Ethernet, 2-slice,
http://www.philpem.me.uk/          | 48xCD, ARCINv6c IDE, SCSI
... I may not always be perfect, but I'm always me.

----- Original Message ----- 

From: "Philip Pemberton" <philpem@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, July 14, 2005 8:23 PM
Subject: [Homebrew_PCBs] PCB drill recommendations


> Hi,
>  Well, I'm getting rather sick of my Expo Reliant breaking drill bits. The
> chuck seems to be quite badly worn, and the bearings are utterly fried 
> (not
> that they were any good to begin with. I'd hazard a guess that the drill 
> bit
> really shouldn't look as if it's vibrating...
>  Anyway, long story short, I'm after a new PCB drill. I've come up with a
> shortlist of three:
>  1) Dremel MultiPro. Saw it in B&Q for \ufffd35, looks like a nice drill.
>     15kRPM-33kRPM, two-speed (IIRC), mains powered. Couldn't find any
>     suitable stands for it - with a bit of luck it might fit the stand 
> I've
>     already got.. with a little modification that is.
>
>  2) Expo (www.expotools.com) Zircon. \ufffd40 including transformer and 
> accessory
>     kit. Build quality looks a little suspect, but it will fit the stand
>     I've already got.
>
>  3) Minicraft MB1012 "High Precision" (see www.shesto.co.uk). 18,000RPM. 
> \ufffd38
>     for the drill, plus another \ufffd55 for the speed controller, then another
>     \ufffd39 for the stand. Hideously expensive for what it is IMO.
>
>  What PCB drills are you guys using? Anyone got any recommendations?

I've got the MB1012, stand and speed controller. I think the drill, 
controller and lots of little brushes and things cost me about \ufffd60 in a kit, 
and I paid about \ufffd30 for the stand. I wouldn't describe the drill as "high 
precision" but it isn't too bad. Tungsten bits are OK drilling the Fotoboard 
I use most of the time but break easily when drilling FR4.

Leon 



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On Thu, 14 Jul 2005 21:23:37 +0200, Philip Pemberton  
<philpem@...> wrote:

> Hi,
>   Well, I'm getting rather sick of my Expo Reliant breaking drill bits.  
> The
> chuck seems to be quite badly worn, and the bearings are utterly fried  
> (not
> that they were any good to begin with. I'd hazard a guess that the drill  
> bit
> really shouldn't look as if it's vibrating...
>   Anyway, long story short, I'm after a new PCB drill. I've come up with  
> a
> shortlist of three:
>   1) Dremel MultiPro. Saw it in B&Q for \ufffd35, looks like a nice drill.
>      15kRPM-33kRPM, two-speed (IIRC), mains powered. Couldn't find any
>      suitable stands for it - with a bit of luck it might fit the stand  
> I've
>      already got.. with a little modification that is.
>  2) Expo (www.expotools.com) Zircon. \ufffd40 including transformer and  
> accessory
>      kit. Build quality looks a little suspect, but it will fit the stand
>      I've already got.
>  3) Minicraft MB1012 "High Precision" (see www.shesto.co.uk). 18,000RPM.  
> \ufffd38
>      for the drill, plus another \ufffd55 for the speed controller, then  
> another
>      \ufffd39 for the stand. Hideously expensive for what it is IMO.
>  What PCB drills are you guys using? Anyone got any recommendations?
> Later.


I'd put the proxxon IB-E on the shortlist.
It has good bearings, and more importantly good hardened precision ground  
collets.
It doesn't take large sideloads well, esp. with long tools, because the  
bearings are close together in the front and not at both ends of the motor  
like in the cheaper tools. But for drilling this isn't an issue.

I think the precision of the chuck/collets might be more important than  
the bearings, even cheap tools often have acceptable ball bearings at both  
ends of the shaft and those could be replaced for better ones too. But if  
the drill isn't exactly straight and centered the bearing runout doesn't  
matter at all. The cheap grinders i have either have jacobs chucks, or  
brass collets, that don't really center well. I've thought about buying  
the collets only from proxxon to convert one of the cheap grinders to a  
permanent PCB only drill, but haven't yet tried it (one would need to  
grind the shaft of the drill to accept the more tapered collets from  
proxxon correctly).


For a drill stand, i have very good results with a pivoting drill press,  
bascally an arm with bearings at the back end and the drill at the front,  
about 40cm long and with either a spring or a counterweight for balance.
Haven't broken a drill with it so far (ok i have broken some while in the  
press, but not during proper operation, always operator fault.
You need to align the drill so it enters straight, then it is a very  
reliable drilling concept.
It has practically no friction to move up and down, and you can really  
feel it drill.
If you want to build one, ask for more details as there are a few tricks.


ST

When running, the drill bit should not look like a dog wagging its tail.

I'm not sure about the others, but those of us on other lists who do a lot of precision drilling have found the Dremel to be useless - unless you want a lot of broken bits.  It just has too much runout - I measured mine at over .005".  I have found Foredom handpieces to be quite acceptable.  An old Unimat would also do a good job.  The Foredome will cost well over £200.  Unimat's have become a bit of a collectors item and cost more than when they were new.

  ----- Original Message ----- 
  From: Philip Pemberton 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Thursday, July 14, 2005 3:23 PM
  Subject: [Homebrew_PCBs] PCB drill recommendations

[Non-text portions of this message have been removed]

On Thu, 14 Jul 2005 22:51:29 +0200, Earl T. Hackett, Jr.  
<hacketet@...> wrote:

> When running, the drill bit should not look like a dog wagging its tail.

The drill bit should not look like any dog, ever, tail or no tail ;-)


What i really wanted to say, has anyone tried the air powered drills?
They are fairly high speed (op to 60k RPM).

Do they work for PCBs?
How loud are they?

ST

In message <000b01c588b5$d02dd590$6401a8c0@family>
          "Earl T. Hackett, Jr." <hacketet@...> wrote:

> When running, the drill bit should not look like a dog wagging its tail.

I suppose that's a good way to describe it... The end of the bit looks like a
vibrating blur.

The Expo Zircon is off my list - apparently it's just as bad as the Expo
Reliant in terms of instability (it certainly seems to use the same "keyless"
chuck). Expo also seem to be very hesitant to give out actual
specifications...

The Proxxons look *VERY* nice, but are a bit too expensive.

I'm using FR-4 (fibreglass) laminates and Kemmer and Tycom tungsten carbide
bits with the enlarged shank. They're regrounds from a commercial PCB fab
plant - quite good quality, actually.

Later.
-- 
Phil.                              | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB,
philpem@...              | ViewFinder, 10BaseT Ethernet, 2-slice,
http://www.philpem.me.uk/          | 48xCD, ARCINv6c IDE, SCSI
... CAD : Can't Anybody Draw?

or an old dental pneumatic drill?  I have several of those handpieces, 
somewhere.

Bill
----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, July 15, 2005 7:01 AM
Subject: Re: [Homebrew_PCBs] PCB drill recommendations


> On Thu, 14 Jul 2005 22:51:29 +0200, Earl T. Hackett, Jr.
> <hacketet@...> wrote:
>
>> When running, the drill bit should not look like a dog wagging its tail.
>
> The drill bit should not look like any dog, ever, tail or no tail ;-)
>
>
> What i really wanted to say, has anyone tried the air powered drills?
> They are fairly high speed (op to 60k RPM).
>
> Do they work for PCBs?
> How loud are they?
>
> ST
>
>
> Be sure to visit the group home and check for new Links, Files, and 
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>
>
>
>

Excellon and TrueDrill both used air powered drill in their NC equipment. 
They had radial air bearings but I'm not sure if the thrust bearings were 
air or mechanical.  When I left the industry they were running 120K rpm and 
would drill through a 4 up stack of .064" FR4 plus entry and backup sheets 
in about 1/4 second.  With time for travel they managed 100 to 120 hits pre 
minute.

Air powered drills can be the ultimate, but you need good bearings.  If the 
bearings aren't up to the task, you'll find out fairly quickly.  Many 
handpieces have fairly good radial bearings to handle side loads (dental 
handpieces for example), but they have relatively poor bearings to handle 
the axial loads from drilling.  You probably won't know until you give them 
a try.

----- Original Message ----- 

From: "Bill Maxwell" <wrmaxwell@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, July 14, 2005 7:53 PM
Subject: Re: [Homebrew_PCBs] PCB drill recommendations


>>
>> What i really wanted to say, has anyone tried the air powered drills?
>> They are fairly high speed (op to 60k RPM).
>>

In a message dated 7/14/2005 2:23:03 P.M. Central Daylight Time,  
philpem@... writes:

What PCB drills are you guys using? Anyone got any  recommendations?



Totally home-brew with "instrument grade" 400 Hz. 3-Ø  quill-motor rebuilt 
with 1/8" collet-chuck.  Turns 12,000 RPM, fixed.   Would prefer twice that, but 
motor was "surplus" cheap, but very  fine.   New, probably $200?
 
This is mounted in a fixture with Thomson linear  ball-bearings.  Only 1/4" 
"Z movement", but drills a hole per second with  ease.  LOTSA "DIY 
work"!!!!!!!!!!!!  
 
Photo under my name, "Jan Rowland" in PHOTOS.    Try this:   _Home-Bre... _ 
(http://photos.groups.yahoo.com/group/homebrew_pcbs/vwp?.dir=/JanRowland&.src=gr
&.dnm=Home-Brew+CNC+PCB+Drill.jpg&.view=t&.done=http://photos.groups.yahoo.com
/group/homebrew_pcbs/lst?&.dir=/JanRowland&.src=gr&.view=t) 


[Non-text portions of this message have been removed]

In a message dated 7/14/2005 4:04:06 P.M. Central Daylight Time,  
stefan_trethan@... writes:

How loud  are they?



VERY!  But worse, they consume a quantity of air when  operating equivalent 
to that sourced by a 3/4 hp compressor running  continuously.  Neat and 
compact, but NOT at all efficient!  ENCO has  (had?) some nice ones with 1/8" collet 
for very reasonable price.  Chinese,  but decent quality.


[Non-text portions of this message have been removed]

On Fri, 15 Jul 2005 01:53:05 +0200, Bill Maxwell <wrmaxwell@...>  
wrote:

> or an old dental pneumatic drill?  I have several of those handpieces,
> somewhere.
> Bill


not sure if the chuck is useable.
You want to try?

ST

In a message dated 7/14/2005 6:54:07 P.M. Central Daylight Time,  
wrmaxwell@... writes:

or an  old dental pneumatic drill? 


Cumbersome to mount; have strange (1/16"???) shank size.   300,000 RPM 
(yes!), but hardly ANY torque at all.  Bit rotation would stall  "deep in work" and  
break  bits "coming UP".  


[Non-text portions of this message have been removed]

On Fri, 15 Jul 2005 07:00:48 +0200, <JanRwl@...> wrote:

>
> VERY!  But worse, they consume a quantity of air when  operating  
> equivalent
> to that sourced by a 3/4 hp compressor running  continuously.  Neat and
> compact, but NOT at all efficient!  ENCO has  (had?) some nice ones with  
> 1/8" collet
> for very reasonable price.  Chinese,  but decent quality.


Ok, thanks everyone, i see there are a few drawbacks.
Depends how cheap i can get one if i'll still try or not (But probably  
not).

Physical size is not really an issue with PCB drilling, and electric  
powered would definitely be nicer.

ST

On 14 Jul 2005, at 20:23, Philip Pemberton wrote:

> I'm after a new PCB drill

The Exxon stuff looks good.

-- 

Cheers

Derryck

On 14 Jul 2005, at 20:23, Philip Pemberton wrote:


> I'm after a new PCB drill
>

The Exxon stuff looks good.

(Of course I meant Proxxon!!)

-- 

Cheers

Derryck

On Fri, 15 Jul 2005 09:26:47 +0200, Derryck Croker <derryck@...>  
wrote:

> (Of course I meant Proxxon!!)


There's identical copies of proxxon by another brand, but i don't remember  
the name.
Black plastic instead of green, but same mould.

ST

Great if you're drilling for oil in 1000 feet of water in the Gulf of Mexico :-O)

> > I'm after a new PCB drill
> 
> The Exxon stuff looks good.
> 
 
> Be sure to visit the group home and check for new Links, 
> Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> 
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
>

It's probably not useable, at least by conventional drill bits. It would 
probably be limited to the smallest dental burrs or whatever they are 
called.  My handpieces are packed away or may still be at my Canberra house, 
so it may take some time to find them.  As somebody else pointed out, 
mounting the handpiece will be problematic - and I hadn't even thought of 
possible problems with the bearings.

Bill
----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, July 15, 2005 3:01 PM
Subject: Re: [Homebrew_PCBs] PCB drill recommendations


> On Fri, 15 Jul 2005 01:53:05 +0200, Bill Maxwell <wrmaxwell@...>
> wrote:
>
>> or an old dental pneumatic drill?  I have several of those handpieces,
>> somewhere.
>> Bill
>
>
> not sure if the chuck is useable.
> You want to try?
>
> ST
>
>
> Be sure to visit the group home and check for new Links, Files, and 
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>
>
>
>

Interesting ideas over here:
http://www.crankorgan.com/index.html

I'm not interested in the plans.  It's the descriptions and pictures that I
find valuable; lots to jog the imagination.

Robert
:)
 



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