Homebrew PCBs

What equipment is best for the amateur when drilling small holes for
IC's, etc.?

I have a large drill press but it is difficult to center the 0.8mm bits.

Don

On Tue, 17 Jan 2006 02:57:18 +0100, glasspusher2001  
<glasspusher2001@...> wrote:

> What equipment is best for the amateur when drilling small holes for
>
> IC's, etc.?
>
>
> I have a large drill press but it is difficult to center the 0.8mm bits.
>
>
> Don
>


Some small drill presses for mini drills work OK, but you can build your  
own "pivoting drill press" far cheaper.

You should use a drill stand that has smooth, straight movement, and  
little play. In it you want a spindle/grinder/mini drill with high RPM (at  
least 10000), little play in the bearings and little runout. The best seem  
to have precision ground collets, the cheaper ones with aluminum or brass  
collets that "can be put in there" but don't really _fit_ might not work  
well.
Having that, you will not have any trouble with drilling.


ST

Hi,

how do I buuild a pivoting drill press?
I have a dremel, where can I get small bits for it?

Don

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

From: "glasspusher2001" <glasspusher2001@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, January 17, 2006 4:36 PM
Subject: [Homebrew_PCBs] Re: which drill press?


> Hi,
> 
> how do I buuild a pivoting drill press?
> I have a dremel, where can I get small bits for it?

I use reground tungsten carbide bits from Rapid Electronics (UK).

Leon

Hi Don,

I bought a $30 drill press stand for Dremel type tools from Jameco 
Electronics (jameco.com).  It has a bit of runout, but it's fine with 
a little pilot hole.

I buy carbide bits on eBay.  Usually 50 for $25 (including shipping).  
I bought 3 of the assortments from Harbor Freight and the assortment 
left me wanting (too many small sizes) and half of the bits were for 
routing.  Unlike Harbor Freight, bit sizes are listed on eBay, so you 
know exactly what you're buying.

Regards,
Dennis
--- In Homebrew_PCBs@yahoogroups.com, "glasspusher2001" 
<glasspusher2001@y...> wrote:

>
> Hi,
> 
> how do I buuild a pivoting drill press?
> I have a dremel, where can I get small bits for it?
> 
> Don
>

On Tue, 17 Jan 2006 17:36:06 +0100, glasspusher2001  
<glasspusher2001@...> wrote:

> Hi,
>
>
> how do I buuild a pivoting drill press?
>
> I have a dremel, where can I get small bits for it?
>
>
> Don


I fear you will have to brave the insane yahoo search for previous  
discussions on this.
You can see pictures of mine here:
<http://trethan.at.tf/pub/img1>

But note that all the stuff shown there is old and changed to some degree  
now.

ST

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> On Tue, 17 Jan 2006 17:36:06 +0100, glasspusher2001  
> <glasspusher2001@y...> wrote:
> 
> > Hi,
> >
> >
> > how do I buuild a pivoting drill press?
> >
> > I have a dremel, where can I get small bits for it?
> >
> >
> > Don
> 
> 
> I fear you will have to brave the insane yahoo search for previous  
> discussions on this.
> You can see pictures of mine here:
> <http://trethan.at.tf/pub/img1>
> 
> But note that all the stuff shown there is old and changed to some
degree  
> now.
> 
> ST
Thanks for the additional photos, Stefan.   They're most helpful, as
the time has come for me to build a rotating drill press.    I see
you're using an inverted wood screw as a downward limit to motion.  I
notice also that you have designed a simple fixture consisting of a
horizontal 3/4 inch (20mm)hole to hold the tool's fitting collar and
two horizontal woodscrews covered in rubber between which you wedge
the tool's opposing handgrips.

That's much simpler than the tool-holding fixture I first had in mind.
Very nice design.  

Let me just ask you a couple of questions about your drill press:

(1)  When you position the rotary tool's bit above the workpiece and
then let go of it, does the weight of the tool cause it to drop the
bit downwards, or does the spring cause the bit to move upwards, or is
it neutrally balanced?    Does it matter?

(2)  If you were to remake a drill press, is there anything that you
would do or make different?

Alan

--- In Homebrew_PCBs@yahoogroups.com, "glasspusher2001"
<glasspusher2001@y...> wrote:
>
> Hi,
> 
> how do I buuild a pivoting drill press?
> I have a dremel, where can I get small bits for it?
> 
> Don

Don, 

I ordered  a 50-piece carbide bit set for $19.95 from
Micro_Mark distributor in NJ. http://www.micromark.com/
plus shipping, just under $30 in less than a week.--item no. 82151,
sizes #80 through #12.

I see they also have a set of ten for $13.80--item no. 60310, sizes
#39 to #73.

I haven't used the bits yet.   I am going to buld a pivoting drill
press like Stefan's first, so I don't break the bits easily.

After I ordered the bits, of course, I found carbide bits at a local
surplus tool distributor for a dollar each.   Their selection wasn't
nearly as good as the 50 piece set, though.

Alan

As i said those are old pictures.

The stop screw is now right at the drill clamp, so that it comes down on  
the PCB. This holds the PCB down and it prevents the frame from beeing  
tilted when reaching the stop and breaking the drill.

There is a counterweight clamped to the back of the frame, it is balanced  
so that it just thinks down, but around neutral seems good so you have a  
good feeling for the force.

Also, the bearing is not in the same hight as the drill tip, this prevents  
it going in a perfect tangent. I now put a wood block under the PCB and  
have angled the drill holder forward to make it straight again (this angle  
is adjustable with a screw). The two red plastic rods are no longer used  
to hold the drill, the front clamp is sufficient.

Added light and vacuum.


If i had to do it again, i would use two plates, the upper one triangular,  
with a piano hinge at the back.

ST

On Tue, 17 Jan 2006 20:21:24 +0100, alan00463 <alan00463@...> wrote:

> Thanks for the additional photos, Stefan.   They're most helpful, as
>
> the time has come for me to build a rotating drill press.    I see
>
> you're using an inverted wood screw as a downward limit to motion.  I
>
> notice also that you have designed a simple fixture consisting of a
>
> horizontal 3/4 inch (20mm)hole to hold the tool's fitting collar and
>
> two horizontal woodscrews covered in rubber between which you wedge
>
> the tool's opposing handgrips.
>
>
> That's much simpler than the tool-holding fixture I first had in mind.
>
> Very nice design.
>
>
> Let me just ask you a couple of questions about your drill press:
>
>
> (1)  When you position the rotary tool's bit above the workpiece and
>
> then let go of it, does the weight of the tool cause it to drop the
>
> bit downwards, or does the spring cause the bit to move upwards, or is
>
> it neutrally balanced?    Does it matter?
>
>
> (2)  If you were to remake a drill press, is there anything that you
>
> would do or make different?
>
>
> Alan

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
<snip>
> 
> I fear you will have to brave the insane yahoo search for 
previous  
> discussions on this.
> You can see pictures of mine here:
> <http://trethan.at.tf/pub/img1>
> 
> But note that all the stuff shown there is old and changed to some 
degree  
> now.
> 
> ST
>

Thanks for posting that link. Nice job on the photos. The pictures 
of your etching tank show it very well. How is it assembled? It 
appears to be put together with RTV or something similar. Is it? Do 
you use CuCl etchant?


Regards, Bob

On Tue, 17 Jan 2006 22:19:28 +0100, Bob_xyz <bob_barr@...> wrote:

> Thanks for posting that link. Nice job on the photos. The pictures
>
> of your etching tank show it very well. How is it assembled? It
>
> appears to be put together with RTV or something similar. Is it? Do
>
> you use CuCl etchant?
>
>
>
> Regards, Bob
>


it is no longer used, i made a better tank soon after taking the photos.  
Maybe one day i make photos of that one.

It is glued with RTV, works great for glass and holds up in CuCl without  
problems. I used huge double seams for that first tank, much less is  
sufficient.

I use CuCl, yes.

ST

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> As i said those are old pictures.
> 
> The stop screw is now right at the drill clamp, so that it comes
down on  
> the PCB. This holds the PCB down and it prevents the frame from beeing  
> tilted when reaching the stop and breaking the drill.
> 
> There is a counterweight clamped to the back of the frame, it is
balanced  
> so that it just thinks down, but around neutral seems good so you
have a  
> good feeling for the force.
> 
> Also, the bearing is not in the same hight as the drill tip, this
prevents  
> it going in a perfect tangent. I now put a wood block under the PCB
and  
> have angled the drill holder forward to make it straight again (this
angle  
> is adjustable with a screw). The two red plastic rods are no longer
used  
> to hold the drill, the front clamp is sufficient.
> 
> Added light and vacuum.
> 
> 
> If i had to do it again, i would use two plates, the upper one
triangular,  
> with a piano hinge at the back.
> 
> ST

Thanks, Stefan, for your comments.    I got my Proxxon drill and am
getting ready to build the drill press.

I am seriously considering the two-plate design, using two pieces of
half-inch thick (12.5mm) wood or plywood with a wood spacer and a
piano-hinge.    I would probably make it about 25 cm (10in) wide.  
Not sure how long of a lever arm to use--what do you think?    I
suppose that I will just let the drill bit eat into the lower board
when top plate is pressed down.   I suppose that I will place springs
between the two plates to hold the drill bit slightly elevated above
the workpiece when the operator lets go.   Then when the operator
applies downward pressure, the drill bit will be exactly vertical when
the drill bit contacts the upper surface of the workpiece.

I think this design would be even better than the one you built,
Stefan.  It would be lighter and occupy less space.    I might have to
attach an L-shaped pieces of wood to the upper wood plate to make sure
the drill bit is always held perpendicular to the upper wood plate.  
 I guess the longer the lever arm the better, so long as it isn't too
hard to store when not in use.    

Alan

The reason i made such a relatively complicated and large drill is because  
it is prepared for a optical projection mechanism that was never fitted.  
That said, the space under the table is dead useful for storing boxes of  
drills and stuff, and the crosspiece on top of the machine is also heavily  
used to put stuff on, so there isn't actually any wasted space.

Make sure the hinge point is at the same height as the PCB. This means  
right at the bottom plate if you don't want to use any block under the  
PCB. I found it comfortable to use a block to raise the PCB about 5cm, it  
makes it easier for me to position the PCB since i can grab the sides. If  
you raise the PCB with a block, you must also put the hinge up at the same  
height for tangential action.

Consider putting a compartment under your drill, depending on where you  
place it and what seating you have there it might be good to get it up off  
the table so the action comes closer to your eyes. Wear a face shield for  
safety.

Make a hole in the top plate behind the drill to put a suction nozzle  
through for your vacuum, and add spot illumination.

I would guesstimate the minimum arm length needed is 30cm, maybe 35.

Use plywood at least for the upper plate since you need to make a drill  
holder. MDF is crap wood and only good if you only need to screw through  
it and don't need any good edges.

ST

I'm not sure about springs, how they compare to a counterweight.

On Tue, 17 Jan 2006 22:49:42 +0100, alan00463 <alan00463@...> wrote:

> Thanks, Stefan, for your comments.    I got my Proxxon drill and am
>
> getting ready to build the drill press.
>
>
> I am seriously considering the two-plate design, using two pieces of
>
> half-inch thick (12.5mm) wood or plywood with a wood spacer and a
>
> piano-hinge.    I would probably make it about 25 cm (10in) wide.
>
> Not sure how long of a lever arm to use--what do you think?    I
>
> suppose that I will just let the drill bit eat into the lower board
>
> when top plate is pressed down.   I suppose that I will place springs
>
> between the two plates to hold the drill bit slightly elevated above
>
> the workpiece when the operator lets go.   Then when the operator
>
> applies downward pressure, the drill bit will be exactly vertical when
>
> the drill bit contacts the upper surface of the workpiece.
>
>
> I think this design would be even better than the one you built,
>
> Stefan.  It would be lighter and occupy less space.    I might have to
>
> attach an L-shaped pieces of wood to the upper wood plate to make sure
>
> the drill bit is always held perpendicular to the upper wood plate.
>
>  I guess the longer the lever arm the better, so long as it isn't too
>
> hard to store when not in use.
>
>
> Alan
>

alan00463 wrote:

>--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
><stefan_trethan@g...> wrote:
>  
>
>>As i said those are old pictures.
>>
>>The stop screw is now right at the drill clamp, so that it comes
>>    
>>
>down on  
>  
>
>>the PCB. This holds the PCB down and it prevents the frame from beeing  
>>tilted when reaching the stop and breaking the drill.
>>
>>There is a counterweight clamped to the back of the frame, it is
>>    
>>
>balanced  
>  
>
>>so that it just thinks down, but around neutral seems good so you
>>    
>>
>have a  
>  
>
>>good feeling for the force.
>>
>>Also, the bearing is not in the same hight as the drill tip, this
>>    
>>
>prevents  
>  
>
>>it going in a perfect tangent. I now put a wood block under the PCB
>>    
>>
>and  
>  
>
>>have angled the drill holder forward to make it straight again (this
>>    
>>
>angle  
>  
>
>>is adjustable with a screw). The two red plastic rods are no longer
>>    
>>
>used  
>  
>
>>to hold the drill, the front clamp is sufficient.
>>
>>Added light and vacuum.
>>
>>
>>If i had to do it again, i would use two plates, the upper one
>>    
>>
>triangular,  
>  
>
>>with a piano hinge at the back.
>>
>>ST
>>    
>>
>
>Thanks, Stefan, for your comments.    I got my Proxxon drill and am
>getting ready to build the drill press.
>
>I am seriously considering the two-plate design, using two pieces of
>half-inch thick (12.5mm) wood or plywood with a wood spacer and a
>piano-hinge.    I would probably make it about 25 cm (10in) wide.  
>Not sure how long of a lever arm to use--what do you think?    I
>suppose that I will just let the drill bit eat into the lower board
>when top plate is pressed down.   I suppose that I will place springs
>between the two plates to hold the drill bit slightly elevated above
>the workpiece when the operator lets go.   Then when the operator
>applies downward pressure, the drill bit will be exactly vertical when
>the drill bit contacts the upper surface of the workpiece.
>
>I think this design would be even better than the one you built,
>Stefan.  It would be lighter and occupy less space.    I might have to
>attach an L-shaped pieces of wood to the upper wood plate to make sure
>the drill bit is always held perpendicular to the upper wood plate.  
> I guess the longer the lever arm the better, so long as it isn't too
>hard to store when not in use.    
>
>Alan
>
>  
>

  Put a hole somewhere, and make it where you can easily hang it up on a 
wall etc.  Sized to fit inside a closet or back side of a closet door 
might be good too.  Other holes to lighten the wood are probably a good 
idea too, need stiff but doesn't have to be 100% solid, 50% would 
probably be just as sturdy..

  3/8" project planks from Lowe's etc make a good backer board, if 
you're making a spacer anyway might take a look at it.  If you screw in 
a piano hinge you might not want to have to mess with it again changing 
the bottom board.  Angle brackets should work out as cheap and easier 
for the L's than using all wood for a right angle.

  1x deflection one way, vertical in the center of the board, and 1x 
deflection the other way should be slightly better as a general rule 
than vertical at top and 2x deflection a single way.  With a decent 
length arm it really shouldn't matter for this, but still good to keep 
in mind for a general rule.

Alan

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
<snip>

> 
> it is no longer used, i made a better tank soon after taking the 
photos.  
> Maybe one day i make photos of that one.
> 
> It is glued with RTV, works great for glass and holds up in CuCl 
without  
> problems. I used huge double seams for that first tank, much less 
is  
> sufficient.
> 
> I use CuCl, yes.
> 
> ST
>

Another question on your setup - It appears that the two tubes 
attached to the air pump provide a supply and a return for the air 
pumped into the etch tank. Is that the case? If so, is there any 
special type of pump required to stand up to the etchant fumes in 
the return air?


Regards, Bob

I use a Dremel drill press that has a table that can be elevated up
and down with a knob.  That is the way I control the actual drill
penetration.  I use reconditioned surplus router bits (box of about
40) from Harbor Freight, I think.  Between the elevation table and the
PCB, I place a 4x4 inch by 3/4-inch softwood block.  The bit
penetrates the block slightly while drilling through the board.  I've
not yet dulled a bit after several hundred holes.

There are much more costly solutions, of course.  I find that sliding
the block around from hole to hole with my left hand and elevating the
table knob with my right is a very fast way to drill the board.

Ted Bruce KX4OM
>

On Tue, 17 Jan 2006 23:41:26 +0100, Alan King <alan@...> wrote:

>   1x deflection one way, vertical in the center of the board, and 1x
>
> deflection the other way should be slightly better as a general rule
>
> than vertical at top and 2x deflection a single way.  With a decent
>
> length arm it really shouldn't matter for this, but still good to keep
>
> in mind for a general rule.
>
>
> Alan


Only that the drill doesn't know this. When it enters the board it won't  
think "hey, lets enter a deflection further forwart to compensate for the  
later movement, it will enter straight where it is at the start of the  
hole.

It doesn't really matter a few mm up or down, but if the hinge is for  
example too high the drill will enter, and then bend forward as it pivots  
down. If the hinge is more or less the same height that's better.


ST

On Wed, 18 Jan 2006 02:22:48 +0100, Bob_xyz <bob_barr@...> wrote:

>
> Another question on your setup - It appears that the two tubes
>
> attached to the air pump provide a supply and a return for the air
>
> pumped into the etch tank. Is that the case? If so, is there any
>
> special type of pump required to stand up to the etchant fumes in
>
> the return air?
>
>
>
> Regards, Bob


Most membrane pumps are all plastic.

The bad thing is the moisture will stick the valve washers, so i no longer  
use closed cycle.

ST

Hi,
It only seems a few days since we had a discussion on drill presses..
It is definitely worth reading back by searching for "drill press".

The pictures for the one I built in under an hour are in the photos
section in the folder "Spiyda". 

If you don't yet have a dremmel or silmilar, I reccomend you buy a
proxxon tool in preference, some parts are a much better quality.

Chris  (-=Spiyda=-)

Spiyda
--- In Homebrew_PCBs@yahoogroups.com, "glasspusher2001"
<glasspusher2001@y...> wrote:

>
> Hi,
> 
> how do I buuild a pivoting drill press?
> I have a dremel, where can I get small bits for it?
> 
> Don
>