Homebrew PCBs

In article <opsnhsgstwmg0lsf@...>,
   Stefan Trethan <stefan_trethan@...> wrote:

> Any ideas how to make bearings for the sprayer tube out of CuCl
> compatible materials? A titanium rod maybe turning in some plastic
> (non nylon)? 

How about PTFE. Not cheap I know but self lubricating and resistant to
pretty well all chemicals

Hi,

anyone using a punch like that?

<http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=44060>

I would like to try one, so before going through the trouble of finding  
one (no luck at the tools shop and no luck at ebay germany), it would be  
good to know if it will work.


thanks

ST

Hi,

we discussed that ages ago.
Has anyone built one successfully?

I think it would be cheap enough to build to solve many uniformity issues  
by using multiple sprayer tubes and motors.

They are not too expensive at ebay (around 100eur), but i asked and the  
motor mount is stainless steel, so it's a no-go for CuCl.

Any ideas how to make bearings for the sprayer tube out of CuCl compatible  
materials? A titanium rod maybe turning in some plastic (non nylon)? Would  
that seize up or would the etchant-cooling be enough?

ST

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

From: "Stefan Trethan" <stefan_trethan@...>
To: <homebrew_pcbs@yahoogroups.com>
Sent: Friday, March 11, 2005 9:04 PM
Subject: [Homebrew_PCBs] board mounting holes


>
>
> Hi,
>
> anyone using a punch like that?
>
> <http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=44060>
>
> I would like to try one, so before going through the trouble of finding
> one (no luck at the tools shop and no luck at ebay germany), it would be
> good to know if it will work.

I think that some radio amateurs use a similar punch to make small pads of 
PCB material, for 'Manhattan' style prototyping. They glue the pads to a 
piece of copper laminate ground plane and use them for circuit tie points.

Leon

At 04:04 PM 3/11/2005, you wrote:


>Hi,
>
>anyone using a punch like that?
>
><http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=44060>
>
>I would like to try one, so before going through the trouble of finding
>one (no luck at the tools shop and no luck at ebay germany), it would be
>good to know if it will work.
>
>
>thanks
>
>ST
>

  I have one of these and it's bigger brother with a bench mount (both 
roper whitney brand) . Very handy to have around. Makes nice, fast, and 
neat holes (especially in clad). A bit of a bother to change dies, so I 
tend to just use for common hole sizes.

   Don't try to muscle through too thick material, otherwise it's fine.



carl
--------------------------------------------------------
Henry Carl Ott   N2RVQ    carlott@...
http://users.rcn.com/carlott/
--------------------------------------------------------
May the bridges you burn light your way.

On Fri, 11 Mar 2005 21:38:42 +0100, lists  
<stuart.winsor.lists@...> wrote:

>
> How about PTFE. Not cheap I know but self lubricating and resistant to
> pretty well all chemicals
>


good idea.
But can't be glued, right? would not be easy to affix a bearing block to  
the rest of the tank...
But not impossible i guess...

Maybe a titanium stud can be mounted to the bottom of the tank, and a  
teflon disk fitted in the totating tube, with the 3 holes as described to  
let etchant in and a smaller hole in the middle to accept the titanium  
stud.

As dimensions are no issue titanium round stock and teflon should be cheap  
enough at ebay.

Going that way would need several lengths of electrical tubing until one  
has worked out the right nozzle size and pattern. I would kind of like to  
be sure it works with CuCl and toner transfer before spending any money on  
it...

ST

On Fri, 11 Mar 2005 16:42:42 -0500, Henry Carl Ott <carlott@...>  
wrote:

>
>   I have one of these and it's bigger brother with a bench mount (both
> roper whitney brand) . Very handy to have around. Makes nice, fast, and
> neat holes (especially in clad). A bit of a bother to change dies, so I
> tend to just use for common hole sizes.
>   Don't try to muscle through too thick material, otherwise it's fine.
> carl


I've once seen a bench mount version that had the dies mounted like a  
chinese fan and you just rotated the right die under the lever and away  
you go. Sadly i haven't seen such a unit for sale and it would be a) too  
expensive and b) too big, but it sure is dead useful.

So i'll try to get a hand-operated version, i reckon it is enough for PCBs.

thanks

ST

G'day Stefan

PTFE can be glued (Haven't done it myself) using Loctite cyanoacrylate glue
with a priming fluid.

The combination apparently required is-
                                                                       
Loctite 406 adhesive
                                                                       
Loctite 770 polyolefin primer

Cheers
Brian

-------Original Message-------
 
From: Homebrew_PCBs@yahoogroups.com
Date: 03/12/05 07:51:32
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] has anyone worked on the rotary spray etcher?
 
On Fri, 11 Mar 2005 21:38:42 +0100, lists
<stuart.winsor.lists@...> wrote:
 
>
> How about PTFE. Not cheap I know but self lubricating and resistant to
> pretty well all chemicals
>
 
 
good idea.
But can't be glued, right? would not be easy to affix a bearing block to
the rest of the tank...
But not impossible i guess...
 
Maybe a titanium stud can be mounted to the bottom of the tank, and a
teflon disk fitted in the totating tube, with the 3 holes as described to
let etchant in and a smaller hole in the middle to accept the titanium
stud.
 
As dimensions are no issue titanium round stock and teflon should be cheap
enough at ebay.
 
Going that way would need several lengths of electrical tubing until one
has worked out the right nozzle size and pattern. I would kind of like to
be sure it works with CuCl and toner transfer before spending any money on
it...
 
ST
 
 
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[Non-text portions of this message have been removed]

On Sat, 12 Mar 2005 08:03:05 +1000, Brian Clancy <bclancy1@...>  
wrote:

>
> G'day Stefan
> PTFE can be glued (Haven't done it myself) using Loctite cyanoacrylate  
> glue
> with a priming fluid.
> The combination apparently required is-
> Loctite 406 adhesive
> Loctite 770 polyolefin primer
> Cheers
> Brian


Ok, i'll remember that.
(But i'm not sure which is easier, finding those glues or using another  
method of fixing)

thanks

ST

I am sure that it would other than on problem on the one page it 
says Max material thickness to be 16ga. In the Manual for it say Max 
material thickness to be 18ga.  

Ben

On Sat, 12 Mar 2005 02:06:46 -0000, Ben H. Lanmon <bhleavi@...>  
wrote:

>
> I am sure that it would other than on problem on the one page it
> says Max material thickness to be 16ga. In the Manual for it say Max
> material thickness to be 18ga.
> Ben
>


that not quite 1.5mm, but i would expect it to be able to punch it, no?
Usually these tools have a rating for steel, and a higher one for soft  
metals and plastic.

ST

> Any ideas how to make bearings for the sprayer tube out of CuCl
> compatible
> materials? A titanium rod maybe turning in some plastic (non
> nylon)? Would
> that seize up or would the etchant-cooling be enough?
>
> ST
>


You can get all sorts of non-metal bearing (ball), including ceramic,
plastic & glass.

From memory, you can get bearings that have glass balls with plastic body,
and are used in food preparation things.  No lubrication to prevent
contamination, and can be washed clean with water.

Look for 'food grade' bearings.  Very low RPM, maybe 200-300 RPM.

Tony

On Sat, 12 Mar 2005 21:40:27 +1100, Tony Smith <ajsmith@...>  
wrote:

>
> You can get all sorts of non-metal bearing (ball), including ceramic,
> plastic & glass.
> From memory, you can get bearings that have glass balls with plastic  
> body,
> and are used in food preparation things.  No lubrication to prevent
> contamination, and can be washed clean with water.
> Look for 'food grade' bearings.  Very low RPM, maybe 200-300 RPM.
> Tony


Low rpm is a no-go and hard to get is a no-go too (which the  
above-mentioned is for me).
Thanks anyway.


I was doing a proof of concept the last hour from a piece of electrical  
tubing, 2 end-caps (spray-can caps), a 4mm steel shaft, a clear plastic  
bucket, a piece of wood, some water, a drill/grinder 100W.


The plastic tubing is maybe 3 to 4cm diameter, glued the endcaps on. made  
3 holes in the lower endcap to allow water in, put the steel shaft through  
the entire thing, glued the wood block in the bottom of the bucket after  
making a 5mm hole in it (not through) for bearing. made another hole in  
the lid of the bucket and attached drill/grinder to shaft.
Oh yes, made a single 1mm hole in the tubing as nozzle.

First results show that it definitely can work (as commercial products  
show).

The water rises easily, in fact i haven't got the top cap sealed all the  
way and it sqirts out there even at moderate RPM.

The single hole shows a spray "line" on the inside of the bucket.

What i want to do next is experiment with differnt nozzle holes (possibly  
with a water hose so i can watch the results in static conditions. I think  
if i use a small cutting disc in the grinder i might be able to create  
"fan" like nozzles.

I also had the idea to allow the whole assy to move up and down (via  
geared motor) to even out any effects from nozzle placement. would not be  
too hard to make but definitely better if not needed.

I further thought about making a triangular tank, with the sprayer in one  
corner and the PCB on the opposite wall. This should reduce ill-effects  
 from different distances/angles/sweep speeds compared to a rectangular  
setup of same volume.
It would be good to know all problems of the commercial units, and i will  
nag Markus off list about it some more.

I will also slowly try to find titanium rod somewhere from 6 to 10mm  and  
teflon plates/blocks.

As for the tubing, i think it might be a good idea to use thick-walled  
water tubing instead of electrical tubing?

Another thing i learnt from the experiment is that care must be taken to  
get things true and balanced.


After the results i have seen now i wonder why nobody seems to have built  
a rotary etcher so far. It shouldn't be hard at all to at least replicate  
the results of the cheap commercial units if not inproove them.

Well, i look forward to hearing about other ideas.

Anyone willing to work out formulas for the pressure at the nozzle per RPM  
(given tube diameter and assumed water "skin" thickness)?


ST