Author Topic: Making a home brew printed circuit board  (Read 4676 times)

Offline Chuck in E. TN

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Making a home brew printed circuit board
« on: December 01, 2012, 12:22:13 PM »
 I have finally succeeded in making a pcb for my Rotary Table indexer project. Next step is drilling the through holes for the components. The component leads range from .020 to .042 Can I use HHS drill bits or should I get carbide?
I have a HF bench model drill press and an X2 mill. Which would be better? What speeds  for the dill bits? Any other suggestions/cautions?

Chuck

 
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Offline Country Bubba

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Re: Making a home brew printed circuit board
« Reply #1 on: December 01, 2012, 12:49:10 PM »
Chuck,
IF your using FR4 board, your best bet is to use carbide as the fiberglass will eat up HSS bits.
As for speed, go with the fastest one. A .020" bit would like in excess of 30,000 rpm (max my spindle will do!) and .042 a tad over 18,000. :smart:

Of course slower rpm means slower drilling.  Good luck cause it can be done. As for bits, I use some off fleabay.

Good luck :beer:

Art
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Offline John Rudd

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Re: Making a home brew printed circuit board
« Reply #2 on: December 01, 2012, 12:57:39 PM »
Chuck,

As he has said, go for the fastest speed you can for the smaller bits....

Carbide is best for FR4 although for small production runs HSS will do for what you are needing...and keeps the expense down by not having to source carbide...That said the number of boards I've made over the years ( and its quite a few I must say) I've not needed carbide...

BTW, if you need carbide bits for reamign small holes or slots, check out your local dentist....for spent bits.. :lol:
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Offline Chuck in E. TN

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Re: Making a home brew printed circuit board
« Reply #3 on: December 01, 2012, 02:44:44 PM »
Thanks for the input folks. Never thought of the dentist ! Good tip.
 
Chuck
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MicroMark 7x14, HF X2 mill, Green 4x6 saw. Harbor Freight 170A mig

Offline andyf

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Re: Making a home brew printed circuit board
« Reply #4 on: December 01, 2012, 02:48:20 PM »
Both the drill press and mill/drill may be a bit lacking in sensitivity for such tiny drill bits, Chuck. 0.042" isn't too bad, but a light touch would be needed for 0.020". And if the drill press is an inexpensive model, the quill may rattle about in the housing, increasing the likelihood of bending the bit and breaking it. I had (they are all broken now) some 0.75mm (30 thou) bits with 3mm shanks, which meant that they were easy to grip in a largish chuck which wouldn't have gone down far enough to grip 0.030" shanks.

I used to make my own PCBs for various electronic projects, and only ever used (and broke!) HSS. If you are only concerned with a one-off, an HSS bit with two or three spares to cope with breakages would probably see you through all the holes you need in glass fibre reinforced board.

Andy
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I've cut the end off it twice, but it's still too short

Offline Chuck in E. TN

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Re: Making a home brew printed circuit board
« Reply #5 on: December 01, 2012, 03:33:51 PM »
Thanks, Andy. I think I will go with HHS. I have a Jacobs  1/4 " chuck on a straight shank for small bits, and think I will standardize the holes at .043" or there abouts. I have a few spare drill bits in a small glass vial that were my Dad's. I'll have to measure them as I don't remember the size. I only need 1 board at the moment, maybe 2.
I think the board material in question may be phenolic, it looks brownish. We'll see after etching!.
Chuck
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Famous TN last words: "Hey ya'll, watch this..."
MicroMark 7x14, HF X2 mill, Green 4x6 saw. Harbor Freight 170A mig

Offline John Rudd

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Re: Making a home brew printed circuit board
« Reply #6 on: December 01, 2012, 04:01:54 PM »
I use a Hobbycraft drill press with a typical 'Dremel' (Hobbycraft MB1)  :dremel:  type tool for drilling...With good results without breaking drill bits....... :clap:

SRBP (Synthetice Resin Bonded Paper) is forgiving for HSS compared with FG........ :coffee:

Good luck with your board....  :thumbup:
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Offline andyf

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Re: Making a home brew printed circuit board
« Reply #7 on: December 01, 2012, 09:58:40 PM »
If it's brownish under the copper, it's probably phenolic, Chuck. The fibre glass stuff is usually grey.

If you didn't etch a little dot in the copper where each hole is to go to help get the drill started in the right place, you will soon wish you had.

I recall drilling about 100 holes in a home-etched board for a 144 to 50Mhz transverter by hand with a pin vice during a particularly long AGM at the local cricket club. It was more discreet than doing a crossword during the meeting.

Andy

Sale, Cheshire
I've cut the end off it twice, but it's still too short

Offline John Stevenson

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Re: Making a home brew printed circuit board
« Reply #8 on: December 02, 2012, 06:07:58 AM »
Chuck, what mods have you made to the Ardunio I'm really interested.
John Stevenson

Offline Chuck in E. TN

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Re: Making a home brew printed circuit board
« Reply #9 on: December 02, 2012, 07:02:25 AM »
John, I'm following Kwackers build  on cnczone which is based on the 18F452 PIC, not arduino.
It's just taken me a long time to get a good toner transfer to the copper for etching. A fellow named Lucas re-drew Kwackers origional board layout to make the traces wider and easier for dummies like me to make. As I'm now retired and don't have access to multiple brands of laser printers, I took the improved artwork to Office Depot and had them print it for me. First attempt at a clothes torn transfer worked great. I have 6 more coppies left if I decide to make a few more.
Chuck
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Offline Chuck in E. TN

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Re: Making a home brew printed circuit board
« Reply #10 on: January 10, 2013, 03:55:28 PM »
I've finally got a working programmer, I hope. Now I find I need to make an adapter board to mount the PIC on and connect the adapter to the programmer. I went the same rout as with the controller board. I had Office Depot print some coppies of the art on a laser printer. Then I used the hot clothes iron transfer method. Problem is, the artwork has such thin conductor pathes, my transfer is not working too well.
My question, can I touch up the pathes that need repair with a sharpie? Will that work? Or do I need to get the art redrawn with bigger traces?
Thanks again to all that have assisted me in this project.
Chuck
Chuck in E. TN
Famous TN last words: "Hey ya'll, watch this..."
MicroMark 7x14, HF X2 mill, Green 4x6 saw. Harbor Freight 170A mig

Offline dakengineermeister

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Re: Making a home brew printed circuit board
« Reply #11 on: January 10, 2013, 11:19:11 PM »
Better to use a PCB etch resist pen.   (search on etch resist pen,  lots of places cary 'em.)   The ink that these pens put out carries a liquid latex rubber that can dry very fine.  They make 1/16-in tips which are quite fat and tend to blot out and 1/64-in tips with a steel  reinforcing barrel around the tip that hold shape quite well.   ~25yrs ago I used these a whole lot.   I even went so far as to build a small 3-axis  stepper motor controlled plotter to use these pens to draw directly onto the copper without using photo resist.

To answer your question, yes, you can use a sharpie but it does react with the etch resist a bit and you'll get weak etch resist where you touch it up.  This can lead to traces that are partially etched though but still conduct for extremely low currents (higer impedance).  It'll work in a pinch for  slow digital stuff.
-Kenneth

Offline ibuildstuff4u

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Re: Making a home brew printed circuit board
« Reply #12 on: January 14, 2013, 06:38:40 AM »
I made this board up for an amp project last month.  I take my paper to Kinkos and have them print it for me.  I have them crank up the toner for me which seems to help provide more toner to transfer to the circuit board.  I also bought a non contact temp gun so I can test my iron which helped me find a good setting to use.

As for the drilling, right now I'm using a Dremal tool with a 90* head on it.  The bits I'm using are really tiny diamond balls which seem to be working good, but I plan to buy better bits in the future.

I don't buy the special etching acid any more and simply brew my own.  It works better and is cheaper.  I buy Muriatic acid from the local hardware store for $5.00 a half gallon.  Then I add hydrogen peroxide to the mix and it's ready to go.  If the etching slows down add more hydrogen peroxide and it will pick back up again.

Good luck!
Dale P.


Offline John Rudd

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Re: Making a home brew printed circuit board
« Reply #13 on: January 14, 2013, 08:30:54 AM »
Dale,

Nice job on the boards...

What are the o/p devices? transistors or mosfets?

Care to share the schematic?

John
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Offline ibuildstuff4u

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Re: Making a home brew printed circuit board
« Reply #14 on: January 14, 2013, 07:41:47 PM »
The amp is not my design, I found the plans on this web site. 

https://sites.google.com/site/quasisdiyaudiosite/nmos-series/nmos200-1

I'm building the TO247 version

The next amp I want to build is the Destroyer DX Blame MK III.  I got some really nice 5 oz copper boards to use for this build.  It takes hours to etch the 5 oz copper!  The only trouble is I don't really need a 300 watt amp, I just want to build it!

Do you have any pictures of your rotary table?  I would be interested in seeing it as well as the circuit.  I have some spare steppers and drives and would love to hook one up to my rotary table.

Dale P.

Offline Brass_Machine

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Re: Making a home brew printed circuit board
« Reply #15 on: January 14, 2013, 10:47:42 PM »
Dale,

I for one would like to see some more of your amp builds.

Eric
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Offline ibuildstuff4u

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Re: Making a home brew printed circuit board
« Reply #16 on: January 15, 2013, 12:22:29 AM »
This one is the first.  My brother is into building them and got me hooked.

Dale P.

Offline John Rudd

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Re: Making a home brew printed circuit board
« Reply #17 on: January 15, 2013, 06:09:49 AM »

Do you have any pictures of your rotary table?  I would be interested in seeing it as well as the circuit.  I have some spare steppers and drives and would love to hook one up to my rotary table.

Dale P.
Dale not sure if you request was directed at me.... :scratch: I havent done anything with an RT  :)  I think you need a reply from Chuck...

But...Thanks for the link...
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