Author Topic: "Let's get down to brass tacks"  (Read 2431 times)

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Offline KonkedoutTopic starter

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"Let's get down to brass tacks"
« on: October 02, 2024, 06:28:07 pm »
I am perfectly good with designing and using etched pcbs (using mostly SMT) for projects.   For the last few years I use KiCad and before that I used ExpressPCB.

But what is a good way to kluge a temporary experiment using through hole components?  The 0.1" pitch x 0.062" diameter hole punched vector board works nicely but that seems sort of expensive.  Maybe that is still what is needed if you are using some DIP ICs.

Just to anchor things down; I wonder about using some small (3/4" length?) nails made of brass which ought to be solderable.    Just use a couple for ground and maybe a few more for other nodes which have multiple components connected:

https://www.mcmaster.com/products/nails/nails-2~/material~brass-1/

 Tack them where needed into a small flat piece of wood.  Solder a short length of AWG20 or AWG 18 wire for ground between two of them.

Just an inexpensive idea.  Anyone tried that?  Any other ideas?

I have done "wadular" construction which has virtually no mechanical support, but this seems too flimsy even for brief use.
 

Offline TimFox

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Re: "Let's get down to brass tacks"
« Reply #1 on: October 02, 2024, 06:41:55 pm »
That's the etymology for "breadboard".
I use pre-made circuit boards with DIP patterns and rails on 0.1" centers for prototyping with THT components and DIP ICs, preferably with plated-through holes.
The best ones I used were Eurocard boards from Vero, that had "colander" ground and power planes on opposite sides, with patterns for 96-pin "DIN" connectors at each end:  somewhat expensive and I'm not sure they are still available.
Adapter boards for SMT ICs to DIP hole patterns are available.
 
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Offline janoc

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Re: "Let's get down to brass tacks"
« Reply #2 on: October 02, 2024, 06:54:35 pm »
What's wrong with a piece of un-etched copperclad and Manhattan or "ugly" construction? (that's a thing, google it up). Maybe not that practical for larger DIP packages unless you use adaptors/breakouts but certainly doable for smaller ICs.

Stripboard and veroboard (not vector board - that's something else) can be had cheaply too - and you can reuse it after you are done with your experiment.

When I was a youngster I didn't have access to copperclad, so I have used nails and such in wood too. But that's an enormous hassle, it is pain to solder those, the heat will make them fall out of the wood constantly because they will enlarge the hole as they expand, etc. Don't bother with that. You would have to be seriously penny pinching if you had to resort to this today.
 
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Offline Xena E

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Re: "Let's get down to brass tacks"
« Reply #3 on: October 02, 2024, 07:11:42 pm »
Get yourself a heavy duty punch from Harbour Freight or similar, and some scrap copper laminate, (even old circuit boards!), then punch out chad's of laminate, and stick those down with CA glue to your chosen substrate, more laminate, end of a tin can, scrap plyboard, whatever, then tack your components to them.

X
 

Offline Zipdox

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Re: "Let's get down to brass tacks"
« Reply #4 on: October 02, 2024, 08:18:31 pm »
Metal thumbtacks in MDF is what I learned as a kid. Works well, even for some low frequency RF stuff.
 

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #5 on: October 02, 2024, 08:29:11 pm »
I am perfectly good with designing and using etched pcbs (using mostly SMT) for projects.   For the last few years I use KiCad and before that I used ExpressPCB.

But what is a good way to kluge a temporary experiment using through hole components?  The 0.1" pitch x 0.062" diameter hole punched vector board works nicely but that seems sort of expensive.  Maybe that is still what is needed if you are using some DIP ICs.

Just to anchor things down; I wonder about using some small (3/4" length?) nails made of brass which ought to be solderable.    Just use a couple for ground and maybe a few more for other nodes which have multiple components connected:

https://www.mcmaster.com/products/nails/nails-2~/material~brass-1/

 Tack them where needed into a small flat piece of wood.  Solder a short length of AWG20 or AWG 18 wire for ground between two of them.

Just an inexpensive idea.  Anyone tried that?  Any other ideas?

I have done "wadular" construction which has virtually no mechanical support, but this seems too flimsy even for brief use.

I hammered copper nails into wood as a kid. Once only.

There are many good and less good techniques and components mentioned at
https://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/

Choose whichever combination suits your taste and job.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline jpanhalt

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Re: "Let's get down to brass tacks"
« Reply #6 on: October 02, 2024, 09:06:21 pm »
That's the etymology for "breadboard".
I use pre-made circuit boards with DIP patterns and rails on 0.1" centers for prototyping with THT components and DIP ICs, preferably with plated-through holes.

Same here.  I use SparkFun or similar cheaper boards laid out in the typical solderless breadboard pattern.  Be sure to get them with plated through holes.  See attachment for a current project's starting board.

 

Offline TimFox

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Re: "Let's get down to brass tacks"
« Reply #7 on: October 02, 2024, 09:24:33 pm »
That's very close to what I do.
To improve the ground-plane illusion, I usually connect across from rail to rail using the transverse DIP pads and short bare wires, wherever space is available.

For "onesie" vacuum-tube circuits, I use 3/32" 2-oz single-clad glass-epoxy board, drilling tube socket holes with a 1-flute "Unibit" step drill or "sheet-metal" hole saw (better than the deeper hole saws used by electricians, etc. to drill holes for pipes and conduits through wood.)
Old-style PTFE and DAP stand-off and feed-through insulators allow simple mounting, especially for axial components.
Ground connections can be soldered directly to the board.
Modern axial aluminum electrolytics:  I drill two holes at the appropriate spacing.  One wire has small shrink-tube insulation to go through a hole to a stand-off, while the other wire goes directly through the other hole to ground.
« Last Edit: October 02, 2024, 09:29:46 pm by TimFox »
 

Offline jpanhalt

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Re: "Let's get down to brass tacks"
« Reply #8 on: October 02, 2024, 09:46:40 pm »
For hookup, I use 24 AWG Kynar insulated wire.  It doesn't char or melt back like PVC does.  You can solder under it or right next to it, if careful, without damage.  Prices vary quite a bit.  My current supply came from Mouser.
 

Offline IanB

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Re: "Let's get down to brass tacks"
« Reply #9 on: October 02, 2024, 09:51:42 pm »
Tack them where needed into a small flat piece of wood.  Solder a short length of AWG20 or AWG 18 wire for ground between two of them.

Just an inexpensive idea.  Anyone tried that?  Any other ideas?

I tried it once, as a child, to prototype a phase angle dimmer circuit with a TRIAC. My circuit did not work. I scratched my head, and decided that perhaps there were leakage currents through the wood at mains voltages.

So I etched a PCB and remade the circuit on that. It then worked fine.

So that was the one and only time I tried using the nails in wood approach.
 

Online langwadt

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Online Doctorandus_P

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Re: "Let's get down to brass tacks"
« Reply #11 on: October 02, 2024, 10:14:00 pm »

For really temporary stuff I use breadboard, but I also used to use vero board quite a lot. I have projects on vero board, and soldered with enameled wire that have been running reliably for over 20 years. The biggest problem with vero board is not long time reliability, but EMI. You don't have a GND plane and such, and I have had quite a bit of microcontroller projects spontaneously being reset when I turn halogen or fluorescent ligts on or off. In those days I learned to use inductors and other filter parts in the power supply of all my projects, and being careful with how to handle projects with long cables.
 

Offline TimFox

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Re: "Let's get down to brass tacks"
« Reply #12 on: October 02, 2024, 10:18:17 pm »
Here are two examples of simple circuits using Nuvistor vacuum tubes, on single-sided FR4.
« Last Edit: October 02, 2024, 10:44:45 pm by TimFox »
 

Offline Bud

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Re: "Let's get down to brass tacks"
« Reply #13 on: October 02, 2024, 11:23:24 pm »
My very first serious project was a Morse key built on a piece of cardboard, it used 74 series ICs. It was not even carboard, it was 0.5mm or something thick paper. A friend of mine BEGGED me to gift it to him, which I did, but sometimes I regret, it would be a nice memorabilia item now several decades later.
Facebook-free life and Rigol-free shack.
 

Online langwadt

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Re: "Let's get down to brass tacks"
« Reply #14 on: October 02, 2024, 11:38:51 pm »

For really temporary stuff I use breadboard, but I also used to use vero board quite a lot. I have projects on vero board, and soldered with enameled wire that have been running reliably for over 20 years. The biggest problem with vero board is not long time reliability, but EMI. You don't have a GND plane and such, and I have had quite a bit of microcontroller projects spontaneously being reset when I turn halogen or fluorescent ligts on or off. In those days I learned to use inductors and other filter parts in the power supply of all my projects, and being careful with how to handle projects with long cables.

deadbug on a pcb and you have your ground plane
 

Offline IanB

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Re: "Let's get down to brass tacks"
« Reply #15 on: October 03, 2024, 12:06:54 am »
My very first serious project was a Morse key built on a piece of cardboard, it used 74 series ICs. It was not even carboard, it was 0.5mm or something thick paper. A friend of mine BEGGED me to gift it to him, which I did, but sometimes I regret, it would be a nice memorabilia item now several decades later.

A slight challenge, I suppose, is that ICs tend to have their pinouts shown in the datasheet in a top-down orientation. If you turn them upside down, dead-bug style, then the pinouts are mirrored and you have to work very carefully to get the right pin numbers in the right place and not make a mistake. Especially since the "dot" on pin 1 is hidden. Unless, perhaps, you print out the datasheets inverted, so that the pin numbers match up again?
 

Offline thermistor-guy

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Re: "Let's get down to brass tacks"
« Reply #16 on: October 03, 2024, 01:57:44 am »
...
But what is a good way to kluge a temporary experiment using through hole components?  The 0.1" pitch x 0.062" diameter hole punched vector board works nicely but that seems sort of expensive.  Maybe that is still what is needed if you are using some DIP ICs.
...
Just an inexpensive idea.  Anyone tried that?  Any other ideas?
...

I sometimes build small circuits on connectors; typically for test jig applications where, if it works, I end up using it for way longer
than "temporary".

Mount the connector(s) on thin steel sheet (coffee can lid), after punching suitable holes and slots to suit. Solder components to the connector leads.
Add wiring.

Typically I use my old stock of DIN41612 and D-subminiature connectors for this.
 

Offline brucehoult

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Re: "Let's get down to brass tacks"
« Reply #17 on: October 03, 2024, 02:29:13 am »
Just to anchor things down; I wonder about using some small (3/4" length?) nails made of brass which ought to be solderable.    Just use a couple for ground and maybe a few more for other nodes which have multiple components connected:

https://www.mcmaster.com/products/nails/nails-2~/material~brass-1/

 Tack them where needed into a small flat piece of wood.  Solder a short length of AWG20 or AWG 18 wire for ground between two of them.

Just an inexpensive idea.  Anyone tried that?
s virtually no mechanical support, but this seems too flimsy even for brief use.

Yeah, you could use a piece of wood sold for the purpose of cutting bread on. Perhaps an old one, not mum's good one.

When I was at the end of primary school ("intermediate" or I think "middle school" in different places) there was a production of a play. Those who didn't have parts were set to making scenery and props. I got the task of creating sequenced coloured lights arranged around the equatorial circumference of a flying saucer. I cut a length of old broom handle, arranged some thumbtacks staggered along the length, wired together. And some springy metal fingers (one per light bulb) from a block of wood, contacting the thumb tacks. Mounted the broom handle so it could rotate. Used an old alarm clock as a gear reduction system from a small 6V electric motor. Used old ballpoint pen ink tubes pressed on to shafts to connect them. And a borrowed Hornby train power supply and rheostat speed control (including reversing).

A complete bodge but it worked for a couple of performances.

In retrospect, a hand crank would have worked as well as the whole motor / controller / reduction gears setup.
 

Offline Smokey

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Re: "Let's get down to brass tacks"
« Reply #18 on: October 03, 2024, 02:35:19 am »
Every time I hack something together I wish I had just waited the week for $10 boards to get here from JLCPCB and skipped right to the end
 

Online themadhippy

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Re: "Let's get down to brass tacks"
« Reply #19 on: October 03, 2024, 03:17:43 am »
Quote
Every time I hack something together I wish I had just waited the week for $10 boards to get here from JLCPCB and
wait another week for the next pcb to cure the cock ups id made on the first attempt

For through hole stuff my goto is either good ole "veroboard" , dont waste your money buying piddle little bits,the large sheets work out much cheaper and will keep you going for ages,or if its a few dip packages  this stuff https://uk.farnell.com/multicomp/mc01010/prototype-board-phenolic-95mm/dp/2768280?pf_custSiteRedirect=true  luckily i managed to buy a load at about a fifth of the price farnells are asking
 
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Offline Smokey

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Re: "Let's get down to brass tacks"
« Reply #20 on: October 03, 2024, 05:42:01 am »
Quote
Every time I hack something together I wish I had just waited the week for $10 boards to get here from JLCPCB and
wait another week for the next pcb to cure the cock ups id made on the first attempt
...

...worst case then would be that your actual PCB would have some bodge wires or maybe an extra part or two air-wired on somewhere.  It's still going to be cleaner and more manageable than pure protoboard bits and tons of wires trying to short against everything. 
 

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #21 on: October 03, 2024, 09:32:35 am »
Every time I hack something together I wish I had just waited the week for $10 boards to get here from JLCPCB and skipped right to the end

Depends on what it is. Many digital signal connections, probably.

But often a good prototype construction is more than sufficient: in some cases people strive to implement their benefits in commercial products.

For examples of a range of good reliable predictable prototye construction techniques, including one recently shipped commercially, see https://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/ 

N.B. that starts with historic commercial production techniques which look like some prototype techniques; skip past those :)
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline Smokey

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Re: "Let's get down to brass tacks"
« Reply #22 on: October 03, 2024, 09:48:13 am »
Every time I hack something together I wish I had just waited the week for $10 boards to get here from JLCPCB and skipped right to the end

Depends on what it is. Many digital signal connections, probably.

But often a good prototype construction is more than sufficient: in some cases people strive to implement their benefits in commercial products.

For examples of a range of good reliable predictable prototye construction techniques, including one recently shipped commercially, see https://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/ 

N.B. that starts with historic commercial production techniques which look like some prototype techniques; skip past those :)

Some of this stuff is really amazing.  Like art amazing.

... but the other side of things is that it's not 1976.  If Jim Williams had modern CAD and modern PCB fab options back then he probably would have made a lot of those designs (even the prototypes) as SMT boards.  He died in 2011.  I was working in 2011.  Getting small quantity quick turn boards back then was still pretty expensive and painful. 
 

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #23 on: October 03, 2024, 10:53:13 am »
Every time I hack something together I wish I had just waited the week for $10 boards to get here from JLCPCB and skipped right to the end

Depends on what it is. Many digital signal connections, probably.

But often a good prototype construction is more than sufficient: in some cases people strive to implement their benefits in commercial products.

For examples of a range of good reliable predictable prototye construction techniques, including one recently shipped commercially, see https://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/ 

N.B. that starts with historic commercial production techniques which look like some prototype techniques; skip past those :)

Some of this stuff is really amazing.  Like art amazing.

... but the other side of things is that it's not 1976.  If Jim Williams had modern CAD and modern PCB fab options back then he probably would have made a lot of those designs (even the prototypes) as SMT boards.  He died in 2011.  I was working in 2011.  Getting small quantity quick turn boards back then was still pretty expensive and painful.

SMD components were around and in commercial devices in 1976.

Given Jim Williams attitudes, I doubt your contention is correct. https://www.edn.com/remembering-jim-williams-5-years-later/ Even if it is correct for him, it isn't correct for other famous designers. Basically, they used whatever technique was appropriate to the job at hand.

More importantly, SMD components are compatible with non-PCB prototypes, for high performance analogue and RF circuits. Several examples of components and products are shown in that web page/blog.
« Last Edit: October 03, 2024, 10:55:20 am by tggzzz »
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline janoc

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Re: "Let's get down to brass tacks"
« Reply #24 on: October 03, 2024, 04:26:50 pm »
...worst case then would be that your actual PCB would have some bodge wires or maybe an extra part or two air-wired on somewhere.  It's still going to be cleaner and more manageable than pure protoboard bits and tons of wires trying to short against everything.

Good luck trying to airwire or bodge out some fundamental design problem. Which is exactly why one prototypes.

And nobody says that a protoboard must be messy or have "wires trying to short against everything".

See e.g. here:

https://aa7ee.wordpress.com/2011/07/24/the-wbr-a-simple-high-performance-regen-receiver-for-40m-by-n1byt/

or

https://aa7ee.wordpress.com/2013/05/11/the-na5n-desert-ratt-2-regen/

And given that the above two are actual regen receivers, they likely work better built like that with that large ground plane and a ton of shielding than anything you could build using a regular 2 layer PCB.

Ordering boards from China and then discovering it doesn't work or something doesn't fit right and now you need to bodge and then respin the board costs you weeks of time and a non-trivial amount of money. I don't know how it is for you but for me if I want the boards within a week from JLCPCB or PCBWay here to Germany, I need to pay about 20€ in DHL shipping out of my pocket. Each time.

E.g. my last order was 2€ boards, 4.40€ VAT + customs - and 21€ DHL shipping charge. The boards took a week to arrive here. If I order from Aisler the shipping is cheaper but the boards take 2x longer to arrive (they have 8 working days lead time) and cost more. So it comes out +/- the same. Given that it is a hobby and not a job and I am paying it out of my own pocket, I will rather spend the money on something more useful than feeding 20 bucks to DHL each time I screw something up.

The cheapest shipping I can get from China is about 7€ - without tracking and takes anywhere from 15 to 20 working days. Does wonders for fast iteration on a design ...

So I do wonder about people who are pooh-poohing others trying to do things without having to order a board for everything (or etching their own boards at home) that they should just order the boards - who is paying for your hobby if you can afford to prototype stuff by ordering everything from China? Or you must have a very cheap shipping available. Or you are so infallible that everything works on the first try, with maximum one or two bodge wires required.

Doing final builds or complex boards with a lot of fine pitch SMD parts or something having specific impedance requirements, or doing it for work etc. is a different matter, obviously. But we aren't talking about that. Prototyping on breadboards (of all types) has its place even today.
« Last Edit: October 03, 2024, 04:32:26 pm by janoc »
 

Offline KonkedoutTopic starter

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Re: "Let's get down to brass tacks"
« Reply #25 on: October 03, 2024, 04:28:06 pm »
Thank you for that great link.  I would like to see some of those photos in greater magnification/detail.  I had tried something vaguely similar to interconnect SMT parts maybe a year ago but my copper connection islands did not stay put. 

However just yesterday I wanted to build something relatively non-critical.  Driving a complementary pair (MPSA06 and MPSA56; both TO-92) with AC coupled 20 KHz drive from a function generator.  Some ancient disc ceramic capacitors, old radial electrolytics and axial resistors.  Power is 40V DC from a lab source.  The wood is maybe 1/4" thick.  Some soft type from a packing crate.  It was amazingly easy to drill 1/16" diameter holes just where I wanted them, using what was my Dad's hand crank drill; it might be 80 years old.

I threw this together and tested it (working OK) in a few hours time.

 

Offline KonkedoutTopic starter

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Re: "Let's get down to brass tacks"
« Reply #26 on: October 03, 2024, 04:33:47 pm »
Gosh it appears that Dave Richards is not just an engineer, but he is also a craftsman.  Some beautiful handiwork.  I am wondering about those node-island-squares; just what they are and how they are made?
 

Offline jpanhalt

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Re: "Let's get down to brass tacks"
« Reply #27 on: October 03, 2024, 04:48:28 pm »
I didn't see any square lands on the main boards.  They all looked like square plates glued or soldered to the main board.  If I were to try isolated square lands, I would use a mill, unless a sloppy job with a Dremel and burr would suffice.  That's what I use to cut traces on the protoboards I use.  Round lands are easy with a brad point drill.  The few times I have done that type of construction for filters, I used a miniature table saw with carbide-tipped blade to cut nice rectilinear pads.  Isolated single pads were done with a brad point drill.  If you have a rigid setup, you can omit the center point on the drll.
 

Online langwadt

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Re: "Let's get down to brass tacks"
« Reply #28 on: October 03, 2024, 06:22:01 pm »
I didn't see any square lands on the main boards.  They all looked like square plates glued or soldered to the main board.  If I were to try isolated square lands, I would use a mill, unless a sloppy job with a Dremel and burr would suffice.  That's what I use to cut traces on the protoboards I use.  Round lands are easy with a brad point drill.  The few times I have done that type of construction for filters, I used a miniature table saw with carbide-tipped blade to cut nice rectilinear pads.  Isolated single pads were done with a brad point drill.  If you have a rigid setup, you can omit the center point on the drll.

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb
 

Offline IanB

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Re: "Let's get down to brass tacks"
« Reply #29 on: October 03, 2024, 06:27:09 pm »
with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

Does the superglue get weakened with the heat of soldering?
 

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #30 on: October 03, 2024, 06:33:22 pm »
I didn't see any square lands on the main boards.  They all looked like square plates glued or soldered to the main board.  If I were to try isolated square lands, I would use a mill, unless a sloppy job with a Dremel and burr would suffice.  That's what I use to cut traces on the protoboards I use.  Round lands are easy with a brad point drill.  The few times I have done that type of construction for filters, I used a miniature table saw with carbide-tipped blade to cut nice rectilinear pads.  Isolated single pads were done with a brad point drill.  If you have a rigid setup, you can omit the center point on the drll.

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

Use a Dremel with a dental bur (spherical is good, but not necessary) to cut through the copper. Doesn't take much expertise before you can hand-cut lands for a 0.1" pitch IC/connector/etc.

In other words, build a subcircuit, then plonk the next IC/component down wherever it turns out to be convenient.

Not particularly pretty, but functional and good enough to ship, e.g.

There are lies, damned lies, statistics - and ADC/DAC specs.
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Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #31 on: October 03, 2024, 06:34:59 pm »
with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

Does the superglue get weakened with the heat of soldering?

I haven't noticed a problem. Components help hold the pads in place. If a problem, use a different adhesive :)

How much shear force do you expect to apply?
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline janoc

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Re: "Let's get down to brass tacks"
« Reply #32 on: October 03, 2024, 06:37:36 pm »
with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

Does the superglue get weakened with the heat of soldering?

No, or at least not that much that it would matter for a prototype. I have even used doublesided tape for this, which does soften and makes the pad slide around while soldering, which is a pain. But easier to remove and reposition if you need to than a superglue. Some people even use the self-adhesive copper tape for this but there one needs to take care because some of those adhesives are conductive and/or the copper doesn't actually have an insulating backing - the glue is directly on the metal layer.

OTOH, superglue doesn't stick to copper all that well, so if you do end up needing to mod the board, the pad usually pops right off with a bit of force.
« Last Edit: October 03, 2024, 06:42:36 pm by janoc »
 

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #33 on: October 03, 2024, 06:40:34 pm »
with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

Does the superglue get weakened with the heat of soldering?

No, or at least not that much that it would matter for a prototype. I have even used doublesided tape for this, which does soften and makes the pad slide around, which is a pain. But easier to remove and reposition if you need to than a superglue.

Agreed, but I would change "makes the pad slide around" to "allows the pad to slide around".

Still not a significant problem in my experience, merely something you get used to - like a component lead moving before the fixed in place by the solder.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline janoc

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Re: "Let's get down to brass tacks"
« Reply #34 on: October 03, 2024, 06:43:53 pm »
Still not a significant problem in my experience, merely something you get used to - like a component lead moving before the fixed in place by the solder.

Yes, exactly. For prototypes it rarely matters and if one needs more mechanical strength one needs to use other ways of fixing the components anyway.
« Last Edit: October 03, 2024, 06:47:59 pm by janoc »
 

Online langwadt

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Re: "Let's get down to brass tacks"
« Reply #35 on: October 03, 2024, 06:47:08 pm »
I didn't see any square lands on the main boards.  They all looked like square plates glued or soldered to the main board.  If I were to try isolated square lands, I would use a mill, unless a sloppy job with a Dremel and burr would suffice.  That's what I use to cut traces on the protoboards I use.  Round lands are easy with a brad point drill.  The few times I have done that type of construction for filters, I used a miniature table saw with carbide-tipped blade to cut nice rectilinear pads.  Isolated single pads were done with a brad point drill.  If you have a rigid setup, you can omit the center point on the drll.

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

Use a Dremel with a dental bur (spherical is good, but not necessary) to cut through the copper. Doesn't take much expertise before you can hand-cut lands for a 0.1" pitch IC/connector/etc.

In other words, build a subcircuit, then plonk the next IC/component down wherever it turns out to be convenient.

Not particularly pretty, but functional and good enough to ship, e.g.

the top one is gold plated, the guy that made them occasionally orders a batch of bare pcbs with ENIG  ;) 

They weren't made for shipping but for figuring out if a concept will work

 

Offline IanB

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Re: "Let's get down to brass tacks"
« Reply #36 on: October 03, 2024, 06:52:42 pm »
Use a Dremel with a dental bur (spherical is good, but not necessary) to cut through the copper. Doesn't take much expertise before you can hand-cut lands for a 0.1" pitch IC/connector/etc.

Missing solder?

« Last Edit: October 03, 2024, 06:56:08 pm by IanB »
 

Offline RoGeorge

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Re: "Let's get down to brass tacks"
« Reply #37 on: October 03, 2024, 07:12:01 pm »
Any other ideas?

I would give up the temporary/plug-able parts idea, and use properly soldered part instead of a breadboard.  As for what to use as an improvised mechanical support, almost any non conductive sheets of material will work.

For proper PCB prototyping, there are many ways if you search online.  w2aew made a video about a few of these:
#122: Electronic Circuit Construction Techniques: review of some prototype circuit building methods

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #38 on: October 03, 2024, 07:29:02 pm »
Use a Dremel with a dental bur (spherical is good, but not necessary) to cut through the copper. Doesn't take much expertise before you can hand-cut lands for a 0.1" pitch IC/connector/etc.

Missing solder?

Looks like you might be right!
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #39 on: October 03, 2024, 07:31:00 pm »
They weren't made for shipping but for figuring out if a concept will work

The two aren't mutually exclusive, of course.

I've shipped prototypes and concept demos.

There's a whole spectrum between a blackboard sketch and a mass production product. Choose whatever  is convenient.
« Last Edit: October 03, 2024, 07:33:22 pm by tggzzz »
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline jpanhalt

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Re: "Let's get down to brass tacks"
« Reply #40 on: October 03, 2024, 07:35:40 pm »
Use a Dremel with a dental bur (spherical is good, but not necessary) to cut through the copper. Doesn't take much expertise before you can hand-cut lands for a 0.1" pitch IC/connector/etc.

I suspect you didn't detect my little bit of sarcasm about being sloppy.  What you describe is exactly what I do with my favorite Dremel.  I prefer by far the smallest round burr in my set.   I have three Dremel hand  tools, but my favorite is the oldest and goes way back to pre-1970.  It's small, light, and doesn't have a lot of useless plastic and rubber in the case.  I easily cut between 0.1" traces (shown in other boards I have posted).  I can cut a relatively straight line, but not as good as those cut on a mill pr table saw.   :D

« Last Edit: October 03, 2024, 07:39:48 pm by jpanhalt »
 

Offline Xena E

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Re: "Let's get down to brass tacks"
« Reply #41 on: October 03, 2024, 07:39:36 pm »

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

You do have to be a little cautious with HF  circuits as using this method, capacitance between the pads and a ground plane can be a significant issue: more so when using very thin laminate.
« Last Edit: October 03, 2024, 07:42:39 pm by Xena E »
 

Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #42 on: October 03, 2024, 07:58:42 pm »

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

You do have to be a little cautious with HF  circuits as using this method, capacitance between the pads and a ground plane can be a significant issue: more so when using very thin laminate.

It can also be a benefit, when combined with the track inductance and a groudplane. There used to be a range of (Wainwright?) stick on tracks with 50ohm impedance.
« Last Edit: October 03, 2024, 08:01:04 pm by tggzzz »
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline janoc

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Re: "Let's get down to brass tacks"
« Reply #43 on: October 03, 2024, 08:20:57 pm »

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

You do have to be a little cautious with HF  circuits as using this method, capacitance between the pads and a ground plane can be a significant issue: more so when using very thin laminate.

That method is pretty common in amateur radio exactly for building HF circuits (see the examples I have posted above). On HF the parasitic capacitance of the pad to the ground plane is still negligible (few pF) compared to the frequencies one works at (<30MHz). If you used a regular PCB and a ground plane, you would have comparable amounts of capacitance. One needs to understand what one is doing, regardless of how the circuit is being built.  :-//

Manhattan style construction is otherwise pretty OK with a bit of care up to several GHz.
« Last Edit: October 03, 2024, 08:24:13 pm by janoc »
 

Offline Xena E

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Re: "Let's get down to brass tacks"
« Reply #44 on: October 03, 2024, 09:36:49 pm »

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

You do have to be a little cautious with HF  circuits as using this method, capacitance between the pads and a ground plane can be a significant issue: more so when using very thin laminate.

That method is pretty common in amateur radio exactly for building HF circuits (see the examples I have posted above). On HF the parasitic capacitance of the pad to the ground plane is still negligible (few pF) compared to the frequencies one works at (<30MHz). If you used a regular PCB and a ground plane, you would have comparable amounts of capacitance. One needs to understand what one is doing, regardless of how the circuit is being built.  :-//

Manhattan style construction is otherwise pretty OK with a bit of care up to several GHz.

Agreed,  I was only making the comment as a caution to someone fresh to the technique.

I have though made it a policy not to use thin stock for the pads if it's for use in tuned circuits, a "few pF" is significant at 100Mhz for instance, not a show stopper but it has to be worked around, just as one has to with parasitic inductance.

Regards.
X
 

Offline Xena E

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Re: "Let's get down to brass tacks"
« Reply #45 on: October 03, 2024, 09:44:58 pm »

with thin fr4 is is easy to make round pads with a hole punch and just superglue them onto the base pcb

You do have to be a little cautious with HF  circuits as using this method, capacitance between the pads and a ground plane can be a significant issue: more so when using very thin laminate.

It can also be a benefit, when combined with the track inductance and a groudplane. There used to be a range of (Wainwright?) stick on tracks with 50ohm impedance.

Also agreed.

You either take time to understand it and make it work for you, or you have to fight it.

I did some 433Mhz work in academia that was a bit hairy until I realised the the capacitors and inductors were often parasitic and even RF gradients in ground planes had to be dealt with.

All good fun.

Regards,
X
 

Offline Xena E

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Re: "Let's get down to brass tacks"
« Reply #46 on: October 03, 2024, 09:54:05 pm »
These are very good indeed, if a little expensive. (I'm too tight to buy but I've seen beautiful work done with them).

https://www.qrpme.com/?p=product&id=MESB

Edit for correct link
« Last Edit: October 03, 2024, 09:59:51 pm by Xena E »
 

Offline RoGeorge

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Re: "Let's get down to brass tacks"
« Reply #47 on: October 03, 2024, 10:03:15 pm »
We use to do repetitive patterns like those on a PCB by simply scratching the copper clad with a sharp metal beak/tooth made out of a blade or a screwdriver corner filed like a scratching tooth (and a metal ruler - to make straight scratches).  It was as easy as drawing lines on a paper, just that the line has to be repeated 3-4 times without moving the metal ruler, until the copper is scratched away completely.

For RF, usually a ground plane helps a lot, because the RF return path follows the shape of the wires above the ground plane (follows the smallest loop area), so less parasitic inductance, less parasitic capacitance (wires are usually farthest from the ground plane then they will be with PCB traces), and the ground plane offers some shielding, too.
« Last Edit: October 03, 2024, 10:21:17 pm by RoGeorge »
 

Offline pqass

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Re: "Let's get down to brass tacks"
« Reply #48 on: October 03, 2024, 11:49:37 pm »
These are very good indeed, if a little expensive. (I'm too tight to buy but I've seen beautiful work done with them).

https://www.qrpme.com/?p=product&id=MESB

I can see them being reproduced by table saw, sled, 45° blade  (or router with V-bit) cutting V-grooves every 200mils in a single sided FR4.


But for quick-n-dirty hacking I use no-copper perfboard (US$0.12/in2). It's reliable and reusable too.
« Last Edit: October 04, 2024, 12:03:38 am by pqass »
 

Offline janoc

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Re: "Let's get down to brass tacks"
« Reply #49 on: October 05, 2024, 08:11:13 am »
Agreed,  I was only making the comment as a caution to someone fresh to the technique.

I have though made it a policy not to use thin stock for the pads if it's for use in tuned circuits, a "few pF" is significant at 100Mhz for instance, not a show stopper but it has to be worked around, just as one has to with parasitic inductance.

Regards.
X

A common trick is to use 1M through-hole resistors as standoffs - one end to the ground plane, the other end is used as a solder point for the signal connections. Then you are away from the ground plane so the capacitance is insignificant and the resistor won't impact the circuit.
 

Offline Victorman222

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Re: "Let's get down to brass tacks"
« Reply #50 on: October 05, 2024, 03:57:40 pm »
Here's some of the methods i used:

1. Dedicated proto boards[1, 2]: expensive, and the ones with plated through holes aren't very prototype friendly, since desoldering becomes a pain. On the other hand rugged. I like the ones where power tracks go under ICs so power connections can be made by just bending a pin. For me it's better to have a bigger board and cut out chunks that are the right size for your project using metal cutting scissors.

2. Cutting slots in FR4 laminated stock[3]. Its the method i go to for simple stuff where i can plan out the cuts in advance. I do it the way RoGeorge described with a sharp "tooth" and a utility knife. This method is smd compatible.

3. Building above a FR4 ground plane[4, 5]: this works better for more complex stuff where i can build it block by block, debugging along the way. I put ICs up in the air by connecting them with a thick ground wire, use capacitors or resistors to ground as spacers. Looks flimsy, but the project i shown fell from my table about 5 times and it still worked (survivorship bias ;) ).

4. Board with pins [6]: not as nice as the other methods but works. The one i have is plastic, but i seen some made out of FR4.

5. Board with pre cut slots [7]: better than the pins board, definitely usable. Maybe if there were power planes below and they came out at designated spots it would be nice. Also may be smd compatible.
 
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Offline RoGeorge

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Re: "Let's get down to brass tacks"
« Reply #51 on: October 05, 2024, 04:38:35 pm »
Nice close up pics!  :-+

Another way I've seen once is this method using tailor rivets made for leather or textiles, which are stapled into cardboard.  :)



You may say this won't scale up, but here he built an entire processor made out of LEDs and photo resistor, no transistors:

LLTP - Light Logic Transistorless Processor
by Dr. Cockroach

https://hackaday.io/project/172413-lltp-light-logic-transistorless-processor
https://hackaday.io/wa4jat

Original project and very creative prototyping method.
 
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Online tggzzz

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Re: "Let's get down to brass tacks"
« Reply #52 on: October 05, 2024, 04:51:31 pm »
Agreed,  I was only making the comment as a caution to someone fresh to the technique.

I have though made it a policy not to use thin stock for the pads if it's for use in tuned circuits, a "few pF" is significant at 100Mhz for instance, not a show stopper but it has to be worked around, just as one has to with parasitic inductance.

Regards.
X

A common trick is to use 1M through-hole resistors as standoffs - one end to the ground plane, the other end is used as a solder point for the signal connections. Then you are away from the ground plane so the capacitance is insignificant and the resistor won't impact the circuit.

With a standoff, a higher value resistor,  or just "airbridged", it also reduces  DC leakage.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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