Author Topic: Why do breadboards have a gap every 5th hole in the power rails?  (Read 589 times)

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Offline Nystemy

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This is generally an answer to Dave's Twitter post:
https://twitter.com/eevblog/status/1183695376278179840?s=19

The reason for why there is a gap is simply due to ease of manufacturing.

The clips inside the bread boards is a U shaped piece of metal, this makes it slightly harder to properly cut into segments without deforming it beyond reason.
The solution for manufacturers to make this easier, is simply to add a section where it isn't U shaped, but rather just a flat strip. (Though, usually this is still having a U shape, but the vertical walls aren't close to as high.  :blah:)

This also makes the strip more bendable, without disfiguring it in the process. So that it can be rolled up on a large reel, making it easier to feed it into the manufacturing machinery.

The reason it is every 5th hole is simply due to the fact that the strip is 5 holes long, and the same strip is used for both the vertical and horizontal segments of the board.
For the longer horizontal segments, it is though not cut into its smallest segments, but rather kept as semi long strips.

The more curious question though is why is the gap larger every 5th segment?

My guess would be to increase the bend-ability yet more, as to reel it up even easier.
 

Online wilfred

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Re: Why do breadboards have a gap every 5th hole in the power rails?
« Reply #1 on: October 15, 2019, 01:19:42 pm »
That doesn't sound right. The continuous red and blue lines along the power rails show the continuous rails and there is a gap midway on each rail. I don't know why that is there but there are no gaps every 5 holes on my breadboards.

I would say the holes are grouped in 5's to make aligning the hole you want easier.  Not that I can see how it matters. Maybe it just looks nicer.

I'm not sure what Dave was asking. He'd know for sure there is a gap only in the middle.He was probably asking two different questions and was to parsimonious with his words. Or maybe he has different breadboards. But it would be annoying bridging them all together.
« Last Edit: October 15, 2019, 01:26:40 pm by wilfred »
 

Offline Nystemy

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Re: Why do breadboards have a gap every 5th hole in the power rails?
« Reply #2 on: October 15, 2019, 01:55:05 pm »
There is many different breadboard manufacturers.

Perusing around on Google images will fairly quickly give a good idea of the verity of breadboards on the market.

Yes, some have far more continuous strips of holes for the power rails without any gaps.
But there is many breadboards on the market that has gaps every 5th hole. There is still an electrical connection through this short gap. Because the metal strip gripping the pins is one continuous piece of metal extending the full length of that power rail.

Some have a larger gap every 5th segment on the power rails, others doesn't. This larger gap sometimes has an electrical connection, but more commonly not. And here we would need to bridge it if we want it all to be one continuous strip.

The reason for this short gap every 5th hole is due to it being the location where the machine cuts the continuous metal strip apart. The metal strip lacks the feature of grabbing onto pins in this position, mainly to aid the machine in cutting the segments apart.

Do note, we don't cut the continuous strip into individual segments for the power rails, but rather cut it every few segments, so that it is all still electrically conductive.
Now it might seem silly to have a cutting point if one doesn't use it 4 times out of 5, but the reason for this feature is due to most breadboards also using the same metal strip for the main working area of the breadboard. That typically has 5 holes for each side of the breadboard.

It is simply manufacturing optimization.
 

Offline T3sl4co1l

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Re: Why do breadboards have a gap every 5th hole in the power rails?
« Reply #3 on: October 15, 2019, 02:10:58 pm »
My reaction: "Ha, Dave doesn't know how to use the three seashells5th hole gap!"

More seriously, my guess would be they need some meat on the ends of a run so the fingers stay in place and don't get pulled too far out of whack.  Haven't looked at a disassembled board in ages so I couldn't tell you if this even makes sense or not. :P

Tim
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Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 

Offline password

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Re: Why do breadboards have a gap every 5th hole in the power rails?
« Reply #4 on: October 19, 2019, 02:07:45 pm »

the 5th hole gap does me bother me all that much , however the 5 column width is annoying. I want 10 columns so i can poke in all sorts of modules.

My guess is simple they use teh same pin ribbon as on the columns for the power rail.
 

Offline mariush

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Re: Why do breadboards have a gap every 5th hole in the power rails?
« Reply #5 on: October 19, 2019, 02:23:35 pm »
I assumed it's to reuse 5 hole long bits of metal and have those mass produced hence cheaper.
 


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