Panel Unit Width?

For my current “In My Head” project… It would be one Processing Module (2U 50mm) Then 1 to 4 2U I/O control modules… And lastly 1 extra 1U 25mm feature module… The Processor module could be combined with the Feature module (3U 75MM) 2 PCBS’s one front panel… Or other combinations of front panel, and modules in the set…


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otherwise you are where with “input / output module”, I made you several messages to help you, but not really some answers

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Not to repeat my pictures from mail day, but here are some that I designed with a little bit of Sams help!




7.5cm Special Shiny Panel (some of these will be given away here!)



LMNC’s Modules are
Filter - 20cm
VCLFO - 10cm
VCO - 10cm
ADSR - 5cm
Dual VCA - 5cm
Quad VCA - 10cm


lol, I think we should call the width KU lol


Or Fixed KU,

only problem with that is it trips of the tong as “FKU”… :slight_smile:



I like seeing the shine of tin in the art.

LMNC’s Filter - 20cm (I’m not to be pedantic rather I’m keeping myself from getting confused between all the grades of unit width…)

-Fumu / Esopus


Whoops you’re correct, I’m sitting at work and wrote that away from my synth haha

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I work in “U” all the time as I have a lot of 19" Racks with equipment to plan/manage.

The performance filter at 20cm = 8units 8FKU
Perf VCO(Tuner) 4U

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sounding great!!! and the standard is refined!!! :smiley:


Take a unit that most people in the modular synthesizer world understand as a measure of height and overload it with yet another different value as a measure of width./s

According to Wikipedia: “As of 2018 there are two competing standards for 1U modules, differing mainly in their height. 1U modules manufactured by Intellijel are 39.65mm high, whereas 1U modules manufactured by Pulp Logic and other manufacturers are 43.2mm high.”

Now instead of this:
- How wide is the ADSR module?
- It’s 5cm wide.
-OK, thanks.
we’ll have this:
- How wide is the ADSR module?
- 2U
- Not its height, its width.
- No, the Kosmo U is horizontal.
- Ah? OK, so how wide is it?
- 5cm
- So the ADSR is 10cm wide?
- No, it’s 5cm wide.
- But you said it’s 2U wide and a Kosmo U is 5cm.
- No I meant the module is 5cm, the Kosmo U is 2.5cm.
- O…K…

What the F**k is wrong with just using centimeters?!? It’s a pretty common unit.
We don’t need another secret language, things are nebulous enough as they are.



… <- to make a long enough response n such.

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Well, as I understand it, MOTM and Modcan B are 1U wide (by 5U high).

But yeah, talking about “Us” when a U is 1.75" makes some sense otherwise you’re spending half your time talking about “eight point seven five inches” and getting everyone confused instead of just saying “5U”. Likewise “4 HP” instead of “eight tenths of an inch”. But cm, that’s easy, it’s clear, it’s not jargony.

(Of course my panels are really e.g. 1" by 7 7/8" for “1U” and 2" wide for “2U” but 3 7/8" for “4U” but don’t get me started on Imperial idiocy.)


I think @twinturbo was saying that in jest. Kosmo exists primarily for two reasons that i know of:

  1. Bigger panels make it easier to use in a performance setting, and is a bit easier to build.
  2. Measurements should be simple. All of those conversions are really inconvenient and unnecessary. “Measurements are for crazy people and mathematicians.”

Even over here in the states, its not terrible working in metric. I could build a case to fit kosmo without much of a fuss, although truth be told, some conversion is needed, and i hear that some folks that source aluminum front panels are experiencing issues with metric requests.


20 cm tall = 7-7/8 "
the width seems to be what ever works for that particular module .
someone suggested 2.5 cm increments .
one thing I have noticed that needs defining is the height of the PCB’s
I have had some not fit in between the rails. 17.5 cm is a good max ?

17.5 is what i think we have in the spec tread. it’s certainly what i use.

and all my pcbs are also -4mm (2mm+2mm) just to aid clerance width wise.

no problem going less than 17.5cm but any more and it will hit most peoples rail material.

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width wise, it could be anything, but for “capacity planning” it’s best to have standard widths which are multiples of 2.5CM.


yep I thought there was a spec thread .

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Kosmo Specification mentions the 17.5 cm limit.

It’s nice to have a standard width but depending on what you use for panels it may be unfeasible. My PCB panels are multiples of 25 mm but for one-off modules I use cut to order aluminum, and the supplier cuts to Imperial measurements with -0 +1/8" tolerances. Fortunately so far the heights have been pretty close to 20 cm.


Who knew there were so many imperial machine tools left in 2020?

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17.5 cm [ 7-7/8" ] is the PCB max .which would give you 1.25 cm [ 1/2" ] top and bottom clearance from your mounting rails .
the width of module is in increments of 2.50 cm [ 1" ] from 2.5 cm to what ever and of course this is tweakable to fit your needs .