A cause of neverending dissapointment....
|Biggles' Elder Brother - Moderator||28/01/2018 21:23:32|
15407 forum posts
There I am in the shed, I need to centralise a servo prior to fabricating a linkage,...sadly my servo checker "went west" a few weeks ago. No problem, as my watt meter has a servo driver on it - so I can use that, right?
Mmm, one catch, the watt meter has an XT90 plug on it. The battery I want to use to drive the servo has a XT60 socket on it. Ah, but I have "a box", a box choca full of adaptors - I been making them up as I need them for years and years - I must have a female to male, XT90 to XT60 mustn't I?
I search the box - it seems to contain just about every adaptor configuration you can think of JST, Deans, Shielded, Balance, pin/socket, XT etc; in every gender combination. You name it I've got one - but it seems NOT a female to male XT90 to XT60. Oh I have male to male, female to female, male to female XT60 to XT90, male to female XT90 to XT60 - but NOT a female to male XT90 to XT60. Grrrrrr!
Now I wouldn't be too upset about this - if it wasn't for the fact that this is far from the first time this has happened - in fact it seems to almost be the norm - I never seem to have the right adaptor no matter what I want!
I standardise as far as possible - I even change connectors on bought in goods to bring into line with my "standard" - but still I seem to have an inexhaustible demand for more and more adaptors!
Anyone else have this issue or similar ones in other areas?
|Capt Kremen||28/01/2018 21:44:46|
213 forum posts
It's called 'It Will Come In Handy Sometime' syndrome many a modeller/handy man etc. has ..... only ....
When 'Sometime' does comes around you can never find the bl#### thing!
|Percy Verance||28/01/2018 22:16:34|
6730 forum posts
BEB go onto the Component Shop site, and after a little dig around you'll find their custom lead ordering thingy. You can choose from virtually any sort of plug or socket on either end. You even get to choose what length you want it. And whatever plugs/sockets you specify, Component Shop will use the heaviest wire possible for the said connectors. That do?
|Biggles' Elder Brother - Moderator||28/01/2018 22:23:52|
15407 forum posts
No Percy - thanks for that, but I'm quite happy making adaptors - I am just puzzled that no matter no many you make there is always one more needed that you don't have. It would just the same if I used someone else to make the adaptors - that's the problem. Logic says there can only be a finite number of combinations - experience suggests differently!
409 forum posts
The list of possible permutations, whilst large, is finite - just keep making them as you need them
EDIT: Haha posted at the same time - maybe set up a spreadsheet and see what you have and what you are likely to need in the future.
Edited By KiwiKid on 28/01/2018 22:27:49
|Old Geezer||28/01/2018 22:34:47|
|510 forum posts|
Regarding the potential number of permutations, it would be nice if one of the mathematicians in the congregation could work out just how many - I think you'd be surprised at the result!
|Mike Blandford||28/01/2018 22:55:45|
380 forum posts
Rather than have adapters from everything to everything, why not just have the connectors with a couple of wires (colour coded and with tinned ends). Then, get what I call a "chocolate block" screw terminal block for connecting wires together. When you need an adapter, just get the two connectors (with their wires), put the wires from one into one side of the block and those from the other connector into the other side.
Then you have, almost immediately, any adapter you require.
I use this method, or an electronics, plug in, breadboard, to make all sorts of adapters as required. Just occasionally, when I find I need a particular adapter frequently, I will make up a dedicated one.
I make it that if you have 10 different, 2-way connectors, each in male and female, you would need 90 adapters, with my suggestion, you need just 20 connectors with wires. Using several "chocolate blocks" you could leave commonly used adapters made up, but quickly change if needed.
Edited By Mike Blandford on 28/01/2018 23:01:42
|Tom Sharp 2||29/01/2018 02:47:57|
3017 forum posts
Would make a good article for RCM&E April edition.
|Dave Bran||29/01/2018 07:20:34|
1892 forum posts
Instead of lengthy discussions on the best way of bodging the problem up at the customer end, why don't we put pressure on the manufacturers to reduce the number of options!
Queue endless discussions on which ones are the best ones to keep...........................................
|Don Fry||29/01/2018 07:26:54|
2543 forum posts
Don't need much maths to know that the result tend to infinity. Bran is wise.
|john stones 1||29/01/2018 07:53:38|
9666 forum posts
Fly I.C cuts down dramatically on plug issues.
|Adrian Smith 1||29/01/2018 08:00:26|
1932 forum posts
The whole connector thing is fraught with inconsistency and confusion for an simple chap like me! As far as the type of connection is concerned I buy 'em in pairs because some connectors I would say are male are actually sold as female for some reason, as I have found to my cost. Seems the connector world was into "gender fluidity" long before it became the fashion now! I like to know when I grab a female (connector that is) I like to know it's as I expect it to be and not dressed up in a male appearance (connector that is). Any way that's my tuppence worth!
516 forum posts
Yes never got the right adaptor is pa 'n parcel with sods law you just got to accept it as fact to be got over
But have you seen the millions of light bulb types out there , you never got the right one or the shop has not got that one. Its the newmodern addition to sod's law
|john stones 1||29/01/2018 08:13:38|
9666 forum posts
Been reading the Guardian have we ?
|The Wright Stuff||29/01/2018 08:30:29|
1253 forum posts
Wow. I'm afraid I'm the maths loving geek and I can't resist:
The formula is:
Number of adapters = (2 x N)^2 - (2 x N)
where N is the number of types available.
The first term is the matrix of every type of plug/socket connected to every other type of plug/socket, with two genders per type. The second term is subtracted because we don't need M-F or F-M adapters for the cases where we are connecting the same type together (because you get back to where you started).
So for N = 1 (just one type of plug/socket), you need 2 adapters (M-M and F-F).
The full table down to 10 types is:
N -> Number of adapters
1 -> 2
2 -> 12
3 -> 30
4 -> 56
5 -> 90
6 -> 132
7 -> 182
8 -> 240
9 -> 306
10 -> 380
This assumes that you don't daisy chain multiple adapters together. You could reduce the number you need and there would be some interesting maths involved. A good GCSE student project, I'd have thought...
Edited By The Wright Stuff on 29/01/2018 08:44:19
|Peter Miller||29/01/2018 08:39:13|
9177 forum posts
I can't help wondering just how many adaptors could have been made in the time spent writing and reading the posts on this thread.
|The Wright Stuff||29/01/2018 08:53:08|
1253 forum posts
Excellent point, Peter, but in my case: none. While travelling for work, my aeromodelling hobby is sadly mainly an academic interest these days!!!
|john stones 1||29/01/2018 09:43:43|
9666 forum posts
|Mike Blandford||29/01/2018 10:55:44|
380 forum posts
I think you have too many! For two sets of connectors I reckon you have:
So 16 permutations from your first term [(2 x N)^2], Those I've marked with (*) are the ones you don't need from your second term [2 x N], but the ones I've marked with (!) are repeats, just wired to "other" way round (M1-M2 and M2-M1 are the same adaptor).
|McG 6969||29/01/2018 10:57:00|
2167 forum posts
I think the majority of the forumites here didn't 'get' BEB's main problem.
He has just been spending a lot of cash to that 'mountain' of mainly useless adaptors... and now, in fact, he just needs a 'servo tester', right? Just a couple of euros at Banggood...
Maybe a very helpful soul around here could relieve him from all that pain just by sending him a spare servo tester...
Thanks on behalf of the ones being in great pain.
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