Crimping tools for dynamo wiring

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tatanab
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Re: Crimping tools for dynamo wiring

Postby tatanab » 14 Nov 2017, 3:29pm

Samuel D wrote:Thanks, tatanab. Final question: am I right in thinking that your CMP5 ---- curls the connector channel into a B-shape, right?
Correct. My background is in electronics and all the decent tools of this type make that kind of shape. Note also that the tool folds the larger "tangs" onto the insulation of the wire, providing some strain relief. Some cheap tools do not do this very well. I still use a piece of heatshrink tube over the whole assembly as extra peace of mind.

Samuel D
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Re: Crimping tools for dynamo wiring

Postby Samuel D » 14 Nov 2017, 3:49pm

Many thanks, all.

Brucey
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Re: Crimping tools for dynamo wiring

Postby Brucey » 14 Nov 2017, 3:49pm

Samuel D wrote:There are so many different types of crimps out there that I’m concerned I’ll end up with an incompatible tool. I’m trying to crimp things that look like the “spade connectors” at the right of this image. They have a U-shaped channel into which the wire is laid..


the proper tool for that type of crimp connector is a specific tool that will probably do that connector and that only. They often work by deforming both 'ears' at the same time so that the resultant connection is sort of 'B' shaped in profile. There is much cleverness involved in the design of both the crimps and the tools , such that there can be barbed parts of the crimp that pierce the insulation on the wire (for improved pull-out strength, and improved contact) and there is a collar that isn't super tight (for strain relief) and at the other end the wire strands are not broken.

But none of these things matters a jot if the connector sees the weather; unless the connection is weatherproofed in some way it will corrode and the contact will be lost. Needless to say the crimps only work exactly as intended on a narrow range of wire specifications, too.

The most common type of ratchet action crimp tool accepts conventional crimp connectors which are coloured red blue or yellow according to the size of the wire bundle that enters in them. Such tools make adequate connections for many applications but they won't crimp connections with U shaped channels and they will not make the kind of crimped connections that will go into military specification connectors. The strain relief in the coloured crimps is achieved via the plastic collar, which softens and moves at relatively low temperatures. In general such crimp connections are suitable for low temperatures, static applications, and dry conditions.

Having bought at least half a dozen special crimp tools for various jobs over the years I am reasonably resolved that I will avoid buying another one if there is any way to avoid it. I shall probably solder the connections even if I have to use the special connectors that are meant to be crimped.

One of the few ways you can go wrong with solder is to allow the solder to run too far up the wire, beyond the strain relief; this can cause the wire to be vulnerable to fatigue failure in certain service conditions.

BTW 99% of crimp connectors are brass or copper, with various forms of plating on them. All such connectors can be soldered easily if needs be. You are extremely unlikely to encounter an aluminium crimp connector since connections to aluminium usually go open circuit by themselves too easily.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

SA_SA_SA
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Re: Crimping tools for dynamo wiring

Postby SA_SA_SA » 14 Nov 2017, 3:54pm

I use small smoothjawed needlenose pliers cos they seemed easier than a crimp tool:

it seems a pity cycle lamps use the mini 2.8mm crimps rather than the larger 1/4in size common for cars and used by the Schmidt hub...

old_windbag
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Re: Crimping tools for dynamo wiring

Postby old_windbag » 14 Nov 2017, 5:05pm

Brucey wrote:the proper tool for that type of crimp connector is a specific tool that will probably do that connector and that only. They often work by deforming both 'ears' at the same time so that the resultant connection is sort of 'B' shaped in profile.


Just back in and read the crimp query. The tool that I linked to for ratchet crimping is as Brucey says designed around the standard red,yellow, blue style crimps( but according to the Q and A also non-insulated, i.e no RYB plastic shroud ). The crimp in the spa image on the right looks more like the tool you imaged earlier, the manual crimper but you'd have to get one that matches the range/type of crimps you wish to use. The crimps can be very tool specific.

If you know the spade size that you wish to use it's more than likely in the range of the RYB style crimps. I've used all manner of crimp ends in that series at work together with that style of crimper. For very fine wires you may end off using crimps that go with correct wire guage and use the manual crimper. I'm thinking a tool like this( ignore price its for example purposes ).

https://www.amazon.co.uk/Universal-Crimping-Micro-Servos-Engineer/dp/B002L6HJ8W?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B002L6HJ8W

You can see the B profile Brucey mentions when you crimp the open sides and "curl" then inward via the tools jaw shape. But there should be a very cheap version of a tool to match the crimp you imaged.

If you know the wire guage then check if an appropriate size push-on end crimp is available for the rachet crimp and use that instead. The ratchet can be seen in the video at the bottom right corner, the toothed edge. If a crimp gets "locked" with jaws wedged shut( it does happen on occasion ) there is a release lever in the handle to free the crimper.

The crimps screwfix have added( from link ) as a purchase are crimped with a totally different style of crimper. These tend to be used on high current cables and the tool is pretty substantial to get a really tight crimp, such as for example on 35mm squared welding cable.

I would also agree that on some smaller crimps with fine guage wire that to solder after crimping can be of benefit.
Last edited by old_windbag on 14 Nov 2017, 5:18pm, edited 1 time in total.

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Heltor Chasca
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Re: Crimping tools for dynamo wiring

Postby Heltor Chasca » 14 Nov 2017, 5:16pm

I managed to get a decent ‘package’ of connectors, a crimping tool and heat shrink from eBay. As a self employed tradesman I value top grade tools as it really makes a difference, but just for my bike bits I was happy with a budget set.

Eventually I will kit myself out with relevant bits to solder the lot together.

axel_knutt
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Re: Crimping tools for dynamo wiring

Postby axel_knutt » 14 Nov 2017, 6:28pm

There's no point in crimp connectors at home, they're used on production lines because they are quicker and cheaper than soldering, and require lower skilled operators. In order to get a reliable joint with a weatherproof, gas-tight seal, you need a calibrated tool, a connector that that was designed to fit it, and the correct size wire for the connector, none of which are particularly convenient at home.
“I'm not upset that you lied to me, I'm upset that from now on I can't believe you.”
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Samuel D
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Re: Crimping tools for dynamo wiring

Postby Samuel D » 14 Nov 2017, 7:09pm

Ah. This is turning into another of those rabbit holes I haven’t got the time to explore. I hope anything would be an improvement on my crimping with pliers and hiding the mess with electrical tape. I appreciate the learned replies.

old_windbag
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Re: Crimping tools for dynamo wiring

Postby old_windbag » 14 Nov 2017, 8:30pm

Samuel I've tried to find a data sheet for the equivalent push-on style crimp that you wished to use in the image posted. The link below should take you to the data sheet for terminals sold by RS. The important aspect is that it gives you for each colour coded crimp and tab width( 2.5mm and 4.8mm IIRC ) the accepted wire gauge in mm squared and AWG. The ratchet crimp tool works with these, so its a case of ascertaining your wire guage in your system and proceeding from there.

http://docs-europe.electrocomponents.com/webdocs/157f/0900766b8157fa44.pdf

Remember you can still use a crimp like this, locate the wire in it, solder from tab end and not revert to crimp tool at all. If you're only wiring once a year then that may be the way to go. A good high wattage temperature controlled iron( 40W+ ) with a 2mm tip will heat the tab and the solder will flow in. Soldering with the right iron makes life easy.

Airsporter1st
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Re: Crimping tools for dynamo wiring

Postby Airsporter1st » 14 Nov 2017, 10:51pm

Just a couple of observations:

1) Just as there is a wide range of tools in terms of both price and quality, so there is in the crimp connectors themselves. It doesn't do to economise on something that even in better quality is not prohibitively expensive.

2) Crimped connections alone are not recommended on vehicle electrics where there is any risk of dampness, which will either directly or by capilliary action find its way inside the connection.

3) If you do want to use crimped connectors consider using those where the insulation is actually heat-shrinkable and coated internally with hot-melt adhesive, so as to produce a secure, waterproof connection.

tim-b
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Re: Crimping tools for dynamo wiring

Postby tim-b » 15 Nov 2017, 6:17am

Hi
As important as the crimp tool is planning to leave some slack wire and support any joints made
The slack wire will allow you to remake joints without rewiring (carry a spare connector or two)
Supporting the joint will reduce the tendency of the flexible wire to break at the inflexible connector
Heat-shrink or tape will keep the elements out and provide some support
Crimping tools will last for decades and see little use by a cyclist, IMHO the cheaper models will be fine
Regards
tim-b
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Mick F
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Re: Crimping tools for dynamo wiring

Postby Mick F » 15 Nov 2017, 6:40am

Mine is very much like this one, and cost all of £4.99 or similar.
https://www.sjscycles.co.uk/tools/schmi ... ping-tool/

Cheap tool shop in Plymouth.
https://toolzonetools.co.uk/product/han ... plier.ashx
Mick F. Cornwall

Randy_Butternubs
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Re: Crimping tools for dynamo wiring

Postby Randy_Butternubs » 15 Nov 2017, 10:07am

axel_knutt wrote:There's no point in crimp connectors at home, they're used on production lines because they are quicker and cheaper than soldering, and require lower skilled operators. In order to get a reliable joint with a weatherproof, gas-tight seal, you need a calibrated tool, a connector that that was designed to fit it, and the correct size wire for the connector, none of which are particularly convenient at home.


+1 I came to the same conclusion from my own experience and after speaking to someone who uses them professionally. I use a cheap crimp tool to hold the terminal on the wire and give some mechanical strength but I always back it up with a bit of solder.

old_windbag
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Re: Crimping tools for dynamo wiring

Postby old_windbag » 15 Nov 2017, 10:40am

Mick F wrote:Mine is very much like this one, and cost all of £4.99 or similar.
https://www.sjscycles.co.uk/tools/schmi ... ping-tool/

Cheap tool shop in Plymouth.
https://toolzonetools.co.uk/product/han ... plier.ashx


The amazon item here:- https://www.amazon.co.uk/Laser-3777-Crimping-Tool/dp/B00386ZRQU?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc08-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B00386ZRQU is just about the equivalent of the schmitt tool you link above mick. The el cheapo from plymouth seems to be the manual tool for the RYB style crimp terminals. But whichever crimp choice is used theres a multitude of cheaper versions than the tools samuelD was looking at. For sporadic use they are absolutely fine. But like many others I'd tend to reinforce with solder to insure of a long term connection and weatherproof with heatshrink etc.

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Mick F
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Re: Crimping tools for dynamo wiring

Postby Mick F » 15 Nov 2017, 11:33am

This one's mine.
Had it cost more than a fiver, I wouldn't have bought one. Deft use of pliers is ok.
Solder too, if required.
IMG_0297.JPG
Mick F. Cornwall