Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: sinjon on September 04, 2007, 03:28:32 PM

Title: Spade connectors
Post by: sinjon on September 04, 2007, 03:28:32 PM
What am I doing wrong?
I keep leaving the spade connectors attached to the battery terminals.
What is the correct way to attach a spade to a cable - and stay attached.

Colin
Title: Re: Spade connectors
Post by: Ghost in the shell on September 04, 2007, 03:33:22 PM
jon

sounds to me like they are not properly crimped down, thats all it probably is.  use a crimping tool not pliers and you should be ok, if in doubt add a little solder to boot.
Title: Re: Spade connectors
Post by: DickyD on September 04, 2007, 03:54:27 PM
Solder the cable in nearest the spade first and when it has cooled down crimp the outer covering furthest from the spade.
Works for me.   O0
Title: Re: Spade connectors
Post by: sinjon on September 04, 2007, 04:12:47 PM
Hey - thank you both.
By luck, I was able to add a crimping tool kit to an order that I had placed with Squires an hour and a half earlier.
Such is the advice and the speed of Mayhem members - Invaluable to amateurs.

Colin
Title: Re: Spade connectors
Post by: Ghost in the shell on September 04, 2007, 04:15:02 PM
no problem :) whats the model that they are going in?
Title: Re: Spade connectors
Post by: sinjon on September 04, 2007, 07:20:34 PM
The boat is the HMS Bulldog - the Dave Metcalf hull, @ 1:48
I must try to get some piccy's posted, I have had help from all over Mayhem, deck planking to electrics, a very big learning curve, I am really enjoying the build - but that's what its all about I suppose.

Colin
Title: Re: Spade connectors
Post by: kiteman1 on September 04, 2007, 07:56:57 PM
Don't forget to add a heatsink to the cable above the spade...........avoids meltdown if too much heat is applied.  O0  :angel:
Title: Re: Spade connectors
Post by: ukengineman on September 06, 2007, 02:31:08 PM
I don't trust any crimped connection in a marine environmet even if made with the correct tool. I agree with DickyD, solder it near the spade to make the electrical connection and crimp at the end to relieve stress from the joint.

Alan
Title: Re: Spade connectors
Post by: R2-D2 on September 06, 2007, 02:33:58 PM
Clean and Tin before the wire goes in you need less heat that way  Luke
Title: Re: Spade connectors
Post by: Bluebird v2 on September 06, 2007, 03:40:50 PM
Hi all,

Ive got to agree 100% with the soldering of the spade connections.  The other thing which I do sometimes is, place a bit heatshrink over the soldered connection on the spade, so it overlaps approximately 3/4 inch onto the insulation of the cable.   This adds that little bit strength to the joint as I have had one or two break at the 'crimped end' of the spade through constant use of pulling the spade off the battery connection.

aye
john e
bluebird   :D
Title: Re: Spade connectors
Post by: sinjon on September 06, 2007, 05:21:18 PM
I had my crimping tool ' kit ' delivered from Squires this morning, I am in the process of replacing all the spades - soldering & crimping.
They now seem extremely permanent.
I did feel a bit of a prat asking such a basic question, but its rewarding to know that there is obviously more to it, than just shoving the cable in, and giving it a bit of a squeeze with a pair of pliers.

Why are Squires not in our directory? - enormous catalogue, very helpfull staff, speed of light delivery.

Colin
Title: Re: Spade connectors
Post by: boatmadman on September 06, 2007, 05:43:43 PM
whats squires interweb address?

Googling dont seem to get the desired result.

Ian
Title: Re: Spade connectors
Post by: dougal99 on September 06, 2007, 05:50:53 PM
Not much there

www.squirestools.com

been promising a better site for months. However, there catalogue is enormous and delivery normally the following day.

Cheers

Doug
Title: Re: Spade connectors
Post by: Ghost in the shell on September 06, 2007, 06:07:23 PM
one idea has sprung to mind, rather than go and have the spades removed everytime you want to charge, adapt the wires with two extra leads coming off the crimped battery leads, forming a Y, with a switch on each the feed to esc and a switch on the charge leads, you could then epoxy the spades off the charge-leads onto a spar, then when you want to charge, throw the switches over on the esc to off, plug the charging leads onto the charge leads, turn on the switch on the charge lead and charge the battery in the boat

that way your connections stay firm and wont fail because you've yanked them out.  I fitted a tamiya plug to my gel cells and a tamiya plug on the charger of my gel cells.  the spades now dont need to be disconnected :)
Title: Re: Spade connectors
Post by: tobyker on September 06, 2007, 06:54:24 PM
Presumably if you put diodes in the leads to the ESC you wouldn't need a switch, because the oomph from the charger couldn't go past the diodes to the ESC.
Title: Re: Spade connectors
Post by: Ghost in the shell on September 06, 2007, 06:57:39 PM
by puttingf a diode in there to stop the flow of power, it by that very action would stop flow of power to the esc from the battery as the leads would be in a Y arrangement, the bottom of the y going to batt, the top of the Y, one half going to esc, the other being the charge leads.

BATT---------
CHARGER-----+-----------ESC
Title: Re: Spade connectors
Post by: sinjon on September 06, 2007, 07:00:17 PM
For my little brain, most of that went over my head, could you, or someone put it down as a drg?

Colin
Title: Re: Spade connectors
Post by: DickyD on September 06, 2007, 07:06:42 PM
I put a female Tamiya plug on the leads from the terminals and a male Tamiya plug on the charger.
Dont have to remove spade connectors and cant mix up battery terminals. O0
Title: Re: Spade connectors
Post by: boatmadman on September 06, 2007, 07:37:58 PM
I put in an on/off/on switch on the positve lead between battery and esc. With switch in one 'on' position, the battery supply goes to the esc, in the other'on' position, the battery charger feeds the battery and the esc is isolated.

Ian
Title: Re: Spade connectors
Post by: Bluebird v2 on September 06, 2007, 08:10:13 PM
Hi All

This circuit is very similar to what Ian (previous post) has described - the only difference is the switch which is a three way switch in my sketch/scribble.

The centre position is OFF (isolating the battery from the charger - and also from the ESC).

A Word of caution though - sometimes it states on the side of the batteries DO NOT CHARGE IN SEALED CONTAINERS - I shouldnt imagine this would affect us charging gel cells in our models - plenty of air circulation, but, I would caution those who charge Nicads and soforth, as they can get rather warm.

Hope this is of some help.

aye
john e
bluebird
Title: Re: Spade connectors
Post by: boatmadman on September 06, 2007, 09:00:35 PM
You copied my circuit John! Thats esactly how I have mine! O0
Title: Re: Spade connectors
Post by: Stavros on September 06, 2007, 09:29:03 PM
Have NEVER had to solder a crimp in my life.If you use a PROPER and I mean a PROPER crimping tool which is readily available through most motor factors,eg Seally tools make a good one,you will have No problems at all.Gentelmen you see the likes of Halfords etc only sell the CHEAP and nasty crimper's you all know hate ones I mean,you've guessed it the ones with the yellow handles,the ones that bend at the drop of a hat,through them away and buy a PROPER crimping tool the RATCHET variety they are preset to crimp at the right torque and the cable WILL NOT pull out of the crimp.Yes I fully agree that the Tam-ya type plugs do need to be soldered but the others no.Oh an the ratchet type crimper's should also be sold at most electrical wholesalers.

Stavros

 
Title: Re: Spade connectors
Post by: boatmadman on September 06, 2007, 09:31:24 PM
We use the ratchet type of crimps at work, as Stavvy says, cables NEVER come out. Would be fluffin embarrassing and costly if they did!

Ian
Title: Re: Spade connectors
Post by: Stavros on September 06, 2007, 09:38:40 PM
Could not agree more some of my rewiring and total wire up on rally cars are still going strong and still will with no pr-obs at all,those cheap and nasty crimper's should BE BANNED

STAVROS
Title: Re: Spade connectors
Post by: sinjon on September 07, 2007, 09:39:00 AM
Nice drg. Now that I can follow.

Thank you John.

Colin
Title: Re: Spade connectors
Post by: Telstar on September 07, 2007, 01:16:17 PM
Hi
One thing I would like to mention regarding crimp connections.
It is as important to use the correct size crimp for the wire/s used as it is to correctly crimp them.
The small crimps I used at work, were colour coded as was the crimp tool. To try to use a yellow (largest wire capacity) crimp on small (0.5 )cable wouldn't work. Also it is not good practice (although sometimes done) to cut strands off the wire to make it fit into smaller crimps.

Cheers Tom
Title: Re: Spade connectors
Post by: wombat on September 07, 2007, 01:19:54 PM
Crimps properly made are as good if not better than soldered joints - hence their use in critical applications. To get a good crimped joint though, you need to make sure you have the right crimp tool for the job.

For spades and things, stick to the Red, BLue and Yellow tpye crimps with a suitable tool - ratchet is best, but I get good results with a plier type crimper  - the trick is to crimp until the handles are in the fully closed position. Other sorts of crimps - forget it without the right tool, which can cost a significant wedge (Last one I bought was 150.00)

However, if the wires are pulling out ofthe crimps - couple of reasons:

1/. The crimp was not made properly  - use the right tool and the right pressure
2/. You were trying to remove the connector by pulling on the cable - don't do it, whether the joint is crimped or soldered. It is actually better that you use a crimp if you are going to pull on the cable, because the failure mode is when you pull it. With a soldered joint you can get a degradation of the joint through stres that will bite you on the bum at the worst possible time.

A spade is designed as an anti-vibration connection - the hole in the spade itself mates with a pip onthe crimp part - this is designed to stop the male and female parts walking apart. You have to overcome the significant holding force to separate the connection. If you need to do it use pliers on the shoulder of the spade.

Remember though that spades are not designed to be separated repeatedly. I would be surprised if the rated life was much more than 5 or 10 disconnections. If you need a charging connection, it is best to provide a suitable connector so the spades can remain undisturbed. I use a 1/4" mono jack for charging the SLAs, which are mounted in the boat permanantly.. IAt the moment, they are set up so the jack socket  is wired striaght across the battery (tip positive) so you have to turn off the power to the rest of the boat before charging. Considering using a DPDT switch for the next one so it is pit into charge mode when the power is off

Wom
Title: Re: Spade connectors
Post by: malcolmfrary on September 07, 2007, 01:28:55 PM
We do tend to use spade connectors out of spec as regards the number of connect/disconnect cycles.  When I remember, I usually secure the cable/connector join with heatshrink.  This forms a strain relief such that there is a gradual transition between rigid on the connector, and flexible in the rest of the world.
Title: Re: Spade connectors
Post by: madrob on September 12, 2007, 11:29:12 PM
Has anybody got a pic of the ratchet type crimpers
Title: Re: Spade connectors
Post by: Telstar on September 12, 2007, 11:39:34 PM
Hi This tool supplier shows typical ratchet type crimp tool



http://www.cromwell.co.uk/static/publication/374/pages/900.pdf

Cheers Tom