Author Topic: Male connectors on screw terminals  (Read 1488 times)

0 Members and 1 Guest are viewing this topic.

Offline StephanieTopic starter

  • Jr. Member
  • **
  • Posts: 46
  • Helpful? 0
Male connectors on screw terminals
« on: August 22, 2009, 06:38:48 PM »
I don't like the Sabertooth screw terminals.

Wires are very fragile and always break, so I'm thinking about putting male connectors instead. I want to cut those in half:

http://www.robotshop.ca/sfe-170mm-mm-premium-jumper-wires-1.html

Has anyone tried putting male connectors in the Sabertooth's screw terminals? Is there any problem?

Thanks.
--- Stephanie

Offline SmAsH

  • Supreme Robot
  • *****
  • Posts: 3,959
  • Helpful? 75
  • SoR's Locale Electronics Nut.
Re: Male connectors on screw terminals
« Reply #1 on: August 22, 2009, 06:41:47 PM »
I can see this as being feasible... but is it worth it?
The wire connectors would be very fragile and would most likely snap or break if anything tugged on them with force...
are you using stranded wires with the screw terminals?
Howdy

Offline StephanieTopic starter

  • Jr. Member
  • **
  • Posts: 46
  • Helpful? 0
Re: Male connectors on screw terminals
« Reply #2 on: August 22, 2009, 06:57:58 PM »
I'm using a servo cable: 3-pin Molex goes to Axon UART, the other end goes to the terminals.
--- Stephanie

Offline SmAsH

  • Supreme Robot
  • *****
  • Posts: 3,959
  • Helpful? 75
  • SoR's Locale Electronics Nut.
Re: Male connectors on screw terminals
« Reply #3 on: August 22, 2009, 07:03:27 PM »
you could try it i suppose, i am just weary of the pins snapping from the sabertooth board :-\
maybe try it with some hot glue for stress relief?
Howdy

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Male connectors on screw terminals
« Reply #4 on: August 22, 2009, 07:41:08 PM »
Hi,

Wires are very fragile and always break, [...]
How do you treat the wires when you hook them up?
  • First you strip a length about double the depth of the screw terminal.
  • Then you twist the free strands of copper hard.
  • Then you fold the twisted end double.
  • Insert with the fold-over end against the screw, it's acting as protection, spreading pressure and adding springiness to the wire-end.
  • Tighten screw to a loose compression of the copper (Too tight and you _will_ cut the wires).
Make sure the isolated wires going to the terminals are not able to move around/vibrate, or the wires _will_ break from metal fatigue.

Follow the above meticulously and you won't need any further outlay in that department.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline StephanieTopic starter

  • Jr. Member
  • **
  • Posts: 46
  • Helpful? 0
Re: Male connectors on screw terminals
« Reply #5 on: August 22, 2009, 10:06:12 PM »
Soeren, I've done that, but my problem isn't the screw. My chassis is pretty small and the wires always warp next to the terminal.

Look at the image:


It's impossible to avoid that thin place because the heat of the solder melts the rubber.

Well, I've installed the male connectors and, though overkill, they're pretty good. It looks like the hot glue isn't needed - the screws hold it fine.

Thanks everyone!
--- Stephanie

Offline chelmi

  • Supreme Robot
  • *****
  • Posts: 496
  • Helpful? 15
Re: Male connectors on screw terminals
« Reply #6 on: August 23, 2009, 11:10:20 PM »
Soeren, I've done that, but my problem isn't the screw. My chassis is pretty small and the wires always warp next to the terminal.

Look at the image:


It's impossible to avoid that thin place because the heat of the solder melts the rubber.

Well, I've installed the male connectors and, though overkill, they're pretty good. It looks like the hot glue isn't needed - the screws hold it fine.

Thanks everyone!


I don't think that Soeren is saying that you need to tin your wire. If I understand correctly he is describing solution A in the drawing joined. I guess you coud also use solution B if your wire is going to move a lot.

Chelmi.

Offline SmAsH

  • Supreme Robot
  • *****
  • Posts: 3,959
  • Helpful? 75
  • SoR's Locale Electronics Nut.
Re: Male connectors on screw terminals
« Reply #7 on: August 24, 2009, 12:51:35 AM »
when using screw terminals i find it always helps to "fold" the wire over a few times...

chelmi, soeren was describing your "solution A", if you know excessive stress will be placed on the connector,
"solution b" would be a good choice...
if its just low current stuff like signals it cant really hurt to put a pin header in, i see no point for screw terminals...
Howdy

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Male connectors on screw terminals
« Reply #8 on: August 24, 2009, 07:51:10 AM »
Hi,

Soeren, I've done that, but my problem isn't the screw. My chassis is pretty small

I think I better not comment that ;D


It's impossible to avoid that thin place because the heat of the solder melts the rubber.

Glad you found something that worked.
But... I never said you should heat anything - tinning an end going into a screw-terminal is bad (ought to be punishable really ;)) since the tinning takes away the springiness of the twisted copper, which is, after all, what holds the connection in place and the impedance low.

Anyway, you can buy crimp terminals like this exactly for the purpose and you can buy some that is just the thin tube part.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline StephanieTopic starter

  • Jr. Member
  • **
  • Posts: 46
  • Helpful? 0
Re: Male connectors on screw terminals
« Reply #9 on: August 24, 2009, 11:04:54 AM »
Thank you all.

Haha. In this webpage, I had seen "not tinned for screw terminal use" and I started thinking I had to tin the wires to put them in the terminals.  ;D

http://www.robotshop.ca/lynxmotion-mw-01-cable.html
« Last Edit: August 24, 2009, 11:07:33 AM by Stephanie »
--- Stephanie

Offline SmAsH

  • Supreme Robot
  • *****
  • Posts: 3,959
  • Helpful? 75
  • SoR's Locale Electronics Nut.
Re: Male connectors on screw terminals
« Reply #10 on: August 24, 2009, 03:29:43 PM »
so, was that the cause of the problems you were having?
Howdy

Offline StephanieTopic starter

  • Jr. Member
  • **
  • Posts: 46
  • Helpful? 0
Re: Male connectors on screw terminals
« Reply #11 on: August 24, 2009, 05:55:23 PM »
so, was that the cause of the problems you were having?
Yup. I thought I had to tin all my cables.
--- Stephanie

 


Get Your Ad Here