molex connectors

i figured this topic deserves its own thread.

i had a big, long reply typed out that must've not been sent. basically, i laid out the reasons i think we should use the molex connectors for the motor hookup on the universal board.

1. cost. based on mousers prices, its cheaper to buy the molex header than to buy the AMP header + connector + crimpons
2. work. its much simpler to splice on the pre-made molex connectors to your motors / extruder than it is to have to create the connectors + splice. our project is already enough work as-is
3. amperage. this can handle higher currents... so there is room to grow. of course, the limit is probably on the board and not the connector.
4. molex are .200 pitch width headers... you can easily use your .100 connectors if you dont feel like doing it my way.
5. we're getting the connectors for free from the PSU. it feels wasteful to have them there and not use them!
6. i already created the 4pin molex kicad drawing and footprint. it would save me time =)


hopefully this will be enough to convince you, but if not then perhaps we should have a vote on it? we could just use the polling stuff in the forums here. i'd rather you guys just agreed with me instead :^)

Whilst I agree with Zach's points, I've also spent the day wiring up
Darwin, and I've gotta say that, after Adrian showed me how, the connectors
are pretty simple. They might take a tad longer (I timed Adrian at 20 secs
per connector... pdq!), but the fact you're non-branded simple parts and
tools certainly appeals from the purist side.

Anyway my point is: why not simply spec standard connectors, but put in a
line, by the way if soldering ain't your bag here's molex .

eD

--On 05 May 2007 01:09 +1200 RepRap Forum Mailer wrote:

> Author: ZachHoeken
> Username: ZachHoeken (74.9.71.138)
> Subject: molex connectors
> Forum: Developers
> Link: [forums.reprap.org]
> Approved: Yes
>
> i figured this topic deserves its own thread.
>
> i had a big, long reply typed out that must've not been sent. basically,
> i laid out the reasons i think we should use the molex connectors for the
> motor hookup on the universal board.
>
> 1. cost. based on mousers prices, its cheaper to buy the molex header
> than to buy the AMP header + connector + crimpons 2. work. its much
> simpler to splice on the pre-made molex connectors to your motors /
> extruder than it is to have to create the connectors + splice. our
> project is already enough work as-is 3. amperage. this can handle higher
> currents... so there is room to grow. of course, the limit is probably
> on the board and not the connector. 4. molex are .200 pitch width
> headers... you can easily use your .100 connectors if you dont feel like
> doing it my way. 5. we're getting the connectors for free from the PSU.
> it feels wasteful to have them there and not use them! 6. i already
> created the 4pin molex kicad drawing and footprint. it would save me
> time =)
>
>
> hopefully this will be enough to convince you, but if not then perhaps we
> should have a vote on it? we could just use the polling stuff in the
> forums here. i'd rather you guys just agreed with me instead :^)
> _______________________________________________
> Developers mailing list
> Developers@reprap.org
> [reprap.org]




_______________________________________________
Developers mailing list
Developers@reprap.org
[reprap.org]

heres the thing: molex is a standard connector! its on every hard drive known to man. we should be trying to make this thing as simple as possible and as cheap as possible... using these connectors accomplishes both in one fell swoop.

you still get the joy of making your own connectors. you have to do it for the power, the signal, and the sensor connections. already right there you are looking at an hour of work making all the cables. lets save us and the rest of the world a bit of time by reusing the extra parts from the power supply.

Quoting RepRap Forum Mailer :

> heres the thing: molex is a standard connector! its on every hard
> drive known to man. we should be trying to make this thing as simple
> as possible and as cheap as possible... using these connectors
> accomplishes both in one fell swoop.
>
> you still get the joy of making your own connectors. you have to do
> it for the power, the signal, and the sensor connections. already
> right there you are looking at an hour of work making all the cables.
> lets save us and the rest of the world a bit of time by reusing the
> extra parts from the power supply.

I have to say I don't agree. They are simply too big for all but the
input to the comms/power board. And you have to use 2.54mm pin headers
for all the other connectors on the board anyway (2 pin and 3 pin) so
one extra 4 pin is neither here nor there. And, if we did do it, we
either we stick with the wire diameters that are used for those Molex
connectors, which will be far too thick and stiff for the stepper
connections, or we'll have a big connector with thin wires coming out,
and that just looks like bad engineering.

And as Ed says, wiring up the connectors is a really fast job anyway -
it takes me about five minutes to do all the ones for one board.

Also I've frozen the stepper-driver PCB design at
[reprap.org] - after freezing it should
be that only bug fixes are allowed up to the release, and this isn't a
bug. (We don't want to have to redo the wiki pages with different
photos, either.)

Incidentally, I was really encouraged that the biggest thing we all
have to disagree about in the Darwin design is which stepper motor
connector to use :-)

I'm happy to be outvoted...

Best wishes

Adrian

Dr Adrian Bowyer
[staff.bath.ac.uk]
[reprap.org]
_______________________________________________
Developers mailing list
Developers@reprap.org
[reprap.org]

okies, i buckle. powercomms/universal going to production tomorrow or monday. i'll blog the boards soon. =)

Zach --

Do you still have the 4pin molex kicad drawing and footprint? If so can you share a link?

Tom Sayles

Here's one for gEDA/pcb: [github.com]

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY