Stepper Board kit always out of stock

Hi folks

Ive been looking for a kit of parts for the Stepper Driver Board 2.3 for a few weeks now. Ideally, I would like a fully assembled one as Im more than a little intimidated by SMT manufacture! (more on that later!)

Anyway, does anyone know of a supplier for the 2.3 kit that currently has them in stock? (ideally in the UK or Europe, as it will save on shipping cost and air miles!)



Also, SMT - I understand that everyone keeps saying how easy it is and it does look quite simple but what if you dont have a hot plate? (We only have gas!)

Could I use a heat plate and put that on top of the gas ring, then gradually increase the temp until the bits start to pop? If I use a heavy plate (like a thick copper bottomed frying pan), the temperature should be pretty even.

Ive just realised that all the reprap stuff uses bipolar motors, and I have a couple that I was going to have to build a H bridge for so the 2.3 kit is a dream come true!

Phil

Hi Phil,
I have just this gas/no hotplate problem - but someone pointed out that a hotplate is just some flat metal over a heating source, so to use a frying pan or something similar over the gas ring. I am looking for a cheap frying pan to be used solely for the soldering.
If it doesn't work, then I'll look at getting an electric hotplate (~£25 Argos/eBay). I'm going to try with an opto endstop first, as they're small and if it all goes awry it'll be cheap to start again!

Hazel.

At work I often do soldering of SMT with a temperature controlled iron, regular 60/40 5 core flux solder wire, and a syringe of flux.

So as long as your temperature is low enough, like 300 degrees, this will be fine for soldering most SMT parts, however when soldering to a ground plane (even if it has thermal relief), I am often forced to turn the heat up, sometimes up to 350 degrees centigrade.

From what I can tell, the solder paste that comes with the kit is a waste, and al the parts are huge compared to what I have to work with on a daily basis
Ie 0402 resistors, 0.635" pitch on integrated circuits.
I also sometimes used what is called a "bath" or "reflow" tip when soldering down ICs

It was me who suggested a frying pan. I haven't tried it. a solid sheet of copper should work as well. In fact, anything that will spread the heat out *should* work - a solid metal sheet (baking tray) might spread heat enough to work?

I also saw another comment about doing SMT soldering in a standard oven - although the temperature control is not that accurate, you can use a kitchen thermometer to monitor the temperature (or a glass door and a strong light to watch it).

SMD tutorials:

[www.scienceprog.com]

[www.seattlerobotics.org]

[www.sparkfun.com]

I'll have to get some of the new boards and try it (mine are older through-hole versions)

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Reprapping blog and other rants: [renoirsrants.blogspot.com]
My Reprap: [sites.google.com]

On this tutorial:
[www.sparkfun.com]

I noticed a comment about adding a high-temperature liquid to help heat transfer (i.e. adding a dribble of vegetable oil). I'd previously wondered if this would help, given that so much of cooking relies on heat transfer at various speeds and temperatures - see Heston Blumenthal's stuff or here :
[www.cookingforengineers.com]

Checking out the smoke temperatures for various oils
[en.wikipedia.org]
it seems that Canola/rapeseed oil (vegetable oil in the UK) handles temps over 230C so should be over the melting point of the solder paste.

A light coating over the bottom of the pan would help the heat transfer and distribution to the bottom of the board.
'deep frying' the board would probably move all the carefully placed components.

If I ever get round to it, I'll give it a try.

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Reprapping blog and other rants: [renoirsrants.blogspot.com]
My Reprap: [sites.google.com]

I don't know if you would want to do soldering in your oven and then cook
in it again...that could cause some health issues and/or spouse issues.

But, I do use a toaster oven to do soldering with. I bought it second hand
at a yard sale for $5 (US). The temperature setting on it wasn't exactly
accurate (+/- 50 degrees Fahrenheit), but it worked. I later added a thermocouple
to the inside of the oven with feedback to a PIC to do the temperature control
and a digital temperature read out, which may have given me better joints but
definitely made the oven a little more geeky. :-)

For boards too large to fit in the toaster oven I use a baking sheet
on an outdoor propane grill. Heat regulation is a pain, but it will work
for that one board every couple of years that is huge.