partial P112 kits

Tony Duell ard at p850ug1.demon.co.uk
Tue Jun 22 13:33:26 CDT 2010


> > Because there's no pain, it's actually fun. And if I do it myself, I =
> can=20
> > use the lead/tin solder which I still believe is more reliable.
> 
> I'm not convinced either way on the "reliability" angle.  And, I think =

A couple of metalurgists have said to me that lead was originally used in 
solder for good reasons... I am not at all convinced that the lead-free 
alternatives are as good.

> decreasing the amount of lead in my diet is a good thing, so I'm "okay" =
> with the Pb-free solder nowadays.

Strangely, I have never had the urge to eat soldered connections.

> 
> >> Note that it wouldn't necessarily make the kit any cheaper.  The cost =
> of =3D
> >=20
> > What has that got to do with it?
> 
> In my experience of making and selling kits, a lot of people think "hey, =
> if I do that myself, it will make it cheaper."  Dave and I have gotten a =

Whereas I know that a kit is likely to be more expensive. Producing the 
parts lists, assembly instructions, counting out and packing all the 
little components is likely to be a lot more expensive than having the 
board assembled. 

But I have never built a kit to save money. I build kits (a) as a 
relaxation), (b) because I understand how it works, (c) becuase I can 
then repair the device if need be, (d) I can make modifications if I want 
to, and so on. 

And many, if not, all of those advantages go away if the PCB comes 
pre-assembled. Put it this way, if I can't solder the part on the board 
in the first place, I am going to have _big_ problems desoldering and 
replacing it should the need arise.

> However, given that the board's design is for surface mount parts for =
> the CPU, the FDC, and a couple of discretes, it might require a board =
> redesign, which Dave has indicated to me he's not interested in doing at =
> this point (except for fixing a few of the quirks in the previous rev).

So hang on, if most of the board is SMD and comes pre-done, just what do 
you get to build yourself?

-tony




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