Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Ballendo,
I am real interested in it at the price! If you can throw in a kitchen
sink, I bet I could get my wife to want to buy one to! ;)
However you design it, please, please, look at any way that it might
be extended, and make sure you don't preclude it (this is my big
philosophy/bitch in software design, which I do). Like Alexandre said,
can it do all that stuff? - Which I think translates to:

Is there extra room for tubing or wiring in the cable runs?
Can you remove the tool mount on the Z axis and replace it without
having to recalibrate everything?
How hard is it to recalibrate?
Is the structure robust enough for extra weight?
Are the positioning motors powerful enough for extra weight?
If not, is there room to put a bigger servo/stepper?
How robust are the power supplies for the positioning system?
How hard is it to upgrade them if they are close to their max. spec?
Is the position sensing system you are using at it's limit in the
current design?
How much effort would it take to use a different one to support a bigger
work area later?
How hard to put in one or two more axis later?

Those are just a few things to ask yourself about your
design.

Other questions to ask yourself:

Are you doing this as a hobby, or as a business?
If it's a hobby, then you need to make sure you don't ruin the fun by
letting the business side take over. If it's a business, then you need
to be strict on how much you 'give away' (time more than materials), and
ask the follow questions:

Is your profit ratio sustainable?
You need to make sure that you don't mistake your markup/profit for what
you are getting paid to do the work of getting the kit together and
inevitable tech support. Your time is valuable, and if you don't take
it into consideration, you will find that you get tired of working for free.

How easy is it to take this design to a larger size?
You might as well have a product growth path built in so that you can
add more products without having to do all the NRE again.

How hard is to add accessory kits?
This is another possible revenue stream to look at.
I wish you much good planning doing this!
Richard