Homebrew PCBs

Hi Ballendo
I'm interested too but is the power supply an area in which a slightly
lesser kit might be considered. Australian AC mains supply is 240 VAC. 50 Hz
so a kit designed for 110 volts, 60 Hz would have some redundant pieces
here, probably also in the UK?
Bill
----- Original Message -----
From: "ballendo" <ballendo@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, March 26, 2004 8:12 PM
Subject: [Homebrew_PCBs] Re: 500 buck CNC drill update


> Brian,
>
> The kit will be complete, including structure, motors, drives, wiring
> and software. (The only item in "debate" is whether I'll include a
> drilling spindle or not.) IMO, The tech support issues from offering
> incomplete kits are not worth the hassle and time for a product so
> low-priced.
>
> There is NO difference between the 800 and 500 buck machines because
> they are the same machine! (At this point, anyway. Explanation
> follows.) Here's the issue...
>
> Even the least expensive cnc drill needs certain things. There is
> a "base" cost for these things which cannot be made less. In this
> case, to be called a CNC PCB drill, you need AT LEAST:
>
> 2 motors for XY drive,
> 2 screws,belts, or other means of moving the axes
> 2 drivers for the motors
> 1 solenoid for actuating the drilling, and a driver for the solenoid.
> rails and bearings for the xy and z axes
> Support for the pcb
> a spindle, or the attachment point for an easily available spindle.
> The machine structure to put this all together, including hardware,
> etc.
> A power supply
> Wiring and connectors
> Software
> Shipping packaging
> A means for customer support and answers to customer questions
>
> Without ALL these things, you don't have a viable CNC drill.
>
> So you play with each category trying to get the best overall value,
> within the 500 buck limit that you guys have set...
>
> And you find that if the machine is made just a bit bigger,stronger,
> faster, then a LOT more can be done than JUST pdb drilling. But as I
> wrote in a post a few days ago, you ALSO find that this "just a bit"
> costs MORE than "just a bit" more...
>
> Start with this: A 5"x8"x1/2", moving table, XY stepper ,solenoid Z,
> pcb DRILL only--(which means the guide rods/rails can be VERY light,
> just look at what the Roland machines use!) In other words, the
> barest minimum that could properly be called a CNC PCB drilling
> machine. (This is what I had in mind originally for a 500buck cnc
> drill.)
>
> Then, luckily for you guys, feature creep kicked in<G>
>
> Anyway, going from that to an 8"x10"x2", 3 stepper, full 3d capable,
> STURDY 3/4" rails, acme drive, AB nuts(because a pcb drill(only)
> doesn't need AB if the software always approaches the drilling point
> from the same direction), A stiffer structure to accomodate the much
> thicker items likely to be placed on the table to be cut(like
> electronics enclosures, for cutouts/engraving), which requires an
> increased throat that changes the moment loads and calcs
> (geometrically)--not necessary if 1/16 pcb material is all you need
> to accomodate, AND all the other related things that make the result
> much MORE than a CNC pcb drill...
>
> In this case it all means a difference in selling price of about 300
> bucks. As I wrote, each "little" upgrade or improvement causes a
> chain reaction to other parts of the design. But for me it's hard to
> use 1/2" rods, when 3/4" will cost the same in volume... And to sell
> a moving table, when I KNOW a fixed table is better for a wider
> variety of things...
>
> Now what I have to decide, is whether I think I can make any profits
> selling an 800 buck machine for 500. And whether simply providing the
> 500 buck CNC PCB drill ONLY, is a better choice, business wise.
>
> Or whether the increased usefullness is worth the 300 bucks to my
> potential customers?
>
> My current belief is that the bigger, better machine will be more
> useful to more people. So I mentioned that what I'm thinking I will
> do is to initially offer an 800 buck machine for 500. But to pretty
> quickly increase the price to 800, and bring a new machine that is
> pcb drill only to market for 500 bucks.
>
> I have no interest in providing a "partial" solution. So whether 500,
> or 800, or 1000, or 5000; my machines are complete. Just with
> differing capabilities of size speed, and "duty cycle".
>
> Side note: I used to work for a copier company as a Service Tech. We
> had a machine that was rated 5000 copies per month. Of course this
> was based on a 20 day work month, so it was REALLY rated for 250
> copies per day. I had a heck of a time getting this point across to
> my customer who had monthly breakdowns due to running 2-5K month end
> reports... "But they said it was good for 5000 copies per month!"
> (that's what duty cycle means.)
>
> Hope this helps,
>
> Ballendo
>
> P.S. About the only "time consuming" step I "could" pass on is the
> pcb assy. and wiring. Since this group obviously can do that, perhaps
> that's something I'll consider...
> But I have to stress that my experience with low-priced products
> shows that customer support can kill profitability quicker than
> almost anything else... So it all has to balance. Because I'm not
> doing this for grins<G>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Brian Schmalz <brian.s@l...>
> wrote:
> > Ballendo,
> > I'm totally interested in the $500 machine. For me, $800 is
> less
> > interesting. What differences would there be between the two
> machines?
> >
> > What software would you need to run it? I'm assuming the $500
> includes no
> > electronics, correct? I really like the idea of giving it the
> flexibility
> > that the user can modify it to do other (simple) things like pnp,
> routing,
> > front panel milling, etc.
> >
> > Are there time consuming steps in the assembly that you can let the
> > user do (more of a kit) to save cost? I'm happy to spend 40 hours
> > putting together a kit if it will cut $100 from the cost. (Just
> > cause it's fun to put together kits!)
> >
> > *Brian
> >
>
>
>
>
>
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