Re: [CAD_CAM_EDM_DRO] Re: What price all this homebrew CNC??

Excellent points Ken.
I priced out the actual costs of some relatively "simple" CNC projects and
found that they become cost prohibitive as soon as you assign a value for
your time.
It doesn't even need to be a large hourly rate.
For example, I checked out the possibility of building a 2 axis orbiter for
my sinker EDM.
Mark Fraser (from this list) was good enough to point me in the right
direction to begin (my electronics knowledge is abysmal), and even provided
me with a couple of shortie ballscrews.
I subsequently found a used commercial model, and figure I saved about 5
grand in labour by buying that used unit rather than doing the "roll your
own".
Even if I had bought a brand-new unit right out of the box, I would have
come out ahead with a purchase rather than a build!
I estimated my time at toolmaker's wages; not even half my regular shop
rate.
Course, if I was going to build a hundred of them and sell them, 'twould be
a different thing.

I think there are three ways you can justify doing it yourself:
First, if you just gotta do it because it's just too much fun!!
Second, if you're going to get something you just can't buy!!
Third, if you've got enough of the right kind of background that you can do
all of it efficiently, and have more time than jobs or money (but could get
more jobs if only you had that CNC capability)

For basically commercial users like myself, I can buy a ready-to-run machine
for a lot less than I could ever hope to build it for.
(Of course, that's no excuse for a company to gouge the unwary with an
overpriced piece of crap)

Cheers

Marcus

----- Original Message -----
From: "Ken Jenkins" <kjenkins@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, March 11, 2002 11:58 PM
Subject: [CAD_CAM_EDM_DRO] Re: Flashcut 9000 mill and an open question


> > Message: 5
> > Date: Mon, 11 Mar 2002 15:39:33 -0500
> > From: "j.guenther" <j.guenther@...>
> > Subject: RE: Re: flashcut 9000 series mill
> >
> > I think I am in the wrong business! Let's see, FlashCUT takes a $900
> > mill/drill and converts it to CNC with a proprietary system and charges
> > $11,000 for it. MicroKinetics takes an RF-31 mill/drill, upgrades it to
CNC
> > and get's $8995 for it. For those prices the average guy could afford
to
> > make the conversion, learn what he did wrong, do it all over again with
> > another machine and then take the wife on a trip and still be bucks
ahead!!!
> >
> > John Guenther
>
> Well when you have a fully proprietary system you gotta recover those
> software costs right ;-) It does raise an interesting question though
> (other than "where to take the wife" on holiday that is ....).
>
> What are the ingredients of an "ideal" comparable sized system if you
> DYI and what are the total costs? No cheating here ... i.e. "first I
> got a great deal on a 2-year old Bridgeport at a rummage sale for
> under $1,000." Start with something "NEW" off the shelf that is going
> to get converted. Here's some thoughts to get the ball rolling if
> anyone wants to play:
>
> 1. If you want to start with a relatively inexpensive platform it is
> a given you're going to change out the leadscrews and nuts right?
>
> 2. I would want servos/encoders/Gecko drives for accuracy and speed.
>
> 3. CAM could be cheap with EMC (BDI with PC hardware matched as closely
> as I could get to a existing "working" setup with hardware that matches
> the EMC compatibility specs.
>
> 4. So the CAM is "not without some pain ... nothing in Linux land
> seems to be" albeit free ... now what about the CAD frontend
> package and integration?
>
> 4. You've also got the interface from the PC to the all the
> limits/homes/Geckos/spindle& coolant relays .... and, of course,
> those switches and relays.
>
> 5. You need power supplies to drive your servos, etc.
>
> 6. ........ ????
>
> How much? Granted .... not $11,000 but ... how much? Another related
> issue is what "part" of the hobby (presuming this is strictly a hobby
> project and cannot be considered a capital business investment which
> changes all the rules of the game) is one interested in?
>
> Some people, myself included, love tinkering and building the tools
> as much as what we make with them, other people are more interested
> in the process of design and programming (i.e. they more want to use
> the tools to some other "end" purpose). How long would the DYI version
> take you to put together? In the original post above the DYI'er is
> "the average guy", and we'll assume to be generous, with some access
> to "tools" other than a drill and a hacksaw :-)
>
> Ken Jenkins
> kjenkins@...