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

No, I didn't forget...

Hello again,

Just wanted to say that the pcb drills/cnc mills I'm bringing out are
still on their way...

Still expect to be taking orders this month for delivery late this
month.

The details and pictures that I promised are coming THIS week instead
of last week. Two reasons. First, I had a really tough time with a
cnc control program last week. It was appearing to work correctly;
but the pulses to the motor were incorrect. It was a VERY subtle
thing, and it took a few days of my time.

Next, there have been some major design changes in the machine. I got
rid of the 3/4" round rails. There are HUGE benefits for both of us,
mostly for you, but an important couple for me too<G> I'll put "your"
benefits at the top<G>

First, the machine is stiffer. Not only have the changes made
component parts stiffer; it has also reduced overhangs and cantilever
ratios. More importantly, the rails have gone from end supported
round rails, to fully supported rectangular rails. Even if this were
the only benefit, it would have been worth making the change. But
there's more. A LOT more...

For instance, it is MUCH easier to build. AND much easier to adjust.

Third, it allows for easy upgrade to bearings and rails capable of
allowing this little machine to mill STEEL. Yes, you read that right.
At some point down the road, these guys will be able to mill steel.
(A rails/bearing upgrade will be required, and offered.)

Fourth, the new bearings have a greater load capability, and are
preload adjustable. The old ones weren't; but they were replaceable.
The new ones are replaceable too, but expected life before needing
too is far longer.

Fifth, the machine TRAVELS HAVE INCREASED. It is now a 10"+ by 10"+
by 2-1/2" machine! (BTW the "+" means that the 10" travel is AT LEAST
that much. There is additional travel beyond this, and some of it
will be usable. I've always thought it was a bit unfair to say a
machine has 10 inch "travel", when that's really the dimension of the
rails minus the sliders. You never can get travel completely to the
ends, IME. For example, this machine has 13-3/8 rails, and the Y
slider is 2-3/4 wide. so the POSSIBLE travel is 10-5/8. I just call
this 10"+, even though you will likely get 10-3/8 or so...

Sixth, in addition to the longer axis travels; you can work on larger
workpieces. The space between the gantry uprights has increased, and
a motor cable which WAS "inside"--between them, is now "outside" so
the full available width is usable for larger workpieces. Figure it
for work that is 13-1/4 max width, of any length, and up to 2-3/8
inches thick.

Most everything else is as before. You still get microstepping
drives, it's still a COMPLETE kit. The wires are still running in
tracks, so you don't have the commonly seen IMO "half-done" flying
wires everywhere, and I won't have to "doctor up" the pics so you
don't notice this fact before buying one...(As many small cnc
makers/builders seem to do<G>) Still leadscrew drive with anti-
backlash nuts. Still a HUGE range of accessories planned and being
implemented, including fourth axes: vinyl cutting(TANGENTIAL)and
rotary tables, "Home shop" pick and place, board inspection--camera
mount and S/W, turning attachments, high speed spindles,
machine "look" customisations, and much more...

It will still take a few hours to put together, but IMO, those hours
will be less frustrating due to better accessibility of needed and
desirable adjustments. This is a very nice machine.

And the best part? It's STILL only 500 bucks for you guys (and gals)
on this list...

Now to my benefits:

A) I was pushing the "limits" of MFG. tolerances, and asking a LOT of
the bearings I was using. That's part of the reason I was using 3/4
inch rails; it reduced the PV (pressure/velocity coefficient). Also
the fact that the round rails were end-supported only made it a good
idea to use a larger diameter. NOW, I am WELL within acceptable
bearing loads. My allowable mfg. tolerances are greater. My suppliers
are breathing easier, which is good for both/all of us<G>.

B) Making it easier for you to build and adjust makes it easier for
me to support.

C) I've eliminated two suppliers. The logistics of MFG. will be
easier. Our cost to mfr. "may" be lower, but only time will answer
that one for sure.

The downside? This "lost" week of re-doing things, money spent for
parts that now won't/can't be used, and I DID lose a really great
little place to join the Z/A/C motor and it's cable inside a housing.
(Still working to see if I can get those wires back "inside"
and "under cover" (And I prob'ly WILL; I hate dangling wiring<G>)

Thank you for your patience, and all the expressed interest. Pictures
this week<G>

Ballendo