Re: k2cnc routers

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "tauscnc" <tauscnc@h...>
wrote:

>
> > I have one.
> >
> > Fred Smith - IMService
> > http://www.cadcamcadcam.com/hobby
>
> Hey Fred,
> That's great! Do you mind expanding on which one and opinion about
> it? I should have asked an opened ended question :)

We had a 14 x 14 x 3 machine with our SYS-3 servo system at the
Cabin Fever Expo in York, PA in January. List price for the bare
frame is now $1150. We used it for live testing of the new homing
script routines. With a DeskCNC SYS-3 and a portercable trim
Router, total price is $2433 plus shipping.

The machine has 4 linear roller bearings and dual hardened guide
rods on each axis and acme lead screws with delrin antibacklash
nuts. Our servo motors mounted directly to the nema 23 motor mounts
and the lovejoy style couplings are adequate for shaft alignment on
a router. I get up to about 100 ipm, maybe more if I tweak
everything better. 70 ipm is rock stable on all axes.

The frame is all machined aluminum with mostly stainless steel
screws. Some of the screws were a tad too short for the main frame
assembly. Too much tightening and they would have stripped out.
Assembling the machine which came in 4 dowel assembly matched parts
was about 5 minutes. The X axis is not quite as smooth as I would
like. I have not had time yet to trouble shoot it though, as the
machine was purchased to quickly get some machining completed. It
took about 10 more minutes to add the motors and wiring.

This machine did not include a worksurface. I purchased an 8 foot
section of pre painted mdf shelf board, cut to 21" lengths at no
charge (thanks to Home Depot).

There was not enough clearance between the gantry supports and the
table top (3/4 thick), so I added a chamfer to both the gantry( 1/4
inch 2 places, probably voided my warranty ;-) and the table top(3/8
inch one place) to assure a clearance fit.

The Y and Z lead screws are not protected from cutting swarf, the X
is covered by the stationary table top, but not fully enclosed. All
6 guide rods are unprotected. My long term concerns are that the
lead screws, drive nuts, guide bars, and linear bearings will get
gummed up and provide less smooth and accurate motion.

I have been using the machine to cut 3/8 scale, prototype saddle
components for a project which will use direct measurements from a
horse, automatically create a saddle design and 3D contouring
toolpaths in Vector Cam, then cut the parts using DeskCNC on the
K2CNC router.

My prototype stock is a standard pine, 2 x 4 board, and I have been
able to consistently machine the material at 1/4 in depth of
cut, .150 in stepover. Our machine included the Porter Cable trim
router bracket. Using a PC trim router, with a 1/2 dia. cove bit(
1/4 shank), I am able to rough out the parts at 25 ipm feed rate.
The spindle starts to over load if I push it much faster. Some parts
of the contour are 1 inch deep, so the bit is sticking a ways out of
the spindle collet. It's pretty exciting because with this small of
a machine, all the noise, cutting, and chips are RIGHT THERE IN YOUR
FACE!

No dust collection is available with the machine so make sure to
consider that as it is required for any CNC router.

I have evaluated several machines in this size/price range over the
last few years. This is one of the better ones, except for the
protection from dust buildup on moving parts. I prefer a machine
with V-rollers on X and Y.


Fred Smith - IMService
THE source for low cost Cad-cam and Desktop CNC
http://www.cadcamcadcam.com/hobby