Re: Sanity check for homebrew CNC milling machine

Hello,

Airplanes, while not made of mdf, ARE made of wood...

Seems they deal with the F=ma thing rather well...

Ballendo

P.S. FWIW, My first gantry router was made of mdf and baltic birch
ply. 30 x 30 x 4 inches travel, 300 IPM. I DID "pattern" after
aircraft construction for strength with light weight.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "vavaroutsos" <pete@v...>
wrote:

> Chris, Future (www.tslots.com) and 8020 (www.8020.net) have 2"x2" T-
> slotted extrusions for 1/2 the price you mention. Their price lists
> are on line.
>
> The "not much more" was refering to total project cost. Seems like

a

> mistake to spend so much money on motors, drives, bearings, screws,
> etc. then use MDF for the machine frame. I think the weight of the
> MDF alone for the bridge will kill the performance of the machine

not

> to mention any other issues.
>
> ~petev
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Chris Cowley
> <rotorheads@e...> wrote:
> > i completely agree with your logic...
> > but the best price i have seen for the extrusions is about $50
> each. 4
> > foot length if i recall. thats a long way from 10 bucks worth of
> MDF...
> >
> > any more competitive sources?
> >
> >
> > C Cowley
> >
> > On Wed, 2003-10-08 at 19:27, vavaroutsos wrote:
> > > Arvid, take a look at some of the designs offered from the

likes

> of
> > > www.campbelldesigns.com and others if you haven't already. I
> think
> > > you could build a better machine from aluminum extrusions for

not

> > > much more money than MDF. You want the rigidity on the bridge,
> but
> > > not the weight as F=MA.
> > >
> > > I have the following drive/servo motors for sale that seem like

a

> > > better match for your system, especially considering the
> efficiency
> > > or you leadscrews:
> > >
> > > 4 Yaskawa SGDA-04AS servo packs, 4 SGMP-04A3A4 servo motors, 4
> > > DP9320089-2 servo pack to motor encoder cables, and programming
> > > software for sale. All are brand new. The motors are 400W
> (0.53HP),
> > > 3000 RPM continuous, 4500 RPM max, 181 oz/in continuous, and

have

> > > 2048ppr encoders. You can get more info at www.yaskawa.com or
> contact
> > > me and I can email the specs in PDF format (large file). A

power

> > > supply is not needed with servo packs as it's built in. $1300
> takes
> > > everything.
> > >
> > big bandwidth saving <snip>