Re: Cast resin for a cnc mill design - good idea?

At the risk of flogging a dead horse, I'd like to make one more post
before I go off and ponder all that has been said in this thread.
First, I'd like to thank everyone that contributed, there has been a
lot of good advice given.

Marcus wrote:

>Hi Tom:
> I think you have a good basic approach for this project, but I am
>concerned that you have underestimated the size of a milling machine

with

>the work envelope you have described.
>A capacity of 18x12x8 implies a pretty large machine; all up weight

is

>probably going to run several thousand pounds if you want to get

decent

>rigidity.

Wow! Talk about biting off more than I can chew!

I've had the new Taig mill in mind when I came up with those
dimensions. One of their mills has an envelope of 18"x 9?" x 7?". The
mill probably weighs in at under 100 lbs. Of course, I would like to
end up with a mill that is tighter than the Taig, but I
have no use for a Bridgeport sized mill…

I am in the jewelry industry and would use a mill to make models,
molds, rapid prototypes and various one-off items. I would be
machining non-ferrous metals, for the most part. So obviously I don't
need something that I can mill transmission housings on. Why have the
extra length, then? Well, this probably won't be the only machine
that I will ever build. Having some extra travel would help out in
the future. Of course, if I am being unrealistic, I can always scale
everything down. It's time to sketch this out in Rhino.

Marcus continued:

>For an 18" stroke machine you need to have a minimum of 36" of

guiding

>surface if you want to keep the table fully supported

Is it alright to have some overhang on the table? Let's say about 5
to 6 inches on both sides (remember - no transmission housings)?

Thanks and a tip of the fez to all,
Tom Murray