Re: [CAD_CAM_EDM_DRO] diversity was Re: Cast resin for a cnc mill design - good idea?

Hi Ballendo:
Yes, you are right on the money when you suggest that my bias is toward
"industrial" applications.
Having said that, I hobbied on a hobby budget for years to get to the happy
place I find myself in now.(blowing lots of loot to get decent quality tools
and pretending to myself that I really NEED this stuff)
I spent lots of time on a Sherline mill and a Sherline lathe, but my
perspective comes from the needs of a moldmaker, for precision and
efficiency.
I have always thought that machining without endless frustration requires a
certain basic set of machine characteristics, and I look for these whenever
I either buy or recommend a machine.
Mass and rigidity are the first things I evaluate.
I know from long and occasionally painful experience that rigidity is one of
the most important characteristics for a machine tool, and both the design
and the mass of the components play a role in this.
The reason I belabour this point, is that I sometimes contemplate the
position of a "Newbie" about to embark on his first machine tool building
project.
He's going to spend maybe 500 hours and a couple of grand to realize his
dream.
What a drag to come out the other end with a machine of marginal capability
when he could have just as easily built a winner if he'd kept these basic
principles more in mind.
This is why I so adamantly trash machines like the Shoptask and Smithy.
It's also why I believe that a smaller but well designed machine is a better
choice than a larger but flimsier tool.
It's why I endorse the Sherline 5400 mill and have less favourable things to
say about the 2000 mills.
So my point was not to trash anyone's ambition, but rather to point out that
the trade off between rigidity and capacity should lean heavily toward
rigidity if you hope for decent performance from the machine.
Cheers

Marcus

-----Original Message-----
From: ballendo@... <ballendo@...>
To: CAD_CAM_EDM_DRO@yahoogroups.com <CAD_CAM_EDM_DRO@yahoogroups.com>
Date: Tuesday, April 24, 2001 4:45 AM
Subject: [CAD_CAM_EDM_DRO] diversity was Re: Cast resin for a cnc mill
design - good idea?

>Tom,
>
>Here is where you get to see the diversity of our group! Everybody
>has different ideas of "rigid" and "stiff" and "accurate" and "big"
>and "heavy"...
>
>Over time, and reading LOTS of posts you get to know some of
>the "givens" about the active people on the list. Marcus is into
>industrial CNC, and his comments will be from that direction. Others
>will have different backgrounds to guide their opinions...
>
>Of course you can make a smaller machine (size/weight) in the travel
>range you specified. Marcus knows that too! But he also knows that
>having the weight and size will allow certain types of usage more
>easily, and it's more in line with what he "does" every day (Marcus,
>If I'm out of line here; please let me know!)
>
>So enjoy the diversity, and try to get to know each of our "bents"
>(means set of assumptions used when pondering a problem).
>
>Hope this helps.
>
>Ballendo
>
>--- In CAD_CAM_EDM_DRO@y..., "Tom Murray" <thomasm923@a...> wrote:
>> 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.
><snip>
>
>
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