RE: [CAD_CAM_EDM_DRO] Re: now ELS on T-CNC

Quote: " It's a bit like the perennial. "I've
got a new linear bearing design that costs nothing and uses skate bearings;
it's just as good as a THK linear bearing".

Then there is the other re-occuring think that THK is the best thing to use all the time on every thing. That is simply not the case. THK is very high quality, very close tolerance (tight) and precise linear device. However, the aforementioned is recipe for binding and excessive friction. Which increase with dynamic load. Looking at the guides themselves, one can measure the distance of actual contact. Much shorter than the guide length. Now impose a twisting load 20" away and it's easy to calculate the amount of force that will be applied to the THK components themselves. Dual cars at greater span will alleviate this, but also add to the restriction in motion. And add cost as well. THK are a great linear component, they have their place and are clearly not always the best thing to use. Their intended use is what the industry uses them for, traversing and position automation components for pick, assembly, etc.

Ron


Paul Kelly <tech@...> wrote:
At the risk of getting kicked off this list too. You don't want an ELS. I
built this one for a mate for the only reason I can think of to do it. He
was (his words) "Too old to figure out the gears". Seriously, all the other
reasons for implementing an ELS boil down to: "I'm intimidated by the
apparent complexity of the whole CNC thing". I've built two ELS's one
software, one hardware. They are not cheaper than CNC. You need to go
through the same setup/tuning process. To express it in terms that may be
more familiar to this lists membership. It's a bit like the perennial. "I've
got a new linear bearing design that costs nothing and uses skate bearings;
it's just as good as a THK linear bearing". Well (and I base this on having
implemented a couple and seen them in use for about a year now) and ELS just
doesn't offer any advantages over CNC..

I realise however that there are a whole bunch of people who are looking at
their skate bearing routers and calling me crazy, so I'll grab the latest
version of the ELS code from my old buddies machine next time I see him and
post it somewhere.

PK

-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of victorf57
Sent: Sunday, 14 October 2007 1:21 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: now ELS on T-CNC

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Paul Kelly" <tech@> wrote:
> >
> > I turn tapered threads with turbocnc at 700-1000RPM.
> > See:
> > http://video.google.com.au/videoplay?docid=-3207102266117280799
> >
> > I've built an ELS on TCNC by modifying the screens and it runs on

$100

> > hardware..
> >
> > PK
>
> Is a copy of this available ?
>
> Dave
>

I would also be interested in seeing it.
I don;t have my lathe cnc'ed yet but I'm looking at options.
Victor

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