Re: [CAD_CAM_EDM_DRO] Re: Vacuum table

The company I work for uses Porex sheets as a consumable table surface.
The cutting tool is a "pizza wheel" blade, or a tangetial (drag) knife,
so the surfaces last quite a while. Might or might not be useful for
your application.

Another thought is to use that grippy plastic mesh like you use under a
hand router on top of a table with multiple holes. The mesh helps
disperse the vacuum.

For any type surface, keep some plastic film on hand. When a section
cuts through and is complete, throw some film over it to reseal that
area.

Regards,
JJ

On 14-Aug-2005, at 17:47, Denis Casserly wrote:

> I haven't tried it but from what I've read porous hold down boards are
> used by
> guys who cut out plywood frames for the furniture manufacturing
> industry.
> It's very inefficient - you need a huge vacuum pump to overcome the
> resistance to airflow through the MDF, so I think the table is zoned
> up with
> valves controlled with a local PLC which monitors the spindle position
> and
> closes off all the other zones, in order to keep the pump size down.
> The
> pumps are huge and expensive because they deal with a 4 by 8 sheet of
> board.
> There an outfit in Langley BC that sells routers using it (Pacific
> Technology
> or some name like that) You could also check out a website named '
> Woodweb' -
> that's where I first heard of it.
> cheers,
> Denis Casserly
>
> On August 14, 2005 03:21 pm, davegsc@... wrote:
>> A couple of years ago, I read somewhere that MDF is porous enough that
>> you can provide a vacuum right through it with a ShopVac - no need to
>> drill millions of holes in your bed.
>>
>> If that's true, that would make it easy to replace sacrificial
>> surfaces.
>>
>> Anyone tried this?
>>
>> Dave
>>
>>
>
> <sniped by moderator, please remeber to trim your posts>
>
>
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...,
> timg@...
> Moderator: pentam@... indigo_red@... davemucha@...
> [Moderators]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
> aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach
> it if you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be
> a sister site to the CCED group, as many of the same members are
> there, for OT subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING
> THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

---
Help everyone. If you can't do that, then at least be nice.