On Sun, 20 Jan 2013 11:18:59 -0500, Steve Walker
wrote:

On 1/19/2013 19:39, Bob La Londe wrote:
I finally decided to make a vacuum formed polystyrene cover for the
encoder on the front of the big mill. Seems pretty straight forward.
I've got my first vacuum box finished except for the port to put the
vacuum hose in. I noticed a lot of the DIY guys make a hole for the
smaller vacuum hose even though they have a full size shop vac with the
big hose. Is there some reason for that? Seems to me that the larger
port for the larger hose would evacuate the box faster and form the
plastic quicker before it cools. Am I missing something obvious?


Vacuum pump has more vacuum than a shop vac. Should suck down quick
enough, and get better corner forming.


The "average" vacuum pump is WAY too slow. You would want a vacuum
reservoir with a sizeable gate valve to apply the vacuum quichly to
the former box.


(I have some PETG on the way to play with in case I don't like the way
polystyrene forms or holds up)

If this goes well, I have all kinds of ideas for vacuum forming...