tkovacs
03-02-2008, 08:28 PM
I have learned so much from this site and most of you have been doing this much longer than I have so with a risk of covering what might be old ground I want to relate what turned out to be a great vacuum hold down idea. I am on my second shop vac powered hold down configuration with a 40x24 inch plenum attached to the table and I have used this to hold smaller pieces by masking off the unused areas with mdf or thin plexi.
It has been working well but I needed to cut a job that was both oddly shaped and bigger then the plenum. Was looking at using some mechanical hold downs but thought possibly I could place the piece on the plenum and mask off the odd open area with a plastic sheet. I tried that - and it worked OK although the lateral holding force was less than ideal, also the plenum was cut with a 1/16 lip to be used for part alignment and this made the center of the piece lower by that amount.
I remembered that we had some soft rubbery material to put under rugs to keep them from sliding around and it works really well. Putting some scraps of this between the plenum and the piece made up for the 1/16" difference but what was really remarkable was the amount of lateral holding force that was added. As you can see from the pictures below the piece extended past the plenum edge by some inches on each side. A good grip could be had on each end of the piece and with the vac on I could not budge the piece laterally by leaning backward with my full weight.
This is a decorative side piece for a kitchen cabinet that is against a log wall in our cabin. The odd side has been scribed to fit the log profile.
Empty Plenum:
6503
Part ready:
6504
After cut:
6505
It has been working well but I needed to cut a job that was both oddly shaped and bigger then the plenum. Was looking at using some mechanical hold downs but thought possibly I could place the piece on the plenum and mask off the odd open area with a plastic sheet. I tried that - and it worked OK although the lateral holding force was less than ideal, also the plenum was cut with a 1/16 lip to be used for part alignment and this made the center of the piece lower by that amount.
I remembered that we had some soft rubbery material to put under rugs to keep them from sliding around and it works really well. Putting some scraps of this between the plenum and the piece made up for the 1/16" difference but what was really remarkable was the amount of lateral holding force that was added. As you can see from the pictures below the piece extended past the plenum edge by some inches on each side. A good grip could be had on each end of the piece and with the vac on I could not budge the piece laterally by leaning backward with my full weight.
This is a decorative side piece for a kitchen cabinet that is against a log wall in our cabin. The odd side has been scribed to fit the log profile.
Empty Plenum:
6503
Part ready:
6504
After cut:
6505