www.TK560.com

[RFC]

The flocked liner will fit into the bottom half of a wood clam shell type case. I would like it to fit with about a 1/16" gap all around. I will trim the part so that there is a small amount of flare out left at the bottom edge to hold it in the case. As soon as I get one to form correctly, I will post pictures. Thanks
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Cheers, Bob

[RFC]

Saturday update:

I built my riser this morning using pine boards laminated to a block 1.5" thick and used my radial arm saw to bevel the sides
until the top was a hair larger than the base of the tool. I then drilled all kind of holes and routed grooves to allow for good air flow.

This is the top view and below is the bottom.





Here is a closeup of the grooves cut for air flow.



Below is the underside of the new tool showing the vents.



The riser and tool on the vacuum box.



Ok, the wood work is done and we will try another pull.
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Cheers, Bob

[RFC]

Well, I had reasonably good luck with the case liner today using the riser and redesigned tool.



The first couple of pulls revealed that I needed to drill some holes in the top sides of the riser as the plastic would not pull tight
to the riser and I shortened the width of the riser to reveal another row of platten holes.

After that modification, the plastic now pulls tight to the sides of the tool with only small webs at each corner. So this gives me
acceptable flat vertical sides to my finished part finally.

The next problem that I am having is the inside corners of the finished part are quite rounded and not as crisp as I would like.
If I can not figure out how to fix this then it will have to be acceptable.
I think the ideal solution would be to use a plug tool to push down into the tray to force the corners down...BUT, whenever I try to
use anything to push the flock covered plastic, it damages the flocking.

NOTE: the light colored area on the right side of the flocked plastic by the guide rail in the above photo is where my glove covered thumb was pushing
on the sheet. Once the material re-hardens, the surface is durable.

Below is a stack of parts ready for trimming.



The underside of the trimmed part showing the "soft" inside corners.



And a couple of shots of the tray insert in the wood case.







Not bad at all but I just wish I could pull the inside corners down tighter. Any ideas guys?
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Cheers, Bob

[IMMark]

Looks very nice.
As for the remaining "soft" corners, I would say your best bet would be to upgrade to a vacuum pump. Ideally to a 2 stage system. That has helped me eliminate some webbing issues, as tanks allowed me to apply the vacuum in a slow controlled manner. As mentioned earlier, a vacuum pump set up could get you nearly 5 times as much draw.
But still a very nice looking project, thanks for sharing.
Mark

[jdougn]

Bob, the insert is looking good! I hadn't considered that the flocking would imprint so easily while hot. It appears that the entire inside bottom edge along the base of the insert has a slight radius to it. As Mark said, getting that out will probably require a vac pump. You could try getting the plastic hotter (more sag) but that may also introduce more webbing. Regardless, it looks like you're getting there!
dn
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DougN - Just in case you're wondering, I got my "rating" legitimately... by posting aimless drivel, useless advice, and pointless questions.

[spektr]

Vac Pumps are the fix for soft pulls, they are really efficient. There was a note that said they pull 5 times harder than shop vacs, this isnt quite correct. Shop vacs measure suction in a unit called "AN INCH OF WATER" Vac pumps use "INCHES OF MERCURY" and really good pumps use MICRONS, which is a measure of contamination of a theoretical perfect vacuum. Microns begin a ways over 29 inches of mercury. Also, you will never get to perfect vac, but 25 inches will move the world..... Scott.

[kayaker43]

Vacuum cleaners only average 4-6 inches of mercury. The marketing depts use waterlift ratingsto make the numbers seem bigger. So the the claim of 5 times improvement in suction is reasonable. Oddly, size or horsepower doesn't seem to matter much, bigger motors just increase the flow which we don't need. Suction is limited by the impeller stalling. Don't waste money on a bigger shop vac.

What's more important is the final vacuum level achieved at the part. Shop Vacs are insensitive to leaks because of their huge flow so thay finish off near their max, usually 4-5 inches.

When using a real vacuum pump, only the best two stage vacuum systems can finish of at full rated pump vacuum and are super sensitive to even pinhole leaks. Tank type systems always finish off below the pumps maximum because of losses as the tank takes in air but are still a huge improvement over shop vacs.

If you upgrade to a vacuum pump, you will need a storage tank to deal with the leakage. A two stage system would require you to start over and build a leak free machine out of non porous materials. Higher vacuum pulls right through wood pretty easily and will kill the second stages effectiveness.

Using what you have, and adding a pump and tank will easily get you much closer to 20-25 inches even without being optimized. This would let you use less sag and the webbing issues will be less.

Where did you get the cool flocked plastic?
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Doug Walsh
www.build-stuff.com
Hobby-Vac and Proto-Form machine plans

Also other plans books and videos for people who like to build things

[RFC]

Thanks for the tips Doug. I will most likely move up to a vacuum pump and tank in time. Flocked plastic is available from many sources that supply sheet plastic. These ones came from National Velour in RI. Lots of colors to pick from.
www.NationalVelour.com
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Cheers, Bob