In Search of off the wall solutions.

Greetings All,
I work for a company called Home Reserve, but a long time ago i join the Creek to search out Laser knowledge. We have 2 SCM industrial CNC routers used to make furniture. And are having issues getting a good seal on the OSB used to make the parts. We are getting about 10-12 inches of mercury being pulled using Ultra light density fiberboard, the pumps dump oil when the pressure reaches around 10 inches. Trying to figure out a way to improve suction to save oil.
Thanks in advance,
Nathan

OSB? I'm surprised you're getting any vacuum benefit. It's not flat, it's often porous...perhaps the ultimate solution is to consider a different material for the parts you are making. In the meantime, you may need even more capable pump(s) to hold that stuff down.

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Originally Posted by Jim Becker

OSB? I'm surprised you're getting any vacuum benefit. It's not flat, it's often porous...perhaps the ultimate solution is to consider a different material for the parts you are making. In the meantime, you may need even more capable pump(s) to hold that stuff down.

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They use OSB because of price difference to plywood. We know that we are losing pressure due to the OSB being porous. the OSB is 2 layers and I am being told that is why we are getting any draw.
The pumps hold it in place, only side cutting on the parts. The issue that i have been asked to figure out is there a way to get the pull stronger so we are not dumping the oil from the pumps. how strong of pumps do you guess we would need?

Your just pulling the OSB down on the spoilboard? Only thing I would think is trying some gasketing if at all possible but if your cutting multiple different shapes and cutting through thats no good. Sealing the edges of your spoilboard, covering any exposed spoil board to kill leaks, or actuated zoning if your controller will handle it. From anything I have ever read I'd think you'd be looking at a mile of vac. Like a couple of 25HP pumps minimum. If they are having these issues with oil and likely production I would think switching to a different material even if its a shade more would be a wash. The initial cost and operating cost of some monster vac would seem to heavily offset a bit of extra material cost but Im sure they've likely done all the long-ball math.

sure, you will cut through the "gasket" but you are already cutting the osb, so you will still be reducing the leakage... and if you are making a lot of the same thing, you can only have vac in places where you are not cutting. drill the spoil board so that there is vac where there is no cut. take your cad models and over lay them to find the best layout. then you could, i think, use some foam similar to sill sealer. thin, closed cell.

Agreed I'd your not random nesting. If a given sheet will have a given set of parts and your only running through the gasket in the same place every time it may help. If parts are randomly nested based on current need... your gaskets will be roached in short order and its back to the cost (time and materials) to re-gasket as needed.

I can only imagine a year or two long excel projection with regards to the cost of a gasketed solution, more vac solution, status quo, or material change solution, would glaringly show the correct course of action.

Kaeser has an interesting story about this problem. Very large vacuums being discussed. Would a roller holddown help? https://www.youtube.com/watch?v=CaSmtuAXWw0

https://ca.kaeser.com/en/compressed-...ufacturer.aspx

What pumps are you using?

Every look into VTLF 2.250SK Becker? Oil free rotary vane

Thank you all for the help! I'll try to keep you up to date on if anything works.

If the material is the cause, would spraying a quick seal coat on the top or side help the Vacuum hold down the work?

If they're standard layouts, a spoil board on the spoil board would be an option I'd look at. In other words, a gasketed fixture that is held down by the vacuum system, and passes it through to the parts.

I've used some generic self adhesive gaskets for doors and windows for fixturing parts. It holds up pretty well, but you need to prep the surface for it to stick. coat of glue or whatever. So there's a fair bit of time building these up.

If they're random, a grid of gaskets that can be replaced might be reasonable. Get them die cut from closed cell foam, so you can peel a shredded one off and stick a new one on in a few seconds. 2 or 3 inch square, 3/8" wide. Basically a poor man's pod setup.

Thank you again for all the different solutions. The table it self is already gridded for using gaskets. What we have tried and worked so far was to add a .5 layer of MDF on top of the Ultra Light Density fiberboard. This added enough resistance to get us to 18 inches of Hg and still have enough draw to hold the OSB in place.

My next experiment is to drill 38,000 3/16 dia holes into the same layering as above and see if we get same resistance and better draw on the OSB. But I am thinking it might be overkill to test it. Run time is over 14 hours.

You've added a flow restriction between the OSB and pump to get the pressure/vacuum up/down. However that works.

Seems like a valve in the line would do the same thing, and be adjustable. At least at the full table level. But it probably won't help with variations from place to place due to the amount of cutting or the OSB itself.

Not likely helpful, just thinking out loud/in print.