Vacuum table trashed

Someone seems to have run several jobs and cut over-lapping scores in the table that range from .02 to .05 deep. The whole top, every zone has been compromised. At the minimum, they should volunteer to repair the top with patch compound and sand flat.

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Are those the new spoilboards? Looks like they might be.

ETA: Ah I’m seeing the back end of the table. They might (hopefully) be the old ones.

No, for something like that the best thing is to just flip them or resurface them. Trying to patch that much will just make a shitty mess if things.

If they are the new ones and weren’t surfaced properly to begin with, then what you see is the inevitable result.

If they arent’t the new ones then great. No huge loss.

And where the hell have you been? Call me. Text me first so I have your number.

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Agreed. That’s too much to patch.

It looks a lot like the spoilboard on our ShopBot in school. Going 0.02-0.05" into the board is fairly standard practice imho, just not allowed at DMS.

I wonder who did that and why that didn’t own up to it.

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I was doing test cuts for a setup using 3/8" (0.15)hard board. The down-spiral cut was only 0.10 deep. There was such a vacuum leak I had to physically hold the board. It should have stuck as though it was glued with contact cement. These destructive channels criss-cross on the table and I expect that the net vacuum is down by 60% or better. This is a complex machine and things do happen. I’m not one to hammer people over a setup failure or basic mistake, but this looks like repeated setups and cuts. It is almost like they moved the next cut down the table after it would no longer hold in the current zone. If this was just a mistake, then that is one thing. If they actually knew they were destroying the surface and kept going I have a difficult time supporting that action. No member I know that uses the MultiCam would be so disrespectful to the other Sig members.
Is there a way we can look back at the user logs and video footage to get a clearer understanding of what happened? If someone will be this cavalier with the most expensive piece of gear next to the Haus, how are they treating everything else? It isn’t like our membership has extra money to burn at this time.

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We do have it on video.

I suggest the person responsible reach out to the multicam team or the woodshop chair to discuss how it happened and what the next steps need to be.

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@mdredmond
I’m not sure flipping them will suffice since many of the cuts have crossed the vacuum boundary lines of the zones. @themitch22 Although I thought the gasket idea was a reasonable approach, if not a great idea, at the time, it seems to have sealing issues. A small amount of saw dust gets between the gasket and the spoil board and seems to greatly increase the slippage between the two surfaces. @bertberaht seems to have already determined the best practice regarding the method of attaching the spoil boards. @bertberaht, I realize as that you are no longer a member, but would you be kind enough to reiterate the spoil board process you embraced in order to reduce the down time on the bed? We also have a broken zone valve that won’t push close. Is there anything special that we need to know in order to return it to the wonderful state you you left it in?

Thanks folks. Maybe we should consider requiring the offending user take retraining with Chris($50 fee) prior to future use of the Multicam, if the board feels that isn’t appropriate, then off with their metaphorical head:)

If we don’t have spoil board material I will be happy to purchase it and donate it to the Multicam sig since we seem to be facing a budget shortfall.

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We have new spoilboards ready to install and surface.

We may be able to get a little more life out of the ones we have by resurfacing them instead of using the new ones.

Flipping doesn’t hurt too much because vacuum is pulled across zones through the edges of the individual boards anyway, unless they are sealed or taped. A little cut or even a bunch aren’t going to make much difference but it’s moot if we surface them.

Frankly, I’m beginning to think the vacuum hold-down is more trouble than it’s worth and when I finally get mine I’m going to put down a 3/4” sub-board and glue a sacrificial chunk of MDF to it. As that gets damaged I’ll surface as needed and when it gets down to 1/4” or less I’ll simply glue another piece of 3/4” to it and surface. Rinse and repeat. I’ll use polymer brads or masking tape + CA glue & accelerant to hold my shit down.

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The one thing we could do to reduce or eliminate these issues is to require people to provide their own sacrificial spoilboard to which they attach their work using any means they like.

I routinely do this. Here are some parts I cut a few days ago with the MDF boards I mounted them to, specifically because I wanted to cut all the way through my part for bottom edge quality.

In this case, the Multicam’s vacuum hold down was still great in that it held my spoilboard down. Then it was just up to me to fix my work to my spoilboard, which I did with 23 gauge pins.

AND the vacuum still pulls through 1/2” MDF enough to hold a sheet (mine was 36x48) down pretty firmly.

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The Brand is Valterra. Available in lots of places. Recommend using the one with a metal gate (or sometimes called paddle) since it has a better gate to shaft connection. Example source: https://www.grainger.com/category/plumbing/plumbing-valves/shut-off-valves/gate-valves?brandName=VALTERRA&filters=brandName&ef_id=CjwKCAiAnvj9BRA4EiwAuUMDf__cuBSi_Pm0SidxZQk0WhO_aekMVezcbrZTDbqnI1fjhKQgkI9yVhoCbKQQAvD_BwE:G:s&s_kwcid=AL!2966!3!431903802175!b!!g!!&gucid=N:N:PS:Paid:GGL:CSM-2294:GN4Z6X:20500731

A valve not closing could be a shaft connection problem or a dislodged gasket within the valve body. When I left, there were some spare gaskets/seals in the brown cabinet. Just know you may have to remove the valve body bolts when working on it … they sorta serve as a union in the piping. Usually a fun job laying on your back in a cramped position with sawdust falling in your face!

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The DMS Multicam certainly suffers from the combination of many users of varying skill and a lack of ownership. When I divided the bed into six zones, I added the option of multiple spoilboard sections under the illusion that damage might be limited to a zone or two at a time which could then be addressed in small segments. I came to realize DMS users are easily capable of damaging way more zones at a time which made the overall benefit of the small spoilboard sections less than hoped for.

To function as best it can, all four edges of each zone need to be sealed. I tested several sealing options and settled on foil tape as the most useful. It has excellent adhesive & is not porous. I would line the top edge of the tape up with the top of the surface and fold the balance underneath. Then I would apply a quality double sided tape to the table at the outer boundary of each zone. Carefully align the segments back on the table so they butt up against each other. Use the table vacuum to suck the spoilboards down so they will bond with the tape. (I used thin double sided tape. Did not want the variable compression of the foam style of double stick.)

Even with this, it will need some oversight and maintenance. The spoilboards will warp with use and the user must address this or the leakage and the dust that goes with it will severely handicap the holding capability.

All that said, knowing what I learned watching DMS folk use the Multicam … I’d try something different now. Since users damage too many zones at a time, the smaller, replaceable sections are not very helpful. I would like to see a test run with a solid full size 5’x10’ spoilboard prepped with foil tape on all the outer edges. Then once it is on the table, cut thin (~1/8" or so) grooves almost all the way through the board on the dividing lines of the six zones. Once these grooves are cut and cleaned out, fill them with a non-porous material (Bondo, Durham’s Water Putty, etc.) so that leakage from zone-to-zone is minimized. Once that is done, start experimenting with ways to prohibit leakage of air and dust around the table perimeter. And you will need to teach enough members how to resurface the entire table so damage can be addressed sooner than later.

Hope that helps. Good luck.

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This was my approach. Additionally, I had an 8 foot board (about 1" wide) that I squared to the table screwed down on one edge to act as a fence. I could throw down a board or sheet and get started easily as I had pre-determined the origin. When I felt like it, I just used some vacuum pods for smaller stuff.

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I think this kind of falls into the bring your own consumables category of tool.

Unfortunately the bed is treated as a consumable by too many members.

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Hi All,

This mistake was on me. I will reach out to the SIG and discuss what I can do to help and how this happened. I am happy to both fix the gouges and/or pay for replacement sections, help with repair, whatever is needed. The earliest I can be available is the evening of either Sunday or Monday.

To be very honest I had not used the machine in years (since about 2017 or 2018) and should have reached out for some pointers before getting started. Clearly the setup has changed since then and from what I read here I did not understand that there was absolutely no touching the spoilboard with the cutter. As michaelb notes I honestly did not realize that .02-.05 cut was actually an issue, I thought it was a standard practice to ensure no onion skin was left.

Obviously I am in the wrong but I believe the way this happened was understandable and the same could easily happen to other members despite good intentions. I would like to help prevent that.

Until then, and until I can contribute physically or monetarily to fix the bed, please accept my apologies.

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To start the converstaion which user/group should I send a message to? I am looking and don’t see a message handle for the Multicam SIG, and I don’t see a Multicam SIG listed in the Wiki. If needed I will continue to post here. Thanks.

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This is the right place and the folks who need to be aware of it are now aware of it. You can PM the woodshop chair (@IanLee) directly for more guidance as to how best to proceed.

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Nobody is here to jam you and you don’t need to fall on a sword. The most important thing when working with the Multicam is to set your surface and max depth after every tool change with vacuum on in every zone in which you intend to cut. If you do that, the machine will prevent cutting into the spoilboards to the extent that they are level and that’s all you can do.

Doing that will probably leave onion skin on your work, which sucks but is easy to knock off with a sander or a flush-trim bit on the router table. I’ve been cutting 4mm material which the latter can’t handle, so I bring my own 1/2” mdf spoilboard in and overcut a few thousandths into it.

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I believe there is a handheld router in the brown cabinet specifically for that purpose.

A metal file also works really well.

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