The reconfiguration of the Multicam was completed today. It has new and different features that should eliminate the need for screws being driven into the spoilboard.
Summary of work accomplished in the past 10 days:
Identified the performance problem on the Republic Vacuum Blower (bad seal, inboard side of blower)
Recalibrated the vacuum relief valve to achieve maximum vacuum performance for the blower
Converted the previous vacuum distribution system below the spoilboard to a more efficient plenum design.
Separated the spoilboard into six 30"x40" zones, each with an independent vacuum source
Sealed the spoilboard zones to the vacuum distribution plenum
Installed a vacuum supply valve to each individual zone
Extended the vacuum valve handles to the front of the table for easy access.
Obtained 30" wide rolls of plastic coated freezer paper to use as a vacuum mask when necessary.
Surfaced the spoilboard.
So, screws are not needed on the table. They are not wanted either!
The available vacuum holddown force is now at excellent levels. By closing idle zones and using freezer paper to cover unused areas of active zones, high vacuum levels can be achieved and focused on the part(s) you are needing to hold down. Only small items, very slick items, or items that do not have a flat bottom surface should need anything beyond table vacuum.
Should you have one of the harder to hold items listed, please take approaches such as:
Use double sided carpet tape or equivalent (there is some in the blue bucket under the table)
Screw your work to a separate board that is larger and flatter than your item. Hold that down with vacuum
Put masking or blue tape on the table and on the bottom of your work. Then use CA (instant) glue on the tape surfaces
For a sheet of ply that is mostly flat, but is warped upward at a corner: try carpet tape or tape & glue.
Google for other ideas!
Did I mention … no screws into the spoilboard? Just wanted to be sure! It’s not just that the screws will damage the spoilboard … they will also damage the vacuum plenum underneath … much harder to repair/replace.
Lots of Makers have put elbow grease into this project and the result is a far better CNC router for all to use. Thanks to those who helped, apologies to those who had to work around our activity or reschedule your Multicam work. I am confident you find it a better machine when next you have opportunity to use.
AND let me or another member of the Multicam SIG know how it works for you and about any problems or suggestions you would like us to address.