as my vacuum source for this exercise as it is portable, efficient and I already own one (actually two) and I had a swag of spare miscellaneous Nitto connectors and plenty of hot air to spare.
I initially designed a very basic base to attach anchor the cup and anchor it to a MFT style bench using my TSO Loc-dogs,
To keep it secure, I made a “Y” key
to wedge the female coupler against the base of the jig,
While toying with this concept, I found that the cup was an ideal vehicle for holding any reasonable sized object (with at least 1 flat face) and it would be nice to be able to take it away from the mount without breaking the seal even for larger pieces.
It was back to SketchUp to try to devise some sort of locking mechanism. After a number of attempts, I came up with the current design,
The white in the picture is the MDF jig and the timber represents my MFT style workbench top.
Again I chose to use MDF as I wasn’t sure of it’s efficiency, but more so because of availability and cost compared to solids. I also found that through the process of lamination, I could profile each layer individually without having to maneuver into tight corners and spaces.
The design incorporated a slider that would captivate the cup working on the geometry of the attaching air hardware,
To captivate the vertical movement, I measured the gap between the jig and the top of the female air coupler. It was 17.5mm… Getting out my slide rule, I pushed the on button of my calculator and came up with 5.83333333333mm per layer,
which I rounded down to 5.8mm due to the limited slide rule tolerances… sanded some 6mm MDF down, and the 3 x 5.8mm,
gave me the 17.5mm "lock washer",
to make up the appropriate locking mechanism
While the holding force can reach up to 360lbs (keep forgetting it has a metric switch) thin material, especially 3mm MDF or softwoods , has the tendency to get sucked into concavity so there is a limit on small pieces.
Of the 3 cups, it seems that the 50mm is too soft for bench clamping, however is ideal to grab small parts and manually maneuver them… for example, over an upside down ROS, with 50mm cup (on a 100mm x 100mm item)
and 75mm cup
The 75mm and 100mm function similarly, with the exception that 75mm can hold smaller pieces…
and you have to watch thin pieces as the suction will concave them,
To extricate the job, including the cup, the lever on the bottom has to be pushed to the right
which will slide the bracing mechanism out of the way,
Permitting the kit and caboodle to be taken out of the base and do whatever you like… The only limitation is that the Grabo will need to be moved side by side to maintain suction.
Furthermore you are not restricted to small timber but can be used for those odd shaped items,
how else would you clamp that if you were crazy enough to want to?
Initially, I was concerned about sawdust being sucked into the Grabo (in one of the videos), however, after RTFMing I realised that there is a removable/cleanable/replaceable filter in the Grabo base.
This is now redundant,
so does anyone need a tuning fork for their next cutting board project?
For those that hate reading as much as I do, here’s a couple of videos what’ll make you enjoy reading after watching,
Stay crafty CRAFTISIANS!
If your first cut is too short... Take the second cut from the longer end... LBD