Air Cup Clamps.

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Boys and Girls,
 
After my introduction to the Fe$tool VAC-SYS and Grabo, my only regret is that it took me sooo long to get on the bandwagon for air assisted clamping.
 
Nevertheless, other than the shekels up front, they both have the limitation of bugga all use on small items asis.
 
Just an FYI...  I apologise if some of the happy snaps seem blurred, as they were extracted out of the videos I made for YouTube, and I have no idea of what BS narrative/picture are to follow here.
 
Now this is not a product spruik, but a method of making a small parts air clamp using a vacuum pump... if you have one and if you don't, get one and come back and read on.
 
I was tossing up whether to post this as a review  (still no formal review facility) of Festo Air Cups 

or as an operational hint in my series, but eventually opted as a projects as it is not a regurgitation from LJ.
 
You can used a vacuum pump or a venturi pump to generate the vacuum… or if you are a thrill seeker, you can maybe use one of the hand pumps,
 
but bugga that.
 
While I have a vacuum pump, 
the connectors were incompatible with my chosen Nitto air fittings.
 
I have chosen to use my Grabo 
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

18 Comments

Sooner or later I want to do something like this. How heavy (kW)  is your vacuum pump? Can you tell us a bit more about which links you need?

https://dutchypatterns.com/

I bet that would come in handy for small pieces. Thanks for sharing.

Main Street to the Mountains

Been following your videos on YT Ducky. I like what you’ve been doing. What are the thin wood pieces you’re demo-big on? Do they bleed air badly? My vac pump setup bleeds pretty heavy on a lot of woods. A coat of shellac helps greatly, but it’s amazing what a difference plastic over wood makes to holding power!!!

Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".

man duckie you sure like sucking ?

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

Best thing I see for my needs is your shot taking the wood to the sander. Can't count the times I flattened my finger tips or had the piece go spinning off into oblivion.
I end up with really short fingernails at times, ouch. That would be a great nail saver.

Main Street to the Mountains

damn you ladies afraid to scuff up your nail polish ! real wood workers dont even have nails, just bloody finger tips with no feeling left !

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

delete

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

Thanks all for looking and avoidance of blasphemy for my crazy brain and methods.


 Dutchy
Sooner or later I want to do something like this. How heavy (kW)  is your vacuum pump? Can you tell us a bit more about which links you need?

I'm no techo so I can only regurgitate the figures I get from my Grabo, From their WEB site,

and listed as "the sensor automatically stops the pump on reaching maximum vacuum capacity of 11.6 PSI".

I placed a piece of hardwood on the cup 
and toggled through the display on the Grabo screen reporting on the "holding" performance... hopefully they will make sense to you,
162 Kg
374 lb
-0.82 bar
11.4 PSI

The vacuum pump system I bought was a BacoEng 5.7L unit

which has 7/16-20 threaded connectors on the hose,

I am trying to get another hose (emails to manufacturer  with no response) so I can attach a Nitto fitting on one end.  Not being technical, I'm floundering in the dark.

If your first cut is too short... Take the second cut from the longer end... LBD


 pottz
 commented 1 day ago
damn you ladies afraid to scuff up your nail polish ! real wood workers dont even have nails, just bloody finger tips with no feeling left !

Most woodworkers use Bos¢h sanders to lay on nail polish... and real sanders to remove it.

If your first cut is too short... Take the second cut from the longer end... LBD

well most woodworkers dont wear nail polish, well maybe you might with your pink boots, so i think my bosh sander will do just fine. maybe ill do the final sanding with my "festool" or probably my "mirka" 😁😁😁

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.


 pottz 
 commented about 4 hours ago 
.....
or probably my "mirka" 😁😁😁

Gotta admit my Mirka is starting to give me the shits.... I'm just getting too bloody old and keep pressing the paddle every time I pick it up...

I also bought a trial pack of new sandpaper that needs the holes aligned for proper extraction (been using Abranet for years)... keep forgetting and placing upside down on the bench to fit the new disk... you'd think I'd have learn after the first dozen times... but then that's (12) imperial, that my feeble brain can't grapple with.  

If your first cut is too short... Take the second cut from the longer end... LBD

what kind of paper ? let me know if it's better than abranet.

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

That's why I miss the old review format...

While reading (ugh!) the old LJ Reviews a while back, I came across the Mirka Galaxy paper, which suggested greater/faster wood removal. Had to give it a try as I'm always ripping my Abranet on small sharp pieces.

That's why I liked that format... it was in-your-face, even though I was not looking for an alternative sanding experience.

The Galaxy is certainly more robust and seems to sand marginally quicker/better, but an absolute pain aligning holes... and the holes being small, it's quite a bit of mucking about... and that's after I chase down my Mirka as I tend to forget to turn the power off as I flip it over and lay it on the workbench to align the holes.

In my opinion (nothing technical testing) they are better, specially for sharp cornered pieces,  if you bother to align the holes, however, if you are an anti-dust freak, you may need to think twice. 
I sand small pieces, in which case it would be better, but also because of the size (limited sanding per piece), I regularly change out girts and I am opting for the convenience of just slapping on the Abranet without fuss. 

To me, convenience is paramount, so I'll probably use up my supply and then stick with the Abranet

Though I believe they are toying with a more robust Abranet type of discs.  I also believe the Abranet Ace is a tad better than the standard.  Though don't quote me as I'm not renowned for a lot of investigative reading (ugh!).

If your first cut is too short... Take the second cut from the longer end... LBD

yeah hopefully martin is working on bringing reviews back ?

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

Nice project! You are an expensive person to know - now I want (need?) more tools.

 Steve Rasmussen 
Nice project! You are an expensive person to know - now I want (need?) more tools.

Sometimes workarounds stop being fun... that's when I don't hesitate to dig into my pockets...  At 30, my motto was "time is free", nowadays my time (left) is pricele$$.

If your first cut is too short... Take the second cut from the longer end... LBD

Mr Duck.....Well Done!!!!
Regards......Cliff.