Clamping ease !

[dvmike]

I'm still considering a vac hold down system . But with as many small peices as I cut , I'm not sure how beneficial it will be unless I make a swiss cheese plenum.
I purchased 20 -8ft sticks of aluminum u groove channel.
I then put a 3/4" peice of extira on as a spoil board.
The channels are 3/4 " wide and 3/8" thick.
I milled my slots the length of the table and made sure my channels were 3/16" below the surface of the spoil board.
I used a couple of the channels (cut into 4" lengths) in the Y axis plane.
The slots in the channels accept 7/16" bolt heads on 1/4 20 machine screws. I bought a box of plastic wingbolts with nuts inserted.
I then cut 3"x6" strips out of scrap oak plywood and drilled holes inn it every 1/2" offset side to side.
It worked out great !
I can now clamp pretty much everything I need to in a snap !

I glean from everyone else's ideas on here . Maybe someone can use this to help their clamping issues. It's inexpensive and makes for very quick setups with no hassle !

[davidp]

Hi Mike,

I built my table to have both T Slots and vacuum. We have a large commercial vacuum hold down. The T slots rarely get used. Last week we machined a slab of 32 mm PVC into 12 three dimensional shapes that were 27 mm by 30 mm by 28 mm high for a chocolate wrapping machine. We did not use the T slots. We relied upon vacuum only. We achieved the required tolerances of +- 0.1mm.

Once you use a good vacuum system you will never be sorry.

[knight_toolworks]

t slots can be handy over vacuum. for oddball pieces and small stuff. but I find it more cost effective to route them into mdf rather then the hassle of the track.
but I also regularly use nails on solid wood and sometimes screws.

[fredtoo]

Mike,

What about some pictures?

[myxpykalix]

When i first set my table up i did a vacumn table with 2 fein vacs thinking i would be doing a lot of flat work but 90% of what i've done is either indexer stuff or in a 2ft square area of the 0,0 corner so the 2 feins sit under the table collecting dust (on the outside, not the inside!)

I have a jig that is noting more then a 3'x3' square of mdf with a 90 degree corner built up then I put my material againt it then take some scraps of mdf and slap it up against it and screw it down to the jig and it holds it pretty good. This is mostly for 3d carvings.


I found the picture of the jig i described above and added it here.

[benchmench]

Pin nails from a pneumatic nailer work very well becaue:
- They hold against lateral movement
- Don't tear up your spoilboard or material
- Pull out (or through) easily with pliers.
- If you hit one with the bit, it is too small to do any damage.
- Won't flatten the tires on your truck if you run over one.

Pin nails with vacuum will hold just about anything!

[dana_swift]

Dan- the pin nailer idea is great, it would allow me to cut some parts that are so small vacuum wont hold em. I can put the pins in the scrap area, and with tabs and vacuum hold everything still till the cut is done.

Then the vacuum just has to hold the part to the spoilboard, and can tolerate a lot of cut-through.

Many thanks for the suggestion! I will certainly give it a try, perhaps tonight or tomorrow.. I have the perfect application for it.

D

[plemon]

I have used a staple gun on thin plywood (3mm, 6mm and 8mm) and it works a treat. Really easy to put in (use a little framing gun with 8 or 10mm staples), easy to get out, holds down really well and puts up little resistance to being hit by a cutter.

Once I have a design in Partworks I add little .5mm deep drill spots using whatever cutter I intend to use in the positions where I intend to staple (ie I always place some around the outside corners and in the middle so it keeps the sheet down everywhere). I run the drill path first, put in my staples in the stencil holes, and then I don't have to worry about hitting staples. I'm not worried about damage to the cutter, I'm more worried about the staple being ripped up and then the piece isn't held so well anymore.

[knight_toolworks]

it really depends on the material. if it is man made and large enough to get held with a vac setup this is the easiest way to go.
the trick for holding parts in place is using a downcut bit on the wood and a straight on the plastic. also using as small of a bit as you can. so the vac only holds the material and the sawdust keeps the part in place. but for thin material you need to cut in a single pass.
also you can glue the material onto another surface and cut all the way through very close then saw or pop the parts off.

[gene]

Has anyone used a 23 ga micropinner or a plastic nail gun for this?

[frank134]

I have a plastic nail gun and have use it to hold parts to my table.

[mikeacg]

Tell me about the gun! Someone was supposed to get me that info at the last Aspire meeting but I never got it. I'm thinking that is the way to go for the work I do...

[dlcw]

I simply use a sheet of MDO cut to size to fit over one of my vacuum table zones. I fasten the part I want to cut/carve to that board using blocks and screws and then vacuum holds the MDO in place. No screw holes in my spoil board (except where the Shopbot has had the occasional brain fart and did its own thing and made holes in my spoilboard :eek:)

[curtiss]

I hold/ "pull down" a lot of items from below with a few lag screws... that you have to miss of course. (so far so good...:eek: )

The grid is on 5.5 inch centers that go through "high spots" on the vacuum plenum. ( In my case from 2,2 to 46,46 ) vac still works great.

The holes are all marked but I have not needed to drill them all out yet.

A number of 8 inch hold downs with 6 inch slots that can be used from above about covers it.

[knight_toolworks]

Tell me about the gun! Someone was supposed to get me that info at the last Aspire meeting but I never got it. I'm thinking that is the way to go for the work I do...
the gun is something like 400 or 450.00 and the nails are expensive.

[mikeacg]

Thanks Steve! Might be more than I can spend right now but it wouldn't take too may bits hitting drywall screws to change my mind... I've come pretty close a few times but so far, so good!