Pneumatic hold downs with slider

[Andrew J. Coholic]

I was was cutting some parts today for melamine drawer boxes. Just thought I’d share how we dado the bottom groove. I reference all settings from the top edge, in this case the fritz/franz is used for placement while one of my shop made pneumatic clamps holds things firmly.

The dado also has a tendency to lift the material so this is far better than holding with hands never mind safer and less wear on the operator.

The clamp body is made from CNC’d Baltic birch, with integral aluminum pieces for strength all epoxied together. Cylinders and valves etc are all imports from Amazon. Work great and very reasonable cost.


http://i83.photobucket.com/albums/j307/ajcoholic/7FAEBACB-CEA1-4D79-A937-B2CC254D1573_zps6v63vey9.jpeg (http://s83.photobucket.com/user/ajcoholic/media/7FAEBACB-CEA1-4D79-A937-B2CC254D1573_zps6v63vey9.jpeg.html)

http://i83.photobucket.com/albums/j307/ajcoholic/96F1ADE9-EF4D-4709-9E80-479B64707083_zpsxh2adogo.jpeg (http://s83.photobucket.com/user/ajcoholic/media/96F1ADE9-EF4D-4709-9E80-479B64707083_zpsxh2adogo.jpeg.html)

[Bill Adamsen]

Very slick. Are both clamps operated from the same switch? Would you be willing to share the make/model of the pneumatic cylinders and switches?

[Andrew J. Coholic]

That front one stays there 100% of the time. I have a second one which is usually set on the back end of the carriage to clamp the tail end of 8’ sheets.

The third one is moveable. The wooden block has some no slip rubber on the bottom.

I can check my records, for the info but it’s at the shop. They are all sourced from Amazon. Each clamp has its own push/pull control. The two moveable clamps just use a cooked air line while the fixed one is plumbed in more permanently.

I ran a hose down the inside of the carriage extrusion, and mounted a disconnect for air at the rear. Everything fed by a single air line in the front of the saw. Nothing gets in the way.

I found several years now that the pneumatics are ideal to hold material.

I change things routinely to improve work in my shop. If something works it stays. If not we improve. This works very well.

If I remember correctly the cylinders were about $40 each with the controls about $10. The Festo style push connectors are a few bucks each. All plumbed with 6mm/1/4” line.

Restricters are required on the clamping strike to prevent the cylinder from slamming down. I’ve bought some needle valve type units but it’s just as easy to turn a small piece of brass rod to press for into the line, and drill a small hole 1/16” works) to slow down the stroke.

[Andrew J. Coholic]

http://i83.photobucket.com/albums/j307/ajcoholic/ajcoholic033/image49_zpstky5qvcv.jpg (http://s83.photobucket.com/user/ajcoholic/media/ajcoholic033/image49_zpstky5qvcv.jpg.html)

[Jim Becker]

Very nice setup, Andrew!

[Warren Lake]

sliders have been around for a long time. Is this method of working always been the way? 50's and 60's? the outboard fence thing, and did they have all the attachments they have now. I asked the old guy what he used and he could not remember what brand just said he was alone in a room they brought him lifts of wood and he could carry 5 x 10's to the saw on his back. I better not tell him about those vacuum lift things or the tables that allow you to change the height as you go.

[Andrew J. Coholic]

Very slick. Are both clamps operated from the same switch? Would you be willing to share the make/model of the pneumatic cylinders and switches?


I checked on Amazon, the seller doesn’t have these exact ones anymore. However, the controls are a push/pull 5-2 way valve. There are different types like lever actuated, etc but I like these push pull style.

The cylinders are 1.25” bore, just under 7” stroke. Sold by “discounttown” on amazon. $42 C dollars at that time (a few years ago).

I have also purchased similar cylinders on eBay. More $$ though. I have about 6 in use in the shop right now.

Just type in the size of cyclinder you want and lots will come up. I run everything at between 90 and 100 psi. Gives a very secure hold down on the 1.25” size cylinder. The pads I turned on my metal lathe from some round bar stock nylon I had on hand. Wood or aluminum would work fine too. I have some PSA backed fine sandpaper on the face to prevent the material from sliding. DOesnt harm anything, not even melamine.

[Brad Shipton]

McMaster sells Bimba cylinders and all sorts of on/off valves. They also carry a lot of 1/8" tubing along with the quick disconnects. 1/8" tubing saves a little bit of space. Looks nice Andrew.