# Modifying the Kreg Pocket Hole Jig



## MT_Stringer (Jul 21, 2009)

*New Life for the Pocket Hole Jig*

Some of you have probably seen my Pocket Hole jig set up (pics shown below). It works great. I have drilled hundreds of pocket holes with it. But, therein lies a problem. When I am drilling holes in panels such as plywood cabinet members, I have difficulty reaching around or over the panel to operate the clamp. In fact, on more than one occasion, I have scraped my arm. That is not good for a guy with thin blood.

So, in the words of Tim, The Tool Man Taylor "So I rewired it!" 

I know what you are thinking - A new model has just come out with the handle on the users side of the jig. I didn't want to buy a new jig when I have a good one already. It just needs to be Mikeyized! 

My plan is to mount an air cylinder on my current setup that is actuated pneumatically by a foot operated switch.

Since the next step up from the manual jig is the Kreg Foreman ($849), I should be able to accomplish my modification for under $100 or maybe a little more.

So if all goes well, I will have the same old jig with a foot operated clamp. I hope to have it ready to go after the first of the year when we start building cabinets for our kitchen.

Here is what I have been using.









And it hangs on the wall when not needed.









To modify my jig, I bought a 2 inch bore air cylinder off ebay.









The rear mount came from the same seller. I purchased the front foot bracket, heavy duty rubber rod foot and air muffler from FreightProps.com. They have a good video explaining how everything goes together and that helped me a lot.

The foot switch also came from a seller on ebay.









I bought a pair of 5 foot air hoses from Harbor Freight. They came with the hose barbs already made up so all I had to do was attach the fittings on each end.


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## Medickep (Aug 22, 2013)

MT_Stringer said:


> *New Life for the Pocket Hole Jig*
> 
> Some of you have probably seen my Pocket Hole jig set up (pics shown below). It works great. I have drilled hundreds of pocket holes with it. But, therein lies a problem. When I am drilling holes in panels such as plywood cabinet members, I have difficulty reaching around or over the panel to operate the clamp. In fact, on more than one occasion, I have scraped my arm. That is not good for a guy with thin blood.
> 
> ...


That's so cool! I love the ingenious of it!


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## MT_Stringer (Jul 21, 2009)

*Designing the new jig*

Something I had on hand is a piece of 1/4 inch aluminum plate 3 inches wide x 12 inches long. I decided to mount the cylinder on it. But first, I made an exact duplicate out of 1/4 inch mdf so I could figure out how and where to mount everything.

After removing the clamp mechanism that came with the jig, I commenced to measure and drill mounting holes in the mdf.


















I don't have a picture, but I used the original nuts that were used to secure the clamp. I used JB Weld epoxy to permanently mount them in the sockets underneath the jig.










I countersunk the heads of the mounting screws for the front and back cylinder mounts.









I spent a lot of time trying to figure out how and where the cylinder should be mounted. I have it positioned so that 1/2 inch → 1 inch material can be easily drilled. For 2×4 type material, I will have to reposition the cylinder, which won't be hard to do.

After I made the decision where to mount the cylinder, I attached the mdf to the aluminum plate with double sided tape and simply drilled the holes on the drill press.




































The cylinder mounts on the plate just like it did on the mdf.









With everything fitted and working, I decided it was time for a new sled to mount the jig on. So, I recycled a piece of 3/4 inch plywood I have had since the mid 80's. It was originally a box that pump parts had been shipped in and I salvaged it from the dumpster at work. Now it has a new life. Unfortunately, it wasn't big enough so I added rear deck by gluing on a piece of maple. Once everything was dry, I added an edge all around and ran it through the drum sander until I had two smooth sides.









I also needed new extensions for each side of the jig so longer material can be supported so I glued up two pieces of 1/2 inch Baltic birch. That turned out nice.


















Just about time to put it all together.


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## moonie (Jun 18, 2010)

MT_Stringer said:


> *Designing the new jig*
> 
> Something I had on hand is a piece of 1/4 inch aluminum plate 3 inches wide x 12 inches long. I decided to mount the cylinder on it. But first, I made an exact duplicate out of 1/4 inch mdf so I could figure out how and where to mount everything.
> 
> ...


great job.


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## MT_Stringer (Jul 21, 2009)

*Final Assembly*

Time to get this project wrapped up.
I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.

Now for the nitty gritty.

Here is a close up of the cylinder mounted on the jig. The original four 10-24×1 inch machine screws secure the front of the plate. Two 1/4 -20×1 inch round knobs attach the rear of the plate to the sled. If necessary, I can remove the cylinder as a unit.



























IT'S ALIVE!!!

Piston retracted.








Piston extended.









Foot operated switch with muffler.









*Overview*





































I have my parts box fastened to the sled near the edge so I can loosen the latches. They secure the lid really well.

The black piece is the Kreg Micro jig.













































And now for the good part. If something breaks, I can simply remove the four screws and the two 1/4 inch round knobs, remove the air cylinder unit and replace it with the original clamp!!!  A special thank you goes out to Crank49 for making that suggestion. 

















But wait, there is more!

If I need to drill pocket holes in 2x lumber, I will have to reposition the air cylinder. To do that, I simply remove the four 10-24 machine screws which will free up the sled. Then I will need to remove the four wood screws on the bottom side of the sled which keep the rear cylinder support in place. After determining the position for the cylinder, put the screws back in the aluminum plate, and drill new screw holes on the underside of the sled so the rear support will stay put. No need to remove the two 1/4 - 20 round knobs.

I drilled a few holes and the jig is working great. I had the air compressor set at 80 psi. I think I can easily reduce it to 60 psi.

The only thing left is to get a filter for the air line. The specs call for a 40 micron filter. HF has one that should work just fine.

I hope you enjoyed reading about this build as much as I did building it. My cabinet making should go a lot smoother next go round.
Mike


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## darthford (Feb 17, 2013)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


Oh man metal working and shiny cylinders and foot switches, very nice! On a larger scale I'd like to build an air clamp jig for gluing up dovetail tube amp head cabinets.


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## Handtooler (Jul 24, 2012)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


MT, Ya gotta patent those ideas and fabrication soon or Kreg will certainly steal them and market the Kit for several hundred dollars. *Very nicely constructed!*


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## sras (Oct 31, 2009)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


Nice project! Looks like you are set up for mass production.


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## MT_Stringer (Jul 21, 2009)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


And now for an update. I finally got a chance to drill some pocket holes in both 3/4 inch material and 1 1/2 inch 2×4 material. What I learned is that I can simply screw the rubber foot into the coupling about 1/2 inch and then lock it down. The piston will extend as far as it can and then stop and hold pressure against the 2x work piece without damaging it. That made the work go smoothly and quick. I am loving the foot switch.










I routed the air line through a 40 micron filter, which I have mounted to one leg of my work bench.


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## MT_Stringer (Jul 21, 2009)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


And…it can also be used as a pean cracker! 



















Here is a short video demonstrating the pecan cracker in action.


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## fge (Sep 8, 2008)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


Wow that is really cool. Never seen that sort of set up.


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## eringuet (May 31, 2011)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


Hi Mike,

Do you have the specs of this pneumatic cylinder?

I'm thinking of building a hinge boring jig to setup permanently on a benchtop drill press and I think your cylinder would work great for this application.

Nice work on the jig. Sorry for reviving this old post.


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## MT_Stringer (Jul 21, 2009)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...





> Hi Mike,
> 
> Do you have the specs of this pneumatic cylinder?
> 
> ...


I got the air cylinder from Ebay - lots of choices. Search for Bimba air cylinder.

Since I didn't know any better, I bought a 2 inch bore 1" stroke. If I had to do it over again, I might get either a 1 1/2 inch stroke or maybe a 2 incher. Actually, it doesn't matter, but would allow you to use thicker stock. When the air cylinder extends, it goes as far as it can then stops. It will hold the pressure against your stock until you release it.

Note: Freight Props.com probably has everything you would need to get set up.

Hope this helps.
Mike


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## eringuet (May 31, 2011)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


I found that you can get these fairly cheap from Aliexpress.

I assume you use a 5-way foot valve with this? Double-action correct?

Thanks for answering.


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## Marxbrothers (Jan 17, 2020)

MT_Stringer said:


> *Final Assembly*
> 
> Time to get this project wrapped up.
> I covered the plywood deck with white Formica as well as the material supports and the rear support for the cylinder. After trimming the laminate flush with the plywood, I used a chamfer bit to bevel the edges slightly.
> ...


Love this set up but Kreg did make an air actuated unit! I bought one about 20 years ago and still use it for making cabinets.


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