Depth Adjustment on a Pocket Hole Machine
A woodworker gets advice on setting the depth of plunge on an old model of the Kreg Foreman pocket hole machine.June 17, 2013
Question
I have what must be an older version of the Kreg Foreman air powered style. The manual that came with it when I purchased it shows a depth stop, but the unit that I have does not have one. I talked to the dealer where I purchased it and they have no idea about it. I am trying to find out how to set the depth of the drill bit DKD8, and unless we put it barely in the collet (just to the flat parts), which is not inserted deep enough and the bit tends to vibrate, we cannot get it to go deep enough into the material. We cannot find, in the manual or on the machine, any adjustments to make the bit go deeper into the material (I am speaking of length of stroke, not height from the table, when I say depth). Also, I purchased a high volume air fitting, checked the oiler, and put in a brand new bit, and still it bogs down when drilling hardwoods. It practically comes to a stop and gets stuck in the wood. Please give me some ideas as I am about to give up on this machine.
Forum Responses
(Cabinetmaking Forum)
From contributor J:
When you remove the table top, there is usually a stop bolt that the air cylinder pushes the bracket against. This bracket is the one that holds the drill. You can loosen the lock nut and then adjust the bolt to get the depth you need.
From contributor P:
You may also need to replace the drill bit guide bushing that is in the table. You may have to call Kreg and ask them about it.
From the original questioner:
Okay, the problem is that my machine does not have the depth stop. It shows in the manual but it is not there. It must have been something they added after my machine was built. It seems like the bit needs to be about 1/2" longer to be the correct length, but it is the correct bit according to the manufacturer. The bit needs to extend 1/2" further to drill correctly, however to get it this long it is only in the collet approximately to the end of the flat part of the bit, which is not really deep enough in the collet and the bit vibrates terribly.
From contributor L:
Make sure you buy the drill bit for the Foreman unit. I have the same one and the bit is longer than the regular Kreg bits. The collet is accessed through the lift up top. You may also need to adjust the fence by moving it forward or backwards.
From contributor M:
Not looking at mine, but the depth stop, if I recall correctly, just limits the throw. I'd look at the entire mechanical linkage. If, on the other hand, you are experiencing the two problems as connected, then just turn up the pressure and go a little slower with the handle.
From contributor L:
You also need a 3/8 to 1/2" air supply to run it with full torque.
From contributor J:
You may want to take a look at the rod that connects the handle to the drill. This rod is threaded into the quick release on the drill motor. If you pull the lever without a part in there, how far does your drill bit travel?
You may need to adjust the stroke with this adjustment to help the drill bit travel further. The depth adjustment is only there to prevent the bit from traveling further. But if your machine doesn't have it, this would be your only adjustment.
From contributor O:
Can't you just move the fence closer?
From contributor K:
Is this a new or used unit? I have one of the first Foremans made and the only stop I have is a stop collar on the bit. I'm still using one of the original 3 bits I purchased when I bought the machine. They are slightly longer than the standard bits you buy at Lowes. As for the bogging down, that sounds like a clogged line or drill. That's why I asked whether it was new or used. I've disassembled my drill 3 times over the last 11 years and it runs like new each time.
From the original questioner:
The fence is already in the furthest position forward that it can go. I have checked the lines and they do not appear clogged. I have changed out the air connections to larger and have changed the bit to brand new. It is the one that is recommended by Kreg. Still, unless I only put the bit in to the end of the flat parts, it is not long enough to travel the correct distance. It appears that the compression of the springs on the shaft is what limits its travel. Once they compress completely, the unit needs to still go another 1/2" to achieve full travel. Adjusting the linkage on the arm will not change this. The only thing I can see is the bit needs to be 1/2" longer than it is now, but this is the DKD8 bit they recommend for the Foreman machine. I have a call in to them, and hopefully they will have an answer for me. I have a DK1100 and have not experienced this trouble with it. We use the different units for different purposes. I like the Foreman for drilling hardwoods as I have more control over the feed speed. I usually figure about 4 seconds to drill maple hardwood with the Foreman, which should be about right.
From contributor M:
I have one of the older Foreman machines also and have been having trouble with it. The only stop that mine has on it is the stop collar on the bit. You just adjust it along the bit where you need it and tighten it up with an Allen wrench. I would try unhooking the air from it, take the springs off, put it back together and make a dry pass to see if the springs are holding off. Other than that, it sure sounds like the bit is for the jig rather than the machine, but the part number you give is the correct one for the machine. If I can think of it tomorrow I will measure one of my bits and give you the length so you can check it against yours just to make sure.
As far as the slow drilling goes... I just posted the same question here a couple of weeks ago and even called Kreg about it. Here are three things to check. Make sure the air is turned up to 120 psi (recommended pressure). There is a screw on the side of the motor that has a =/+ sign on it; make sure it is turned all the way to +. And last and most important, disconnect it from the air and on the back of the motor where the little line hooks onto it there is a big nut. Unscrew that (normal right hand threads) and there is a little screen in there which will stop up and prevent air from going through the motor. Watch the way you take it apart so you can put it back together again, but it is easy as pie. I put a new motor on mine back in the summer and it was already bogging down, and the screen was almost totally stopped up. There is also a muffler in there - blow that off too.
From the original questioner:
Okay, here is what I determined after reading all your comments and talking to Kreg. I did put on a high volume air fitting, changed to a brand new drill bit (I can only insert the bit in the collet approximately 5/8" in order to have enough length of stroke). This is not nearly enough in my opinion for the bit to seat properly and I discussed this with Kreg. I took apart the air inlet and cleaned out the screen (it was not very dirty), and checked to make sure I had full volume of air coming to the machine. It finally is drilling pretty good with about a 4 second cycle in hardwood. I think I am going to shorten the springs slightly as when they compress fully, they stop the drill motor from going in further. If the motor would travel further, then the bit could be set in the collet deeper. Thanks for all your suggestions. As always this is my greatest resource when problems arise and it is great to know that there are others who are willing to share their experiences as we all benefit in the end. Hope you all have a good year in 2013.
From contributor O:
Take the springs off and make sure shortening them will give you the extra travel and there isn't something else stopping it that you can't see.
From the original questioner:
I agree and will do that first. Thanks for the advice. Always better to check things out one at a time.
From contributor M:
I remembered to measure a bit this morning. It measures 6 5/8''. As far as depth goes, I have mine set to where the pilot is about 1/16 from going all the way through the wood.
