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Through Drilling Jig
7 replies to this topic
Posted 05 December 2010 - 11:29 AM
I just made this jig, as I tired of setting up my drill press every time I wanted to through drill. I posted the design on another forum, as a possible solution. I then thought, I really need this myself, so went ahead and built it. I won't bother with a write up, as the pics are self explanatory, but if you have any questions, I will be happy to respond.
It should be useful for those members who through drill larger lures and are limited by the size of drill press.
Hope someone finds this useful.
Posted 05 December 2010 - 12:15 PM
Poor man's horizontal drilling machine. I like it. Its very neat. I assume the home made center is to illustrate the hole relative to the bit that drilled it?
I am confused about its necessity if you have a drill press.
I get roughly the same functionality out of my drill press by clamping a fence to the table with a pair of welding clamps. If I need modestly accurate positioning relative to the fence a piece of smooth drill stock in the chuck and a caliper helps with either fence or table positioning.
I also don't understand about setting up your drill press. Mine sits there plugged in and ready to go whenever I need it.
Now if you don't have a drill press, this invention of yours is an awesome bit of ingenuity allowing for modestly accurate drilling using any drill motor that has a location for clamping on a side handle. I have a bench vise made by Zyllis with an adaptor to use a drill motor in a similar fashion.
As a side note for anybody looking for quick and dirty solutions... I have used similar solutions to yours in a pinch to make small wooden pins in a lathe like application when I didn't want to leave the shop and go buy some. I do not have a wood lathe, and until last year I didn't have a metal lathe either. My regular drill press has found itself being used as a crude wood lathe a couple times as well. In fact the wood top and bottom bunks of my sons bed are fitted with a couple pins I made this way when two of the original ones broke when we dissassemble the bed to move it from one room to another.
Anyway. I like it. Very nice way to approach a task from a different perspective.
Now for another idea. Make the drill on a jig/shuttle that fits the square groove on a table saw. Set up a clamping jig/clamp/vise that clamps to the edge of the table also in the square groove on the table. I can't think of a specific use at the moment that would be superior in anyway to your soultion for drilling results. That isn't the point. Its a just another way to make a drilling machine that should self align whenever you set it up after the first time. I suppose any table with a groove for a sliding square would work. You slide the drill motor clamping shuttle up and down the groove in the table The advantage to this application is it puts your hands behind the drill motor moving it instead of in front moving the workpiece.
Posted 05 December 2010 - 12:23 PM
ALL RIGHT BOB, attaboy You can call it the poor mans gun drill.
Posted 05 December 2010 - 12:28 PM
Edited by toadfrog, 05 December 2010 - 12:29 PM.
Posted 05 December 2010 - 12:58 PM
Actually, the pin is the centre of the design (excuse the pun). The pin hole was drilled by the clamped drill, so guaranteeing alignment.
The way it works is, a small pilot hole is started at each end of the body to be drilled. These only need to be a couple of millimeters deep. These holes define the start and end position of the through hole. One hole is located on the pin and the pin block and body slid forward. The drill starts cutting at the other pilot hole.
Cut the hole half way through the body, frequently backing off to release the swarf. Then the body is reversed and cut from the opposite end, meeting in the middle of the body.
It is important to take the trouble to line up the drill bit parallel to the base plate. This only needs doing once, when you make the jig. This is achieved by trimming the profile plate which supports the rear of the drill. If you trim too much, you can shim the cradle block. Fiddly process, but necessary for the best results, but like I already said, only needs doing once.
The setting up of the drill press that I was talking about, was aligning a pin plate directly under the drill bit and clamping it in place. Not a big inconvenience, but I never have to do it again. Also, the bench mounted drill press in my cave, has a very small travel and useless for tackling larger bodies. This jig will be able to handle a 10" body, if I ever want to increase this number, I will simply extend the base and add a couple of angles.
Posted 05 December 2010 - 04:25 PM
Ok, I get it now. Excuse me for seeming a bit slow today. Its only because I am a bit slow today. Makes perfect sense, especially if you have a drill press not big enough for some of what you want to do.
As an aside,here is another way to approach the problem of aligning a center pin on the table with the drill spindle on a drill press fairly quickly.
Make a center pin holder out of solid stock of some kind that you can easily bolt to your drill press table. I favor aluminum because of it relative ease to cut, light weight, and decent srength. Machinable cast iron alloy (think chinese machine tools) would be even better if you have a mill to cut it, but it is heavy. Clamp it in place as close to centered over the hole in your table as you can. Drill all the way through it with a drill bit the same diameter as your centering pin. Drill and tap into that hole from the side for a set screw. For modest precision you are finished. Good enough for the quality of most drill presses. For more precision drill smaller and then ream to size. Your ability to make something like this will vary based on the tools you have, but I can think of two or three different ways to approach that also, and I am sure there are ways I never thought of. You could make it out of wood also, but I think I would want a harder center to hold the pin. Wood might also work if you designed it to clamp the stock instead of using a set screw. If you used a clamp one side of the clamp would need to be fixed relative to the overall fixture.
Here is how you use it. Place it loosely on the table with clamping bolts in place, but loose. Slide a piece of rod stock the same diamter as your hole up through the bottom and into the drill chuck. Snug the set screw. Snug the drill chuck and lightly shake the fixture to elimate any side binding as you do. tighten the bolts that clamp your fixture to the table. Loosen the chuck and set screw dropping the rod out the bottom of the table. Insert your center and retighten the set screw. This would work very quickly on a floor model. There would be some limitations on a benchtop model depending on its size.
Posted 05 December 2010 - 09:53 PM
Bob, I like it, a very doable solution.
I agree that the set screw assembly would have to be something more substantial than wood. But having said that, I have used bolts in wood for clamping in the past. Providing you use a block of denser wood and a clamp bolt of a reasonable diameter, I am thinking 8mm diameter, it would work.
The whole assembly would be dowelled to the bench, under the drill press, so that it could be easily removed and stored.
My drill press only has a travel of 48mm (pitiful). But even this allows me to through drill a 4" lure. But this clamped pin method would allow me to stop the drill, slacken the clamp bolt, slide the pin and stock onto the drill and re-clamp. Not sure if this is considered a safe way of working, but I have had to do this in the past and had no problems, providing you keep a firm grip on the wood stock.
I should have posted the problem first, as I would have had a go of this idea. Much easier to initially align than mine. I also liked your idea of using the chanels in the table saw plate, another very doable solution. Don't you just love being an engineer.