How to make the Pattern?
September 16, 2009 by admin
Filed under Router Tips
So Folks the last post has presented many questions about the making of the pattern and not about the router procedure.
Sorry, I can’t give out the step by step procedure of making the pattern as this is one of the modules in our paid Jigs and Fixtures E-Course.
But if you put your thinking cap on this is not really that hard to do. Let’s first inspect the pattern and then discuss what the procedure might be to make such a pattern.
What are the features of the pattern?
1) It uses a guide and a drilled hole as the pattern. In this case it’s a 1″ hole drilled with a Forstner bit. What is the most efficient way to drill 1 holes? The Drill Press, the router etc…
2) The holes are centered on a piece of plywood that is twice the width of shelf hole position for the cabinet side. If you want the holes on the side of the cabinet to be 2″ from the edge. How wide is the pattern plywood?
3) Next we need to determine the position of the first hole. How far from the bottom is the first hole? Remember this point determines the start position on the cabinet sides for the pattern location. FYI pattern location: It is flush to the edge and the bottom of the pattern is positioned at the inside edge of the bottom Dado. So where is the first hole? 6″, 8″, 10″ etc…you choose.
OK lets recap what we have,
a) The center position of the hole is determined by the hole distance away from the edge or in this scenario 2″ from the edge. Plywood pattern width is 4″.
b) What is the first hole position from the bottom of the pattern…for argument sake let’s say 8″. So the first hole is 8″ from the bottom edge and in the center of pattern width of 4″. Let’s set up the drill press to drill holes in the center of a 4″ piece with the first hole at 8″ up from the pattern bottom.
4) OK the drill press is set up now to drill holes in the center of the pattern but not set up to drill holes exactly positioned with equal spacing…Here are a couple of question to think about when figuring a way to drill the holes at a equal distance apart?
1) What do we have on the pattern to position the hole exactly equal distance?
2) How do we drill holes with equal spacing with a drill press?
3) Can we use the just drilled hole as a positioning pin for the next hole to be drilled?
and/or
4) Does it matter if the holes are not positioned exactly centered and equal distance?
If you have an idea on how to make this pattern please use the comment portion of this post to describe how you would do it? The more comments we have the better…please just comments about how to make the pattern.
Make the pattern on the drill press with a 1 inch Forstner bit and a fence. Measure and mark on the pattern a center line along the length of the board, and at 2 inch intevals. Make an adjustable holder for a inexpensive lazer pointer to mount on the fence. Adjust it to point 2″ from the first hole. Drill the first hole, then slide the pattern down the fence to line up the hole with the lazer mark, drill the next hole, etc. This lazer could be used for other jobs in the shop also.
Drill 2 holes in a piece of plywood exactly 2″ apart, put a dowel pin in the first hole drilled and center the bit over the second hole. Clamp the plywood in place and drill your first hole and place it over the dowel pin and continue drilling 2″ apart perfectly. I,m talking about a drill press.
Comment from Rick,
Gary now we are talking, that’s a great tip on “How To” make a equidistant hole pattern using the drill press. I hope everyone can visualize the process.
Now, is there anyone else with a way to do it with the router and a drilling fixture? And is it possible to make this pattern with a portable hand drill?
draw a line down the center of your 4″ wide piece of plywood lengthwise. Mark up
8″ from the bottom and make a mark on the center line. Put the smallest drill bit you have in the chuck and drill a hole where the lines intersect. With the drill bit still in the hole, set your fence so it’s touching the edge of the plywood, or 2″ away from the edge. Lift up the drill bit and use a square to draw a reference line on the fence perpendicular to the hole from the drill bit, and a mark on the edge of the plywood where it touches the fence. Set a compass to 2″, and mark the edge of the plywood every 2″ with the compass.
Now, put in your 1″ or correctly sized forsner bit, and drill a hole where your first hole was drilled 8″ up from the bottom. Then set the mark made with the compass against the reference mark on the fence and drill your holes, working your way up the board.
From Rick:
“And is it possible to make this pattern with a portable hand drill?”
One way to make the pattern with a hand drill is to take a piece of 1/8″ pegboard as long as your pattern blank and three peg holes wide. Carpet tape or tack the pegboard to the plywood with the middle line of holes aligned with a centerline marked on the plywood.
Since the spacing of the holes in the pegboard is approximately 1″ drill through every other pegboard hole to get 2″ between centers. You can use a small VIX bit (self-centering hinge screw bit) to create pilot holes, remove the pegboard and then use a 1″ spade bit to bore the holes or, if you don’t want to save the pegboard, just use the spade bit and bore through both the pegboard and the plywood letting the pilot on the spade bit center on the pegboard holes.
I prefer spade bits with a spur at the edge rather than a totally flat bit. It cuts cleaner because the spurs score the wood before the flat hits and is easier to keep straight. They also usually cut cleaner on the back side without a lot of tearout. Be sure to use a backer board to avoid tearout on the back side. You can also bore part way through from the front until you have a pilot hole on the back and then back-drill. As long as you don’t go too far in from the front you’ll get an accurate back-drilling because the spade bit will still accurately center on the pilot hole.
I made 2 or 3 of these patterns of various lengths. After drilling the holes, I attached a 6″ – 8″ horizontal board at the top of the vertical pattern board. This top board has to be exactly 90 degrees perpendicular to the vertical board. This top piece then rests along the top (or bottom if you prefer) of the wood to be drilled and the pattern is clamped. This saves having to tape or nail it to the wood.
As long as you mark the holes (on the pattern) where you begin and end drilling and place the horizontal board along the top or bottom of each “cabinet side”, the four lines of holes should align.
Drill it by hand! ! !
It actually makes no difference if all the holes are spaced “EXACTLY’ the same distance. It would be sufficient to just mark off all the holes on a line scribed down the APPROXIMATE center of the pattern with a yo-yo tape measure then drill them with a spade bit. Any differences in elevation of the shelves would not be detectable with the “necked” eye as long as the bottom end of the pattern was on the same end of the piece being drilled.
Tear out is not a problem because the router pilot extends into the hole in the pattern and a pattern is not the finished piece. The pattern is just that, a pattern.
Rick’s Comment,
Great observation, Paul…
So to recap your comment Paul, your saying it doesn’t matter if the holes are exactly 2″ apart and in the center of the pattern. Why, because all holes are drilled with the same pattern so the hole position will exactly the same on each corner.
To add to Paul’s observation about the pattern, you might consider marking one edge of the pattern as the outer edge. Then by flipping the pattern one face as the left corner and one face as the right corner and keeping the marked edge on the outside edge of the cabinet sides. This will make the pattern of the hole positions exactly the same.
This technique creates a right and left handed pattern and all holes are going to be exactly positioned the same. Example, if pattern hole 3 is set at 2-1/8″ and not 2″ all four holes are going to be the same…
My only comment: The closer to the 2″ on center and the center on the pattern width the better the position of the holes will be on the cabinet sides. The naked eye will not be able to distinguish the different positions. If you are drilling by hand you have to be at the very least close on the hole positions.
Regards, Rick
Thank you for your encouraging comments Rick.
A beginning wood worker should be able to get the hole spacing as close by hand as with a piece of peg-board. My experience with peg-board shows that it is not very accurate. If you cannot get the spacing close enough that any variation is not detectable with teh “necked” eye, you should take up knitting.
Rick’s comment…
Paul everything was good until you added the knitting comment…Please be advised we don’t want anyone changing hobbies, right? Ha, Ha…
So your position is to measure and mark the drilling positions then drill by hand, right? OK… Thanks again Paul.