Replies

1. 
   Midnight | Jan 06, 2005 01:25am | #1

   I'd a similar prob a little while ago; needed to drill through 6.5" thick oak with a rig that gave me repeatability. What I ended up doing was using some auger bits rated to be used in a power drill, and set the drill into a jig that turns the drill into a mini pedistal drill. I needed to oversize the clearence hole in the base casting to clear the auger, but other than that I got 8 holes exactly where I needed them; the drift over 6 1/2" was only about 1/16" (I could only drill from one side in this instance).

   Your bench top should be easier to do using the same method. Drill a pilot hole first to ease the passage of the auger tip, drill about hanf way through every hole on one side, flip the top over and complete each hole. Drilling from both sides cuts the run out in half, and gives a good clean finish to both sides of the hole; no tear-out.

   Mike Wallace

   Stay safe....Have fun

1. 
   TPZ | Jan 06, 2005 09:01am | #3

   Mike,

   Thanks for the advice. I tried a few holes per your advice, but with a forstner bit. It took a lot of elbow grease and createe a bunch of heat to get it through the maple. The hole was beautifully smooth, but I could only get through a few before I ran out of gas. I've got about 20 more holes to bore... ouch!

   I recently moved and haven't yet unpacked the box that has my 3/4" auger bit.  Incidently, this (moving) is the reason I'm building a bench in the first place. It's modeled after the one Lon Schliening (spelling?) built in last year's FW Tools and Shops. I tried to fancy it up a bit w/ walnut and cherry inaid legs, my initials carved in the front, etc., so I'm hesitant to use an auger bit because I've never been able to get a good clean hole. And this benchtop is 4' x 6' w/ 6 1/2" wide aprons - too heavy to flip, I think.  Were your holes clean? Again, maybe I was doing something wrong w/ the auger bit. Mine has an aggressive screw tip, so maybe it's not meant for finer wood projects.

   Again, thanks again for your help. This was the first "chat" I ever tried and it paid off!!

   Tony Z

2. 
   oldercdn | Jan 06, 2005 05:17am | #2

   I had exactly the same problem that you described. My solution was to make a jig using a square piece of hardwood (mine was 1-1/2 inches square). I started by drilling a small pilot hole 1/4 inch diameter through the hardwood block. Next I enlarged it to 3/4 inch. Both of these holes were drilled on my drill press.

   Once I had the jig made, I clamped it to the top of my workbench and used the jig to drill the 3/4 inch holes in the bench top.

   To make sure I aligned the holes correctly, I drew a centre line across the top and down both sides of the jig. To hold the jig in place, I use two pieces of scrap that were the same height as the jig and were long enough to extend beyond the edge of the workbench. Then it was a simple matter of clamping the two scraps pieces to hold the jig in place. Worked like I knew what I was doing.

    

1. 
   TPZ | Jan 06, 2005 09:11am | #4

   Lefty,

   Thanks - this is a good idea. I tried Mike Wallace's idea and it worked out pretty well - but it took a long time for each hole because I didn't use the auger bit as he suggested. I might give your idea a try since it would only take a few minutes to make the jig. I'll let you know how it worked out for me.

   In either case, I'm going to get my hands on a good quality auger bit or maybe even a brad point bit and save the forstners for the drill press and save my back for the projects I'm building the bench to help me with. At least I now have two methods to get the job done.

   Thanks again!!

   Tony Z 

1. 
   Midnight | Jan 07, 2005 02:46am | #6

   ummmm... you weren't turning that thing with a brace by any chance huh...???? man.... if I'd attempted them deep holes with my hand brace I woulda had me another heart attack.....lol... Sounds like your Forsners could use a wee tickle with a sharpening stone; along with cutting a clean hole, they should be able to hog out the waste pretty fast, certainly fast enough to avoid heat build up.The holes I made were to rough out the waste for tapered wedges going into a through tennon; I'd one shot to get it right and they had to be perfect every time. I'm glad to say that they came out just fine, but I think that's down to the design of the auger; the business end looks more like a Forsner design than a traditional auger, the auger screw had a lot more threads packed more closely than a hand cranked auger has. With the RPM's held well below 20, there was plenty waste being ejected. The buisness end was maybe a bit too efficient; I'd to focus more on preventing the bit from advancing too fast into the work than trying to push it through.. talk about keen... lol.

   For the record, the method I described earlier is perfect for hand brace and auger, just remember the little pilot hole first (I use a 2.5mm drill bit). If you can't work from both sides, try to secure a piece of scrap stock to the underside of the workpiece, securing it as tightly as you can. Any break or tearout should be controlled if not entirely contained in the scrap stock. Mike Wallace

   Stay safe....Have fun

1. 
   TPZ | Jan 07, 2005 08:29am | #7

   Mike,

   I unpacked my auger bit and considering the coarse threads, I think you're right on - it must be meant for hand drilling. I tried to control it through a scrap piece of fir (soft, I know) and there's simply no controlling the rapid self feed rate, and the quality of hole is poor.

   I used your suggestion in conjunction w/ another one I received and I think I've got a good solution:

   The other suggestion (you may have seen  it) was to create a simple drilling jig from a scrap of hard wood w/ a drill-pressed hole. Well, since I'm drilling hard maple already, I used the drill guide and the forstner bit to bore a 1 " deep hole - enough to guide a bit w/ a continous diameter. Then I chucked a 3/4" brad point bit into a beast 1/2" Dewalt drill that I rarely get to use and used the first hole as a guide to keep the hole true. Works great - fast, clean, and right at 90 degrees every time. Oh, one more thing. I used a small step stool so I could use body weight instead of elbow grease (some of the holes are far enough away from the edge of the table that my arms are essentially cantileavered, allowing little leverage. These things together did the trick.

   Hopefully this idea finds a place in your back pocket for when something like this comes up.

   Thanks again.

1. 
   Midnight | Jan 07, 2005 11:07pm | #11

   glad to hear things worked out Tony...

   bottom line is there's no set "you gotta do it this way" rule for getting things done; work with what you have, improvise, adapt and overcome  ;)Mike Wallace

   Stay safe....Have fun

3. 
   Peter36 | Jan 06, 2005 10:51pm | #5

   I went through this a couple of years ago building a bench as well. I had the bench built and I put some blocks under each leg to lift it up and level it. I then litterally dragged my drill press over and went to town. It worked very well but if you have a drill press and want to try this then get some help, I wish I did.

1. 
   TPZ | Jan 07, 2005 08:34am | #8

   Peter,

   Thanks for the reply. Pls see my last reply to Mike. It describes a good-working solution that came from input from him and another gentleman from my question. I don't think I'd have thought of it without asking the question.

   By the way, I got a kick out of your solution. I'm sure you sliding the table top around those blocks under the drill press was something to see.

   Thanks again.

   Tony

1. 
   Peter36 | Jan 07, 2005 08:41pm | #10

   I moved the drill press around, a lot lighter than my bench!

4. 
   sprocket | Jan 07, 2005 05:26pm | #9

   The most fool-proof (and cleanest, most accurate and safest and fastest too) is so simple using a plunge router that any other method just doesn't make sense. Here's what I did: 1) take a scrap rectangle of plywood as wide as your router base and a little longer than your benchtop is wide then lay out your 3/4 bench puppy holes at whatever spacing you select centered on the piece of plywood. 2) Drill 1" diameter through holes with a forstener bit on your drill press to accept a standard Porter- Cable template guide. 3) Attach your simple jig to your workbench using carpet tape, or with a little bench hook attached to the front of the jig to reference it to the front of the bench and hold it in place with a clamp. 3) Finally, chuck a 3/4" plunge-cutting straight bit into your 1/2" plunge router and with no stops at all just register your 1" template collar in your jig and "drill" right through your top.
   I was astounded by the speed, accuracy and repeatability of this method. I wouldn't fool around with auger bits and braces or try to take a big benchtop to a drill press or attempt to use forstener bits in a hand-held drill when you can take your plunge router right to the source in this manner.

1. 
   TPZ | Jan 08, 2005 10:01am | #12

   Sprocket,

   My original plan was to plunge rout the holes but the plunge bit I had ($30 or something Whiteside) left an unrouted spot in the middle (between the carbide) that wouldn't let me get too far down. The Woodcraft guy said it's the bit to use but I think it was the wrong one. I tried to find a 3/4" spiral bit, but didn't have any luck doing so.

   In any case, thanks for the tip, sincerely. I finally drilled all of the holes (over 40, I think - big bench) and put a sealer coat of Waterlox on it tonight.

   By the way, my original plan included a nifty jig idea (never tested it, though). My thought was to create an oversized base with equally spaced 3/4" holes that I'd use to index the jig for the next plunged hole. No layout (except on paper) required and guaranteed proper spacing. (I was anal about the spacing because I'd like to be able to make generic jigs, etc. to fit anywhere in the grid later.) I figured that it would have to look like a triangle (or square, I suppose) with two holes along each leg of it so I could create a grid of holes in any direction. I can only dream that it would have worked...

   Thanks again.

   Tony Z

1. 
   sprocket | Jan 09, 2005 12:50am | #14

   The plunge cutting straight bit I used is a Porter Cable #43722 (1/2" shank, 1.25" cutting length, 3/4" diameter. This bit does leave a raised dimple in the middle of the hole, which wasn't much of an issue for me since I was using a Porter Cable 7539 plunge router. I think I saw a review of large plunge routers a few years ago and this one can plunge like 3 and 5/8's inches or something like that. I was able to do the job of drilling holes clear through the benchtop which is 1.75" maple pretty well. Where my record vise hardware was located (directly in line with the little built-in benchdog) I had to just put a blind hole there which only goes down about an inch. In this location I use a little Jorgensen mini bench dog and it works great. I have the Veritas Wonder Dog and Veritas bench dogs. I've only done 4 holes in line with the vice but plan to do many more. I like your idea of the geometric grid. I think what you're describing is entirely possible.

1. 
   TPZ | Jan 09, 2005 01:03am | #15

   Thanks again. Let me know if you ever try the grid-jig idea. I'll do the same.

    

   Best Regards,

   Tony

5. 
   nikkiwood | Jan 08, 2005 08:59pm | #13

   Here is a drill guide you can use with a forstner bit:

   http://www.woodcraft.com/Family.aspx?familyid=3121&refcode=04ING143

   Another brand is called Portalign Drill guide.

   Both work as nifty devices where you need to drill precise holes in work that is too big for a drill press.

   I use one to drill 3/4" holes in workbenches.