May 24, 2012

Posts Comments

You are here: Home / Archives for finger joint

A new wooden hinge form

December 7, 2010 By

This article continues with the wooden hinge theme. I made some changes to the simple form I showed earlier. My thanks to Julio, in Spain, for the inspiration to develop a new hinge form. The business part of the hinge is now rounded. What follows is how I went about doing this.

I used walnut boards for the new hinges; in fact, I used the remains of the the boards I used for the first set of wooden hinges. This time I simply used a 3/16″ roundover bit on both edges at the router table:

Creating a round-over on the walnut stock.

After rounding over both edges on each board, I got a stepped edge along the entire length of the boards. But after a minute or two with sand paper, the step disappeared and I had a nice, smooth round edge:

The rounded walnut, after a bit of sanding.

The rounded edges of the boards went under the finger assembly of the F3 finger joint template. I cut the fingers and sockets on the Leigh D4R Pro jig — the results were great. I had enough material to make new hinges for 3 boxes:

A very large rounded "hinge".

I outlined a shape on the edges of two of the new hinges, and then spent a little time at the spindle sander removing wood to that outline. Soon I had the following form:

The prototype rounded hinges, as I tried a dry-fit on a box.

Thanks again, Julio!

Note 1: I was worried about completely rounding over both sides of the hinges; depending on the design of the hinge, a complete roundover may allow the lid to open fully; the lid may even touch the surface where the box is resting. In this case, the lid will open a bit beyond 270°. I will be able to determine the exact angle once I secure the hinges to the lid and the box; I will report on this, as it is an important issue. Normally we want the lid to open to 95°, and (almost) never beyond 110°.

Note 2: I will continue to refine the form, by creating new curves at the distal ends. This was a great suggestion from an online friend.

— Al Navas

Filed Under: Blog, Box making, Design, F3 finger joint, Finger joints, Joinery Tagged With: ,

3/4-inch finger joints on the D4R Pro dovetail jig

November 12, 2010 By

If you follow the blog, you will already know I tested the Leigh D4R Pro dovetail jig to make 3/8-inch finger joints. It worked beautifully, without the need for additional templates like the F3 finger joint template. Since the D4R also promises 3/4-inch finger joints without additional anything, I had to try it.

Note: Please click on any image to enlarge; once viewing an enlarged image, you can navigate through all the images using the arrows on the bottom-right hand corner of the images.

Following the 3/4-inch procedures included in the User Guide, I made the joint shown in the following photograph using thick quarter-sawn white oak 5-3/8″ wide boards (please refer to Chapter 15, “Box Joints”, starting on Page 53):

3/4-inch finger joints on thick quarter-sawn white oak.

The use of very thick oak is as demanding a test for finger joints with good fit, as it is for dovetail joints. It is demanding because the wood cannot be compressed when assembling the joint by hand only; maybe a mallet will compress the wood sufficiently, at the risk of something failing from pounding together the joint.

What would happen if thinner boards were used, and the wood is walnut? This would mean slightly more compressibility of the wood; also, the joint should be a tad tighter, to account for the added compressibility. I adjusted the e7 e-Bush by 1 division to the “tighter” side; this translates to a tighter glue line fit of 4 thousands of an inch (0.004″ ). Using walnut boards 6-15/16 inches wide, the following photo shows the resulting finger joint:

3/4-inch finger joints on walnut.

On the first dry fit I was able to tell the joint was just a tiny bit tighter with the wider walnut boards, compared to the joint I made earlier with the white oak boards. However, by the second and third time testing the same joint, it seemed to be just perfect, as the walnut had compressed ever so slightly. For boards this wide, I was satisfied.

Most importantly, I made 3/4-inch finger joints on thick boards and on thin boards, using oak and also walnut boards.

Worth noting, #1: I also made 3/4-inch finger joints on narrow boards 2-9/32 inches wide, and on boards 3-27/32 inches wide. I had difficulty making 3/4-inch joints; I called Leigh Customer Support, and also sent e-mail messages with photos of the results I was getting. The long story made short: I was not placing the work piece perfectly vertical under the finger assembly. The “problem” is now solved! I am now very careful with placement of narrow boards under the guide finger assembly when making 3/4-inch finger joints. Why does this “problem” happen? Easy, once I understood what was going on. To make this large finger joint requires first routing all sockets and pins boards; a spacer is then placed against the integral stop on the jig body, and the pins and the sockets boards are routed a second time. ♦♦♦ With narrow boards it becomes very tricky to properly align the boards under the finger assembly, because several of the routed recesses fall directly under the surfaces of the guide fingers ♦♦♦ In other words, there is not sufficient surface area on the board registering properly under the finger assembly. Solution: Do whatever you must do, to properly align the work piece with the support board under the finger assembly.

The following photo shows this dilemma in detail (click to enlarge) – enlargement of single finger under one guide finger:

Misaligned board.

In reality, the board looks like this – it is the middle guide finger I showed in the photo above:

Full misaligned board.

Worth noting, #2: Although I will (likely…maybe…) get rid of my old D4 dovetail jig, I will keep the F3 finger joint template. I will need it when I make finger joints different from 3/8″ and 3/4″.

My opinion on making finger joints on the D4R Pro dovetail jig:

Bottom line: The D4R Pro dovetail jig is a terrific jig to make finger joints in two sizes, 3/8″ and 3/4″; it makes these two sizes without the need for additional templates or gizmos. The use of the e7 e-Bush gives the user the capability to dial in the fit of the finger joints in 0.001″ increments; the full range of adjustment of glue line is a whopping 0.020″ — in practice, adjustment of only a couple of divisions is required on the e7 e-Bush (0.004″). If you have been wanting to get a top-of-the-line dovetail jig that also makes finger joints, your wishes are now reality.

Disclosure: Leigh Industries is a sponsor of this blog. I sometimes receive tools from my sponsors, for evaluation purposes. I also receive a small commission from your purchases through my Affiliates (Woodcraft, Woodworkers Book Shop,Amazon.com, Rockler, and StudioPress); these help defray my costs some. I thank you for your support!

Still-to-do: Single-pass half-blind dovetails with the D4R Pro. This is also a new feature of the D4R Pro. I will publish an article about it in the near future. If you would like to upgrade your D4R to the D4R Pro, visit this page — the page also shows upgrades to older jigs.

— Al Navas

.

Filed Under: Blog, D4R Pro, Finger joints, Jigs, Joinery, Leigh jig Tagged With: , , ,

The D4R Pro to replace the D4 dovetail jig

November 8, 2010 By

Lies, and more lies

I lied recently; and I also lied some time ago.

I lied some time ago, when I said I would not get rid of my D4 dovetail jig. Then Megan suggested I ditch the old dovetail jig, as I can now competently hand-cut through dovetails, and half-blind dovetails; I lied, because the D4 has been a workhorse in my shop for many years -  I did not intend to ditch it, replace it. It works hard when I make multiple drawers, boxes, cases, etc.

I lied, because now I can ditch the D4 jig <sigh…> But I am a happy! Honest – I am very, very happy! Because…

I now have the D4R Pro jig

It all changed Friday (this past Friday). Sandy called me while I was in the shop, to let me know she had something I did not have (neener, neener…). What the…  Hmmm – what was going on? She finally broke the news (she was pulling my leg). Two packages from Leigh Industries were delivered just minutes before: a brand-new D4R Pro dovetail jig, and a new VRS (Vacuum and Router Support).

Disclosure: I sometimes receive tools from my sponsors, for evaluation purposes. I also receive a small commission from your purchases through my Affiliates (Woodcraft, Woodworkers Book Shop,Amazon.com, Rockler, and StudioPress); these help defray my costs some. I thank you for your support!

3/8-inch finger joints made on the D4R Pro.

I spent part of Saturday finishing the installation of the jig. And on Sunday I tweaked the installation, and spent time getting to know the ins and outs of making small (3/8-inch) finger joints. I documented my work in a 5-minute video (see below), to show how easy it is to make the finger joints with the jig.

Impressions:

Fit and finish. Classic Leigh product – nice, tight fit of all parts that must be assembled to the main body of the jig. My only difficulty was with the threads one of the bolts that hold the clamps to the body – and this was minor, as the nut mounted properly, without damage to its threads (simple debris, from cutting the threads). The finger assembly was almost perfect; all guide fingers were attached to the bars nicely – and all but one of the machine screws holding the fingers in place popped nicely when loosened, just as they are supposed to pop to allow movement of each finger. I must check more closely to determine what might be going on with the one finger, as it remains relatively tight, and is harder to move than others.

Finger joints. A little while ago I wrote about having to make a lot of boxes. I started making a bunch of little boxes on the old, trusty D4 jig equipped with the F3 finger joint template. The old D4 made 1/4-inch finger joints, but it required precise machining of spacers, which had to be taped to the body of the jig. And if the tape slipped even a little bit, all the fun would go to waste. That was the main reason I was ecstatic when I received the F3 template (it makes it possible to make a whopping 11 different sizes of square finger joints, plus 3 sizes of half-blind finger joints!)

Making finger joints. On Saturday I learned the adjustments to the D4R Pro to make finger joints. And on Sunday I made some 3/8-inch finger joints, and documented the process in the video below. The steps are easy; if I can do this, anyone can do it. It is dead simple; the steps are as follows:

  • Prepare boards: select board width from Chapter 15, Box Joints. For symmetric dovetails I selected a board width of 2—11/16 inches.
  • Adjust finger assembly for finger joints, and lower the assembly onto the support board.
  • Insert and clamp the first board. For very thin boards this can be a bit tricky on the older D4, as you must ensure the edges are square to the sides top, and flush to the bottom of the finger assembly. With the D4R Pro this is much easier, as the integral side stops are always perfectly square to the jig body, and to the finger assembly.
  • Mark and adjust the depth of cut to the mating boards.
  • Raise the finger assembly, and adjust the guide fingers using the spacer with the straight edges, not the one with the dovetail shape on one edge. In the video I illustrate how to first set the horizontal spacing between adjacent finger pairs, and then use the spacer aligned vertically to adjust the spacing between the fingers in each pair.
  • I confirmed correct spacing adjustments using calipers. I do this, especially when getting familiar with new equipment, to confirm I am doing things correctly. Three different times I set the larger spacing incorrectly; I simply redid the finger setup, avoiding sloppy configuration.
  • When finished making all the guide finger adjustments, lower the finger assembly onto the support board.
  • Use two scrap boards to make a test joint:
    • Route one end of the scrap board, making the cuts between all openings. Run the router along the sides of both fingers.
    • insert the spacer in the jig body, insert the second scrap board into the jig and push against the spacer. Route this board.
    • Remove the second board, and test with the first board for joint fit. If too loose or too tight, the e7 guide bush mounted to the router base allows adjusting the fit in 0.001″ increments (that is one-thousand of an inch!).
  • Once the proper fit is achieved, it is time to make a box. Simply route opposite sides of the box first; then insert the spacer and route the second set of boards.

The entire process is easy. And no special template is required to make two sizes of box joints. This is a very nice improvement in the D4R Pro over the much older D4 jig!

What about the F3 template?

This is good news, as the F3 fits the D4R Pro perfectly. I will keep the F3. But I will need it only when I make finger joints different from 3/8″ or ¾”!

Summary

I was able to set up the D4R Pro in just a couple of hours. It helped that I was familiar with the D4 – take it step-by-step, with assembly instructions well documented in the User Guide; it may take YOU 2 hours and 1 minute, or only one hour. In the video I used maple to make the test joint. I also made test joints using sycamore, and quarter-sawn white oak, using thin and thick boards. I believe that using thicker boards makes it more demanding to get a perfect joint fit, as the wood cannot be compressed readily. In all cases, the fit was excellent. I can now (maybe) ditch the D4!

The bottom line: Leigh has pulled quite a feat modifying the D4R to make finger joints. At the same time they improved the jig by making it possible to make half-blind dovetail joints in one pass. I will cover this feature in a future article.

I would like to hear from you:

  • Do you make boxes (large or small) with finger joints?
  • If you do, are you already using a special jig or template?
  • Regardless the system you currently use to make finger joints, are you happy with the joint fit you get?
  • Or are you so frustrated that you are ready to renounce making finger joints…period?
  • Do you believe this may mean you are ready for the D4R, and eventually the F3 for the D4R. Ready – get set – GO!

Download this episode in Quicktime format (low res)
Size: 34 MB
Duration — 5:08 minutes

Acknowledgement: The music tracks in the video are Jolie, and Year to the Day, by my friend Jason Riley, from the Notes CD.

— Al Navas

Filed Under: Blog, D4R Pro, F3 finger joint, Finger joints, Jigs, Joinery, Leigh jig, Video Tagged With: , ,

Page optimized by WP Minify WordPress Plugin