Scroll Saw Joinery questions

[BobD]

Hey everyone,
If you have any questions about the scroll saw joinery article, please post them here!

Bob Duncan
Scroll Saw Workshop

[Grizz]

Video/DVD

Hey everyone,
If you have any questions about the scroll saw joinery article, please post them here!

Bob Duncan
Scroll Saw Workshop

The only problem I have is usually the understanding through written communication only. I'm a very visual person... it would help to 'see' it being done on a video or dvd. Just like those Christmas cards people are talking about in here. I've seen pictures and they've 'said' what to do.. but I don't get it. I need to see it being done.

[SawTooth]

Sled and Jig are inadequately covered

Bob,

I am very familiar with table saw crosscut sleds of different designs... but I've never seen one referred to as a 'table saw shooting board'. Is there a reason this is called a "shooting board"?

I suppose the table saw sled and 90 degree jig is somehow related to the technique of scroll saw "joinery" or they wouldn't be mentioned and plans wouldn't be made available online. At minimum, I have to guess that Gary MacKay finds them useful when he makes boxes with the "joinery" technique he described. However, I can't tell one thing about their significance. I've read and re-read the info provided and I cannot visualize how the 90 degree jig is constructed or used.

The downloaded pages are so brief as to be useless.
The 90 degree Jig begins with this instruction:
"...place a single sheet of newspaper to the right of the saw kerf." For what? Does it need to be large enough to protect something or small enough to not interfere with the steps that follow? Does it become glued in place? Is it ever used? Is it ever removed? Does it matter if it is from Saturday's or from Sunday's paper? It is never mentioned again.

IMHO, the instructions go downhill from there ... I don't see how following the instructions, as written, will end up with the jig as pictured in the download... and I don't think the jig pictured in the download is of the same design as the jig shown in Step 6 of the article.

I'd appreciate if someone who knows the author's intentions would re-write the instructions for its construction, including more pics and/or drawings, (video would be a luxury, but not a necessity)...and please describe how it is used in the construction of the project illustrated in the article.

Thanks.

SawTooth / Spence

[BobD]

I'll see what I can do!

Bob

[Gill]

Thank you for that contribution, Spence. After reading the article, I was beginning to doubt my own intelligence. I couldn't understand it but I was too embarrassed to say so in public.

Gill

[gmackay]

Scrollsaw Dovetails

Hello,

I would like to post a reply to a couple of questions that were asked in the Scrollsaw Dovetails article. A "shooting board" is a jig that is used as a cutoff box on tablesaws. The "Table Saw Techniques" book by Roger Cliffe (1984) refers to making "shooting boards" as does several other books on woodworking jigs.

The single sheet of newpaper referred to on making the 90 degree jigs protects the tablesaw jig's surface. When you build the 90 degree jig, on the tablesaw jig you would glue the jig to the tablesaw jig's surface without the use of the newspaper. Now it doesn't have to be Saturday's or Sunday's newpaper. The materials list in the article says to use "Old Newpaper". You could even use yesterday's news if you wanted to.......................

Hopefully this answers some questions......



Gary MacKay

[Grizz]

Thank you for that contribution, Spence. After reading the article, I was beginning to doubt my own intelligence. I couldn't understand it but I was too embarrassed to say so in public.

Gill

We all belong together on this.

There's a jig for the dovetails? I lost something there in translation as well. I've tryed to do the dovetails... and they are either to loose or will not go together. I would really love to get those down. But it is frustrating....

[BobD]

I think they're talking about a table saw shooting board (a jig to cut the 45-degree miter corners) that makes it easier to cut the small pieces...Now you have me nervous about cutting the joints! I know wiht traditional dovetails, it is possible to slip a small shim into the joint to tighten it up...

Bob

[Grizz]

Bob,

I've never been able to dove tail joints in any form. If I bought a boxe that had them, it would find a way to become screwed up. Funny, I'm not really fearful of trying anything with wood. I just can't get dovetails, or fingers to work.

I think it's a mental thing.

[BobD]

I've cut some by hand--and they never turned out...but I think I'll get some cheap wood and practice until I can get them right--my wife wants me to assembly line them for holiday presents.

Bob

[Grizz]

Bob,

I guess that might be my problem. If it doesn't come easy or with little effort of 'getting it right', I often will quit early on a project or skill. Find something else to play around with.

[GrayBeard Phil]

Another very, very long reply / post

Saw Tooth:

I have been waiting for some authority on the SSW article to reply to your questions, but so far none have.

Therefore, I am going to post my interpretation of the questions you pose just to see if my answers are close to the answers some authority might given at some later time. This is a long post.

These are just my humble opinion; don't think of them as knowledgeable expert's opinion.

1. Over all I would replace "newspaper" with Wax Paper because the newspaper seems to be used to keep excess glue squeezed out from gluing up the project pieces from sticking to the jig or workbench. I find Wax Paper better than newspapers.

2. The dovetail joinery shown in the article has nothing to do with structural strength of a dovetail joint (or box joint). The joinery shown in the article is just for show. The actual joints, 45 degree miters, are the weakest joint possible for the 4 corners. But, OH MAN, do they ever look good. I am amazed at just how pretty those boxes on the magazine cover look.

3. The description of the wooden hinges making is very good. I just might try that for another project.



4. The boxes for the project in the SSW have a slot, or a blind dado / rabbet, cut near the bottom for the 1/4 inch plywood base. The table saw jig shown is just a method for cutting this slot. The method uses a table saw. The jig does not appear in the article to be used as a cut-off fixture, and I am guessing another name was coined, or researched, to fit the use of the jig.

4.A. While this jig (or fixture) could also be used to cut the 45 degree miters (bevel cut) for the corners, there is not direct, specific, or precise directions to use it as such. Cutting the 45 degree miters accurately on small boxes has a major visual impact on the completed project. Opening miters detract from the visual impact. In addition, there is a safety factor when cutting small items like in this project with out using a fixture for holding the various pieces.


4.B. Aside: on small pieces like in the project article, when cutting a 45 degree bevel, it turns out there is a significant force exerted by the table saw blade to push the project stock away (to the left) of the blade. A stop block or hold down clamp is needed on the left of the project stock to counter this force. Hold down using a scrap block like in photo 6 of the article may not be sufficent for all operators and all table saws.

5. You could use a Dremel Moto-tool with a Dremel accessory "router base" to cut the dado slots. There are many, many other jigs to use with other power tools that could be used to cut the dadoes.

6. My assumption here is that anyone who has read a lot of WoodSmith magazine, the holy grail of jig making, is just plain spoiled by such descriptions of use, building instructions, plus side-bars on details of the many design considerations, plus the CAD drawings that are published in that magazine.

6.A. SSW is not WoodSmith. I also doubt that many of SSW readers have the tools or the woodworking knowledge to construct such complex WoodSmith jigs.

6.B. I do not intend, imply, or suggest that SSW should not try for clarity, accuracy, and concise drawings, instructions, notes, and sidebars so that an "average reader" (however or whoever that is decided) can reasonably construct fixtures or jigs to help assemble projects. Aside: The efforts they expend on project drawings and instructions are outstanding. Improvements can be made on fixtures and jigs.





6.C. In the magazine article photo step 6 and at the web site download page there is a Table Saw 90 degree jig mentioned. Each reader of this post should ask themselves the following:

6.C.1. Just how clear is it in the description of the jig use that it is providing the function of an alignment "rip fence" for cutting the slot for the base in the sides?


6.C.2. Just how clear and lucid are the instructions that the 90 degree jig is clamped securely to the "shooting board" and the position it is clamped is critical to accurate placement of the dadoes?


6.C.3. Just how much emphasis made to accuracy of the construction of corner of the oak fence and rail that make up the Table Saw 90 degree corner?

6.D. This Table saw 90 degree jig is used to establish an alignment "rip fence" stop on the right side of the table saw blade and must be made with a very accurate 90 degree corner. There are two oak sides, a "fence" and a rail. The rail is attached to the "work piece support."

6.D.1 However, I feel the "fence" oak side should, in fact, be made exactly parallel to the saw blade kerf. Not necessarly 90 degrees to the "work piece support." This is a subtle but very important distinction.

7. As with any jig, or more technically correct a fixture, a large effort is expended making a fixture accurate. Then when the raw stock (product) is attached to the fixture, and the cutting edge tool is applied and engaged to the stock, the waste material is removed. Only the waste material, but all of the intended waste material is removed. The tolerance of error, in removing more than just the waste or not removing all the waste, should be limited to the design of the fixture, and its use.

7.A. My opinion is that the jig's design meets this critical. While it may be time consuming to adjust, setup, and use. I can think of lots of suggestions to improve the design, and it would only take a wood shop like Norm's on PBS TV "New Yankee Workshop" to make the fixture as I would modify it. And no, I wouldn't be able to make it myself.

8. Any fixture should be made to provide safety for the operator. Considering the small pieces and just how close the fingers could be getting to the power tool cutting edges (table saw blade's teeth), mandates the jig (fixture) me designed for operator safety.

8.A. This fixture meets this criterion, but only as shown in use in photo "Step 6" of the article. There is a lack of description of the need for the second project side-piece on the left (in the photo), and the safety reasons for the scrap block of wood on the top of the two project pieces. (Balance down forces to avoid sideway force into blade on “hold-down” scrap.)



8.B. A better option would be to use a toggle clamp to hold the project piece, which would remove the operators hand even further from the spinning blade.

Overall, I think Gary MacKay did a good job. Eight stars out of 10 as it were. I am going to be a little harsher on SSW and give them only 6 stars of 10; the effort SSW expends for project drawings and descriptions demonstrates the standards of professionalism they could attain, but fell short of here.


I ask that each reader not to just take my word for the content of this post, but to look at the article, the web page instructions for building the fixture and the PDF download file for the drawings for the fixture. Make up your own mind.

Phil

[Max]

I liked the look of the boxes and had to try it. I used some scrap cedar and walnut and made the box from the article (haven't done the lid yet). The dovetails came out OK but I didn't expect them to be as perfect as using a dovetail jig for a router. I think with some practice I may get the hang of it. As for the miters, I didn't use a jig. I just set the table saw to 45 degrees measured the first board and made the cut. I adjusted the fence with a small block of wood between it and my work and duplicated the miter. I was surprised at how accurate the corners were.

From a distance of a few feet the dovetais look great, but I know where my mistakes are. My wife loved the box (minus the lid). If I could put the ego boost she gives me into a drink I'd make millions.

[BobD]

Hanging my head in shame...

Phil, I appreciate the criticism. I'm looking at this as a learning experience!

Bob

[dtoggs]

cutting dove tail joints on scroll saw,my method:

I mark out the pins, and cut them first(can use an inclined board for angle (if preferred),I also use a flat pc of brass to limit my cut depth. I then mark tails,using the pins as guides,and also using the brass strip to limit depth. My joints sometimes need a little touch up with a knife,but mostly fit well. I use brass strip so its not hard on blade,one could use aluminum,wood or heck,steel.I suppose if your are good,you don't need a stop. I find critical factor is the pcs of wood must be same thickness as the width of the pin increases as the thickness of the board-you math people would enjoy the trig envolved here ha ha. I came in on the hind end of this discussion so pls excuse an redundancy,I just want to spout my method of cutting dove tails. May as well be dovetails if one is going to the laborious task of sawing them out-box joints are just as tedious,just don't have the angle to contend with. Thanks(whew!)Paul W