Dovetail Jig 95% Finished and Test Run

[Mac McAtee]

Just finished up the most of the detail work on building a dovetail jig.

In a post I put on here yesterday there was a question about the plans for this thing. They came from Workbench Magazine, ShopNotes, Vol. 8, Issue 43, dated January 1999. For the most part I followed the plans. I did change the way that the plans made the rail on top to hold the fingers. Here I used a T-Track instead of what they recommended. A T-Track will hold 1/4" nuts in place so you can turn a screw into them. I thought that this was a simpler solution to the issue.

Sitting on top of the jig is the first test piece out of the jig, other than pieces that I had to cut to fine tune the fingers. The fingers in these pictures are made of 1/2" thick phenolic.

The next test will be to cut a dovetail corner on a 12 1\2" wide boards and see how the accuracy holds up over that distance.

[Mac McAtee]

Workbench Magazine has this back issue. They charge $4.99 plus postage for it. Sorry I didn't mention that above.

[John Miliunas]

Nice job on the jig, Mac! Heck, I have enough problems making dovetails with a factory-made jig.:( I can't imagine what the joints would look like if I had to rely on a jig I made myself, too! :eek: Yeah, definitely post some results pics when you get a full-blown joint done! Good work! :cool:

[aurelio alarcon]

Workbench Magazine has this back issue. They charge $4.99 plus postage for it. Sorry I didn't mention that above.Thanks Mac. I'll have to send for that issue.

[Hal Flynt]

Looks good Mac,

I have that issue and intended to make 2, one for me and one for my son-in-law but didn't get a "round tuit".

I like the T-track idea a lot. I see the slot on the bottom of the fingers and if memory serves me well, the plans had a 1/8 " thick flat aluminum bar positioned vertically to align the fingers. Do you have any trouble keeping them aligned? It looks like an 1/8" wider dado would allow for the bar behind the T-Track or a simple kerf in the right position would allow the insertion of that piece. For me I need the alignment.

Where did you get the phenolic?

Good job, keep us posted.

[Byron Trantham]

I make jigs but my goodness! :) Nice job!

[Mac McAtee]

I like the T-track idea a lot. I see the slot on the bottom of the fingers and if memory serves me well, the plans had a 1/8 " thick flat aluminum bar positioned vertically to align the fingers. Do you have any trouble keeping them aligned? It looks like an 1/8" wider dado would allow for the bar behind the T-Track or a simple kerf in the right position would allow the insertion of that piece. For me I need the alignment.

Where did you get the phenolic?

Hal,
Your memory has not failed. There is a 1/8" aluminum flat bar across the top of the jig that is used to register the fingers.

The fingers have a slot in them that I cut with my table saw blade, 1/8" thick. Fits quite nicely.

The plans use two pcs. of aluminum 90° angle to make the channel that the nuts to hold the fingers slide in. T-Track is just a much simpler and handier way to do the same thing. Just keep in mind to add 1/8" to the heighth of the wood cause you won't have the aluminum angle sitting on top.

The phenolic came from McMaster Carr. They sell different thicknesses of it that are 2" and 3" wide by 48" long. The 2" stuff cost $12.69 per piece and the 3" $17.58 per piece. It is rather chippy as you can see by the chips out of it that show up in the photos. That wouldn't happen if I had put a new fence on my table saw miter before making the cuts, I don't think it would anyway.

Only other advice I could give you is to take extra care when cutting the fingers. Take the time to make everything square and accurate when you cut. It all depends on each finger being exactly uniform. One bad cut on one of the fingers and that finger will not give you an accurate dovetail to match all the other ones. Just take your time and do it right.
Mac

[Hal Flynt]

Thanks Mac,

I had an idea once of buying one Leigh Jig Finger (the split type=2 pieces) and use it as a template and rough cut the fingers on a band saw and then use a 1/4 " flush cut to trim them to size. It seems that the angle is the key to proper fit and must match the angle of the cutter, right?

Now if i can find that round tuit.

[Mac McAtee]

Hal,
Right again. The slot on one end of the finger is to accomodate your router bushing. I used a 5/8" bushing. That slot has to be exactly centered on the finger or you won't get good results. The article explains how to do that and get it accurate.

The other end of the finger, the pointed end, is cut to match the taper of the router bit you are using. In this case I used a 1/2" - 8° taper bit. So the angles that make the point are 8°. If you used a 14° bit then you would make those two angles 14°.

The thing is rather simple once you get into it. But, I'll repeat myself, when cutting out those fingers make sure that you do every cut exactly the same on every finger. Make 3 or 4 extras, cause if you are like me, some little detail will not come out right. I have two fingers that I am gluing strips on so I can re-cut the points because I didn't hold them in exactly the right place when I cut them. I have two other ones that the slot for the router bushing was sloppy in. I didn't hold them exactly right and now I am going to glue strips inside the slot and re-cut them also.
Mac

[Hal Flynt]

Thanks again,

Well I might find my tuit wile on vacation in FLA the end of the week. I will take the article for reading on the plane.