I want to learn how to make a sliding dovetail on a shaper. I have a number of books on shapers and building jigs for them but only one page on sliding dovetails. I hope I am clear with my questions:
1. The one reference to dovetails shows running stock from right-to-left against a fence and the dovetail cutter. Then adjusting the fence and run the stock left-to-right between the cutter and the fence. Is this dangerous? Some books said never to put the stock between the cutter and the fence. Others show situations where they do it.
Normally one would flip the stock over and run it right-to-left again. But if the stock was not exactly the right thickness, the tongue would not be correct.
The purpose of this reference is to avoid problems with variations in stock thickness since the same face would always be against the fence. In my opinion moving the fence for the second cut makes the attempt to eliminate stock variations irrelevent since the book says to make a trial cut anyway.
2. Female part: How deep should I cut the dovetail? What diameter cutter should I use? I have 3/4″, 1/2″ and 1/4″ dovetail bits. I want to join a 3×3/4 apron to a 3×3 inch cross-section table leg.
3. Male part: How do I set the cutter and fence to shape the end of the apron piece? That is, one cannot measure the width of the tongue until after it is cut.
I would like a jig that would not need to flip the stock. It would allow shaping one surface then adding a spacer to move the stock past the cutter so the other face can be shaped while keeping the same face of the stock against the spacer and fence.
Replies
Have you considered a regular sliding dovetail jig? Porter-Cable makes templates to go on the Omnijig and I also found this on http://www.easyslidingdovetail.com/
These have the advanatage of doing taperd sliding dovetails
Both the Porter-Cable jig and the EasySliding Jig look interesting. I already have the router but the prices for these jigs are too much for me right now since I only want to make a couple of cuts.
Seems to me that bit is gonna be buried in the female cut no matter how you do it, and I've never done them on a shaper...or a jig for that matter.
And I don't see the advantage over merely using a router with a straightedge clamped to the work surface as a fence. I do most of my carcase joinery with sliding dovetails and I find this simple method fast, efficient, and compensates for variations in stock thickness.
http://pic3.picturetrail.com/VOL12/1104763/2594265/36609507.jpg
Your method appeals to me. Can you supply more details such as how you guide the router (brass guide or the outrigger fence) and how you determine the distance to the second face cut. Do you work from the straight-edge clamped to the same face when cutting the other face?
I have found that at least for me the outrigger fence is not such a stable method when doing critical work.
Don't have a handy pic, but for long sliding dovetails I just clamp the workpiece to the table and clamp down a straight board of greater thickness the appropriate distance away to act as a fence.
Male sliding dovetails I do on the router table against a fence. I cut the female dovetails first and begin the males a little fat and adjust the fence for fit by trial and error.
I've also freehanded the female dovetails using a router for short pieces and also made tapered sliding dovetails as above by setting up the fences to cut the taper...again, starting fat for the male dovetail and tapping the fence inward by trial and error until I get the fit I want.
These female drawerback and carcase dovetails were all freehanded:
http://pic3.picturetrail.com/VOL12/1104763/2594265/36624669.jpg
http://pic3.picturetrail.com/VOL12/1104763/2594265/36609494.jpg
http://pic3.picturetrail.com/VOL12/1104763/2594265/36609507.jpg
Edited 11/13/2003 2:21:48 PM ET by Bob
I can not believe this.
You actually watched "Waterworld"?
Even more amazing, you bought the VHS?
Bob you really have some explaing to us for this.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Ha ha Boris. That's pretty damned funny. I'd like to hear an explanation too.
Bob
When routing the female slider, do you do a preliminary cut with a straight bit and then go with the dovetail or do you do the dovetail in one pass? I managed to break off a dovetail routing oak and I am wondering whether I am using the wrong technique (i.e. should do a preliminary cleanout first).
Thanks - Seth
Both ways...depends on the wood and what bits I happen to have sharp at the time.
Seth,
Your experience is fairly common. Because of their shape dovetail bits are weak at the bottom of the taper. To avoid the problem you need to remove the bulk of the wood first with a straight bit or on the tablesaw with a dado blade.
John W.
When you say sliding dovetail, are you talking about a moveable joint (like for an expanding table) or a joint you're going to glue (like for a cabinet or bookcase)? If the latter, for anything over about 10" long, you need to think about a tapered sliding dovetail so the joint doesn't lock up (because the wood swells when the glue hits it) during assembly. You make the TSD by clamping the work on the bench and cutting the female dovetail using a solidly clamped fence for the router. Then you keep the front of the fence in the same place, and move the back of the fence about 1/32" towards what will be the bottom of the slot you just cut , clamp, and make another pass with the same bit/setting. The slightly too large rear fit of the dovetail is hidden by the back of the cabinet.
My dovetail will only be about 3" long. Something like a pedestal lamp table that has a single column and 4 curved legs attached near the bottom. These legs I want to attach with a sliding dovetail.
Nick, I use a Rockwell 3hp shaper with 1/2", 3/4" and 1" spindles, and I thought I had every shaper cutter known to mankind, Woodworker's Supply, Grizzly, Amana or God. I just checked the catalogs for 3 of the above, and I do indeed have them all. I have never heard of a dovetail cutter for a shaper, so I think you're either talking about a router table or or a chuck or collet which fits on the shaper, so that the bit is vertical.
Last year I built a balustrade with 96 balisters. They were 2.25" x1.125" , 36" high, dovetailed into a long 2" x 8" base. I used a 1" dovetail 14 degree router bit and a jig I made (for spacing) to cut 5" long female dovetails 1/2" deep in the base, a single pass with a Bosch router. I cut the male dovetails on the bottoms of the balisters with the same bit, using an up and down adjustable vertical router table called a Jointmatic. I cut these from both sides, flipping the work and coming from the other direction. I'd adjust till a piece of dovetailed scrap fit perfectly, then cut the good stuff in 2 passes.
Then I'd squirt in some Titebond II in the female dovetail, drive in the ballister, and lock it in place with a glued "key" cut on the TS with the blade at 14*, from 1/2" wood cut across the grain, so it exposed long grain at the ends.
You don't really need a movable router holder, and can do your work on a regular RT if you make the correct jig(s) to hold the leg absolutely vertical and solid when you cut the male DT. Remember, BOTH of the passes on the leg will be with the wood between the bit and the fence, since you'll be using the fence as a support to keep the leg vertical.
Sorry, I wasn't clearer about the dovetail bit. It is a router bit but I have a Delta shaper with a 1/2" collet adapter.
You answered one of my questions about running the stock between the fence and the bit. That was my biggest worry about safety.
It appears that you are using the same technique as I found in the book that I mentioned when I started this thread. I was hoping that I would not have to reset the fence for the second cut.
You don't always have to reset the fence. If you make the male DT slightly oversize, you can pare it to the right size by putting a piece of tape at the top and bottom of the fence and making one pass each way riding on the tape.
Don't forget to knock the corners off the leading end of the male DT before you apply the glue. Dry fit first. I'd use a 3/4" DT bit if you're only doing one pass. but remember that if you make the first pass for the female DT dead center, you can then move the fence back 1/4" , make a pass from both directions and you have a 1 1/4" female DT. Remember that on one of those passes the bit will be trying to pull the work into the bit, not push it away. There IS a safety problem on cutting the male DTs on your Delta unless you make an insert for the table whick totally supports the wood being cut. Otherwise it will try to dip into the hole in the table where the spindle comes through. Delta makes multi part inserts, but the ridges where the parts go together are not smooth and the work wants to twitch when it hits the ridges. I use a round piece of waxed maple as an insert for this kind of work.
When the bit exits on the male DT, there will be tear-out. You can either use a sacrificial block of wood behind the work, or before you make the cut, go to the outfeed side of the bit and back the work in about 7/16". Rob
You are correct about the Delta inserts. Even on other cuts I found the ridges were a problem. Using a hand-made insert is an excellent suggestion.
I still do not understand how you avoid resetting the fence. Did you mean to flip the board over to make the second pass?
Yes, you flip the board over. But make the male DT a little fat, then "pare" to correct size by putting a strip of tape on the fence and making 2 more passes, one on each side.
Thanks. I will do it that way.
Hey Rob Reading your post I see you are a Jointmatic owner also! I must have bought mine 18 years ago and have used the heck out of it. Have seen one for sale used some time back, and I guess Strong tool company went out of business some time back.
Marsh
I did make one change to the Jointmatic. I mounted an idler pulley on a slide block to take slack out of the chain. Didn't have a sprocket to fit, so I used a 1.25" dia cylinder of plastic (Delrin). Works like a charm and now 1/32 of a turn on the crank is actually .002" with no slop. Everyone who sees it work wants to buy it so I keep it locked up. I've never seen a used one for sale.
Edited 11/17/2003 10:28:42 PM ET by rob
Edited 11/17/2003 10:33:50 PM ET by rob
The one that I saw advertised was for more than mine was new "I think" haven't really looked but had thought of starting a thread a couple weeks ago to see if anyone else had one. I haven't felt the need to lock mine up yet though!
I looked up my old paperwork. In 1986 I paid $699 for the Jointmatic and $129 for the sliding adjustable miter gauge, at a So. Cal. wood show. Don Strong was selling them. He threw in a few bits, etc. and no tax (considerable in Calif.) I went on the net a few yrs ago looking for one for a friend, found none for sale, but there was a school in England that listed theirs as availabe for student use, among other machinery.
Some tips here.
That is an excellent article. Last night before seeeing the pictures I had thought of some kind of open slot jig similar to what was shown in this picture. I will go with this technique.
I had searched Google for articles but did not find this one.
This forum post is now archived. Commenting has been disabled