Leigh Jig Help

[Greg Caputo]

I have a Leigh D4 jig. Used it successfully for several years making through dovetails and some occasional half-blind doevetails. Just purchased the parts from Leigh for milling blind dovetails in one pass, routing both the pin board and tail board at the same time. I'm having a terrible time trying to make it work. I've followed all the setup steps, milled the tail board shim to the recommended size, and am using the guidebushing they sent with the kit. The main problems are: inconsistent depth in the pins, and the tail board moving out of position and away from the stop during the routing process. I'm convinced that it's my set-up or technique that is causing these issues which is why I'm hoping for some guidance from the group. Thank you for your advice.
Greg

[Mark Bolton]

I have a Leigh D4 jig. Used it successfully for several years making through dovetails and some occasional half-blind doevetails. Just purchased the parts from Leigh for milling blind dovetails in one pass, routing both the pin board and tail board at the same time. I'm having a terrible time trying to make it work. I've followed all the setup steps, milled the tail board shim to the recommended size, and am using the guidebushing they sent with the kit. The main problems are: inconsistent depth in the pins, and the tail board moving out of position and away from the stop during the routing process. I'm convinced that it's my set-up or technique that is causing these issues which is why I'm hoping for some guidance from the group. Thank you for your advice.
Greg

Cant speak directly to the one pass half blind setup but it doesnt look to be anything different than any other operation on the jig other than the rod and the spacer neither of which would seem to have any relevance to your problems. The board slipping away and from the stops would seem to be inadequate clamping pressure. Dont know if your inserting a matching board on the opposing side of the clamp but perhaps try not doing that, using a thinner board, and increasing your clamping pressure to as much as you feel comfortable with. I have rarely had trouble with slippage on our jig but when I do seem to see it is when I need to tighten up my clamping a bit or my tooling is getting dull (lots of high frequency vibration and catching on the end grain), or when working with super hard/crazy grained materials.

In consistency makes me wonder if your fingers are resting solidly against the board. If there is any flexure or rocking in the finger assembly you I could see having inconsistent lengths.

If your fit was inconsistent I would be concerned with finger slippage or bushing/bit alignment.

[Charles Lent]

The best thing to do is to call Leigh tech support. Get help from the experts on this one. I have the Leigh D4R, but did not buy the option for milling the 1/2 blind fingers and dovetails in one pass so I can't provide the assistance from my own experience. The tech support people should be able to tell you exactly whats going on.

Charley

[Larry Frank]

The Leigh people have always given me good help when I have had a question or problem. Also, there are some good youtube videos.

If I have a slipping problem, I will put a piece of sandpaper between the clamp and board. I made some pieces of sandpaper with grit on both sides to use and keep it with the other Leigh things.

Good luck and post a picture when you have it solved.