HELP! Leigh dovetail jig fingers moving

[Joe McMahon]

I am at my cabin shop in Northern Wisconsin trying to build Christmas gifts for my daughters. I am making large boxes 26 X 14 X 14. Since I have so many I am using my Leigh D4 dovetail jig which is about 10 years old. I have used it in the past with success.

After setting the fingers of the jig and tightening them, I cut all of the dovetailed sides for all four boxes. All of the dovetails in all of the sides line up with each other. The fingers did not move.

Next I cut the first back, pin board. After finishing the first edge of the pin board, I found that it wouldn't fit with any of the sides. One end would fit, but the pins at the other end were too large. It was then that I noticed that three of the spacers had moved, making the pins larger, and not very symmetrical.

I am using curly maple, quarter sawn white oak and mahogany. I do not have replacement wood available to me up here, so new pieces are not going to happen. I have to run what I brung. I do not want to attempt to readjust the jig as it would be impossible to get the moved fingers exactly where they were when I cut the dovetails.

I assume that I can re-cut the dovetails to fit the new finger position? If I do this, what is to say that the fingers are not going to move again? I checked again and they are tight. I have no wax or grease on the jig. It is not worn out. Why do the tightened fingers move and how can I prevent this?

HELP!!!!!

[Paul McGaha]

Joe,

Are both the fingers and the finger assembly tight? Correct guide bushings on the router?

Last time I had some dovetails not line up I had a board turned the wrong way in the jig. My fault rather than the jig.

PHM

[Joe McMahon]

Finger and. finger assembly are both tight. I have the correct guide bushing attached. As a matter of fact I use two routers for the Leigh and leave them assembled since I now do mostly hand work. All I did was change bits to new, identical replacement Whiteside bits

[Paul McGaha]

Joe,

Edge stops correctly positioned and tight?

Running out of ideas here. It's sounding like the jig and the routers are good to go.

PHM

[Shawn Pixley]

I don't use a leigh jig often and haven't had the fingers slip. If anything, i have found them occasionally difficult to readjust. After lossening the screw, a light tap seems to help break the aluminum to aluminum bind. I wonder if your technique is a bit strong. I seem to remember the directions stating use light lateral pressure against the fingers.

Without seeing you pieces, I can't provide good advice on the re-cut. Could your piece tolerate losing two thicknesses of stock to completely re-cut?

[Randy Rizzo]

I am at my cabin shop in Northern Wisconsin trying to build Christmas gifts for my daughters. I am making large boxes 26 X 14 X 14. Since I have so many I am using my Leigh D4 dovetail jig which is about 10 years old. I have used it in the past with success.

After setting the fingers of the jig and tightening them, I cut all of the dovetailed sides for all four boxes. All of the dovetails in all of the sides line up with each other. The fingers did not move.

Next I cut the first back, pin board. After finishing the first edge of the pin board, I found that it wouldn't fit with any of the sides. One end would fit, but the pins at the other end were too large. It was then that I noticed that three of the spacers had moved, making the pins larger, and not very symmetrical.

I am using curly maple, quarter sawn white oak and mahogany. I do not have replacement wood available to me up here, so new pieces are not going to happen. I have to run what I brung. I do not want to attempt to readjust the jig as it would be impossible to get the moved fingers exactly where they were when I cut the dovetails.

I assume that I can re-cut the dovetails to fit the new finger position? If I do this, what is to say that the fingers are not going to move again? I checked again and they are tight. I have no wax or grease on the jig. It is not worn out. Why do the tightened fingers move and how can I prevent this?

HELP!!!!!

had the same problem. I had nicked the finger bar and ordered a replacement. The fingers would not tighten on the new bar. Thought there was a manufacturing defect or a change in spec. Contacted Barry in Leigh tech support. He requested one of the fingers and the bar to check it out. He got the same result. Sent me all new tapered plastic pieces that is in the finger and cinches the finger tight to the bar. Worked. He also suggested I not leave the fingers tightened on the bar when done using it, so far no more problems.

[Chris Rosenberger]

I had the same problem a few years back. I solved it by taking the screws out of the fingers & putting a small amount of light oil on each screw & reinserting them.
The oil allows the screws to tighten just a little more.

[Randy Rizzo]

Joe, this was the culprit in my case, replacing all the finger wedges (p/n 7220)solved my problem. With the old wedges no matter how tight I cranked on the finger screw the finger still slid on the bar.

[Larry Frank]

I have not had this happen with my D4. However, I appreciate the information and will take a look at mine when I get it out next. I think that I will order some replacement wedges so that I have them on hand.

Thanks for the info!!

[John Piwaron]

My D4 is a little old, but not the original. Per this message thread, I looked at my finger lockdowns. mine are 2 piece. a wedge part tightening against another wedge shape. My fingers have never slipped - that is, self adjusted so one finger is farther or closer to it's neighbor.

But I have experienced some problems with not having the fingers parallel to the workpiece. perhaps the whole finger assembly has moved? a little forward at one end? a little back at the other? This situation if/when it happens *will* result in pins too big to go into the tails. Or they'll be small resulting in gaps.

What I eventually came to was an extremely painstaking critical reassembly where I checked, measured and checked again each step of the way. Then during setup to take my cuts, I'm checking and triple checking the workpiece for square and sides parallel. Everything. It seems that cutting the tails is perhaps a bit less critical with forward/rearward finger location, but that becomes a whole 'nuther animal when it's time to make the pins. This is where a shopmade fixture comes into play. I made a holder for a dial indicator that references the workpiece and positions the indicator for me to measure the finger set at each end. I'm looking to see how parallel to the work it is. When I see that it's parallel, it's o.k. to cut.

I know that doing so also makes lots and lots of other assumptions - that all the relevant jig parts are equally sized and so on. In my case, what I'm doing is working for me. At the time I was having trouble I spent a LOT of time thinking about the situation and making sketches to help my understanding before deciding on using a dial indicator. I'm not a machinist or I'd have made a few new parts altogether for my D4. I think the D4 is a great jig, but I also think some parts of it would benefit from more precision. But precision costs money and if Leigh included them in every jig it might price it out of reach for most people. Including me.

One other thing - my recent experience with my Festool Domino also leads to another idea. My Domino's fence was slipping. It changed height during use. After some internet searching, I found info from someone that said it was possible the coolant used during manufacture may not have been fully cleaned off. Leaving the surfaces slightly lubricated. The advise was to clean all related lockdown surfaces with some mild soap (dishwashing or Simple Green) solution. Then use an ignition file (remember those?) to slightly roughen the mating surfaces. I did that and today it locks down and doesn't move. Maybe it's possible something like that is happening to the D4.

Also, and this isn't related to pin size, I also noted on my jig that one or two screws had some galling. I was always struggling with raising lowering the fingers. I found that those screws had galled. A little work with a tap and die set fixed that and I put some anti-sieze lubricant on those threads. It works much smoother now.

[Joe McMahon]

Randy, I am guessing that is my problem as well. I will call them tomorrow and order the parts. Thanks!!!

[Bob Reda]

Same problem, replaced both the fingers which replaced the wedges and screws (after 15 years of use) works fine. I believe I did it this way because of price. It was almost as cheap to do the fingers if I remember correctly. Reading the guide I believe over tighting to be the culprit.

Bob

[Joe McMahon]

I just spoke to Barry at Leigh and he has solved my problem! He believes the wedges have become distorted. GREAT customer service, Leigh, thanks!