Using non Leigh dovetail bits in a Leigh Dovetail Jig

[Robert Wachtell]

I am learning to Dovetail with a Leigh Super 12 and am starting to pick things up. Last night I got so excited at my success and forgot to slide the router out of guide pin clearance before lifting it out. ZZAMMOOO! Blew up my bit and shredded one guide pin. Picked some fragments of metal off my glasses. Soooo, while I don't need new eyes, fingers, arms, legs or toes I do need a new bit.

Leigh is out of stock on there bits and naturally will not recommend any other bits.

And of course they say that any bits without the "Exact Specifications" as their bits will "not work". And of course there are no bits with the "Exact Specifications" as their bits.

I suppose they would tell me I am an ugly American if I told them the Phfizer vaccine will not work anywhere but in the United States.

I am doing some half blind dovetails for small drawer boxes. In particular I have been using the Leigh 120-8 bit which is now out of stock everywhere.

I noticed Rockler has the same size bit with 8 degree angle rather then Leighs 14 degree angle. Anybody know of reasons why the 8 degree would not work in the jig VS the Leigh 14 degree bit???? Seems to me the only difference in theory should be the angle of the tail tips. 14 degrees VS 8 degrees in this case.

Any suggestions on this bit frontier would be extraordinarily appreciated.

[Jamie Buxton]

Most router bit companies make bits specifically to fit major brands of dovetail jigs. For my Keller jig, I’m currently using a dovetail bit from Whiteside and a straight bit from Infinity. Look around the web sites of MLCS, Whiteside, Infinity, and the like. I bet you can search each site with “Leigh”, and find bits for your jig.

[Paul F Franklin]

Most router bit companies make bits specifically to fit major brands of dovetail jigs. For my Keller jig, I’m currently using a dovetail bit from Whiteside and a straight bit from Infinity. Look around the web sites of MLCS, Whiteside, Infinity, and the like. I bet you can search each site with “Leigh”, and find bits for your jig.

+1... For example, search for Whiteside D108 and you'll find a 7 piece set for the Leigh jigs. I imagine if you dig a little you can find the whiteside no for the specific bit you need. The D108 kit seems to be available from various sources.

[Christopher Herzog]

I have used whiteside, cmt and leigh with my jig. Almost no issues. Once in a while I find them to have barely enough carbide cutter but it had no effect on the finished project.

[Robert Wachtell]

I have used whiteside, cmt and leigh with my jig. Almost no issues. Once in a while I find them to have barely enough carbide cutter but it had no effect on the finished project.

What kind of jig do you use?

[Christopher Herzog]

Leigh D4pro. Regular and a couple isoloc templates

[Charles Lent]

Most any brand of router dovetail bit will work as long as it is designed and sold to work with your jig. They have a slightly longer shaft length for the ones that work with Leigh jigs to account for the thickness of the jig guides. For routing dovetails, you should use fixed base routers and never plunge bases. You also need to remember not to lift the router off the jig unless the bit has completely stopped spinning. I prefer D handle bases mostly because of the convenient trigger switch. If a bit change is necessary during the project, you will likely find a slight difference in your joint fit, maybe too tight or too loose, because of slight differences in the bit and the exact bit length match between the old and new bit in the collet, so a very slight router height adjustment may be needed. I use 1/2" bits because 1/4" bits tend to flex too much for accurate smooth dovetail cuts.

A phone call to Leigh CS will get you replacement parts for your jig quite easily. It's true that they will only recommend their own brand of bits, but every company that's offering a product for sale will not suggest using another brand. I have and use other brands and find no significant difference other than what I noted above.

Charley

[Alex Zeller]

Do you know the Leigh number for the bit you were using? If so then you can just do a search for that number and you should get lots of hits. I would invest in a better brand, like Whiteside, bit.

[Robert Wachtell]

Most any brand of router dovetail bit will work as long as it is designed and sold to work with your jig. They have a slightly longer shaft length for the ones that work with Leigh jigs to account for the thickness of the jig guides. For routing dovetails, you should use fixed base routers and never plunge bases. You also need to remember not to lift the router off the jig unless the bit has completely stopped spinning. I prefer D handle bases mostly because of the convenient trigger switch. If a bit change is necessary during the project, you will likely find a slight difference in your joint fit, maybe too tight or too loose, because of slight differences in the bit and the exact bit length match between the old and new bit in the collet, so a very slight router height adjustment may be needed. I use 1/2" bits because 1/4" bits tend to flex too much for accurate smooth dovetail cuts.

A phone call to Leigh CS will get you replacement parts for your jig quite easily. It's true that they will only recommend their own brand of bits, but every company that's offering a product for sale will not suggest using another brand. I have and use other brands and find no significant difference other than what I noted above.

Charley

Charley, A serious thanks to you for providing your helpful insight and information.

"You also need to remember not to lift the router off the jig unless the bit has completely stopped spinning" .... or make sure you pull straight out clear of the guide pins and then lift up.

Either one is just as hard to remember to do for me. If you got memory pills with no side effects I will take those over this advice.

"I use 1/2" bits because 1/4" bits tend to flex too much for accurate smooth dovetail cuts."

How does the 8mm compare to the 1/2" for flex problem?

"A phone call to Leigh CS will get you replacement parts for your jig quite easily."

A phone call to Leigh informed me that their bits or at least the ones I need are out of stock for a while AND OTHER BITS WILL NOT WORK UNLESS THE SPECIFICATIONS ARE IDENTICAL TO THEIR SPECIFICATIONS.

The British measurements (inches) they provide for their bit 120-8 in their specifications/manual Page 74 Appendix II are off. For example the bit is much closer to 2.5 inches in overall length then 2.25 inches in overall length as stated in the Appendix. There are 2 other errors in the stated specifications for this bit in that Appendix as well.

Perhaps something got lost in their conversion from MM to inches.

So there is not a bit out their that has the same "Manual Specifications" as Leighs 120-8 bit. However Whiteside does make a bit that according to Whiteside specifications has the exact same measurements as the Leigh 120-8 bit. At least when I measure my Leigh 120-8 bit that I got from them.

My hunch is that Whitesides bit is much closer in size to Leighs 120-8 bit then it is to Leighs specifications for this bit in their manual.

I will find out tomorrow.

So this is what has made finding the replacement bit difficult, at least for a new customer to the arena like me.

Rob

[Robert Wachtell]

Do you know the Leigh number for the bit you were using? If so then you can just do a search for that number and you should get lots of hits. I would invest in a better brand, like Whiteside, bit.

Thanks Alex

Last night I bought the Whiteside version of Leighs 120-8 bit. It was difficult to be sure it was the correct bit at first for the reasons mentioned in my previous post.

From the pics it looks like the tip of the Whiteside blade shows a little wider/thicker then the Leigh bit.

Rob

[Charles Lent]

Robert,

I bought my Leigh D4R through Highland Woodworking in Atlanta and I ordered the full set of bits with it. What I received from them was their own brand and not the Leigh brand, but they were much lower in cost. I have been using these bits for about 20 years with my Leigh D4R jig and have never experienced a problem with them. I have never measured them to see how close they are to the Leigh specs. I just used them without ever having a problem. I am not near my shop now, so I can't study them to see what is stamped on them or to measure them, but again, they work fine. Leigh wants to sell their bits, so they are not going to tell you that others will work. Buy a bit set for the D4R from Highland Hardware and they should work fine for you. Mine do, and have for almost 20 years. I have even bought replacements for a few of them, again from Highland Hardware over the years with no problems found when using them. I'm fussy about the quality of my joints when I'm making furniture. I would have been very quick to complain and return these bits if they didn't work perfectly.

Charley

[lowell holmes]

I would shop here, https://www.lowes.com/search?searchTerm=dove+tail+bit

When you see it, you will know, also Home Depot can help.

[Charles Lent]

I would shop here, https://www.lowes.com/search?searchTerm=dove+tail+bit

When you see it, you will know, also Home Depot can help.


You WILL NOT find the proper length bits for a Leigh D4R at Lowes and Home Depot. You need to buy from a place that sells the bits that have the longer shanks necessary for use with the jig. They will always list them as "for the Leigh D4R jig" or similar. They are available from just about ALL of the major woodworking tool sources, and especially the ones who offer the Leigh Jigs. A lumber yard or other construction trades supplier is not going to have the right ones.

Charley

[Alex Zeller]

Also don't forget that most Leigh bits need to be 8mm to work with their more common 7/16" guide bushing. Not sure if the big box stores even sell 8mm bits. You could try to find a 1/4" bit but then you're sacrificing stiffness. I'll stick with good brand name bits made to the same specs.

[Robert Wachtell]

You WILL NOT find the proper length bits for a Leigh D4R at Lowes and Home Depot. You need to buy from a place that sells the bits that have the longer shanks necessary for use with the jig. They will always list them as "for the Leigh D4R jig" or similar. They are available from just about ALL of the major woodworking tool sources, and especially the ones who offer the Leigh Jigs. A lumber yard or other construction trades supplier is not going to have the right ones.

Charley


Don't worry ... I would not go to home depot or lowes for this item or advice on it if somebody were holding a gun to my head. Although I certainly will go for other things.

Whitesides version of Leighs 120-8 bit came yesterday and I will say this about it.

1) It matches Leighs 120-8 bit exactly in size. However the width of the Whiteside blades is slightly wider then the Leigh blades. ( The Whiteside bit does more cutting on the bottom sweep of the bit then the Leigh bit does ) The length and thickness of the blades appear to be the same.

4) I created my first half blind dovetails worthy of the marketplace last night after one practice cut with the Whiteside bit. I used the same settings/measurements I was using with the Leigh bit on my pin guides and depth of bit on the router.

That's the way it is for me at least.

So even with the good products ... you need to sort out the BS that they come with. Thanks to all for the great input here on helping me do that as in the end .... clobbering my Leigh bit the other night was a blessing in disguise coupled with a nice learning experience.

[Charles Lent]

Robert,

Don't hesitate to ask if you should have any other D4R questions.

Watch the Leigh demonstration videos closely. Their method of climb cutting across the width of the cut first, and then following up with deep cuts into the jig slots makes the edge and corner of each dovetail cut nice and clean with no splintering, if done correctly.

I check in here almost every morning and will answer any future question that you have to the best of my ability and experience. I have made A LOT of dovetails with my D4R, but not so many in the last few years. I also own an FMT Pro jig and have about the same amount of use on that.

The 1/2" shank bits or the 12 mm (?) Leigh bits won't flex as much during the cuts, so the 1/2" shank is what all of my dovetail and straight bits are. I had tried a few of the 1/4" shank and wasn't at all happy with the result. Leigh recommends the larger shank bits as well.

Charley

[Robert Wachtell]

Robert,

Don't hesitate to ask if you should have any other D4R questions.

Watch the Leigh demonstration videos closely. Their method of climb cutting across the width of the cut first, and then following up with deep cuts into the jig slots makes the edge and corner of each dovetail cut nice and clean with no splintering, if done correctly.

I check in here almost every morning and will answer any future question that you have to the best of my ability and experience. I have made A LOT of dovetails with my D4R, but not so many in the last few years. I also own an FMT Pro jig and have about the same amount of use on that.

The 1/2" shank bits or the 12 mm (?) Leigh bits won't flex as much during the cuts, so the 1/2" shank is what all of my dovetail and straight bits are. I had tried a few of the 1/4" shank and wasn't at all happy with the result. Leigh recommends the larger shank bits as well.

Charley

Charley

The bits that came with my Leigh Super 12 are 8 mm bits. The Whiteside bit I bought is 8 mm as well.

Are you saying I would get a better cut with a 12 mm.

The 8 mm seemed to provide a clean cut.

One thing that seems difficult with the Leigh Super 12 is that it can be difficult to get the guide pin assembly to lay PERFECTLY flat on the work piece. It might be micro higher on one side versus the other side of the work piece ultimately causing a micro deeper dovetail cut on one end of the work piece vs the other end. Its flexible and wants to warp up or down ever so little. You can see the difference when you look at the contact to the work piece on the underside.

Also the guide pins are easily tightened in a non level position with respect to each other, even if you do push down on the center of them while tightening. Although this problem is easier to correct then the above mentioned one.

Rob

[Alex Zeller]

As far as I know the only options are 8mm and 1/2" shanks. But each requires a different guide bushing. Obviously the 1/2" shank router bits will be stiffer, but how much, I don't know. My jig came with two bushings for the 8mm bits so that's what I'm learning with. It sounds like you have the router support/ vac accessory, but if you don't you should get it. It does help. I also agree with Charlie that technique is everything. Starting with getting the guide bushing centered, not twisting the router, and how you move the router.

It would be nice to have a sheer cut or even spiral bits. I think it would reduce the tearout.

[Paul Haus]

I realize I'm late to the game here but a couple of comments for anyone looking at this later. I bought a D4R back around 2004-2005 and got a couple of bits with it. I later bought a set of bits for the jig from MLCS with 8 mm shanks and 1/2" shanks. long and short of it is I've made a bunch of dovetailed pieces and I'm more than happy with how they worked. Happens I have a couple of Bosch routers and that have an available 8 mm collet which I have.

[Dave Sabo]

8mm collets are available for just about any router, not just Bosch and Festool.