how to make box/finger joints with a Mark V

mwhizz · Post by **mwhizz** » Sun Aug 02, 2009 11:42 pm

How do you make finger/box joints with an older Mark V with an original table? I have tried with out any luck. the backs get blown out & the tenon(pin) is too small. Is it posable to do on a mark V with a simple jig & ruler??? I just want to make a few small boxes with 1/4 to 3/8" joints.

beeg · Post by **beeg** » Mon Aug 03, 2009 12:21 am

As far as the tear out on the back. Scoring it with a utility knife should prevent the tear out.

navycop · Post by **navycop** » Mon Aug 03, 2009 1:02 am

Check out post "can you make finger joints without a dado blade".

dusty · Post by **dusty** » Mon Aug 03, 2009 6:51 am

mwhizz wrote:How do you make finger/box joints with an older Mark V with an original table? I have tried with out any luck. the backs get blown out & the tenon(pin) is too small. Is it posable to do on a mark V with a simple jig & ruler??? I just want to make a few small boxes with 1/4 to 3/8" joints.

Are you cutting the box joints (sizing the fingers) by hand or do you use some sort of the jig?

The fit problem you describe is a function of "how accurate is your work" or "how accurate is your jig".

The blow out that you are experiencing can be minimized by using a backer board and a sharp blade and slow feed rate.

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Have you considered using a router?

mwhizz · Post by **mwhizz** » Mon Aug 03, 2009 11:36 pm

WOW! GREAT BOX JOINTS. Did you do them with a router?
Yes i made a jig or 2... used a 1x4 with a 3/8" pin then put a slot 3/8" off the pin, then mounted it on the Mark V miter handle with 4-20 screws & wing nuts. I wanted to use the dado blade that I've never used I have 2 of them. a stacking ShopSmith & a Craftsman Woble type. no luck with ether blade. How do you make the mesurements. All I used was a 1"tape. I did get batteries for my digital calipers. Thanks

dusty · Post by **dusty** » Tue Aug 04, 2009 7:37 am

These cuts were made with a router and the measurements were made tape measure with 1/32" markings.

Measuring and cutting the guide pin to match the measurements of the dado blade or router bit is, IMHO, the key to success.

If you declare the router bit to be 1/2" and it is actually .495", the joints do not fit perfectly. The error, .005" is pretty darn good until it begins to accumulate with multiple cuts. The accumulated error can result in a set of joints that won't go together at all.

Spend some time determining the width of your cut and then matching it with a perfectly fitting pin.

Incidentally, this is what makes box joints with a saw blade so difficult. Each and every edge defining cut with the saw blade needs to be exact.

Ron309753 · Post by **Ron309753** » Tue Aug 04, 2009 10:01 am

mwhizz,

Watch Sawdust Session #2. Nick and Jim demonstrate a jig for cutting finger joints with a dado blade. The jig backs up the stock to reduce tear out. You can download the plans for the jig on the blackboard. I haven't tried it, but it should work great with any table series and table saws.

Hope this helps!

Sincerely,

Ron 309753

8iowa · Post by **8iowa** » Tue Aug 04, 2009 10:12 am

Last Winter I went through "finger joint Hell" when making a small treasure chest for my grandson. I made a finger joint jig from plans shown in one of Nick Englers books and attached it to my miter gauge, which by-the-way should work the same on a 500, 510, or 520.

One of the first critical dimensions is to make the stud spacer on the jig exactly the same width as your dado blade, and I mean down to a couple thousands of an inch. Then the spacer must be placed exactly....not just close........but exactly the same distance from the dado blade. The jig design allows for this space between the blade and the spacer stud to be incrementally adjusted.

I gave up on 1/4" fingers. In an 8 inch width I just couldn't get the fingers to line up regardless of how carefully I tried to adjust the jig. In going to 3/8" fingers I had acceptable success, but again with a lot of frustrating jig allignment efforts.

I'm hoping to make more of these treasure chests for great-nephews, and great-neices but I will now place my finger joint jig on a shelf to gather dust and cut my finger joints on my new Rockler dovetail jig.

tango · Post by **tango** » Wed Aug 05, 2009 3:36 am

So what everyone is saying then is that a router is the way to go... am I right? I've downloaded several plans for finger joint jigs, but haven't tried them yet. From what I'm reading here it may be more of a headache than it's worth. The spacing of the pin and blade and the overall width of the pin seem to be in the area of head-pounding frustration coupled with a lot more waste than the normal sawdust junkie may want.

Me thinks a router may be in order... or on order, whatever

dusty · Post by **dusty** » Wed Aug 05, 2009 7:34 am

The router would be my choice but using a router rather than a table saw does not guarantee good joints.

The measurements that, when not made properly, result in poor fit are just as likely to occur with a router as they are with a saw.

Yes, if you want 1/2" joints and you have a 1/2" router bit you have a pretty good chance of 1/2" cuts. A lot better chance than setting the 1/2" dado blade to 1/2" and going for it.

But if you want really good fit, you have to make sure of all the measurements. The width of the pin, the size of the bit or blade and the offset of the pin from the blade are all equally important. Any one of these set incorrectly contribute to a less than perfect fit.

Box joints are demanding. Once you have them mastered it is then time to advance to dovetails.

I have yet to cut a full set of dove tails that I am pleased with.