Making Bridle joint question?

Re: Making Bridle joint question?

Hank Knight

Barry, I've been cutting bridal joints on my bandsaw using an "almost" automatic process. First, I mill all of the stock to exactly the same thickness and I mill an extra piece for setup. I mark out the female socket on one piece and cut the socket on the bandsaw by flipping the workpiece for the second cut. I nibble out the waste and finish with a chisel. I repeat for all the remaining female sockets with the same fence setting. Then I move the fence to account for the saw kerf, cut a male tenon on the extra setup piece flipping the workpiece for the second cut, test the fit, adjust the fence and recut until I get the fit right. Then I cut all the rest of the male tenons without moving the fence. I remove the waste from the faces on the table saw using a crosscut sled with a stop. This process involves a little trial and error and test cutting, but once the fit of the male tenon is dialed in, the rest is automatic. It gives me very consistent results. Initial careful dimensioning of the stock and flipping the workpiece for the second cuts on both pieces of the joint insure that the joint is centered and the fit is consistent.

My first try was on the bandsaw....

Barry Irby

What blade are you using? I have a 1/2" 3tpi blade on mine. The cuts were too rough. Clearly I need a better blade.

I agree with you about the milling. It must be accurate.

Re: Making Bridle joint question?

William Duffield

I've been using the Bridge City Toolworks KM-1 Kerfmaker for many years. It works very well and is easily recalibrated for whatever width kerf your particular saw blade cuts. It's limitation is the width of the stock you want to bridle.

https://bridgecitytools.com/collections/layout-tools-2/products/km1-kerf-maker

I need to make legs/trestles for Nakashima style tables, and it does not work for stock thickness more than 2", so I recently ordered the KM-2 Kerfmaker. I'm very pleased with it's larger capacity, additional features and larger size.

https://bridgecitytools.com/collections/layout-tools-2/products/km-2v2-kerfmaker-pro

Of course, once you understand the concept behind it, if you can do some precise machining, you could easily make your own. (exercise left to the interested apprentice ).

I need to use a bigger hammer....

Barry Irby

I could have assembled some of my more snug joints with a hammer that size.

Thanks for posting that William, I may get one. Any reason to have both? Won't the larger one do everything the smaller one will do? You do find it useful?

A hundred bucks is a lot to spend. I don't actually NEED to make bridle joints at the moment, I was just playing to see if I could simplify and speed up the process in case someone challenges me.

I just put a fresh blade on the BS and gave it another try. Much better. I had a Diemaster 2 on it that is practically new but somehow it was cutting rough.

Re: Making Bridle joint question?

John McGaw

I never have figured out a really good way of handling these joints. I was mystified by a large commercial display case made my John Hartvigson in Anchorage, AK which had multiple-fingered bridle joints at the corners (3 and 2 IIRC). Hell, I can't even get a single to work more than 1 time out of 3. I guess I could try to find John and ask but it has been a long time and he has probably moved on by now.

Re: I need to use a bigger hammer....

William Duffield

The trick is to get the joint to fit without a hammer.

No, you don't need the KM-1 if you have a KM-2. I bought the KM-1 when the KM-2 saw not available, and before they added the magnets and whatever other enhancements they may have added.

There are several posts on the Interwebs on how to build your own, for a lot less than $100.

Re: I need to use a bigger hammer....

Barry Irby

I have seen some of those videos. I may look again. But, I may just cough up the $100. It's kind of like the Festool thing. Better to be sad the day you buy it, coughing up the cash, and happy with it for the long haul, than to buy the cheap one and hate it forever.

I was stunned at them hammering those joints together. I was sure something was going to break.

Re: Making Bridle joint question?

Barry Irby

My 9 year old grand daughter was here and I was fiddling with those joints. She is very smart and may be a future wood worker and had lots of suggestions. Some worth listening too. We went to dinner and there was a display in the restaurant made with triple joints. She pointed them out to me. They were beautifully made. How do they do that?

Some of mine are pretty good, well they would be very strong if I glued them, but not all that beautiful.

Re: Making Bridle joint question?

John McGaw

The only way I ever figured out that might work reliably without errors involved precise large diameter cutters, maybe 1/4" wide, stacked on the shaper with 1/4" spacers. Passing the parts across that, oh so carefully, would give the necessary slots and then shifting down by 1/4" would give the mating part. In theory one could easily make even wide multiple joints using a bunch of cutters but the expense would likely be horrible; not to mention being scary but for some reason the shaper always did scare me so much that I haven't powered mine up for years now.

Re: Making Bridle joint question?

Barry Irby

You may be right. Perhaps something like a scaled up box joint jig. HMM?

I was trying to come up with something that would be quick and easy without a lot of setup or special cutters and equipment.

I agree with you about the shaper being scary. I have owned one for a long time but get less and less use out of it.

Re: My first try was on the bandsaw....

Hank Knight

Barry, my bandsaw is used primarily for resawing. I currently have a 1" Laguna Resaw King blade on it. It makes very smooth cuts and works very well for this application. In truth, however, it's overkill for bridle joints. I've used Highland Woodworking's Wood Slicer blade and gotten very good results, and I've gotten decent results with a Timberwolf 3/8" X 6PC blade, but not as good as with either resaw blade.

Re: I need to use a bigger hammer....

William Duffield

The gauge mechanically does two measurements and a simple subtraction. Unless you hit the stop too hard with your fence on one of your cuts, it is precise enough go give you the desired tolerances to push the joint together manually, but not have it slip apart due to gravity.

If you are going to reverse engineer your own kerf maker and don't have aluminum machining capability, I would suggest a hard, stable wood like boxwood, bloodwood, dogwood, or even well seasoned lignum vitae or other dense, oily tropical hardwood. Hmmm…I should try making one from some scraps of salvaged ipe decking.

Re: Making Bridle joint question?

William Duffield

You might find this YouTube video by David O Wade on Greene and Greene finger joints useful for your application.

https://www.youtube.com/watch?v=ZHGuqXUI-eg&frags=pl%2Cwn

Without a picture of what you are attempting to do, I can just guess. Sorry if I've led you down a rabbit hole.

Interesting....

Barry Irby

I like some of the Greene and Greene stuff. That was good way to cut those joints and I will remember that method. Not sure it would work for bridle joints because I think the router bit would be a 1/4" and would "whip" if extended far enough to cut the joint.

I had not thought of the paper shims. I like the idea.

This whole thing has been an experiment to fill in a dead spot between projects. Just an effort to teach myself something new that might be useful. Trying to think outside the box of skills and tools I have or at least expand the box a bit. Thanks for the help.

That was really cool!

Re: I need to use a bigger hammer....

William Duffield

Searching the intertubes, I found several copies of a very close Chinese knock-off of the original KM-1 (smaller) KerfMaker. Here is a link to a relatively inexpensive one. The metric graduations on these neither add to nor subtract from the usefulness of the original, which has neither Imperial nor metric graduations.

https://www.amazon.com/wang-JESS-Measuring-Compensation-Woodworking/dp/B0827LBMTG/

I had to go look, just to figure out how much I might be able to sell mine for, now that I have both the KM-1 and KM-2V2.