# Cutting Dados on a TS WITHOUT a Dado Head ?



## wizer (14 Aug 2009)

Something new from Bridge City...

http://www.youtube.com/watch?v=PQ6_S6lZ ... r_embedded


----------



## BigShot (14 Aug 2009)

I think you might just have cost a few people even more money.
I think I might be one of them.
pipper!


----------



## big soft moose (14 Aug 2009)

do bridge city have a uk distro ?


----------



## Philly (14 Aug 2009)

I think Classichandtools sell their stuff.
Cheers
Philly


----------



## RogerS (14 Aug 2009)

Philly":32w9u1n1 said:


> I think Classichandtools sell their stuff.
> Cheers
> Philly



Can't see it on their website. Lovely bit of kit.


----------



## Niki (14 Aug 2009)

And, for the more creative among you....

http://www.shopsmith.net/forums/showthr ... ometrylink

Nice idea...I might try it one day...

Regards
niki


----------



## wizer (14 Aug 2009)

yep there is a guy on LumberJocks selling a copy. Infact when John E got wind of it he offered the drawings for a $10 donation to charity. What a very kind and unusual man.


----------



## OPJ (14 Aug 2009)

RogerS":309segy9 said:


> Philly":309segy9 said:
> 
> 
> > I think Classichandtools sell their stuff.
> ...



Even if it's not on their website, I've discovered it's worth asking them whether they can stock it. I asked them yesterday about some Veritas 'bench hold-downs and they appeared online within a couple of hours! 8)


----------



## wizer (14 Aug 2009)

The Kerfmaker is not available anywhere yet. It's on pre-order from Bridge City Tools. $59


----------



## big soft moose (14 Aug 2009)

it looks like a fairly simple idea - i wonder if we could copy it in hardwoods and brass - strictly for personal use natch.


----------



## wizer (14 Aug 2009)

Like I said above, a few people have done it in the states. Drawings are available.


----------



## FogggyTown (14 Aug 2009)

wizer":15pk6yty said:


> The Kerfmaker is not available anywhere yet. It's on pre-order from Bridge City Tools. $59



And if it follows the usual pattern (like the recent Joint Genie) it will cost about £60 when sold here. :shock:


----------



## FatFreddysCat (15 Aug 2009)

Wizer

It seems to me that you and a few others are willing to pay £60 for a device which is a variation on the technique used by pattern makers to copy cut timber to length. I often use this sort of technique to cut housings for door frames using a sliding compound mitre saw.

The technique for a table saw is simple:

1. Cut a piece of the material you wish to hog out the housing for. Let's call that the thickness gauge
2. Fix the thickness gauge onto the face of the crosscut stop using a piece of double sided tape
3. Pull the crosscut stop out to the width of your material plus a bit more (say 100mm)
4. Set the work piece up against the stop and hold a piece of PAR scrap, say 125mm long against the right hand side of the work piece and hard against the fence. You are going to trim this to length
5. With the saw blade fully raised make a cross cut. This will cut the 125mm long offcut down to 100mm (or so, the actual length isn't critical). Let's call this the spacer
6. Move the work piece to across to the right and place the spacer so that it sits between the cross cut stop with the thickness gauge and the work piece. Drop the blade down to the height you need for the housing groove
7. Make your first cut in the work piece
8. Remove the thickness gauge from the cross cut stop but leave the spacer in place between it and the work piece. Push the work piece and spacer left against the crosscut stop
9. Make the next cut. This will give you the right and left side cuts for your housing

After that it's up to you if you want to make more cuts or simply chop out with a mallet. The plus point is that you use up scrap (for spacers) - and you save yourself £60 into the bargain


----------



## plug (15 Aug 2009)

Here is another one.
http://home.cogeco.ca/~kerfmaster/


----------



## SketchUp Guru (15 Aug 2009)

The Bridge City jig is nice because you can adjust it for various kerf widths but if you only plan to use it with a single blade, you could make it without that adjustment.

John Economaki was indeed very gracious to offer the plans in exchange for a $10 donation to a charity.


----------



## plug (15 Aug 2009)

And these,
bottom left has some drawings halfway down page.

http://lumberjocks.com/projects/tag/kerfmaker


----------



## Steve Maskery (15 Aug 2009)

What an excellent application of the spacers principle. I use spacers a lot for accuracy whether it's cutting double biscuit slots on thick stock, tenons on the bandsaw or setting back a row of dominoes to get a reveal. It's very easy and very reliable.

Bridge City have grown a reputation for producing first-rate kit. What a pity that people appear to be ripping off the idea even before it's gone into general production. It's another case of someone with a good idea not getting his due reward.

On a technical note, why do most of those home-made versions seem to have the two halves held together just by friction (using the big washer to hold over the join), as opposed to compression clamping? Never has Ruskin's aphorism been truer.

Cheers
Steve


----------



## SketchUp Guru (15 Aug 2009)

Steve, I agree with you.

I expect the reason for the friction clamping was to avoid cutting a slot for the screw.


----------



## wizer (15 Aug 2009)

I do also agree with you Steve. But 2 points. Firstly, People have been making home-made jigs for years. You even made a DVD on it. David Thune, creator of the KerfMaster clone, claims he 'redesigned it' from ground up. Bridge City have a patent pending on their design. But as you say, the concept is very very basic. You can't expect woodworkers to just ignore that fact. Secondly, the cloned versions all seem to offer more capacity than the BC version. I think that the publicity around this has probably done BC a favour. Those who have built their own probably would never have bought BC's one. Those of use who are too butt stupid (yes me), would never make one. Even tho David Thune is undercutting BC, it's not by much and I hope only a few people will buy it. The thing about Bridge City Tools is that as well as innovative, they're pretty  and people like pretty tools (even tho Mike G doesn't like to admit it).


----------



## Steve Maskery (15 Aug 2009)

True, Tom, but there is a difference between a woody at home making a copy of a good traditional idea for his own use, or making jigs from published designs, where the author published them with the hope and intent that others would make them, and copying an innovative design for commercial purposes without any thought to the rights of the design originator.

At least, I think there is a difference. I certainly hope so, otherwise I'm as guilty as hell.

Cheers
Steve


----------



## wizer (15 Aug 2009)

yes, the guy selling them is out of order, I admit.


----------



## plug (16 Aug 2009)

I thought I would have a go at making one of these,
what do you think?


----------



## wizer (16 Aug 2009)

looks good. Is it as simple as that? How have you set the kerf width?


----------



## plug (16 Aug 2009)

Couple of hours work this morning, kerk is set with the small brass screw on the end in pic 2


----------



## SketchUp Guru (16 Aug 2009)

Wizer, are you going to build one like that?


----------



## wizer (16 Aug 2009)

I might do Dave.


----------



## SketchUp Guru (16 Aug 2009)

Let me know. I haven't had time to do much in the shop over the weekend.


----------



## 9fingers (16 Aug 2009)

Even though I am an advocate of the safe use of dado heads fitted to large solid tablesaws, there are times when I just want a quick few slots cutting and use my combination blade to nibble these out.
Hence I have been very interested in this thread and after some thought have built my own to a revised design with an extra feature that I’ve not seen elsewhere. 
I’m publishing my work here for interest only and for no commercial gain. If others wish to copy or further improve it then please feel free.

I started out with a block of beech approx 155 x 26 x 55 out of the scrapbox with the intention of a gauge that could handle slots/dadoes upto 75-80mm.






The first step is to plane all over.

Then cut by whatever means into what I will call the body (L shaped part) and the slide.






Run the cut face of the slide over the jointer and then cut a central female dovetail slot 6mm deep along the length. I used a ½” x 11 degree cutter and after the first cut, cleaned up each face by moving the cutter 0.1mm. The resulting slot was therefore 12.9mm at the widest point.






Then cut a male dovetail centrally on the body making fine incremental cuts until the slide will just fit but be a bit tight. This dovetail should be a shade less than 6mm deep to ensure the parts and retained by the flanks of the dovetail. Mine was set to 5.9mm.
You won’t be able to cut all the way up to the jaw face on the body due to the radius of the cutter. This it dealt with in the next step.






Fit the two parts together as far as they will go.






Make a rip cut against a fence set to take a shade off the slide and to cut the body jaw level. (Oops! no picture of this).

Make sure your saw is set to cut spot on 90 degrees for this next step. Use a piece of scrap wood against the mitre gauge to minimise tearout. With the gauge placed jaws-down and the blade height set to kiss the shoulder of the body dovetail, cut a sliver off the fixed jaw and progressively open up the jaw gap until you have taken a sliver off the sliding jaw. This should be the last time you have to cut a slot by eye!!





The jaws should be clean cut, and parallel by now. 






Slide the jaws shut tight and take a cross cut over the other end to make that level.






When closed it should look like a single block of wood again!

and when slid open, like this.






Separate the parts and make a kerf cut 15mm deep in the slide using a fine kerf blade if you have one but don’t worry if not.











Refit the parts and close up the jaws

Drill a hole for the clamp bolt approx 40mm from the jaw end and to pass though the kerf cut and not touch the dovetail. – About 18mm down from the top of the slide in my case.
Counter bore this 5mm deep 10mm diameter for the head of an M6 bolt. Carefully cut a hexagon with a small chisel 






The next picture shows the hex bolt plain washer and brass knurled nut. The latter is not essential but adds a bit of glitz and makes it easy to use. Trivial to knock up if you have a metal lathe and some scrap brass. Otherwise a hex nut is just as effective.






A couple of shots of the assembled jig so far.











The finals steps are to add an adjusting screw to allow for the blade kerf and to add my main modification, a second adjusting screw to make dados with a sliding clearance such as a panel door or other application where a tight fit is not desireable.

Drill a hole 5mm diameter hole counterbored 10mm diameter and 7mm deep. Tap both holes M6 and fit a socket cap screw into each end.











Finally smooth over all the sharp corners and apply a wax finish, allowing the wax to lubricate the dovetail which until now will have been tight and now should slide nicely and yet lock up tight with the thumb screw.

The blade kerf screw can be set as per the original method and the clearance screw turned to get the required fit. For an M6 thread, 1 turn is 1mm advance so by judging the position of the allen key, it is relatively easy to set to the required clearance.

The final picture:-






Hope you find this useful

Bob


----------



## plug (16 Aug 2009)

I like it, better than mine, it can only do slots upto 60mm, and you don't need a hex key to tighten yours up.


----------



## wizer (16 Aug 2009)

:shock: Miles and Miles beyond me.


----------



## plug (16 Aug 2009)

wizer":3l1i5r66 said:


> :shock: Miles and Miles beyond me.



This is not beyond anyone on here, I am a site chippy, hanging doors pitching roofs etc. 
I have only in this past year got my own workshop and started doing some proper joinery. Last time I was in a workshop was as an apprentice 17 years ago.


----------



## filsgreen (16 Aug 2009)

wizer":1eqri41z said:


> :shock: Miles and Miles beyond me.



Same here Tom!! Bob, I thought that was a Niki special, well done mate  

Phil


----------



## Niki (16 Aug 2009)

Bob

Beautiful presentation...

I "Bookmarked" you...even though, it's a little bit beyond me because of the Dove Tail (believe it or not - I've never cut a Dove Tail in my life)    

Regards
niki


----------



## 9fingers (16 Aug 2009)

Niki":1pm1i8lc said:


> Bob
> 
> Beautiful presentation...
> 
> ...



Thanks Niki!

Praise indeed from the "Jig Master"

Bob


----------



## Steve Maskery (17 Aug 2009)

As we all seem to be at it...





Sliding dovetail like Bob's (well actually not like Bob's- I bet his is a good fit  It was tight and I took of just one molecule and now you can drive a bus through the gap )

American Black Walnut and Ripple Sycamore, brass bolts, phenolic knobs. It's a bit long, I can see me cutting it down a bit.

Now where am I going to keep it?

Cheers
Steve


----------



## wizer (17 Aug 2009)

That looks good Steve. I assume the gap at the sycamore end is for the kerf? Is the sycamore just glued?


----------



## Steve Maskery (17 Aug 2009)

The gap at the end is indeed for the kerf, adjustable by the shorter half of the front section. The sycamore is glued and two 25mm brass screws hold it in place. I know that's screwing into end grain, but it's not under any strain so I expect it to hold well.

Cheers
Steve


----------



## 9fingers (17 Aug 2009)

Steve Maskery":13aj3pu9 said:


> Sliding dovetail like Bob's (well actually not like Bob's- I bet his is a good fit  It was tight and I took of just one molecule and now you can drive a bus through the gap )
> 
> Cheers
> Steve



I guess you need to be working at atomic level to get those fits spot on Steve :lol: 

Mine was cut deliberately tight with the intention of easing it on completion but when I put some wax on the jig, it eased up a lot so no fettling needed.

The walnut/sycamore looks good. I've not got much choice in my scrapbox so it had to be beech (from Sarah's science table legs)

Bob


----------



## Steve Maskery (17 Aug 2009)

Yes, well, I don't cut sliding dovetails every day. But I know from experience that it's a mistake to make them too tight, it's so easy to break the pin. And if you leave it together and the pin shrinks or the tail expands, you are scuppered. On the other hand, because of the angle, one shaving makes an enormous amount of difference.

I was hoping that applying a couple of coats of finish would tighten it up, and I think it has, a bit. After all, 2 coats = 8 layers. Perhaps I should just keep polishing it!

Cheers
Steve


----------



## jlawrence (17 Aug 2009)

Looks like a very useful gadget. I think I've some ABW in the bit box so might have a go at making one of these.


----------



## FogggyTown (18 Aug 2009)

Steve Maskery":1288uy7m said:


> As we all seem to be at it...
> 
> Sliding dovetail like Bob's (well actually not like Bob's- I bet his is a good fit  It was tight and I took of just one molecule and now you can drive a bus through the gap )
> 
> ...



Surely any man capable of doing such fine work can easily make a little box to hold it? :lol:


----------



## wizer (18 Aug 2009)

FogggyTown":1dafkjdn said:


> Surely any man capable of doing such fine work can easily make a little box to hold it? :lol:



I think I'd just embed a Neodymium magnet in it and stick it to the side of the TS.


----------



## woodbloke (18 Aug 2009)

I assume that all of these sorts of devices rely on using an unguarded blade of some description? If so, there might be one or two additions to Nikki's table saw thread :shock: - Rob


----------



## SketchUp Guru (18 Aug 2009)

If you have an overarm blade guard or that cool magnetic guard Steve designed, there'd be no reason to remove it. Since this little thing is to be used for non-severing cuts, I guess you'd have to remove a riving knife-supported guard.

I know this will get some folks' small clothes in a twist but ...

I've removed the text that did. I had a momentary lapse.


----------



## woodbloke (18 Aug 2009)

Dave - there are _nine_ threads on Nikki's post on separate table saw incidents that have happened in _one_ week in the good 'ol US of A...seems to me that ya'll doing something wrong on your side of the pond ('scuse vernacular) - Rob


----------



## SketchUp Guru (18 Aug 2009)

I'm not advising anyone to do what I do. I have had more injuries from hand tools than power tools in 40 some years of woodworking. Actually, other than the two incidences I mentioned, I've never had any other injuries from power tools. I am only talking about my own experience.

I would guess that every one of those accidents could have been avoided had the person just thought through the possibilities and options. Perhaps part of the reason I'm so slow at getting anything done in the shop is because I tend to think things through before I flip a switch. Fortunately it isn't a race for me.


----------



## wizer (18 Aug 2009)

Now Now let's not go down this very well trodden road. We're all responsible people here (ahem).


----------



## woodbloke (18 Aug 2009)

wizer":36la1bbh said:


> Now Now let's not go down this very well trodden road. We're all responsible people here (ahem).


Agreed...will spout no more - Rob


----------



## big soft moose (18 Aug 2009)

wizer":1ybyy3nw said:


> Now Now let's not go down this very well trodden road. We're all responsible people here (ahem).



yep none of us would do anything as daft as to take all the safety guards off then stick our hand in the router ....... or for that matter try to rough down a big out of balance block with a 3/8 spindle gouge, snap it and jam the jagged broken end into our palm

oh no we've got far more sense .....  :^o


----------



## SketchUp Guru (19 Aug 2009)

My apologies. I'll refrain from talking about my shop in the future so as not to offend as that's the last thing I want to do.

And now. We return you to your regularly scheduled programme.


----------



## xy mosian (20 Aug 2009)

Thinks :idea: 
Now this device allows stops/jigging to be independant of blade thickness. Could something similar be used with a router based morticing jig to allow for different cutter diameters??

xy


----------



## wizer (20 Aug 2009)

xy mosian":3iugvceu said:


> Thinks :idea:
> Now this device allows stops/jigging to be independant of blade thickness. Could something similar be used with a router based morticing jig to allow for different cutter diameters??
> 
> xy



yes


----------



## 9fingers (20 Aug 2009)

wizer":36y7bfz2 said:


> xy mosian":36y7bfz2 said:
> 
> 
> > Thinks :idea:
> ...



It is not always easy to set a jig to the diameter of a router cutter especially single blade types. You might have to devise something involving a trial cut and then transferring that to a jig so two possible sources of error.

Bob


----------



## Niki (20 Aug 2009)

Hi Bob

I'm using this kind of jig to cut dados with the router...I can use any bit diameter - smaller than or equal to the dado width and it always gives me a very accurate dado...

The secret is in the measuring, marking and positioning methods...

A few picies...
































Regards
niki


----------



## 9fingers (20 Aug 2009)

Thanks Niki,

But when it comes to dados the only way for me is on the table saw. Either I use a blade set designed for the job or nibble away with a standard blade especially now I have made the kerf jig.

I know this is not to everyones taste but ........

Bob


----------



## Niki (20 Aug 2009)

9fingers":1bd5ey6c said:


> I know this is not to everyones taste but ........
> 
> Bob


It's also not everyones choice...

I cannot use a dado set on my TS...the arbor is short...

As I know, all the new generation TS's with the brake cannot use dado blade.

Regards
niki


----------

