GG

Greg Guarino

26/04/2015 12:48 AM

Tenon cutting sled

I designed mortise and tenon joinery into my next project, which means I
am currently figuring out how I'm going to make both. I don't have a
table saw.

I intended to make the tenons with a handheld router, a pattern bit (or
maybe a guide bushing) and a jig that consists mostly of a board with a
rectangular hole in it. In fact, I built a prototype which worked.

But I got to thinking that I'd need to clamp and reclamp and clamp and
reclamp and ... you get the picture. One day I had another idea, a
take-off on a crosscut sled.

https://www.flickr.com/photos/gdguarino/17064629907/in/album-72157651767591129/

[scroll right for more angles]

It's basically a sled with a steel guide that fits into the miter slot
of my router table. The guide is set into a dado in the bottom of the
sled. The sled has a slot down the middle that's the width of the bit
(3/4"). It also has an adjustable stop that sets the length of the tenon.

It was pretty easy to build, and so far it seems to work pretty well,
with two possible caveats. I need to remake the stop, it doesn't sit
quite flat on the surface if the sled, which introduces some
imprecision. I knew that as soon as I made it, but I wanted to see if
the method would work at all before I improved it. I may also make the
stop with thicker stock.

The second caveat is that I have only (so far) tried this method with
about a 1/8" depth of cut. But I think it might still be faster to do it
this way even If I have to make two shallow passes to remove more material.

It worked nicely at that depth. And quickly too. I wasn't that careful
about cutting my test scrap and it came out well. Even the short sides
cut nicely. The router bit has a tendency to pull the work *toward* the
stop, which wasn't really a problem. I have so far avoided adding toggle
clamps; if it works well enough holding the work by hand, I won't.

The one other tweak I think I'll make is to cover the back of the slot
with a piece of something hard like maple, so I can't get absentminded
and cut into the heel of my hand. That's not the natural place to put
either hand, but I try to be safe.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com


This topic has 17 replies

Ll

Leon

in reply to Greg Guarino on 26/04/2015 12:48 AM

02/05/2015 8:00 AM

Greg Guarino <[email protected]> wrote:
> On 4/28/2015 9:22 AM, Leon wrote:
>> On 4/25/2015 11:48 PM, Greg Guarino wrote:
>>> I designed mortise and tenon joinery into my next project, which means I
>>> am currently figuring out how I'm going to make both. I don't have a
>>> table saw.
>>>
>>> I intended to make the tenons with a handheld router, a pattern bit (or
>>> maybe a guide bushing) and a jig that consists mostly of a board with a
>>> rectangular hole in it. In fact, I built a prototype which worked.
>>>
>>> But I got to thinking that I'd need to clamp and reclamp and clamp and
>>> reclamp and ... you get the picture. One day I had another idea, a
>>> take-off on a crosscut sled.
>>>
>>> https://www.flickr.com/photos/gdguarino/17064629907/in/album-72157651767591129/
>>>
>>>
>>>
>>> [scroll right for more angles]
>>>
>>> It's basically a sled with a steel guide that fits into the miter slot
>>> of my router table. The guide is set into a dado in the bottom of the
>>> sled. The sled has a slot down the middle that's the width of the bit
>>> (3/4"). It also has an adjustable stop that sets the length of the tenon.
>>>
>>> It was pretty easy to build, and so far it seems to work pretty well,
>>> with two possible caveats. I need to remake the stop, it doesn't sit
>>> quite flat on the surface if the sled, which introduces some
>>> imprecision. I knew that as soon as I made it, but I wanted to see if
>>> the method would work at all before I improved it. I may also make the
>>> stop with thicker stock.
>>>
>>> The second caveat is that I have only (so far) tried this method with
>>> about a 1/8" depth of cut. But I think it might still be faster to do it
>>> this way even If I have to make two shallow passes to remove more
>>> material.
>>>
>>> It worked nicely at that depth. And quickly too. I wasn't that careful
>>> about cutting my test scrap and it came out well. Even the short sides
>>> cut nicely. The router bit has a tendency to pull the work *toward* the
>>> stop, which wasn't really a problem. I have so far avoided adding toggle
>>> clamps; if it works well enough holding the work by hand, I won't.
>>>
>>> The one other tweak I think I'll make is to cover the back of the slot
>>> with a piece of something hard like maple, so I can't get absentminded
>>> and cut into the heel of my hand. That's not the natural place to put
>>> either hand, but I try to be safe.
>>>
>>> ---
>>> This email has been checked for viruses by Avast antivirus software.
>>> http://www.avast.com
>>>
>>
>> Nice jig but I have always simply used the router table fence as the
>> depth stop and a square piece of plywood to square and push the work
>> through. This affords me the ability use any bit in my router table and
>> gives me a exact match back up for any shape bit to prevent tear out on
>> the back side of the cut. This is especially helpful when using rail
>> and stile router bits.
>>
>>
>>
> I thought of that. And in fact, a couple of years ago (when I was even
> more ignorant) I did that to rout spline grooves in the ends of my panel door rails.
>
> But I didn't feel that good about it; too many things that can move in
> ways they shouldn't. This jig gives a guy like me, whose "hand skills"
> may be lacking, a nice secure way to keep the work square and to set the
> proper tenon length.
>
> But you've got me thinking about the tear out. It wasn't a problem on any
> of the 4 test tenons that I cut, but now I'm thinking that I could clamp
> on a sacrificial backer piece for use with shaping bits, should the need arise.

By all means, use what you are comfortable with. I was just sharing how I
always do it. :-)

Sk

Swingman

in reply to Greg Guarino on 26/04/2015 12:48 AM

29/04/2015 9:40 AM

On 4/29/2015 7:59 AM, Leon wrote:
> What I don't like with that method is setting the fence to be parallel
> to the miter slot,

Never had a problem with that. I simply use the squared end of the
backer board, that is attached to the miter gauge, to set the fence
parallel to the miter slot from one end of the other.

Works just fine, unless your fence is not flat, which means you would
have been screwed to start with.

> especially when sneaking up on the length of the tenon.

Just like when making tenons on the table saw using a miter gauge, the
first pass already sets the length of the tenon.

--
eWoodShop: www.eWoodShop.com
Wood Shop: www.e-WoodShop.net
https://www.google.com/+eWoodShop
https://plus.google.com/+KarlCaillouet/posts
http://www.custommade.com/by/ewoodshop/
KarlCaillouet@ (the obvious)

Ll

Leon

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 2:12 PM

On 4/28/2015 1:53 PM, John McCoy wrote:
> Leon <lcb11211@swbelldotnet> wrote in news:NJWdnbJYR-
> [email protected]:
>
>> I agree but typically you need something to keep the piece square to the
>> fence when feeding. I use a square piece of scrap plywood indexed
>> against the fence.
>
> Good point, and I do, in fact, use a square piece of scrap as
> a pusher whenever I'm routing an end. It's such a routine
> thing it didn't occur to me to mention it.
>
> John
>


;~)

Sk

Swingman

in reply to Greg Guarino on 26/04/2015 12:48 AM

29/04/2015 7:02 AM

On 4/25/2015 11:48 PM, Greg Guarino wrote:

> The one other tweak I think I'll make is to cover the back of the slot
> with a piece of something hard like maple, so I can't get absentminded
> and cut into the heel of my hand. That's not the natural place to put
> either hand, but I try to be safe.

What I like about my old Benchdog router table top, it takes my table
saw miter gauge:

https://picasaweb.google.com/111355467778981859077/EWoodShopJigsFixturesMethods?noredirect=1#6143128167298548386

A fence and a miter slot combination, a classic methodology for table
saw or router table for both safety and repeatability.

--
eWoodShop: www.eWoodShop.com
Wood Shop: www.e-WoodShop.net
https://www.google.com/+eWoodShop
https://plus.google.com/+KarlCaillouet/posts
http://www.custommade.com/by/ewoodshop/
KarlCaillouet@ (the obvious)

Ll

Leon

in reply to Greg Guarino on 26/04/2015 12:48 AM

29/04/2015 7:59 AM

On 4/29/2015 7:02 AM, Swingman wrote:
> On 4/25/2015 11:48 PM, Greg Guarino wrote:
>
>> The one other tweak I think I'll make is to cover the back of the slot
>> with a piece of something hard like maple, so I can't get absentminded
>> and cut into the heel of my hand. That's not the natural place to put
>> either hand, but I try to be safe.
>
> What I like about my old Benchdog router table top, it takes my table
> saw miter gauge:
>
> https://picasaweb.google.com/111355467778981859077/EWoodShopJigsFixturesMethods?noredirect=1#6143128167298548386

What I don't like with that method is setting the fence to be parallel
to the miter slot, especially when sneaking up on the length of the
tenon. I still prefer the square piece of plywood to reference off of
the fence to push the work through.

The miter gauge Works great on the table saw however, I have made
countless cuts to make tenons this way.




>
>
> A fence and a miter slot combination, a classic methodology for table
> saw or router table for both safety and repeatability.
>

Ll

Leon

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 8:39 AM

On 4/28/2015 7:39 AM, John McCoy wrote:
> whit3rd <[email protected]> wrote in
> news:[email protected]:
>
>> On Monday, April 27, 2015 at 1:58:33 PM UTC-7, Greg Guarino wrote:
>
>>> Ah. So the work piece is held in the jig vertically?
>>
>> Oh, yes, of course. The alternative was to slide a vertical board
>> held against the fence of a router table (very awkward: better to fix
>> the board and slide the router). This was for half-dovetails, the
>> cut with a router had to have the router spindle parallel to the grain
>> direction.
>
> For doing sliding dovetails, I can see you'd have the board
> vertical (altho I don't see holding it against the fence
> as being especially difficult, if you have a reasonably
> tall fence and a push block).
>
> For tenons, tho, I'm a little lost why you'd need a jig if
> you have a router table. Just set the fence at the right
> distance for the tenon length and lay the boards flat on
> the table.

I agree but typically you need something to keep the piece square to the
fence when feeding. I use a square piece of scrap plywood indexed
against the fence.



JM

John McCoy

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 12:39 PM

whit3rd <[email protected]> wrote in
news:[email protected]:

> On Monday, April 27, 2015 at 1:58:33 PM UTC-7, Greg Guarino wrote:

>> Ah. So the work piece is held in the jig vertically?
>
> Oh, yes, of course. The alternative was to slide a vertical board
> held against the fence of a router table (very awkward: better to fix
> the board and slide the router). This was for half-dovetails, the
> cut with a router had to have the router spindle parallel to the grain
> direction.

For doing sliding dovetails, I can see you'd have the board
vertical (altho I don't see holding it against the fence
as being especially difficult, if you have a reasonably
tall fence and a push block).

For tenons, tho, I'm a little lost why you'd need a jig if
you have a router table. Just set the fence at the right
distance for the tenon length and lay the boards flat on
the table. If the tenon is longer than the width of the
router bit, either move the fence or put a spacer on, or
even freehand the end (carefully!).

John

JM

John McCoy

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 6:53 PM

Leon <lcb11211@swbelldotnet> wrote in news:NJWdnbJYR-
[email protected]:

> I agree but typically you need something to keep the piece square to the
> fence when feeding. I use a square piece of scrap plywood indexed
> against the fence.

Good point, and I do, in fact, use a square piece of scrap as
a pusher whenever I'm routing an end. It's such a routine
thing it didn't occur to me to mention it.

John

ww

whit3rd

in reply to Greg Guarino on 26/04/2015 12:48 AM

27/04/2015 1:34 PM

On Monday, April 27, 2015 at 6:27:53 AM UTC-7, Greg Guarino wrote:
> On 4/26/2015 6:57 PM, whit3rd wrote:
> > On Saturday, April 25, 2015 at 9:48:21 PM UTC-7, Greg Guarino wrote:
> >> I designed mortise and tenon joinery... with a handheld router, ... and
> >>a jig that consists mostly of a board with a rectangular hole in it.

> > I've expanded on that idea, with a wedge-operated vise/clamp to hold the
> > board end in that rectangular hole.
> > Here's pix:
> > <https://plus.google.com/118343199678883181101/posts/LmHmSLu4KL5>

> I'm finding the geometry of your jig a little puzzling. The pictures are
> pretty small. I think I can imagine how such a design *could* work, but
> from the angle in the pictures, I don't see where the work goes.

Maybe you should expand the pictures; it's slow, but there's pixels to spare.
The whole jig clamps to the top of my table (or table saw) and the workpiece comes
up from the bottom, roughly centered in the rectangular cutout.

> Presumably through the front, but then how do the wedges hold it in?

You can see the edge of the fixed plate in the cutout, and on bottom view
it's the plywood chunk in the groove, with a 2x4 brace glued on...
Fixed plate-workpiece-nonsliding_wedge-sliding wedge is the order.
The cutout plate on top is where the router rides, it does obscure the
other parts...

> In any case, judging by my quick tests with some oak 1x3, I think I can
> use my jig without clamping at all. It looks like it will work well,
> unless it is just on its best behavior while I'm still working on scrap. :)

I don't have a thicknesser, and the prospect of trusting the cut from two sides
of a board to get the right edge thickness, is daunting. Once I register the jig
fence accurately to the fixed plate, and clamp (flatten) the possibly cupped
board, a single router pass makes an accurate tongue or half-dovetail.
I still have to cut the board end square, and position it flush with the cutout
plate.

To do a tenon, one would clamp the board, router pass against the fence
for one cheek, then make a second cut with a false-fence (spacer) of size
fence_spacer = cutter_diameter + tenon_width

I haven't done that yet (it'll probably chew a bit of the fixed plate up).

ww

whit3rd

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 1:28 PM

On Tuesday, April 28, 2015 at 5:41:02 AM UTC-7, John McCoy wrote:
> whit3rd <[email protected]> wrote in
> news:[email protected]:
>
> > On Monday, April 27, 2015 at 1:58:33 PM UTC-7, Greg Guarino wrote:
>
> >> Ah. So the work piece is held in the jig vertically?
> >
> > Oh, yes, of course. The alternative was to slide a vertical board
> > held against the fence of a router table (very awkward: better to fix
> > the board and slide the router). This was for half-dovetails, the
> > cut with a router had to have the router spindle parallel to the grain
> > direction.
>
> For doing sliding dovetails, I can see you'd have the board
> vertical (altho I don't see holding it against the fence
> as being especially difficult, if you have a reasonably
> tall fence and a push block).
>
> For tenons, tho, I'm a little lost why you'd need a jig if
> you have a router table.

I like using knotty boards, and recycled wood (often cupped
or of uncertain or mixed thickness), and a cupped three-foot shelf
board wouldn't get an accurate cut on a router table. A four-foot
board would hit the basement ceiling.

As for tenons, I usually do those with a table saw, in one of the
usual ways... but there's a recently-acquired battery circular saw
that might get a trial on tenons with the jig.

Roy Underhill showed a two-screw vise that has similar function to
this clamp/jig, but he wasn't exploring the power-tool options. I've also
considered making a cutting-gage variant, to start my half-dovetail
with a clean woodfiber slice (there's a lot of edge cleanup otherwise);
the gage stop has to be pretty wide to bridge the open throat of the jig.

ww

whit3rd

in reply to Greg Guarino on 26/04/2015 12:48 AM

27/04/2015 5:25 PM

On Monday, April 27, 2015 at 1:58:33 PM UTC-7, Greg Guarino wrote:
> On 4/27/2015 4:34 PM, whit3rd wrote:
> > On Monday, April 27, 2015 at 6:27:53 AM UTC-7, Greg Guarino wrote:
> >> On 4/26/2015 6:57 PM, whit3rd wrote:
> >>> On Saturday, April 25, 2015 at 9:48:21 PM UTC-7, Greg Guarino wrote:
> >>>> I designed mortise and tenon joinery... with a handheld router, ... and
> >>>> a jig that consists mostly of a board with a rectangular hole in it.
> >
> >>> I've expanded on that idea, with a wedge-operated vise/clamp to hold the
> >>> board end in that rectangular hole.

> Ah. So the work piece is held in the jig vertically?

Oh, yes, of course. The alternative was to slide a vertical board held
against the fence of a router table (very awkward: better to fix the
board and slide the router). This was for half-dovetails, the cut
with a router had to have the router spindle parallel to the grain direction.

Now that I think of it, an edge-up clamp jig could also be used with
a Skilsaw (or the smaller battery-powered saws), with some slight adjustments
to the design. Saws cut quicker than routers, straighter (with wood on both sides of
the cut). I wasn't thinking of tenons, though, at the time it all went together.

ww

whit3rd

in reply to Greg Guarino on 26/04/2015 12:48 AM

26/04/2015 3:57 PM

On Saturday, April 25, 2015 at 9:48:21 PM UTC-7, Greg Guarino wrote:
> I designed mortise and tenon joinery into my next project, which means I
> am currently figuring out how I'm going to make both. I don't have a
> table saw.
>
> I intended to make the tenons with a handheld router, a pattern bit (or
> maybe a guide bushing) and a jig that consists mostly of a board with a
> rectangular hole in it. In fact, I built a prototype which worked.

I've expanded on that idea, with a wedge-operated vise/clamp to hold the
board end in that rectangular hole. It's pretty quick to put the board
loosely in the clamp and adjust the end flush, then tap the wedge to
tighten. The vise is a 3-side plywood box, one wall of which is the fixed
vise jaw (cement a bit of fine sandpaper on it for grip).
Then two sidewalls get a (roughly) 2x 5 aperture, through which you put
a points-left and points-right wedge cut from a 2x4.

Here's pix:
<https://plus.google.com/118343199678883181101/posts/LmHmSLu4KL5>

The board on bottom is for clamping the jig (usually to the bed of my
table saw). The steel piece (Unistrut) is a screw-adjusted router fence.

It's near perfect for a sliding half-dovetail (position board, tap the wedge to clamp,
and make a single cut). The wedge (and the bracing behind the fixed-jaw
plate) will flatten a cupped board for accurate thicknessing, and a bit of
springback just makes the half-dovetail fit tighter.

Ll

Leon

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 8:22 AM

On 4/25/2015 11:48 PM, Greg Guarino wrote:
> I designed mortise and tenon joinery into my next project, which means I
> am currently figuring out how I'm going to make both. I don't have a
> table saw.
>
> I intended to make the tenons with a handheld router, a pattern bit (or
> maybe a guide bushing) and a jig that consists mostly of a board with a
> rectangular hole in it. In fact, I built a prototype which worked.
>
> But I got to thinking that I'd need to clamp and reclamp and clamp and
> reclamp and ... you get the picture. One day I had another idea, a
> take-off on a crosscut sled.
>
> https://www.flickr.com/photos/gdguarino/17064629907/in/album-72157651767591129/
>
>
> [scroll right for more angles]
>
> It's basically a sled with a steel guide that fits into the miter slot
> of my router table. The guide is set into a dado in the bottom of the
> sled. The sled has a slot down the middle that's the width of the bit
> (3/4"). It also has an adjustable stop that sets the length of the tenon.
>
> It was pretty easy to build, and so far it seems to work pretty well,
> with two possible caveats. I need to remake the stop, it doesn't sit
> quite flat on the surface if the sled, which introduces some
> imprecision. I knew that as soon as I made it, but I wanted to see if
> the method would work at all before I improved it. I may also make the
> stop with thicker stock.
>
> The second caveat is that I have only (so far) tried this method with
> about a 1/8" depth of cut. But I think it might still be faster to do it
> this way even If I have to make two shallow passes to remove more material.
>
> It worked nicely at that depth. And quickly too. I wasn't that careful
> about cutting my test scrap and it came out well. Even the short sides
> cut nicely. The router bit has a tendency to pull the work *toward* the
> stop, which wasn't really a problem. I have so far avoided adding toggle
> clamps; if it works well enough holding the work by hand, I won't.
>
> The one other tweak I think I'll make is to cover the back of the slot
> with a piece of something hard like maple, so I can't get absentminded
> and cut into the heel of my hand. That's not the natural place to put
> either hand, but I try to be safe.
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> http://www.avast.com
>

Nice jig but I have always simply used the router table fence as the
depth stop and a square piece of plywood to square and push the work
through. This affords me the ability use any bit in my router table and
gives me a exact match back up for any shape bit to prevent tear out on
the back side of the cut. This is especially helpful when using rail
and stile router bits.


GG

Greg Guarino

in reply to Greg Guarino on 26/04/2015 12:48 AM

27/04/2015 9:27 AM

On 4/26/2015 6:57 PM, whit3rd wrote:
> On Saturday, April 25, 2015 at 9:48:21 PM UTC-7, Greg Guarino wrote:
>> I designed mortise and tenon joinery into my next project, which means I
>> am currently figuring out how I'm going to make both. I don't have a
>> table saw.
>>
>> I intended to make the tenons with a handheld router, a pattern bit (or
>> maybe a guide bushing) and a jig that consists mostly of a board with a
>> rectangular hole in it. In fact, I built a prototype which worked.
>
> I've expanded on that idea, with a wedge-operated vise/clamp to hold the
> board end in that rectangular hole. It's pretty quick to put the board
> loosely in the clamp and adjust the end flush, then tap the wedge to
> tighten. The vise is a 3-side plywood box, one wall of which is the fixed
> vise jaw (cement a bit of fine sandpaper on it for grip).
> Then two sidewalls get a (roughly) 2x 5 aperture, through which you put
> a points-left and points-right wedge cut from a 2x4.
>
> Here's pix:
> <https://plus.google.com/118343199678883181101/posts/LmHmSLu4KL5>
>
> The board on bottom is for clamping the jig (usually to the bed of my
> table saw). The steel piece (Unistrut) is a screw-adjusted router fence.
>
> It's near perfect for a sliding half-dovetail (position board, tap the wedge to clamp,
> and make a single cut). The wedge (and the bracing behind the fixed-jaw
> plate) will flatten a cupped board for accurate thicknessing, and a bit of
> springback just makes the half-dovetail fit tighter.
>
I'm finding the geometry of your jig a little puzzling. The pictures are
pretty small. I think I can imagine how such a design *could* work, but
from the angle in the pictures, I don't see where the work goes.
Presumably through the front, but then how do the wedges hold it in?

In any case, judging by my quick tests with some oak 1x3, I think I can
use my jig without clamping at all. It looks like it will work well,
unless it is just on its best behavior while I'm still working on scrap. :)

GG

Greg Guarino

in reply to Greg Guarino on 26/04/2015 12:48 AM

27/04/2015 4:58 PM

On 4/27/2015 4:34 PM, whit3rd wrote:
> On Monday, April 27, 2015 at 6:27:53 AM UTC-7, Greg Guarino wrote:
>> On 4/26/2015 6:57 PM, whit3rd wrote:
>>> On Saturday, April 25, 2015 at 9:48:21 PM UTC-7, Greg Guarino wrote:
>>>> I designed mortise and tenon joinery... with a handheld router, ... and
>>>> a jig that consists mostly of a board with a rectangular hole in it.
>
>>> I've expanded on that idea, with a wedge-operated vise/clamp to hold the
>>> board end in that rectangular hole.
>>> Here's pix:
>>> <https://plus.google.com/118343199678883181101/posts/LmHmSLu4KL5>
>
>> I'm finding the geometry of your jig a little puzzling. The pictures are
>> pretty small. I think I can imagine how such a design *could* work, but
>> from the angle in the pictures, I don't see where the work goes.
>
> Maybe you should expand the pictures; it's slow, but there's pixels to spare.
> The whole jig clamps to the top of my table (or table saw) and the workpiece comes
> up from the bottom, roughly centered in the rectangular cutout.
>
>> Presumably through the front, but then how do the wedges hold it in?
>
> You can see the edge of the fixed plate in the cutout, and on bottom view
> it's the plywood chunk in the groove, with a 2x4 brace glued on...
> Fixed plate-workpiece-nonsliding_wedge-sliding wedge is the order.
> The cutout plate on top is where the router rides, it does obscure the
> other parts...

Ah. So the work piece is held in the jig vertically?


>> In any case, judging by my quick tests with some oak 1x3, I think I can
>> use my jig without clamping at all. It looks like it will work well,
>> unless it is just on its best behavior while I'm still working on scrap. :)
>
> I don't have a thicknesser, and the prospect of trusting the cut from two sides
> of a board to get the right edge thickness, is daunting.

I hadn't thought of that. I'll be using S4S lumber, and should be able
to get the rails for whole project out of a small number of pieces,
maybe 4. I'll be sure to check that the thicknesses are consistent.

GG

Greg Guarino

in reply to Greg Guarino on 26/04/2015 12:48 AM

28/04/2015 3:43 PM

On 4/28/2015 9:22 AM, Leon wrote:
> On 4/25/2015 11:48 PM, Greg Guarino wrote:
>> I designed mortise and tenon joinery into my next project, which means I
>> am currently figuring out how I'm going to make both. I don't have a
>> table saw.
>>
>> I intended to make the tenons with a handheld router, a pattern bit (or
>> maybe a guide bushing) and a jig that consists mostly of a board with a
>> rectangular hole in it. In fact, I built a prototype which worked.
>>
>> But I got to thinking that I'd need to clamp and reclamp and clamp and
>> reclamp and ... you get the picture. One day I had another idea, a
>> take-off on a crosscut sled.
>>
>> https://www.flickr.com/photos/gdguarino/17064629907/in/album-72157651767591129/
>>
>>
>>
>> [scroll right for more angles]
>>
>> It's basically a sled with a steel guide that fits into the miter slot
>> of my router table. The guide is set into a dado in the bottom of the
>> sled. The sled has a slot down the middle that's the width of the bit
>> (3/4"). It also has an adjustable stop that sets the length of the tenon.
>>
>> It was pretty easy to build, and so far it seems to work pretty well,
>> with two possible caveats. I need to remake the stop, it doesn't sit
>> quite flat on the surface if the sled, which introduces some
>> imprecision. I knew that as soon as I made it, but I wanted to see if
>> the method would work at all before I improved it. I may also make the
>> stop with thicker stock.
>>
>> The second caveat is that I have only (so far) tried this method with
>> about a 1/8" depth of cut. But I think it might still be faster to do it
>> this way even If I have to make two shallow passes to remove more
>> material.
>>
>> It worked nicely at that depth. And quickly too. I wasn't that careful
>> about cutting my test scrap and it came out well. Even the short sides
>> cut nicely. The router bit has a tendency to pull the work *toward* the
>> stop, which wasn't really a problem. I have so far avoided adding toggle
>> clamps; if it works well enough holding the work by hand, I won't.
>>
>> The one other tweak I think I'll make is to cover the back of the slot
>> with a piece of something hard like maple, so I can't get absentminded
>> and cut into the heel of my hand. That's not the natural place to put
>> either hand, but I try to be safe.
>>
>> ---
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>>
>
> Nice jig but I have always simply used the router table fence as the
> depth stop and a square piece of plywood to square and push the work
> through. This affords me the ability use any bit in my router table and
> gives me a exact match back up for any shape bit to prevent tear out on
> the back side of the cut. This is especially helpful when using rail
> and stile router bits.
>
>
>
I thought of that. And in fact, a couple of years ago (when I was even
more ignorant) I did that to rout spline grooves in the ends of my panel
door rails.

But I didn't feel that good about it; too many things that can move in
ways they shouldn't. This jig gives a guy like me, whose "hand skills"
may be lacking, a nice secure way to keep the work square and to set the
proper tenon length.

But you've got me thinking about the tear out. It wasn't a problem on
any of the 4 test tenons that I cut, but now I'm thinking that I could
clamp on a sacrificial backer piece for use with shaping bits, should
the need arise.

Ll

Leon

in reply to Greg Guarino on 26/04/2015 12:48 AM

29/04/2015 4:49 PM

On 4/29/2015 9:40 AM, Swingman wrote:
> On 4/29/2015 7:59 AM, Leon wrote:
>> What I don't like with that method is setting the fence to be parallel
>> to the miter slot,
>
> Never had a problem with that. I simply use the squared end of the
> backer board, that is attached to the miter gauge, to set the fence
> parallel to the miter slot from one end of the other.

I guess I could use a square to keep the fence perpendicular to the
miter gauge fence while adjusting the fence. With the TS the fence is
self squaring to the miter slot so there is no issue of the fence
locking perpendicular to the slot.

Either works as well as the other once set up but I figured the fence
set up on a router table would be a bit more finicky, to get it
parallel, and to have the precise location set.


> Works just fine, unless your fence is not flat, which means you would
> have been screwed to start with.
>
> > especially when sneaking up on the length of the tenon.
>
> Just like when making tenons on the table saw using a miter gauge, the
> first pass already sets the length of the tenon.
>
I typicality set the fence to the correct location then butt the
sacrificial fence on the miter gauge up to the fence.


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