I've had this jig for a good 4 or so years and have primarily used it for
1/2 blind dovetails for drawers. Every time I use it, I spend a great deal
of time getting it set up and in the past have finally "settled" for as
good as I can get. I decided not to settle this time and have spent a
great deal of time trying to get the jig to provide me with gap-free 1/2
blind joints. I get the part about adjustment up and down loosening or
tightening the joint. The problems I am having are getting gaps on the
*side* of some of the joints, and the bottom gaps when adjusting tightness
not being even across the width of the board (only 3 1/4") despite the fact
that the fingers are flat on the pin board and the spacer board and the
tail board is uniform across the width of the spacer board. I've tried
recentering the router bit (one of the reasons I bought template bases for
my Bosch laminate trim router was so I could easily center the bushing),
I've tried swapping jig fingers (now I've got a bit of springiness when
tightening the finger jig because of having to remove the ends). I've tried
rotating the router 180 degrees to rout the pins after routing the pins.
Nothing seems to be helping much.

Next thought is lapping the router baseplate dead flat. I've been trying
to hold it flat to the center, but am getting rocking. Would a 5 mil rock
cause significant problems?

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.

--
If you're going to be dumb, you better be tough

Mark & Juanita wrote:

Just added a picture at abpww illustrating the problem.


I've had this jig for a good 4 or so years and have primarily used it
for
1/2 blind dovetails for drawers. Every time I use it, I spend a great
deal of time getting it set up and in the past have finally "settled" for
as
good as I can get. I decided not to settle this time and have spent a
great deal of time trying to get the jig to provide me with gap-free 1/2
blind joints. I get the part about adjustment up and down loosening or
tightening the joint. The problems I am having are getting gaps on the
*side* of some of the joints, and the bottom gaps when adjusting tightness
not being even across the width of the board (only 3 1/4") despite the
fact that the fingers are flat on the pin board and the spacer board and
the
tail board is uniform across the width of the spacer board. I've tried
recentering the router bit (one of the reasons I bought template bases for
my Bosch laminate trim router was so I could easily center the bushing),
I've tried swapping jig fingers (now I've got a bit of springiness when
tightening the finger jig because of having to remove the ends). I've
tried rotating the router 180 degrees to rout the pins after routing the
pins. Nothing seems to be helping much.

Next thought is lapping the router baseplate dead flat. I've been
trying
to hold it flat to the center, but am getting rocking. Would a 5 mil rock
cause significant problems?

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.




--
If you're going to be dumb, you better be tough

I'm not sure how much this matters, if at all, but I've watched the demo
at many shows before I bought mine, and I remember the presenter saying
that you need to push straight down on each finger as it is tightened.
I don't remember if he said just what the significance of that act was,
but I've always done it that way and have not had these type of
problems. The guy who I bought mine from is Mark Hensley and he runs a
shop and a school at his home in Florida. Maybe try sending him your
pictures at .. .. .. .. .. .. and ask him for
a response. If anyone is qualified to give an opinion, it would be
Mark. I think he knows that jig better than the engineers who designed it.

Mark & Juanita wrote:
Mark & Juanita wrote:

Just added a picture at abpww illustrating the problem.


I've had this jig for a good 4 or so years and have primarily used it
for
1/2 blind dovetails for drawers. Every time I use it, I spend a great
deal of time getting it set up and in the past have finally "settled" for
as
good as I can get. I decided not to settle this time and have spent a
great deal of time trying to get the jig to provide me with gap-free 1/2
blind joints. I get the part about adjustment up and down loosening or
tightening the joint. The problems I am having are getting gaps on the
*side* of some of the joints, and the bottom gaps when adjusting tightness
not being even across the width of the board (only 3 1/4") despite the
fact that the fingers are flat on the pin board and the spacer board and
the
tail board is uniform across the width of the spacer board. I've tried
recentering the router bit (one of the reasons I bought template bases for
my Bosch laminate trim router was so I could easily center the bushing),
I've tried swapping jig fingers (now I've got a bit of springiness when
tightening the finger jig because of having to remove the ends). I've
tried rotating the router 180 degrees to rout the pins after routing the
pins. Nothing seems to be helping much.

Next thought is lapping the router baseplate dead flat. I've been
trying
to hold it flat to the center, but am getting rocking. Would a 5 mil rock
cause significant problems?

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.

"__ Bøb __" wrote:

I'm not sure how much this matters, if at all, but I've watched the demo
at many shows before I bought mine, and I remember the presenter saying
that you need to push straight down on each finger as it is tightened.
I don't remember if he said just what the significance of that act was,
but I've always done it that way and have not had these type of
problems. The guy who I bought mine from is Mark Hensley and he runs a
shop and a school at his home in Florida. Maybe try sending him your
pictures at .. .. .. .. .. .. and ask him for
a response. If anyone is qualified to give an opinion, it would be
Mark. I think he knows that jig better than the engineers who designed
it.

Thanks. I'll try re-setting the fingers as you suggested and if that
doesn't work, will contact Mr. Hensley.


--
If you're going to be dumb, you better be tough

Mark & Juanita wrote:

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.

No solution, but feel your pain.

As much as I like the jig, I continually fight with it when attempting
to do a "production run" of drawer sides for dozens of drawers at a time.

I've pretty well accepted that there are simply too many parameters,
from stock, to router, to jig, to obtain the kind of ideal CONSISTENCY
in that situation, from first to last.

But, I do remember my "pre-jig" days, and the alternative was worse ...

On the current project I'm toying with going with the Multi-Router just
to see if the "consistency", from first to last in a many part run,
improves.

--
www.e-woodshop.net
Last update: 10/22/08
KarlC@ (the obvious)

Swingman wrote:

Mark & Juanita wrote:

Any help would be appreciated. As a pre-emptive, the answer, "just
chop
them by hand" is not an answer I'm seeking -- I'm really trying to
figure out why this machine is not working as advertised.

No solution, but feel your pain.

As much as I like the jig, I continually fight with it when attempting
to do a "production run" of drawer sides for dozens of drawers at a time.


Thanks. It's helpful knowing that I'm not the only person who has been
fighting this.

I've pretty well accepted that there are simply too many parameters,
from stock, to router, to jig, to obtain the kind of ideal CONSISTENCY
in that situation, from first to last.


That pretty well describes the issue -- piece to piece consistency even
after getting things set up as best as possible is an issue.


But, I do remember my "pre-jig" days, and the alternative was worse ...

On the current project I'm toying with going with the Multi-Router just
to see if the "consistency", from first to last in a many part run,
improves.


--
If you're going to be dumb, you better be tough

Mark & Juanita wrote:

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.

Is there any possibility of movement between stock/fingers?

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Morris Dovey wrote:

Is there any possibility of movement between stock/fingers?

After I posted that, it occurred to me that movement of the bushing
could produce a same/similar effect...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Morris Dovey wrote:

Morris Dovey wrote:

Is there any possibility of movement between stock/fingers?

After I posted that, it occurred to me that movement of the bushing
could produce a same/similar effect...


That I'm pretty certain is not happening. The bushing is very solidly
seated in the base plate. I was also seeing the same problem when using my
1613 for the router, so I think this cause can be eliminated.

--
If you're going to be dumb, you better be tough

Morris Dovey wrote:

Mark & Juanita wrote:

Any help would be appreciated. As a pre-emptive, the answer, "just
chop
them by hand" is not an answer I'm seeking -- I'm really trying to
figure out why this machine is not working as advertised.

Is there any possibility of movement between stock/fingers?


Morris,

I don't think so, I've got things clamped down pretty tight. I'll look at
that a little closer, it may be that router torque is causing something I
can't see, will have to look more carefully.


--
If you're going to be dumb, you better be tough

Mark & Juanita wrote:

Every time I use it, I spend a great deal
of time getting it set up and in the past have finally "settled" for as
good as I can get. I decided not to settle this time and have spent a
great deal of time trying to get the jig to provide me with gap-free 1/2
blind joints.

I get the part about adjustment up and down loosening or
tightening the joint.

The problems I am having are getting gaps on the
*side* of some of the joints, and the bottom gaps when adjusting tightness
not being even across the width of the board (only 3 1/4") despite the fact
that
- the fingers are flat on the pin board and
- the spacer board and the tail board is uniform across the width of the
spacer board.
- I've tried recentering the router bit
(one of the reasons I bought template bases for my Bosch laminate trim
router was so I could easily center the bushing),
- I've tried swapping jig fingers (now I've got a bit of springiness
when
tightening the finger jig because of having to remove the ends).
- I've tried rotating the router 180 degrees to rout the pins after
routing the pins.

Nothing seems to be helping much.

Next thought is lapping the router baseplate dead flat.

I've been trying to hold it flat to the center, but am getting rocking.

Would a 5 mil rock cause significant problems?

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.

Mark:

As you've discovered - while having variable spacing fingers - there are
several inherent problems with the Leigh DT Jig design - starting with
those moveable fingers. To move them you have to have SOME slop
in the hole in the finger - and some way of locking the fingers in
postion
where you want them. That's the first design flaw. ANY slop introduced
error is DOUBLED because of the Flip The Fingers Over design of the
jig.

The second design flaw is support for the router. You didn't mention
if you have the accessory Front Support Bar. If you don't, you're
supporting the weight of the router plus any downward force you're
exerting on those adjustable then locked down fingers. And the longer
the support bar is - the more it must resist flexing, bowing downwards
under the weight of the router and the downward force you provide.
You didn't mention if this is the 12" model, the 16 or 18" model or
the 24" model.

Now to what YOU may be doing to cause the problem.

The Tails board appears in the photo to be cupped a little - which
could explain some of the problem

The most common problem with using dovetail bits is that they want
to pull themselves out of their holding collet. Since ALL of the DT
Jigs that use Fingers require that the bit's shank diameter be small
- 1/4" or 8mm diamter, the router's collet holding the bit doesn't
have that much gripping surface area - even with the four slots
collets. And if you've got gunk in the slots the collet can't close all
the way.

The other common problem is setting the bit ALL the way down in
the router. THAT can lead to a jack hammering affect as the bit
cuts - sometimes pushing the bit up out of the collet - and even
just a little height change can screw up the fit.

Then there's the router itself. I may be mistaken but I think you said
you were using a Bosch - and I think it was the COLT - a small, fairly
light weight trim type routers - with a relatively small base - and not
a whole lot of weight - and thus not much inertia. While the lighter
weight may be of benefit in terms of less weight on the ends of the
jig's fingers, there's not much mass to resist "bouncing" as the bit
begins cutting harder then softer grain. A full sized router may
be part of a solution to your problem.

Have you checked to see if the GAP is on both sides of the joint
and not just at the Show Face side? Rub a pencil lead on the faces
of either the pins or the tales, put the joint together, take it apart
and see where marks have been transfered to the sides of the tails.
This might give you a clue as to what's happening.

Also, are you sneaking INTO each cut or going all the way in and
then to the side and then back out? A "fronter board" can reduce
or eliminate grain tear out.

Hope this gives you some more things to check out.

BTW - The AKEDA, by design, eliminates the Fingers Slop Problem
AND
the router support tilting problem.

charlieb wrote:


BTW - The AKEDA, by design, eliminates the Fingers Slop Problem
AND
the router support tilting problem.

Thanks, Charlie ... I think you hit the nail on the head with many of
your points.


--
www.e-woodshop.net
Last update: 10/22/08
KarlC@ (the obvious)

charlieb wrote:

Charlie,

Thanks for your detailed and thoughtful response. I'll interpose some
additional information.

Mark & Juanita wrote:

Every time I use it, I spend a great deal
of time getting it set up and in the past have finally "settled" for as
good as I can get. I decided not to settle this time and have spent a
great deal of time trying to get the jig to provide me with gap-free 1/2
blind joints.

I get the part about adjustment up and down loosening or
tightening the joint.

The problems I am having are getting gaps on the
*side* of some of the joints, and the bottom gaps when adjusting
tightness not being even across the width of the board (only 3 1/4")
despite the fact that
- the fingers are flat on the pin board and
- the spacer board and the tail board is uniform across the width of the
spacer board.
- I've tried recentering the router bit
(one of the reasons I bought template bases for my Bosch laminate trim
router was so I could easily center the bushing),
- I've tried swapping jig fingers (now I've got a bit of springiness
when
tightening the finger jig because of having to remove the ends).
- I've tried rotating the router 180 degrees to rout the pins after
routing the pins.

Nothing seems to be helping much.

Next thought is lapping the router baseplate dead flat.

I've been trying to hold it flat to the center, but am getting rocking.

Would a 5 mil rock cause significant problems?

Any help would be appreciated. As a pre-emptive, the answer, "just
chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.

Mark:

As you've discovered - while having variable spacing fingers - there are
several inherent problems with the Leigh DT Jig design - starting with
those moveable fingers. To move them you have to have SOME slop
in the hole in the finger - and some way of locking the fingers in
postion
where you want them. That's the first design flaw. ANY slop introduced
error is DOUBLED because of the Flip The Fingers Over design of the
jig.

The second design flaw is support for the router. You didn't mention
if you have the accessory Front Support Bar. If you don't, you're
supporting the weight of the router plus any downward force you're
exerting on those adjustable then locked down fingers.

I don't have a front support bar. Not sure if it was available for the D4
or not -- I'll need to check into that.

And the longer
the support bar is - the more it must resist flexing, bowing downwards
under the weight of the router and the downward force you provide.
You didn't mention if this is the 12" model, the 16 or 18" model or
the 24" model.

I've got the 24" model


Now to what YOU may be doing to cause the problem.

The Tails board appears in the photo to be cupped a little - which
could explain some of the problem


That was a bit misleading. The cupping is due to the thin remaining stock
after I cut the tails from the test stock. The tails tended to curl the
off-cut. The original stock was square and flat.

The most common problem with using dovetail bits is that they want
to pull themselves out of their holding collet. Since ALL of the DT
Jigs that use Fingers require that the bit's shank diameter be small
- 1/4" or 8mm diamter, the router's collet holding the bit doesn't
have that much gripping surface area - even with the four slots
collets. And if you've got gunk in the slots the collet can't close all
the way.

The other common problem is setting the bit ALL the way down in
the router. THAT can lead to a jack hammering affect as the bit
cuts - sometimes pushing the bit up out of the collet - and even
just a little height change can screw up the fit.


At this point, the bit does not seem to be moving in the collet -- what I
set it at depth-wise is where it stays.


Then there's the router itself. I may be mistaken but I think you said
you were using a Bosch - and I think it was the COLT - a small, fairly
light weight trim type routers - with a relatively small base - and not
a whole lot of weight - and thus not much inertia. While the lighter
weight may be of benefit in terms of less weight on the ends of the
jig's fingers, there's not much mass to resist "bouncing" as the bit
begins cutting harder then softer grain. A full sized router may
be part of a solution to your problem.


You are correct, I am using the Colt router with a template base. In the
past, I've used my Bosch 1613, but had issues with being able to center the
bit in the template bushing. I saw the same issues with the side gap with
the 1613 as I'm seeing with the Colt. However, depth adjustment was
better. I think you may have something here as far as the bit bouncing.


Have you checked to see if the GAP is on both sides of the joint
and not just at the Show Face side? Rub a pencil lead on the faces
of either the pins or the tales, put the joint together, take it apart
and see where marks have been transfered to the sides of the tails.
This might give you a clue as to what's happening.


Good suggestion, I'll try that with a solid test piece. I just tried it
with the cut-off and am not seeing a mark all the way through, so the gap
is all the way through.


Also, are you sneaking INTO each cut or going all the way in and
then to the side and then back out? A "fronter board" can reduce
or eliminate grain tear out.

Definitely sneaking into the cut, not trying to go in all the way at once,
not seeing any tearout at this point.



Hope this gives you some more things to check out.


Yep, this was very useful. It helps eliminate some things and points to
other areas to investigate further.


BTW - The AKEDA, by design, eliminates the Fingers Slop Problem
AND
the router support tilting problem.

I'm also going to look into this. I've wasted enough time already with
the Leigh that if I were charging for my time, I could have bought another
jig. This is definitely getting to the point of not being fun nor
enjoyable. Hobbies aren't supposed to drive a person to the verge of
profanity. :-(




--
If you're going to be dumb, you better be tough

A couple of thoughts...

To check how much you have to lower the dovetail bit, pull the two
boards apart as hard as you can, and use feeler gauges to measure the
biggest gap. Lower the bit that much(*). I use a 1.5hp (yea, right)
PC router with the fixed base, and I've calculated how many thou each
tic on the ring represents so I can do this "accurately" (again, yeah
right).

Beware of cupped boards.

I always do two corners at a time, one on each end of the jig. Not
only is it faster, but it keeps the jig squarer to the boards. At
least put a spacer on the other end, using one of your other milled
boards.

Yes, your router base should be flat. Compare it to some reference
flat, not to the jig. I got a cheap granite surface plate from
Grizzly for this purpose.

Don't rotate the router when routing - hold it in a fixed orientation
throughout. Consistency is more important than concentricity.

When I do through dovetails for batch jobs, I do all the tail boards
first, then all the pin boards, and it doesn't matter which tail
boards I match up with which pin boards - all the joints are the same.
The D4 *can* make accurate joints, so keep working on it.


(*) If that's way too tight, next time do half the thickness, I lose
track of when the adjustment doubles the results and when it
doesn't.

DJ Delorie wrote:


A couple of thoughts...

To check how much you have to lower the dovetail bit, pull the two
boards apart as hard as you can, and use feeler gauges to measure the
biggest gap. Lower the bit that much(*).

Yep, that's what I've been doing.

I use a 1.5hp (yea, right)
PC router with the fixed base, and I've calculated how many thou each
tic on the ring represents so I can do this "accurately" (again, yeah
right).


The Colt is a little more fussy setting depth, but I had the same issues
with the 1613 EVS with the microadjust.


Beware of cupped boards.

Will double-check, but I'm very fussy about getting both flat and square
stock.


I always do two corners at a time, one on each end of the jig. Not
only is it faster, but it keeps the jig squarer to the boards. At
least put a spacer on the other end, using one of your other milled
boards.

Have been putting a spacer on the other end to make sure


Yes, your router base should be flat. Compare it to some reference
flat, not to the jig. I got a cheap granite surface plate from
Grizzly for this purpose.


That seems to be the next action I need to take. I know for certain the
router base on the Colt is not flat. I can't speak for the one on the 1613
when I used it last time.


Don't rotate the router when routing - hold it in a fixed orientation
throughout. Consistency is more important than concentricity.

After considering this, I think it is also necessary to rotate the router
180 degrees when doing pins vs. tails. When you look at where the router
bushing contacts the jig, it seems that you want the same point contacting
the jig for both pins and tails. To do that, the router needs to be
rotated 180 degrees. Would you concur?


When I do through dovetails for batch jobs, I do all the tail boards
first, then all the pin boards, and it doesn't matter which tail
boards I match up with which pin boards - all the joints are the same.
The D4 *can* make accurate joints, so keep working on it.


That's good to know. I'm still struggling with whether this is setup or
technique.


(*) If that's way too tight, next time do half the thickness, I lose
track of when the adjustment doubles the results and when it
doesn't.

--
If you're going to be dumb, you better be tough

Mark & Juanita writes:
After considering this, I think it is also necessary to rotate the
router 180 degrees when doing pins vs. tails. When you look at
where the router bushing contacts the jig, it seems that you want
the same point contacting the jig for both pins and tails. To do
that, the router needs to be rotated 180 degrees. Would you concur?

No, because you want to consistently register the center of the
bushing against the same reference edge with the same offset. For
example, if your bushing was 1/4" to the left (assuming that were
possible), you want that offset to move the pins to the left *and*
move the tails to the left. If you rotate the router, you end up with
the pins moved to the left but the tails get moved to the right.

If the bushing has an in/out position error, you compensate for that
when you position the D4 rack after flipping it.

This assumes that the largest error in the bushing is it's position
relative to the router bit. Errors in the shape of the bushing, while
nonzero, are likely far smaller than the position error.

DJ Delorie wrote:


Mark & Juanita writes:
After considering this, I think it is also necessary to rotate the
router 180 degrees when doing pins vs. tails. When you look at
where the router bushing contacts the jig, it seems that you want
the same point contacting the jig for both pins and tails. To do
that, the router needs to be rotated 180 degrees. Would you concur?

No, because you want to consistently register the center of the
bushing against the same reference edge with the same offset. For
example, if your bushing was 1/4" to the left (assuming that were
possible), you want that offset to move the pins to the left *and*
move the tails to the left. If you rotate the router, you end up with
the pins moved to the left but the tails get moved to the right.


I agree with needing to offset the same amount from the reference edge.
However, the reference edge changes when you flip the template.
Here was the thought process:

Say the offset is as shown below:
bush bit bush
--| |-- offset
----| | | |-------
| | | |
/_\


When cutting the tails:

--| |-- offset relative to jig
----| | | |-------
| | | | ---- this part of the bushing contacts the jig,
/_\ The cut will be offset by the off-center
here

| Cutting wood on this side

If I don't rotate the router 180 degrees when cutting the pins:

--| |-- This is the now offset relative to the jig
----| | | |-------
| | | |
/_\
| Cutting wood here
This is the
side that will
contact the jig

| Now cutting wood on this side of the bit

It seems like the cut will now be greater for this offset on the pin side
than on the tail side.

However, if I rotate the router 180 degrees:
--| |-- This is the offset relative to the jig
----| | | |-------
| | | |
/_\
| Cutting wood here
This is the
side that will
contact the jig

and the same offset from the bushing to the workpiece will be obtained.

It seems like I want the second condition to get the same offset. What am
I missing?




If the bushing has an in/out position error, you compensate for that
when you position the D4 rack after flipping it.

This assumes that the largest error in the bushing is it's position
relative to the router bit. Errors in the shape of the bushing, while
nonzero, are likely far smaller than the position error.

From what I can tell right now, I agree, the biggest offset is in the
router bit centering.



--
If you're going to be dumb, you better be tough

Mark & Juanita wrote:

DJ Delorie wrote:


Mark & Juanita writes:
After considering this, I think it is also necessary to rotate the
router 180 degrees when doing pins vs. tails. When you look at
where the router bushing contacts the jig, it seems that you want
the same point contacting the jig for both pins and tails. To do
that, the router needs to be rotated 180 degrees. Would you concur?

No, because you want to consistently register the center of the
bushing against the same reference edge with the same offset. For
example, if your bushing was 1/4" to the left (assuming that were
possible), you want that offset to move the pins to the left *and*
move the tails to the left. If you rotate the router, you end up with
the pins moved to the left but the tails get moved to the right.


I agree with needing to offset the same amount from the reference edge.
However, the reference edge changes when you flip the template.
Here was the thought process:

Say the offset is as shown below:
bush bit bush
--| |-- offset
----| | | |-------
| | | |
/_\


When cutting the tails:

--| |-- offset relative to jig
----| | | |-------
| | | | ---- this part of the bushing contacts the jig,
/_\ The cut will be offset by the off-center
here

| Cutting wood on this side

If I don't rotate the router 180 degrees when cutting the pins:

--| |-- This is the now offset relative to the jig
----| | | |-------
| | | |
/_\
| Cutting wood here
This is the
side that will
contact the jig

| Now cutting wood on this side of the bit

It seems like the cut will now be greater for this offset on the pin
side
than on the tail side.

However, if I rotate the router 180 degrees:
--| |-- This is the offset relative to the jig
----| | | |-------
| | | |
/_\
| Cutting wood here
This is the
side that will
contact the jig

and the same offset from the bushing to the workpiece will be obtained.

It seems like I want the second condition to get the same offset. What
am
I missing?




If the bushing has an in/out position error, you compensate for that
when you position the D4 rack after flipping it.

This assumes that the largest error in the bushing is it's position
relative to the router bit. Errors in the shape of the bushing, while
nonzero, are likely far smaller than the position error.

From what I can tell right now, I agree, the biggest offset is in the
router bit centering.




Hopefully the ASCII art turned out better for others than when I read the
posting. If not, my apologies, let me know what I can clarify
--
If you're going to be dumb, you better be tough

The offset you care about is the center of the bit relative to the
center of the bushing. The offset from the finger to the bit is
irrelevent here - the jig is designed to accomodate *that* offset.

When pondering your diagrams, think to yourself "the bit is to the
left of where it should be".

Since the MultiRouter was brought up as an alternative to
the Leigh, PC and the AKEDA, you might consider another
alternative - which eliminates the centering of the bit and
the roundness of the guide collar - the JoinTech Cabinet
Maker precision positionable router fence - with dovetail
templates. In addition to through and half blind dovetails,
box/finger joints - it does all the other things a good router
fence on a decent router table can do. And it does permit
variable spacing of dovetails. And unlike its competitor
it has a built in centering feature - eyeballing being one
of the problems with the competitor.

No fingers that can move, no flexing of the finger support
bars, etc.

charlieb writes:
And unlike its competitor it has a built in centering feature -
eyeballing being one of the problems with the competitor.

Does it make joints with air pockets in them, like the competitor?

DJ Delorie wrote:
charlieb writes:
And unlike its competitor it has a built in centering feature -
eyeballing being one of the problems with the competitor.

Does it make joints with air pockets in them, like the competitor?

Only if the user screws up, like its competitor.

charlieb wrote:
Since the MultiRouter was brought up as an alternative to
the Leigh, PC and the AKEDA, you might consider another
alternative - which eliminates the centering of the bit and
the roundness of the guide collar - the JoinTech Cabinet
Maker precision positionable router fence - with dovetail
templates. In addition to through and half blind dovetails,
box/finger joints - it does all the other things a good router
fence on a decent router table can do. And it does permit
variable spacing of dovetails. And unlike its competitor
it has a built in centering feature - eyeballing being one
of the problems with the competitor.

Eyeballing? One can measure you know.

No fingers that can move, no flexing of the finger support
bars, etc.

J. Clarke wrote:

charlieb wrote:
Since the MultiRouter was brought up as an alternative to
the Leigh, PC and the AKEDA, you might consider another
alternative - which eliminates the centering of the bit and
the roundness of the guide collar - the JoinTech Cabinet
Maker precision positionable router fence
snip
And unlike its competitor
it has a built in centering feature - eyeballing being one
of the problems with the competitor.

Eyeballing? One can measure you know.

Sure, you can measure, find and mark the center of the board
- that's not the problem. It's the aligning that center of
of the board mark with the center of the router bit that's
the problem. Few, if any, dovetail router bits have a convenient
center mark to align to.

If you looked at the photo of the sample DT with the gap problem.
you'd notice that either the pins part or the tails part is off by
a noticeable amount so that the pins part's top edge sits proud
of the top of the tails part - the two parts being of identical
width.
THAT indicates the pins or tails or both are not centered on the
parts width.

My Oh Bull**** alarm goes off whenever I see ANY machine dovetail
making tool claim "fool proof" and/or "no test cuts necessary".
It's getting the damn bit heights right that raises all the hell -
and
takes so much time to get right. And when you have to use TWO
bits to make the DT joint - you'e going to lose one set up to get
the other - unless you're using TWO routers - which you can do with
a JIG but not with a router table and fence system.

Thanks for all the responses thus far. Based upon all of the input, I've
determined the following is my best path forward:

1. Ditch the Colt and go back to the Bosch 1613. Having used the Colt for
test cuts was leading me to that conclusion anyway, it just isn't built for
that kind of extended hard use. My purpose for using it was because I did
have a way to fix the router base offset on it while not having a similar
capability for the 1613. The small router also has a tendency to chatter
and depth adjustment has been less than simple. However, I'm seeing the
same kinds of gaps with the Colt as I was seeing with the 1613 when I used
it on previous projects, so this just returns me to my starting point.

2. Because of the centering issue and because I would prefer to use a PC
style screw-in bushing: order one of Pat Warner's clear router bases for
the 1613 and probably the centering kit to aid in getting the alignment
correct. This will alleviate the centering problem and might address some
of the gapping by making sure that the base is uniformly flat -- I was
seeing gaps before, even when presenting the same side of the router to the
template (I didn't try the 180 degree rotation until this time) so flatness
may have been an issue with the 1613.

3. Reset all of the finger guides, starting from the left and using a
machinist's square to ensure the finger guides are square to the guide bar.

4. Verify that the guide bar is uniformly distanced from the work piece
along the entire work piece width.

5. Pay particular attention to technique to ensure that I'm not rocking the
router or tipping the router.

6. Take a very serious look at the Akeda jig. After looking at it on-line,
I see some really significant benefits to this vs. the Leigh, particularly
from the router support standpoint. The only downside I see is having to
change out fingers each time one changes from pins to tails. I'm good with
the 1/8" discrete steps and can live without infinitely variable spacing if
the discrete setup guarantees that the fingers will be positioned reliably.
The only uncertainty then is that the fingers are precisely machined for
repeatability.

--
If you're going to be dumb, you better be tough

One more thing to strongly consider.

BIT CHATTER. If you are using 1/4" shank bits or a light weight router the
bit could be spinning outside of it normal area of travel. In other words
the bit could be bending while spinning and cause too much material to be
removed. This could be exaggerated at higher bit speeds. Leigh recommends
8mm and 1/2" bits to help fight chatter.

I typically don't have a problem but I do use the larger shank bits.





"Mark & Juanita" wrote in message
m...

Thanks for all the responses thus far. Based upon all of the input, I've
determined the following is my best path forward:

1. Ditch the Colt and go back to the Bosch 1613. Having used the Colt for
test cuts was leading me to that conclusion anyway, it just isn't built
for
that kind of extended hard use. My purpose for using it was because I did
have a way to fix the router base offset on it while not having a similar
capability for the 1613. The small router also has a tendency to chatter
and depth adjustment has been less than simple. However, I'm seeing the
same kinds of gaps with the Colt as I was seeing with the 1613 when I used
it on previous projects, so this just returns me to my starting point.

2. Because of the centering issue and because I would prefer to use a PC
style screw-in bushing: order one of Pat Warner's clear router bases for
the 1613 and probably the centering kit to aid in getting the alignment
correct. This will alleviate the centering problem and might address some
of the gapping by making sure that the base is uniformly flat -- I was
seeing gaps before, even when presenting the same side of the router to
the
template (I didn't try the 180 degree rotation until this time) so
flatness
may have been an issue with the 1613.

3. Reset all of the finger guides, starting from the left and using a
machinist's square to ensure the finger guides are square to the guide
bar.

4. Verify that the guide bar is uniformly distanced from the work piece
along the entire work piece width.

5. Pay particular attention to technique to ensure that I'm not rocking
the
router or tipping the router.

6. Take a very serious look at the Akeda jig. After looking at it
on-line,
I see some really significant benefits to this vs. the Leigh, particularly
from the router support standpoint. The only downside I see is having to
change out fingers each time one changes from pins to tails. I'm good
with
the 1/8" discrete steps and can live without infinitely variable spacing
if
the discrete setup guarantees that the fingers will be positioned
reliably.
The only uncertainty then is that the fingers are precisely machined for
repeatability.

--
If you're going to be dumb, you better be tough

"Leon" wrote in message
the bit could be bending while spinning and cause too much material to be
removed. This could be exaggerated at higher bit speeds. Leigh
recommends
8mm and 1/2" bits to help fight chatter.

Hmmm. You could be right, but that's an awful lot of bit chatter for the
amount of dead space shown in the pictures he presented. I'd freak out if
any router I had caused that much wobble.

"Upscale" wrote in message
...

"Leon" wrote in message
the bit could be bending while spinning and cause too much material to be
removed. This could be exaggerated at higher bit speeds. Leigh
recommends
8mm and 1/2" bits to help fight chatter.

Hmmm. You could be right, but that's an awful lot of bit chatter for the
amount of dead space shown in the pictures he presented. I'd freak out if
any router I had caused that much wobble.


Chatter along with a smaller based and light weight router could do that.

Leon wrote:


"Upscale" wrote in message
...

"Leon" wrote in message
the bit could be bending while spinning and cause too much material to
be
removed. This could be exaggerated at higher bit speeds. Leigh
recommends
8mm and 1/2" bits to help fight chatter.

Hmmm. You could be right, but that's an awful lot of bit chatter for the
amount of dead space shown in the pictures he presented. I'd freak out if
any router I had caused that much wobble.


Chatter along with a smaller based and light weight router could do that.

Chatter may be a contributor, but I've seen the same kind of gapping when
using the heavier plunge router as well. I'm starting to really lean to
the idea that neither of my router bases is flat enough and that there is
enough rocking that I'm getting excessive cutting.

I need to look into the 8mm bits but then will need a collet adapter to
work in my router


--
If you're going to be dumb, you better be tough

On Mon, 25 May 2009 19:02:24 -0700, Mark & Juanita
wrote:


I've had this jig for a good 4 or so years and have primarily used it for
1/2 blind dovetails for drawers. Every time I use it, I spend a great deal
of time getting it set up and in the past have finally "settled" for as
good as I can get. I decided not to settle this time and have spent a
great deal of time trying to get the jig to provide me with gap-free 1/2
blind joints. I get the part about adjustment up and down loosening or
tightening the joint. The problems I am having are getting gaps on the
*side* of some of the joints, and the bottom gaps when adjusting tightness
not being even across the width of the board (only 3 1/4") despite the fact
that the fingers are flat on the pin board and the spacer board and the
tail board is uniform across the width of the spacer board. I've tried
recentering the router bit (one of the reasons I bought template bases for
my Bosch laminate trim router was so I could easily center the bushing),
I've tried swapping jig fingers (now I've got a bit of springiness when
tightening the finger jig because of having to remove the ends). I've tried
rotating the router 180 degrees to rout the pins after routing the pins.
Nothing seems to be helping much.

Next thought is lapping the router baseplate dead flat. I've been trying
to hold it flat to the center, but am getting rocking. Would a 5 mil rock
cause significant problems?

Any help would be appreciated. As a pre-emptive, the answer, "just chop
them by hand" is not an answer I'm seeking -- I'm really trying to figure
out why this machine is not working as advertised.


I've used what may be an older version of this jig for quite a few
years, in its 24" version and have had no problems with it.

Will admit that I set up the left side for my stock height short
drawers and the right side for the taller ones. Used the middling
version of Loctite on the screws.

Used a full width backer and fillers, so that the clamping comes out
even.

Router set up is a 3 hp Porter Cable and the cutters are CMT's.

Have not had fit problems but that may be because I mic my pieces
coming out of the planer.

Remember having some blowout problems when I started with the jig but
the waste board cured that.

Have had good results on multiple runs using this method but stock
prep for flatness and thickness has been critical.

Only problems that I've had were from not setting the router dead flat
throughout the cut.









Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

Tom Watson wrote:


Used a full width backer and fillers, so that the clamping comes out
even.

Important!

--
www.e-woodshop.net
Last update: 10/22/08
KarlC@ (the obvious)

replying to Mark & Juanita, Gene Foeler wrote:
I have the jig, an excellent router, sharp bits, and tighten the clamps. The
results are inconsistent, gaps in joints on one drawer, great on the next.
Gave up on the last batch of drawers and used a miter lock router bit and had
excellent results and good looking drawers. Dove tails are great, but a
finished, functioning project is better! I am going to try placing a second
board beside the drawer side Im routing to see if it will hold the side in
place. Good luck!
Gene

--
for full context, visit https://www.homeownershub.com/woodwo...ts-460937-.htm