Incra - dovetails don't fit
 

I have an Incra Pro - I know, it's old but at least I have it, lol. I
am learning the dovetail cuts but can't get past the test cuts. When I
cut two test boards and turn them around to fit them together (to check
depth of cut) I can't get them together - the fit is so tight I have to
bang the heck out of em to get them together. I've tried both lowering
and raising the bit but still the same problem. Anyone have any
suggestions??

Thanks

"GVJeeper" wrote in message
oups.com...
I have an Incra Pro - I know, it's old but at least I have it, lol. I
am learning the dovetail cuts but can't get past the test cuts. When I
cut two test boards and turn them around to fit them together (to check
depth of cut) I can't get them together - the fit is so tight I have to
bang the heck out of em to get them together. I've tried both lowering
and raising the bit but still the same problem. Anyone have any
suggestions??

If cutting Blind DT's
I have never used that jig but with the "regular" style DT jig the proper
fit is controlled by the depth of cut. Every bit has its own unique sweet
spot and once found that depth should always be used for that bit. Remember
to make slight adjustments and NEVER try to recut DT's. If the joint is too
tight, start with 2 new scraps and cut shallower in both pieces. If the fit
is too loose, start with 2 new scraps and cut deeper. DO NOT mix pieces
that have been cut at different depths.

GVJeeper,

I cut some half-blind dovetails a couple of weeks ago and as I was
testing the fit on scraps they were loose (so I needed to lower my bit
more). I was making minor adjustments a bit at a time, but it wasn't
looking like it was making a difference. I was running short on the
scrap in the thickness I had already milled so I went for it and
lowered the bit quite a bit (almost 1/4" I believe, can't remember now,
I only remember thinking that it was quite a bit) and sure enough
that's what I needed -- I had started way too shallow and I couldn't
tell that I was improving the fit but too slight to notice.

Just a suggestion.

Good luck,
Mike

I guess I just didn't keep tweeking it enough. Thanks for the help -
I'll give it another try tomorrow.

I do the same thing but use any small board. I simply put it on edge and
run it into a spinning bit until the wide part of the dovetail bit makes an
imprint - the exact height is guaranteed. It hasn't let me down yet.

Don

"10x" wrote in message
...
In article .com,
GVJeeper wrote:

I guess I just didn't keep tweeking it enough. Thanks for the help -
I'll give it another try tomorrow.


One of the solutions I came up with to solve this problem for future
use...

Once you find that "sweet spot" on a particular dovetail bit / dovetail
jig combination, take a scrap piece of hardwood about 2" x 12" and run
it through a surface planer until the thickness precisely matches how
far the bit protrudes from the base of the router. I then drilled a
hole to hang it, put a coat of finish on it, and labeled it with a
marker so I wouldn't throw it out some day when I had a brain fart.

Now, when I set up to cut a dovetail, I get the router, the bit, and my
homemade depth gauge. After putting the bit in the router, I use the
gauge to set the depth for the bit and it always gets me VERY close to
the exact depth of cut. If it isn't right the first try, I usually nail
it after the first adjustment.

just my .02¢ on what works for me.


Joe
aka 10x

"10x" wrote in message
...
In article .com,
GVJeeper wrote:

I guess I just didn't keep tweeking it enough. Thanks for the help -
I'll give it another try tomorrow.


One of the solutions I came up with to solve this problem for future
use...

Once you find that "sweet spot" on a particular dovetail bit / dovetail
jig combination, take a scrap piece of hardwood about 2" x 12" and run
it through a surface planer until the thickness precisely matches how
far the bit protrudes from the base of the router. I then drilled a
hole to hang it, put a coat of finish on it, and labeled it with a
marker so I wouldn't throw it out some day when I had a brain fart.

Keep a can of international orange paint around for these things. Label
with all the information you think you won't ever need next time, because,
odds-on, you will.

"10x" wrote in message
...

Once you find that "sweet spot" on a particular dovetail bit / dovetail
jig combination, take a scrap piece of hardwood about 2" x 12" and run
it through a surface planer until the thickness precisely matches how
far the bit protrudes from the base of the router. I then drilled a
hole to hang it, put a coat of finish on it, and labeled it with a
marker so I wouldn't throw it out some day when I had a brain fart.

Alternatively, route a hard wood board with the bit profile in it at the
correct depth.

Or,...buy/setup a router in the table such that you can precisely set it to
any given height. Consider, once the Incra is zero'ed, you can always return
the fence to any given distance. If you're going for the Incra's advantage,
why not go for the same with the router? My box of dovetail bits has a height
by each bit. I zero the router, then just dial in the height.

Alternatively, I'd use a height guide (as in the board he mentions below) and
raise the bit until a flat piece of wood swept across the top just scrapes the
bit without catching. I suggest this is more precise than trying to visually
match a profile.
GerryG

On Sun, 06 Mar 2005 15:08:46 GMT, "Leon"
wrote:


"10x" wrote in message
...

Once you find that "sweet spot" on a particular dovetail bit / dovetail
jig combination, take a scrap piece of hardwood about 2" x 12" and run
it through a surface planer until the thickness precisely matches how
far the bit protrudes from the base of the router. I then drilled a
hole to hang it, put a coat of finish on it, and labeled it with a
marker so I wouldn't throw it out some day when I had a brain fart.

Alternatively, route a hard wood board with the bit profile in it at the
correct depth.

"GerryG" wrote in message
...
Or,...buy/setup a router in the table such that you can precisely set it
to
any given height. Consider, once the Incra is zero'ed, you can always
return
the fence to any given distance. If you're going for the Incra's
advantage,
why not go for the same with the router? My box of dovetail bits has a
height
by each bit. I zero the router, then just dial in the height.

Alternatively, I'd use a height guide (as in the board he mentions below)
and
raise the bit until a flat piece of wood swept across the top just scrapes
the
bit without catching. I suggest this is more precise than trying to
visually
match a profile.
GerryG

Actually when the bit is clocked so that the bit is at its widest when you
slide it into the profile, if it is not the right height, either too high or
too shallow it simply will not go into the profile. This is not a new
method, it is practiced for set up for raised panel bits to match stile bit
cuts and for matching rail and stile cuts to each other. Not having to zero
to start with saves a bit of time. With that said, I use a Bosch 1716 evs
for cutting DT,s because it is simple to adjust in very small increments but
I have never entertained the idea of zeroing the bit first.

10x wrote:
[snip]

Once you find that "sweet spot" on a particular dovetail bit /
dovetail
jig combination, take a scrap piece of hardwood about 2" x 12" and
run
it through a surface planer until the thickness precisely matches how
far the bit protrudes from the base of the router.

Don't forget that the router depth being "reusable" is dependent on the
stock being the same thickness as well (e.g. if you thicknessed it to
..780 when you set it up the first time, going to .750 will result in a
different setup requirement).

I guess that's why most people go to .750 all the time, but sometimes
I'm too lazy and can't be bothered to run it through my planer any more
(once it's flat and close enough). I just make sure that all the stock
is the same thickness and then do the router setup. Probably a pain,
but I suppose I save on the life of my equipment that way???

Mike

"Mike in Idaho" wrote in message
oups.com...
Don't forget that the router depth being "reusable" is dependent on the
stock being the same thickness as well (e.g. if you thicknessed it to
.780 when you set it up the first time, going to .750 will result in a
different setup requirement).

I guess that's why most people go to .750 all the time, but sometimes
I'm too lazy and can't be bothered to run it through my planer any more
(once it's flat and close enough). I just make sure that all the stock
is the same thickness and then do the router setup. Probably a pain,
but I suppose I save on the life of my equipment that way???


Huh? Maybe the Incra is different but for the typical DT jig for blind DT's
The stock thickness matters NOT as long as it is thick enough to accept the
cut. Thicker pieces of wood do not matter. The particular DT router bit is
always used at the same depth regardless of material thickness.. I often
mix 3/4" drawer fronts with 1/2" thick sides and NEVER change the bit depth
setting.

With that said, I use a Bosch 1716 evs for cutting DT,s because it is
simple to adjust in very small increments

I was thinking of getting a mid-sized router for dovetails, and have
narrowed it down to the Bosch or Milwaukee. How do you find the Bosch for
backlash?

"mp" wrote in message
...
With that said, I use a Bosch 1716 evs for cutting DT,s because it is
simple to adjust in very small increments

I was thinking of getting a mid-sized router for dovetails, and have
narrowed it down to the Bosch or Milwaukee. How do you find the Bosch for
backlash?

Not enough to be concerned about. You turn the knob it moves. That said
however then the lock lever is released, the motor can move a slight bit.
If you adjust the lock lever tighter a bit the base does not open as much
and the motor tends to not wiggle much when releasing the lock knob. Do no
over tighten as this may increase backlash. Typically though increments of
1/256" is not a problem at all.

I was thinking of getting a mid-sized router for dovetails, and have
narrowed it down to the Bosch or Milwaukee. How do you find the Bosch for
backlash?

Not enough to be concerned about. You turn the knob it moves. That said
however then the lock lever is released, the motor can move a slight bit.
If you adjust the lock lever tighter a bit the base does not open as much
and the motor tends to not wiggle much when releasing the lock knob. Do
no over tighten as this may increase backlash. Typically though
increments of 1/256" is not a problem at all.

That's good to know. Thanks.