Help w/ T-slot router bit

On Fri, 5 Sep 2003 19:30:32 -0400, "Frank K." <[email protected]>
wrote:

>I have never seen a T slot bit with a bearing and don't fully understand how
>you are using it. If you could give more info as to all the steps you go
>through to make your cuts, we could assess your problem better.
>
>I have never had that problem. I make a lot of picture frames and use the T
>slot bit to make slots for hanging all of them. I don't use feather boards
>for them. The only way I can see a bit pulling the wood is if you are
>widening the slot and move the fence closer to the bit, making it try to
>climb cut. The fence should always be moved away from the bit when widening
>a cut and the wood should be fed from right to left along the fence.
>
>I hope this helps.
>

Yes, I mis-wrote about the bearing -- see my errata post.

Well, you win the prize. The final cut will actually be a little wider
then the bit profile. I had planned to make a cut down the center with the
bit and then two more cuts, one to either side. The unmentioned way that I
damaged the bit was when I did the following: After the initial "pulling"
problem, I figured I'd try making a few passes on the TS to cut out some
material from the center. I then moved the fence _closer_ to the bit
rather than away. The CPVC stock started to zoom, then jump, and then jam
-- which led to the bending of the 1/4" shaft of the bit. Hooray!
Fortunately, only damage (beyond embarrassment) was to the bit. Anyway,
while the consensus is that part of the problem on the first cut into a
solid piece of stock (no pre-cuts) is unavoidable perhaps, you guessed "the
rest of the story".

Thanks to everyone of the comments. A key point is that faster might help.
I think for the new bit I will start by using the TS for some clearing cuts
and then use the bit cutting _towards_ the feather boards. Even then, the
passes will cause the bit to contact both sides of the groove, but the
greater contact will be towards the feather boards -- so, in theory, the
push-back force should be greater than the pulling force.

On Sat, 06 Sep 2003 18:13:42 GMT, "George" <[email protected]>
wrote:

>I try to help you with your English. As defined, "admit" means to
>acknowledge. You acknowledged that the worst happened when using the bit
>other than as intended. I mentioned that even when used as intended, one
>side of this bit, and others which engage the wood with both cutters
>simultaneously _must_ be climb cutting. Other replies were somewhat
>obsessed with this, I merely wished to clarify that it is inevitable, not
>the result of carelessness. The other side is working against rotation.
>
Yes, thank you mister. I not doing so good in my nite ESL coarses at the
hi skol. So all I say is, screw away.

The Amana 5/16" T-slot cutter I bought today at Berland's cost me $58.
Thats reason enough to use my pitifully inexpensive straight bits to make
relief cuts if it'll make my T-slot bit last a little longer.

Besides that, think of the quality of the resulting work. You will you get
a better cut due to less hogging / kickback, and theres now two sides for
the dust to evacuate. Make the relief cut.

The software said it ran under Windows 98/NT/2000, or better.
So I installed it on Linux...
"Frank K." <[email protected]> wrote in message
news:[email protected]...
>
> "CW" <[email protected]> wrote in message
> news:xqv6b.377696$o%2.170577@sccrnsc02...
> > Other than it reduces cutter load, reduces heat, .makes it last longer,
> > reduces clogging.
> > > There is no reason to cut a relief slot before using a T-slot or any
> other
> > > bit
> >
>
> I don't have those problems when I feed the material at the proper rate. I
> also feel that reducing the number of steps to do a task makes it go
faster
> and be more enjoyable. Plus, it saves wear and tear on the saw and that
> expensive blade.
>
>
>
>

Nothing. You've got it right. You could try using a saller outer bit
(strait) to cut a groove to get some of the material out of the way. YOu
might want to increase the speed. If you do that and keep the feed the same,
you will be taking less per revelution.
"Igor" <[email protected]> wrote in message
news:[email protected]...
Maybe this is my most embarrassing moment
> here, but what am I missing?

"CW" <[email protected]> wrote in message
news:xqv6b.377696$o%2.170577@sccrnsc02...
> Other than it reduces cutter load, reduces heat, .makes it last longer,
> reduces clogging.
> > There is no reason to cut a relief slot before using a T-slot or any
other
> > bit
>

I don't have those problems when I feed the material at the proper rate. I
also feel that reducing the number of steps to do a task makes it go faster
and be more enjoyable. Plus, it saves wear and tear on the saw and that
expensive blade.

> Yes, I mis-wrote about the bearing -- see my errata post.
>
> Well, you win the prize. The final cut will actually be a little wider
> then the bit profile. I had planned to make a cut down the center with
the
> bit and then two more cuts, one to either side. The unmentioned way that
I
> damaged the bit was when I did the following: After the initial "pulling"
> problem, I figured I'd try making a few passes on the TS to cut out some
> material from the center. I then moved the fence _closer_ to the bit
> rather than away. The CPVC stock started to zoom, then jump, and then jam
> -- which led to the bending of the 1/4" shaft of the bit. Hooray!
> Fortunately, only damage (beyond embarrassment) was to the bit. Anyway,
> while the consensus is that part of the problem on the first cut into a
> solid piece of stock (no pre-cuts) is unavoidable perhaps, you guessed
"the
> rest of the story".
>
> Thanks to everyone of the comments. A key point is that faster might
help.
> I think for the new bit I will start by using the TS for some clearing
cuts
> and then use the bit cutting _towards_ the feather boards. Even then, the
> passes will cause the bit to contact both sides of the groove, but the
> greater contact will be towards the feather boards -- so, in theory, the
> push-back force should be greater than the pulling force.

There is no reason to cut a relief slot before using a T-slot or any other
bit as long as the bit is cutting on both sides of the bit. It's just like
cutting dados. The problems associated with climb cutting happen when the
bit is only cutting material on the side closest to the fence.

When you know you will be widening a cut, your first cut MUST be made
closest to the fence.

Thanks for admitting you were using the bit in a manner other than normal.
For all the others, when both wings of a bit are in the work, one must, of
necessity be "climb cutting."

Of course the other is cutting in the proper direction.


"Igor" <[email protected]> wrote in message
news:[email protected]...
> On Fri, 5 Sep 2003 19:30:32 -0400, "Frank K." <[email protected]>
> wrote:
> >I have never had that problem. I make a lot of picture frames and use the
T
> >slot bit to make slots for hanging all of them. I don't use feather
boards
> >for them. The only way I can see a bit pulling the wood is if you are
> >widening the slot and move the fence closer to the bit, making it try to
> >climb cut. The fence should always be moved away from the bit when
widening
> >a cut and the wood should be fed from right to left along the fence.

> Well, you win the prize. The final cut will actually be a little wider
> then the bit profile. I had planned to make a cut down the center with
the
> bit and then two more cuts, one to either side.
>
> Thanks to everyone of the comments. A key point is that faster might
help.
> I think for the new bit I will start by using the TS for some clearing
cuts
> and then use the bit cutting _towards_ the feather boards. Even then, the
> passes will cause the bit to contact both sides of the groove, but the
> greater contact will be towards the feather boards -- so, in theory, the
> push-back force should be greater than the pulling force.

On Fri, 05 Sep 2003 20:57:12 GMT, Igor <[email protected]> wrote:

>I am using a T-slot router bit, with bearing guide.
>http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_keyhl.html#T-slot%20cutter%20Anchor

Whoops! Correction. As my eyes should tell me, _no_ bearing guide.
(Thinking about a different slot cutter I have meant for edges.)

Simple solution. . . . Do it they way that gets you the results you want
while being safe and not destroying your tools.


"David Binkowski" <[email protected]> wrote in message
news:[email protected]...
> The Amana 5/16" T-slot cutter I bought today at Berland's cost me $58.
> Thats reason enough to use my pitifully inexpensive straight bits to make
> relief cuts if it'll make my T-slot bit last a little longer.
>
> Besides that, think of the quality of the resulting work. You will you
get
> a better cut due to less hogging / kickback, and theres now two sides for
> the dust to evacuate. Make the relief cut.
>
> The software said it ran under Windows 98/NT/2000, or better.
> So I installed it on Linux...
> "Frank K." <[email protected]> wrote in message
> news:[email protected]...
> >
> > "CW" <[email protected]> wrote in message
> > news:xqv6b.377696$o%2.170577@sccrnsc02...
> > > Other than it reduces cutter load, reduces heat, .makes it last
longer,
> > > reduces clogging.
> > > > There is no reason to cut a relief slot before using a T-slot or any
> > other
> > > > bit
> > >
> >
> > I don't have those problems when I feed the material at the proper rate.
I
> > also feel that reducing the number of steps to do a task makes it go
> faster
> > and be more enjoyable. Plus, it saves wear and tear on the saw and that
> > expensive blade.
> >
> >
> >
> >
>
>

I try to help you with your English. As defined, "admit" means to
acknowledge. You acknowledged that the worst happened when using the bit
other than as intended. I mentioned that even when used as intended, one
side of this bit, and others which engage the wood with both cutters
simultaneously _must_ be climb cutting. Other replies were somewhat
obsessed with this, I merely wished to clarify that it is inevitable, not
the result of carelessness. The other side is working against rotation.

Now, if you are going to use it in an other than normal mode, you must
assume the "inside" router direction rather than the outside.

Sorry to hear your feathers are ruffled, but it's important for those who
might not otherwise use the bit to realize that your bad experience was
perhaps self-abetted. As was, it would seem, your morning disposition


"Igor" <[email protected]> wrote in message
news:[email protected]...

> Maybe it's just my recovery from the late night last night, but when you
> use the word "admitting" it suggests that at first I was denying something
> or hiding something that was relevant to what I was asking. Not so.
> Thanks. -- Igor

"Igor" <[email protected]> wrote in message
news:[email protected]...
> I am using a T-slot router bit, with bearing guide.
>
http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_key
hl.html#T-slot%20cutter%20Anchor
>
> Carbide. In a router table using a 1.5HP Craftsman router. 1/4" (Due to
> my own screw-up, I damaged it and am waiting for the replacement.)
Anyway,
> before that, as I started to push the material through (actually 3/4" CPVC
> bar) -- the piece I am routing is only about 12" long -- the bit really
> "bit" into the stock and started to pull it into itself. Because of the
> shape of the bit, the purpose, I cannot take multiple passes at different
> depth settings as is SOP with many bits. I had set the speed down to
maybe
> 10K.
>
> Questions: Any advice about using this bit? To keep the bit from pulling
> the stock in, would a lower or higher speed help? Thanks. -- Igor

You are feeding the stock from the wrong direction! What you did is called
climb cutting. Used only in a few special cases.
--
Jim in NC

"Igor" <[email protected]> wrote in message
news:[email protected]...
> On Fri, 5 Sep 2003 17:20:48 -0400, "Morgans" <[email protected]> wrote:
> >
> >You are feeding the stock from the wrong direction! What you did is
called
> >climb cutting. Used only in a few special cases.
>
> Well, I thought about that -- I thought about a lot of possibilities. I
am
> feeding it from the side where the bit is turning towards the fence.
>
> I had the piece between featherboards and the fence. Because of how the
> bit is shape and is cutting, it seems that, essentially, if would not
> matter what side I was feeding it from. Either way, one side is pushing
> and one side is pulling. As I fed the stock, the pulling side was against
> the fence and the pushing side was against the featherboards.
>
> For example, when cutting a mortise, isn't either direction the same --
> versus when routing an edge? Maybe this is my most embarrassing moment
> here, but what am I missing?
________________________________________

I see the problem now. I didn't catch exactly what kind of cut you were
doing.

As you are in the shop, if you were looking at the machine and seeing the
bit, then the guide, you should be feeding from the right. The featherboard
sounds good, but not so tight as to make the wood impossible to feed without
with out being smooth.

It is a tough type of cut to do, and my only advise is to keep your hands
anchored to the table, and use your fingers to feed a little at a time.
That way, when it tries to take off on you, are better able to control the
rapid movement.

I would set the speed as high as you can without burning the wood.

Good Luck
--
Jim in NC
--
Jim in NC

"CW" <[email protected]> wrote in message
news:Sy86b.371123$uu5.71339@sccrnsc04...
> This is a T slot cutter taking a full diameter cut. Think about it.
> "Morgans" <[email protected]> wrote in message
> news:[email protected]...
> > You are feeding the stock from the wrong direction! What you did is
> called
> > climb cutting. Used only in a few special cases.
> > --
> > Jim in NC
> >
> >
>
>

In the original, he mentioned a ball bearing guide on the bit. I took that
to mean he was only using one side of the T.

See my other post. I got it figured out.:-)
--
Jim in NC

Other than it reduces cutter load, reduces heat, .makes it last longer,
reduces clogging.
> There is no reason to cut a relief slot before using a T-slot or any other
> bit