EC

Electric Comet

18/01/2017 12:49 PM

why such high rpms

the routers get occasional use but lately i discovered i avoid them just
because they are so noisy

i never thought about it until now and i cannot understand why they have
to spin so fast

5000 rpm should be plenty


what am i missing







This topic has 38 replies

ww

whit3rd

in reply to Electric Comet on 18/01/2017 12:49 PM

25/01/2017 1:51 PM

On Wednesday, January 25, 2017 at 9:36:56 AM UTC-8, John Grossbohlin wrote:
> "Jack" wrote in message news:[email protected]...
>
> >On 1/18/2017 3:49 PM, Electric Comet wrote:
> >> the routers get occasional use but lately i discovered i avoid them just
> >> because they are so noisy
> >
> >> i never thought about it until now and i cannot understand why they have
> >> to spin so fast

> >> 5000 rpm should be plenty

> >Ear muffs and buy a shaper.
>
> I concur... I initially went with a 1.5 HP Jet floor model shaper ...

> As I understand it, the surface speed of the shaper's cutter isn't much
> different than a router's bit

That's the key; the high speed of a router is most useful for small-diameter
cutters (1/4") such as a shaper does not employ. Practically, though,
the smaller cutters aren't much good on a router, either. I wonder if that's mainly
because of chip clearance?

rr

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 4:54 PM

On Wednesday, January 18, 2017 at 2:49:41 PM UTC-6, Electric Comet wrote:
> the routers get occasional use but lately i discovered i avoid them just
> because they are so noisy
>=20
> i never thought about it until now and i cannot understand why they have
> to spin so fast
>=20
> 5000 rpm should be plenty
>=20
>=20
> what am i missing

Its really about the strength of the bit while cutting. Bits are commonly =
1/4", 1/2", 3/4", 1" diameter and bigger. Smaller is weaker of course. Ev=
eryone moves the router bit through the wood at roughly the same pace. Mor=
e or less. The smaller bit, because it is weaker, has to take a smaller bi=
te. Lets pretend this bite is one third as large as the big bit. (Pi at 3=
.14 comes in here to get the bite of one third.) So it has to spin faster =
than a large bit so when you push it through the wood at the predetermined =
speed everyone uses, the wood all gets cut. If the small bit spun at the s=
low speed of the big bit, then you the operator would have to push the rout=
er through the wood at one third the pace. Doubt people are going to do th=
is, so you solve it by speeding up the router speed.

Lets use your example of slow speed, or fixed speed, from the table saw. T=
able saws all spin the same speed no matter how thick wood is you are cutti=
ng. Cut 1/2" wood or 3" wood. Blade spins the same speed. I'll bet you p=
ush the 1/2" wood through the blade much faster than you push the 3" wood t=
hrough the blade. You manually vary the feed rate of the wood through the =
fixed speed blade. You could do the same with routers by being 1/3 as fast=
with the small bit compared to the large bit. With table saws you vary th=
e feed speed so the amount of wood, thickness of wood divided by amount of =
teeth, is the same over a given time period. You cut the 1/2" thick wood 6=
times faster than you cut the 3" wood.

I'm guessing some engineer, scientist figured out the optimal cut speed, fe=
ed rate, bit size, teeth number, etc. some time ago for router bits, saw bl=
ades, etc.

Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

04/02/2017 10:56 AM

On 2/4/2017 10:21 AM, -MIKE- wrote:
> On 2/4/17 8:57 AM, Brewster wrote:
>> On 1/29/17 4:39 PM, -MIKE- wrote:
>>> On 1/29/17 10:09 AM, Brewster wrote:
>>
>>>>
>>>> A table saw/router table is a great combination. The table saw fence
>>>> can
>>>> work double duty, space is saved, and some companies make cast iron
>>>> router plates that replace/add directly and precisely to the table saws
>>>> iron top. Most big plunge routers have height screws accessible from
>>>> the
>>>> bottom of the router (top of the table) making the purchase of a router
>>>> lift redundant.
>>>> -BR
>>>>
>>>
>>> This is the one I made.
>>> https://goo.gl/photos/zoyUGmwcZS8jGP5KA
>>>
>>>
>>
>> Well built. Is that Formica/melamine on the top?
>>
>> -BR
>>
>
> Yes, melamine. It was leftover from some on-site worktables I built.
> It's great for assembly tables since glue doesn't stick to it.
>
>

Be careful, glue does stick to Melamine not as good as wood but my old
right extension table had missing melamine. ;~)

Pp

Puckdropper

in reply to Electric Comet on 18/01/2017 12:49 PM

19/01/2017 2:55 AM

Electric Comet <[email protected]> wrote in news:o5p6cd$4b9$3
@dont-email.me:

> On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
> "[email protected]" <[email protected]> wrote:
>
>> I'm guessing some engineer, scientist figured out the optimal cut
>> speed, feed rate, bit size, teeth number, etc. some time ago for
>> router bits, saw blades, etc.
>
> am still not convinced so i guess i need to do more research
>
> also using a router table changes things a bit
> there is a pun

I do know this: I had a variable speed Ridgid router, and experiemented
with the speed. Once I hit 16,000 RPM, the cuts were happening very
nicely so I just left it there.

Is it the optimal for every material? Probably not. Is it more than
good enough for wood? Yep!

Puckdropper
--
http://www.puckdroppersplace.us/rec.woodworking
A mini archive of some of rec.woodworking's best and worst!

Pp

Puckdropper

in reply to Electric Comet on 18/01/2017 12:49 PM

30/01/2017 8:27 PM

Electric Comet <[email protected]> wrote in news:o6o0rn$u8o$3
@dont-email.me:

> On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
> "[email protected]" <[email protected]> wrote:
>
>> I'm guessing some engineer, scientist figured out the optimal cut
>> speed, feed rate, bit size, teeth number, etc. some time ago for
>> router bits, saw blades, etc.
>
> maybe everyone assumes that but in fact no one really questioned it

Machinists question it all the time. It's crucial to their work and tool
life. Spin a bit too fast or feed too slow and bad things happen.
Sometimes it's just less tool life, other times things birdsnest or stick
and break things.


> my routers are single speed so the bit size does not change the speed
> the router
>
> so the router speed should be based on the bit dimensions from what you
> say

It may be at the speed most routers run the bit sizes are close enough to
be in the "happy" or at least the "not discontented enough to do
something about it" range. It may also be that woodworkers naturally
adjust the feed rate to compensate for varying bit diameters. They
probably don't even realize they're doing it!


> my lathe tops out at 3000 rpm and i have no problem turning half inch
> spindles
>
> maybe some day i will experiment with router speeds

Turning is a process of suddenly changing the direction of a piece of
material, while routing is a process of slicing and accelerating a piece
of material.

Puckdropper
--
http://www.puckdroppersplace.us/rec.woodworking
A mini archive of some of rec.woodworking's best and worst!

JG

"John Grossbohlin"

in reply to Electric Comet on 18/01/2017 12:49 PM

25/01/2017 12:36 PM

"Jack" wrote in message news:[email protected]...

>On 1/18/2017 3:49 PM, Electric Comet wrote:
>> the routers get occasional use but lately i discovered i avoid them just
>> because they are so noisy
>
>> i never thought about it until now and i cannot understand why they have
>> to spin so fast
>
>> 5000 rpm should be plenty
>
>
>> what am i missing

>Ear muffs and buy a shaper.

I concur... I initially went with a 1.5 HP Jet floor model shaper and
eventually replaced it with a 3 HP Grizzly. I found the shaper to be much
quieter, and being heavier with a larger table safer to use with large stock
than the router table. I could also spin much larger cutters and take deeper
cuts with no bog down. The router and router table saw little use over the
years as a result.

As I understand it, the surface speed of the shaper's cutter isn't much
different than a router's bit once you take the diameters of the shaper
cutters and router bits into account. This despite the seemingly large
difference in spindle speed... As such, at least in theory, the quality of
the cuts should be similar. In practice I suspect that the shaper wins due
to lower vibration and consistent speed/power... especially if you use a
stock feeder.

Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

04/02/2017 1:07 PM

On 2/4/2017 12:30 PM, -MIKE- wrote:
> On 2/4/17 10:56 AM, Leon wrote:
>> On 2/4/2017 10:21 AM, -MIKE- wrote:
>>> On 2/4/17 8:57 AM, Brewster wrote:
>>>> On 1/29/17 4:39 PM, -MIKE- wrote:
>>>>> On 1/29/17 10:09 AM, Brewster wrote:
>>>>
>>>>>>
>>>>>> A table saw/router table is a great combination. The table
>>>>>> saw fence can work double duty, space is saved, and some
>>>>>> companies make cast iron router plates that replace/add
>>>>>> directly and precisely to the table saws iron top. Most big
>>>>>> plunge routers have height screws accessible from the bottom
>>>>>> of the router (top of the table) making the purchase of a
>>>>>> router lift redundant. -BR
>>>>>>
>>>>>
>>>>> This is the one I made.
>>>>> https://goo.gl/photos/zoyUGmwcZS8jGP5KA
>>>>>
>>>>>
>>>>
>>>> Well built. Is that Formica/melamine on the top?
>>>>
>>>> -BR
>>>>
>>>
>>> Yes, melamine. It was leftover from some on-site worktables I
>>> built. It's great for assembly tables since glue doesn't stick to
>>> it.
>>>
>>>
>>
>> Be careful, glue does stick to Melamine not as good as wood but my
>> old right extension table had missing melamine. ;~)
>
> Perhaps it depends on the type of glue.
> All I know is that any time I do a glue-up on melamine and I get drips
> or swears on it, the smears peel right of and the drip pop off with the
> pass of a putty knife. And I do mean "pop" off. I know where goggles
> when doing that. :-)
>
>
Yes that works but if you have a piece of wood sitting on the melamine
and glue got in between you might be sanding the melamine off of the
wood after you pry it loose. I always cleaned mine and now Formica with
a scraper.



Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 7:46 PM

On 1/21/2017 5:50 PM, Bill wrote:
> Leon wrote:
>> On 1/21/2017 12:24 PM, -MIKE- wrote:
>>> On 1/21/17 12:02 PM, Electric Comet wrote:
>>>> On Wed, 18 Jan 2017 22:06:55 -0500
>>>> Ed Pawlowski <[email protected]> wrote:
>>>>
>>>>> Put a router bit in the drill press and see how well it works at
>>>>> lower rpm. Try it in a hand drill too. The bits are designed to
>>>>> perform at high rpm and there is a lot of thought and design
>>>>> experience that determine the cutting edge for best finish and chip
>>>>> removal.
>>>>
>>>> 5000 rpm whould be enough but no way to test that since the drill press
>>>> does not do that
>>>>
>>>
>>> Please stop, it's embarrassing.
>>> Do you even have a router and do you use it.
>>
>> No.
>>
>> I can assure you that not
>>> only would 5000rpm be way to slow for the typical router bit, but it
>>> would be more dangerous as well. You're much more likely to get
>>> kick-back and jumpy action at slower speeds.
>>
>> He does not understand tip speed. Small bits demand higher RPM's to
>> have the proper tip speed. 10" saw blades turn under 5K because the
>> tip is 10" from the center of rotation, so the tip is moving very fast.
>>
>
> C = 2 *Pi * d, where d is the diameter. Or, replacing d by 2r,
> C=4*Pi*r~~ 12.52*r. In particular, C is a linear function of r. As an
> example, if r=1/4" then 5000RPM corresponds to 3.14*5000=15000 inches
> per minute, or 15000/60 =250 inches per second. I s'pose whether that is
> fast, is relative. The length of the edge of the cutting bit, as well is
> its shape, would seem to be important too. Intuitively, I would want to
> cut a complex shape slower, but I suspect that is backwards
> thinking--surely better to cut a complex shape by taking shallower
> cuts. If all that the reader remembers is the previous sentence, they
> may be well-served by this post.
>

I think you may have missed something in your calculations...

If your bit diameter is 1/2" the circumference would be 1.57 inches,
not 3.14.

1.57" *5000 = 7850 inches per minute, and that = 130 inches per second
or about 7.4 MPH, way too slow to make a smooth cut.

Ideally and if a 1/2" diameter router bit could withstand being spun
this fast, 50,000 would be the idea cutting speed. The tip speed at 50K
would be 74 MPH and or about the same speed as a 1" diameter bit
spinning at 25K.


I am not sure what you are trying to say here and understand that you
have corrected part of you equation in another post.
I appreciate the effort.....

The speed at which the tip of a cutter strikes wood is important within
a specific range. Too slow and the cut ends up rough, maybe splintery,
and maybe stall the motor.

Feed rate has little to no effect on the optimum cutting speed other
than taking small bites typically yields a flatter result with a router
bit. Feed too fast and you get bigger bites out of the wood and smooth
scallops, too slow and you get flatter results and maybe burn marks.
The proper feed rate for any given tool is something a woodworker has to
learn by practicing to get the best result.


Anyway the typical 10" saw blade has a tooth tip speed
of approximately 104 MPH, assuming 3500 RPM

A 1" diameter router bit has a tip speed of
approximately 74 MPH, assuming it is spinning at 25000.


I think ideally router bits in this size range and smaller should spin
faster but this becomes dangerous. Typically 2 or 3 cutting tips are
removing all of the wood, compared to a 10 saw blade with a tooth doing
1/10 of the amount of wood as the router bit.

Go up to a 1.5" diameter router bit and slowing the speed down to 18000
RPM and you get a speed of 80 MPH.

Go up to something like a panel raising bit that is 3" in diameter and
the speed should be reduced to about 12,000 for a tip speed of 107 MPH










Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

25/01/2017 6:26 PM

On 1/25/2017 3:51 PM, whit3rd wrote:
> On Wednesday, January 25, 2017 at 9:36:56 AM UTC-8, John Grossbohlin wrote:
>> "Jack" wrote in message news:[email protected]...
>>
>>> On 1/18/2017 3:49 PM, Electric Comet wrote:
>>>> the routers get occasional use but lately i discovered i avoid them just
>>>> because they are so noisy
>>>
>>>> i never thought about it until now and i cannot understand why they have
>>>> to spin so fast
>
>>>> 5000 rpm should be plenty
>
>>> Ear muffs and buy a shaper.
>>
>> I concur... I initially went with a 1.5 HP Jet floor model shaper ...
>
>> As I understand it, the surface speed of the shaper's cutter isn't much
>> different than a router's bit
>
> That's the key; the high speed of a router is most useful for small-diameter
> cutters (1/4") such as a shaper does not employ.

Actually the router really does not spin 1/4" cutters fast enough, for
the best cut, either. Routers typically work better with 1" diameter
bits at top speed and slower for the larger bits.




Practically, though,
> the smaller cutters aren't much good on a router, either. I wonder if that's mainly
> because of chip clearance?
>
Probably so and contrary to the way I would think, the small bits, 1/4",
have better chip removal if they have only "1" cutting edge.

wn

woodchucker

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 3:53 PM

On 1/18/2017 3:49 PM, Electric Comet wrote:
> the routers get occasional use but lately i discovered i avoid them just
> because they are so noisy
>
> i never thought about it until now and i cannot understand why they have
> to spin so fast
>
> 5000 rpm should be plenty
>
>
> what am i missing
>
>
>
>
>
>
>
um, aside from a brain?

5000 is not enough. It all depends on the size of the bit, a 1/8 bit
needs to spin at a high speed to cut since it is moving so slowly.

So it's all about FPM.

--
Jeff

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

sS

[email protected] (Scott Lurndal)

in reply to Electric Comet on 18/01/2017 12:49 PM

19/01/2017 1:48 PM

Electric Comet <[email protected]> writes:
>the routers get occasional use but lately i discovered i avoid them just
>because they are so noisy
>
>i never thought about it until now and i cannot understand why they have
>to spin so fast
>
>5000 rpm should be plenty
>
>
>what am i missing

A shift key, apparantly.

k

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 8:03 PM

On Sat, 21 Jan 2017 10:59:08 -0800, Electric Comet
<[email protected]> wrote:

>On Sat, 21 Jan 2017 13:38:12 -0500
>Ed Pawlowski <[email protected]> wrote:
>
>> and bit makers are wrong so why not give it a try?
>
>nothing i have does 5000

Then why are you wasting everyone time with your bullshit?

Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 10:37 PM

You are very welcome, Bill! ;~)

EP

Ed Pawlowski

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 10:06 PM

On 1/18/2017 8:57 PM, Electric Comet wrote:
> On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
> "[email protected]" <[email protected]> wrote:
>
>> I'm guessing some engineer, scientist figured out the optimal cut
>> speed, feed rate, bit size, teeth number, etc. some time ago for
>> router bits, saw blades, etc.
>
> am still not convinced so i guess i need to do more research
>
> also using a router table changes things a bit
> there is a pun
>


Put a router bit in the drill press and see how well it works at lower
rpm. Try it in a hand drill too. The bits are designed to perform at
high rpm and there is a lot of thought and design experience that
determine the cutting edge for best finish and chip removal.

I rarely use a hand held router as I have a table and lift that works
very well.

EC

Electric Comet

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 5:57 PM

On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
"[email protected]" <[email protected]> wrote:

> I'm guessing some engineer, scientist figured out the optimal cut
> speed, feed rate, bit size, teeth number, etc. some time ago for
> router bits, saw blades, etc.

am still not convinced so i guess i need to do more research

also using a router table changes things a bit
there is a pun




BB

Bill

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 9:26 PM

Electric Comet wrote:
> On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
> "[email protected]" <[email protected]> wrote:
>
>> I'm guessing some engineer, scientist figured out the optimal cut
>> speed, feed rate, bit size, teeth number, etc. some time ago for
>> router bits, saw blades, etc.
> am still not convinced so i guess i need to do more research

You'll only achieve the exact results you desire with moulding planes.


>
> also using a router table changes things a bit
> there is a pun
>
>
>
>
>

EC

Electric Comet

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 10:02 AM

On Wed, 18 Jan 2017 22:06:55 -0500
Ed Pawlowski <[email protected]> wrote:

> Put a router bit in the drill press and see how well it works at
> lower rpm. Try it in a hand drill too. The bits are designed to
> perform at high rpm and there is a lot of thought and design
> experience that determine the cutting edge for best finish and chip
> removal.

5000 rpm whould be enough but no way to test that since the drill press
does not do that


i think 20000 plus is higher than needed











Mm

-MIKE-

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 12:24 PM

On 1/21/17 12:02 PM, Electric Comet wrote:
> On Wed, 18 Jan 2017 22:06:55 -0500
> Ed Pawlowski <[email protected]> wrote:
>
>> Put a router bit in the drill press and see how well it works at
>> lower rpm. Try it in a hand drill too. The bits are designed to
>> perform at high rpm and there is a lot of thought and design
>> experience that determine the cutting edge for best finish and chip
>> removal.
>
> 5000 rpm whould be enough but no way to test that since the drill press
> does not do that
>

Please stop, it's embarrassing.
Do you even have a router and do you use it. I can assure you that not
only would 5000rpm be way to slow for the typical router bit, but it
would be more dangerous as well. You're much more likely to get
kick-back and jumpy action at slower speeds.
That slow of a speed is also going to give you a really crappy cut.

>
> i think 20000 plus is higher than needed
>

You think? Maybe get a variable speed router and do some test cutting
before you throw around completely unwarranted and uninformed opinions
about it.

I'm sure all the mechanical and electrical engineers who have been
designing and manufacturing routers and router bits for the past century
have no idea what they've been doing.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

EC

Electric Comet

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 10:59 AM

On Sat, 21 Jan 2017 13:38:12 -0500
Ed Pawlowski <[email protected]> wrote:

> and bit makers are wrong so why not give it a try?

nothing i have does 5000






BB

Bill

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 6:50 PM

Leon wrote:
> On 1/21/2017 12:24 PM, -MIKE- wrote:
>> On 1/21/17 12:02 PM, Electric Comet wrote:
>>> On Wed, 18 Jan 2017 22:06:55 -0500
>>> Ed Pawlowski <[email protected]> wrote:
>>>
>>>> Put a router bit in the drill press and see how well it works at
>>>> lower rpm. Try it in a hand drill too. The bits are designed to
>>>> perform at high rpm and there is a lot of thought and design
>>>> experience that determine the cutting edge for best finish and chip
>>>> removal.
>>>
>>> 5000 rpm whould be enough but no way to test that since the drill press
>>> does not do that
>>>
>>
>> Please stop, it's embarrassing.
>> Do you even have a router and do you use it.
>
> No.
>
> I can assure you that not
>> only would 5000rpm be way to slow for the typical router bit, but it
>> would be more dangerous as well. You're much more likely to get
>> kick-back and jumpy action at slower speeds.
>
> He does not understand tip speed. Small bits demand higher RPM's to
> have the proper tip speed. 10" saw blades turn under 5K because the
> tip is 10" from the center of rotation, so the tip is moving very fast.
>

C = 2 *Pi * d, where d is the diameter. Or, replacing d by 2r,
C=4*Pi*r~~ 12.52*r. In particular, C is a linear function of r. As an
example, if r=1/4" then 5000RPM corresponds to 3.14*5000=15000 inches
per minute, or 15000/60 =250 inches per second. I s'pose whether that is
fast, is relative. The length of the edge of the cutting bit, as well is
its shape, would seem to be important too. Intuitively, I would want to
cut a complex shape slower, but I suspect that is backwards
thinking--surely better to cut a complex shape by taking shallower
cuts. If all that the reader remembers is the previous sentence, they
may be well-served by this post.

BB

Bill

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 6:55 PM

Bill wrote:
> Leon wrote:
>> On 1/21/2017 12:24 PM, -MIKE- wrote:
>>> On 1/21/17 12:02 PM, Electric Comet wrote:
>>>> On Wed, 18 Jan 2017 22:06:55 -0500
>>>> Ed Pawlowski <[email protected]> wrote:
>>>>
>>>>> Put a router bit in the drill press and see how well it works at
>>>>> lower rpm. Try it in a hand drill too. The bits are designed to
>>>>> perform at high rpm and there is a lot of thought and design
>>>>> experience that determine the cutting edge for best finish and chip
>>>>> removal.
>>>>
>>>> 5000 rpm whould be enough but no way to test that since the drill
>>>> press
>>>> does not do that
>>>>
>>>
>>> Please stop, it's embarrassing.
>>> Do you even have a router and do you use it.
>>
>> No.
>>
>> I can assure you that not
>>> only would 5000rpm be way to slow for the typical router bit, but it
>>> would be more dangerous as well. You're much more likely to get
>>> kick-back and jumpy action at slower speeds.
>>
>> He does not understand tip speed. Small bits demand higher RPM's to
>> have the proper tip speed. 10" saw blades turn under 5K because the
>> tip is 10" from the center of rotation, so the tip is moving very fast.
>>
>
> C = 2 *Pi * d, where d is the diameter.

Oops, C = Pi*d. Divide by 2 accordingly. Sorry 'bout that.

Bill



> Or, replacing d by 2r, C=4*Pi*r~~ 12.52*r. In particular, C is a
> linear function of r. As an example, if r=1/4" then 5000RPM
> corresponds to 3.14*5000=15000 inches per minute, or 15000/60 =250
> inches per second. I s'pose whether that is fast, is relative. The
> length of the edge of the cutting bit, as well is its shape, would
> seem to be important too. Intuitively, I would want to cut a complex
> shape slower, but I suspect that is backwards thinking--surely better
> to cut a complex shape by taking shallower cuts. If all that the
> reader remembers is the previous sentence, they may be well-served by
> this post.
>

BB

Bill

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 10:50 PM

Leon wrote:
>
> I think you may have missed something in your calculations...
>
> If your bit diameter is 1/2" the circumference would be 1.57 inches,
> not 3.14.
>
> 1.57" *5000 = 7850 inches per minute, and that = 130 inches per second
> or about 7.4 MPH,

Yes, I was able to confirm this (it took me a few tries without a pencil
to get the units right!)
130 inches per second sounds faster than 7.4 mph (think of "how fast" we
push a chisel by hand).


> way too slow to make a smooth cut.
>
> Ideally and if a 1/2" diameter router bit could withstand being spun
> this fast, 50,000 would be the idea cutting speed. The tip speed at
> 50K would be 74 MPH and or about the same speed as a 1" diameter bit
> spinning at 25K.
>
>
> I am not sure what you are trying to say here and understand that you
> have corrected part of you equation in another post.
> I appreciate the effort.....

Thanks, I was mostly just doing my own "investigation", for the sake of
my own learning/curiosity, and that of anyone else concerned.

Thanks for the tips below!

Bill


>
> The speed at which the tip of a cutter strikes wood is important
> within a specific range. Too slow and the cut ends up rough, maybe
> splintery, and maybe stall the motor.
>
> Feed rate has little to no effect on the optimum cutting speed other
> than taking small bites typically yields a flatter result with a
> router bit. Feed too fast and you get bigger bites out of the wood
> and smooth scallops, too slow and you get flatter results and maybe
> burn marks. The proper feed rate for any given tool is something a
> woodworker has to learn by practicing to get the best result.
>
>
> Anyway the typical 10" saw blade has a tooth tip speed
> of approximately 104 MPH, assuming 3500 RPM
>
> A 1" diameter router bit has a tip speed of
> approximately 74 MPH, assuming it is spinning at 25000.
>
>
> I think ideally router bits in this size range and smaller should spin
> faster but this becomes dangerous. Typically 2 or 3 cutting tips are
> removing all of the wood, compared to a 10 saw blade with a tooth
> doing 1/10 of the amount of wood as the router bit.
>
> Go up to a 1.5" diameter router bit and slowing the speed down to
> 18000 RPM and you get a speed of 80 MPH.
>
> Go up to something like a panel raising bit that is 3" in diameter and
> the speed should be reduced to about 12,000 for a tip speed of 107 MPH
>
>
>
>
>
>
>
>
>
>
>

Jj

Jack

in reply to Electric Comet on 18/01/2017 12:49 PM

25/01/2017 9:43 AM

On 1/18/2017 3:49 PM, Electric Comet wrote:
> the routers get occasional use but lately i discovered i avoid them just
> because they are so noisy
>
> i never thought about it until now and i cannot understand why they have
> to spin so fast
>
> 5000 rpm should be plenty
>
>
> what am i missing

Ear muffs and buy a shaper.
--
Jack
Add Life to your Days not Days to your Life.
http://jbstein.com

EC

Electric Comet

in reply to Electric Comet on 18/01/2017 12:49 PM

26/01/2017 2:44 PM

On Wed, 25 Jan 2017 09:43:21 -0500
Jack <[email protected]> wrote:

> Ear muffs and buy a shaper.

have the ear muffs but maybe i buy some for the neighbors too

no more room for equipment so no shaper in my future







Jj

Jack

in reply to Electric Comet on 18/01/2017 12:49 PM

28/01/2017 10:55 AM

On 1/25/2017 12:36 PM, John Grossbohlin wrote:
> "Jack" wrote in message news:[email protected]...

>>> what am i missing
>
>> Ear muffs and buy a shaper.
>
> I concur... I initially went with a 1.5 HP Jet floor model shaper and
> eventually replaced it with a 3 HP Grizzly. I found the shaper to be
> much quieter, and being heavier with a larger table safer to use with
> large stock than the router table. I could also spin much larger cutters
> and take deeper cuts with no bog down. The router and router table saw
> little use over the years as a result.
>
> As I understand it, the surface speed of the shaper's cutter isn't much
> different than a router's bit once you take the diameters of the shaper
> cutters and router bits into account. This despite the seemingly large
> difference in spindle speed... As such, at least in theory, the quality
> of the cuts should be similar. In practice I suspect that the shaper
> wins due to lower vibration and consistent speed/power... especially if
> you use a stock feeder.

I always chuckle when I see how much cash people spend on routers,
router tables, router lifts and all that. I say people because really,
if you are a woodworker, you could build a router table in part of a
morning. For the money they spend, they could buy a shaper for less,
and it does a better job most of the time, has built in lift, and easy
to change bits, and is much quieter.

--
Jack
Add Life to your Days not Days to your Life.
http://jbstein.com

Mm

-MIKE-

in reply to Electric Comet on 18/01/2017 12:49 PM

28/01/2017 10:52 AM

On 1/28/17 9:55 AM, Jack wrote:
> On 1/25/2017 12:36 PM, John Grossbohlin wrote:
>> "Jack" wrote in message news:[email protected]...
>
>>>> what am i missing
>>
>>> Ear muffs and buy a shaper.
>>
>> I concur... I initially went with a 1.5 HP Jet floor model shaper
>> and eventually replaced it with a 3 HP Grizzly. I found the shaper
>> to be much quieter, and being heavier with a larger table safer to
>> use with large stock than the router table. I could also spin much
>> larger cutters and take deeper cuts with no bog down. The router
>> and router table saw little use over the years as a result.
>>
>> As I understand it, the surface speed of the shaper's cutter isn't
>> much different than a router's bit once you take the diameters of
>> the shaper cutters and router bits into account. This despite the
>> seemingly large difference in spindle speed... As such, at least in
>> theory, the quality of the cuts should be similar. In practice I
>> suspect that the shaper wins due to lower vibration and consistent
>> speed/power... especially if you use a stock feeder.
>
> I always chuckle when I see how much cash people spend on routers,
> router tables, router lifts and all that. I say people because
> really, if you are a woodworker, you could build a router table in
> part of a morning. For the money they spend, they could buy a shaper
> for less, and it does a better job most of the time, has built in
> lift, and easy to change bits, and is much quieter.
>

I'm with you. :-)
I've gone through several versions of router tables. One was a cheap,
manufactured one I got on clearance, for which I ended up fabricating
new, much better top. I ended up selling it for a heft profit when I
built a router extension for my table saw, which is what I use now.

But none of the versions produced better results than my first one which
was made by simply screwing the router to a piece of melamine and
drilling a whole through it for the bits.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

Bb

Brewster

in reply to Electric Comet on 18/01/2017 12:49 PM

29/01/2017 9:09 AM

On 1/28/17 9:52 AM, -MIKE- wrote:

>>
>
> I'm with you. :-)
> I've gone through several versions of router tables. One was a cheap,
> manufactured one I got on clearance, for which I ended up fabricating
> new, much better top. I ended up selling it for a heft profit when I
> built a router extension for my table saw, which is what I use now.
>
> But none of the versions produced better results than my first one which
> was made by simply screwing the router to a piece of melamine and
> drilling a whole through it for the bits.
>
>

A table saw/router table is a great combination. The table saw fence can
work double duty, space is saved, and some companies make cast iron
router plates that replace/add directly and precisely to the table saws
iron top. Most big plunge routers have height screws accessible from the
bottom of the router (top of the table) making the purchase of a router
lift redundant.
-BR

Mm

-MIKE-

in reply to Electric Comet on 18/01/2017 12:49 PM

29/01/2017 5:39 PM

On 1/29/17 10:09 AM, Brewster wrote:
> On 1/28/17 9:52 AM, -MIKE- wrote:
>
>>>
>>
>> I'm with you. :-)
>> I've gone through several versions of router tables. One was a cheap,
>> manufactured one I got on clearance, for which I ended up fabricating
>> new, much better top. I ended up selling it for a heft profit when I
>> built a router extension for my table saw, which is what I use now.
>>
>> But none of the versions produced better results than my first one which
>> was made by simply screwing the router to a piece of melamine and
>> drilling a whole through it for the bits.
>>
>>
>
> A table saw/router table is a great combination. The table saw fence can
> work double duty, space is saved, and some companies make cast iron
> router plates that replace/add directly and precisely to the table saws
> iron top. Most big plunge routers have height screws accessible from the
> bottom of the router (top of the table) making the purchase of a router
> lift redundant.
> -BR
>

This is the one I made.
https://goo.gl/photos/zoyUGmwcZS8jGP5KA


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

EC

Electric Comet

in reply to Electric Comet on 18/01/2017 12:49 PM

30/01/2017 10:34 AM

On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
"[email protected]" <[email protected]> wrote:

> I'm guessing some engineer, scientist figured out the optimal cut
> speed, feed rate, bit size, teeth number, etc. some time ago for
> router bits, saw blades, etc.

maybe everyone assumes that but in fact no one really questioned it

my routers are single speed so the bit size does not change the speed
the router

so the router speed should be based on the bit dimensions from what you
say


my lathe tops out at 3000 rpm and i have no problem turning half inch
spindles

maybe some day i will experiment with router speeds




Mm

-MIKE-

in reply to Electric Comet on 18/01/2017 12:49 PM

30/01/2017 5:15 PM

On 1/30/17 12:34 PM, Electric Comet wrote:
> On Wed, 18 Jan 2017 16:54:14 -0800 (PST) "[email protected]"
> <[email protected]> wrote:
>
>> I'm guessing some engineer, scientist figured out the optimal cut
>> speed, feed rate, bit size, teeth number, etc. some time ago for
>> router bits, saw blades, etc.
>
> maybe everyone assumes that but in fact no one really questioned it
>
> my routers are single speed so the bit size does not change the
> speed the router
>
> so the router speed should be based on the bit dimensions from what
> you say
>
>
> my lathe tops out at 3000 rpm and i have no problem turning half
> inch spindles
>
> maybe some day i will experiment with router speeds
>

Hey, you know what? I think you've proven to all of us that you know
everything better than any of us and anyone who has ever come before us.

So congratulations on that and I guess there's no more need for you to
ask any more questions in here since you obviously already have the
answers.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

Bb

Brewster

in reply to Electric Comet on 18/01/2017 12:49 PM

04/02/2017 7:57 AM

On 1/29/17 4:39 PM, -MIKE- wrote:
> On 1/29/17 10:09 AM, Brewster wrote:

>>
>> A table saw/router table is a great combination. The table saw fence can
>> work double duty, space is saved, and some companies make cast iron
>> router plates that replace/add directly and precisely to the table saws
>> iron top. Most big plunge routers have height screws accessible from the
>> bottom of the router (top of the table) making the purchase of a router
>> lift redundant.
>> -BR
>>
>
> This is the one I made.
> https://goo.gl/photos/zoyUGmwcZS8jGP5KA
>
>

Well built. Is that Formica/melamine on the top?

-BR

Mm

-MIKE-

in reply to Electric Comet on 18/01/2017 12:49 PM

04/02/2017 10:21 AM

On 2/4/17 8:57 AM, Brewster wrote:
> On 1/29/17 4:39 PM, -MIKE- wrote:
>> On 1/29/17 10:09 AM, Brewster wrote:
>
>>>
>>> A table saw/router table is a great combination. The table saw fence can
>>> work double duty, space is saved, and some companies make cast iron
>>> router plates that replace/add directly and precisely to the table saws
>>> iron top. Most big plunge routers have height screws accessible from the
>>> bottom of the router (top of the table) making the purchase of a router
>>> lift redundant.
>>> -BR
>>>
>>
>> This is the one I made.
>> https://goo.gl/photos/zoyUGmwcZS8jGP5KA
>>
>>
>
> Well built. Is that Formica/melamine on the top?
>
> -BR
>

Yes, melamine. It was leftover from some on-site worktables I built.
It's great for assembly tables since glue doesn't stick to it.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

Mm

-MIKE-

in reply to Electric Comet on 18/01/2017 12:49 PM

04/02/2017 12:30 PM

On 2/4/17 10:56 AM, Leon wrote:
> On 2/4/2017 10:21 AM, -MIKE- wrote:
>> On 2/4/17 8:57 AM, Brewster wrote:
>>> On 1/29/17 4:39 PM, -MIKE- wrote:
>>>> On 1/29/17 10:09 AM, Brewster wrote:
>>>
>>>>>
>>>>> A table saw/router table is a great combination. The table
>>>>> saw fence can work double duty, space is saved, and some
>>>>> companies make cast iron router plates that replace/add
>>>>> directly and precisely to the table saws iron top. Most big
>>>>> plunge routers have height screws accessible from the bottom
>>>>> of the router (top of the table) making the purchase of a
>>>>> router lift redundant. -BR
>>>>>
>>>>
>>>> This is the one I made.
>>>> https://goo.gl/photos/zoyUGmwcZS8jGP5KA
>>>>
>>>>
>>>
>>> Well built. Is that Formica/melamine on the top?
>>>
>>> -BR
>>>
>>
>> Yes, melamine. It was leftover from some on-site worktables I
>> built. It's great for assembly tables since glue doesn't stick to
>> it.
>>
>>
>
> Be careful, glue does stick to Melamine not as good as wood but my
> old right extension table had missing melamine. ;~)

Perhaps it depends on the type of glue.
All I know is that any time I do a glue-up on melamine and I get drips
or swears on it, the smears peel right of and the drip pop off with the
pass of a putty knife. And I do mean "pop" off. I know where goggles
when doing that. :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

EP

Ed Pawlowski

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 1:38 PM

On 1/21/2017 1:02 PM, Electric Comet wrote:
> On Wed, 18 Jan 2017 22:06:55 -0500
> Ed Pawlowski <[email protected]> wrote:
>
>> Put a router bit in the drill press and see how well it works at
>> lower rpm. Try it in a hand drill too. The bits are designed to
>> perform at high rpm and there is a lot of thought and design
>> experience that determine the cutting edge for best finish and chip
>> removal.
>
> 5000 rpm whould be enough but no way to test that since the drill press
> does not do that
>
>
> i think 20000 plus is higher than needed
>

If 5,000 is enough, 500 should work too. if 20000 is too high, maybe
2000 is too. You are contending that decades of experience of router
and bit makers are wrong so why not give it a try?

Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 5:01 PM

On 1/18/2017 2:53 PM, woodchucker wrote:
> On 1/18/2017 3:49 PM, Electric Comet wrote:
>> the routers get occasional use but lately i discovered i avoid them just
>> because they are so noisy
>>
>> i never thought about it until now and i cannot understand why they have
>> to spin so fast
>>
>> 5000 rpm should be plenty
>>
>>
>> what am i missing


Cutting tip speed. The smaller the diameter the faster the cutter has
to spin.

Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

21/01/2017 2:53 PM

On 1/21/2017 12:24 PM, -MIKE- wrote:
> On 1/21/17 12:02 PM, Electric Comet wrote:
>> On Wed, 18 Jan 2017 22:06:55 -0500
>> Ed Pawlowski <[email protected]> wrote:
>>
>>> Put a router bit in the drill press and see how well it works at
>>> lower rpm. Try it in a hand drill too. The bits are designed to
>>> perform at high rpm and there is a lot of thought and design
>>> experience that determine the cutting edge for best finish and chip
>>> removal.
>>
>> 5000 rpm whould be enough but no way to test that since the drill press
>> does not do that
>>
>
> Please stop, it's embarrassing.
> Do you even have a router and do you use it.

No.

I can assure you that not
> only would 5000rpm be way to slow for the typical router bit, but it
> would be more dangerous as well. You're much more likely to get
> kick-back and jumpy action at slower speeds.

He does not understand tip speed. Small bits demand higher RPM's to
have the proper tip speed. 10" saw blades turn under 5K because the tip
is 10" from the center of rotation, so the tip is moving very fast.


Ll

Leon

in reply to Electric Comet on 18/01/2017 12:49 PM

18/01/2017 8:20 PM

On 1/18/2017 6:54 PM, [email protected] wrote:
> On Wednesday, January 18, 2017 at 2:49:41 PM UTC-6, Electric Comet
> wrote:
>> the routers get occasional use but lately i discovered i avoid them
>> just because they are so noisy
>>
>> i never thought about it until now and i cannot understand why they
>> have to spin so fast
>>
>> 5000 rpm should be plenty
>>
>>
>> what am i missing
>
> Its really about the strength of the bit while cutting.

Actually, smoothness of cut is what it is about. The faster the speed
the more cuts with a given speed.



Bits are
> commonly 1/4", 1/2", 3/4", 1" diameter and bigger. Smaller is weaker
> of course. Everyone moves the router bit through the wood at roughly
> the same pace. More or less. The smaller bit, because it is weaker,
> has to take a smaller bite. Lets pretend this bite is one third as
> large as the big bit. (Pi at 3.14 comes in here to get the bite of
> one third.) So it has to spin faster than a large bit so when you
> push it through the wood at the predetermined speed everyone uses,
> the wood all gets cut. If the small bit spun at the slow speed of
> the big bit, then you the operator would have to push the router
> through the wood at one third the pace. Doubt people are going to do
> this, so you solve it by speeding up the router speed.

Many routers have fixes single speeds.


>
> Lets use your example of slow speed, or fixed speed, from the table
> saw. Table saws all spin the same speed no matter how thick wood is
> you are cutting.

Actually many TS do not run at the same speed. The larger the blade the
slower they typically run. Again, tip speed. A number of miter saws
spin their blades even faster that a TS and typically have more teeth
than you commonly see on a TS.
If you are saying the TS's are not variable speed, that is close to
true, Shopsmith's have variable speed, but should be run at a suggested
speed.


Cut 1/2" wood or 3" wood. Blade spins the same
> speed.

Except when it does not. Under ideal conditions the blade maintains its
speed but time and again under powered saws spin slower when cutting
thicker material. Hence think kerf blades.



I'll bet you push the 1/2" wood through the blade much faster
> than you push the 3" wood through the blade.

You learn to not do that to get smoother cuts.. Smaller bites normally
mean smoother cuts.


You manually vary the
> feed rate of the wood through the fixed speed blade. You could do
> the same with routers by being 1/3 as fast with the small bit
> compared to the large bit. With table saws you vary the feed speed
> so the amount of wood, thickness of wood divided by amount of teeth,
> is the same over a given time period. You cut the 1/2" thick wood 6
> times faster than you cut the 3" wood.

Really? 6 times faster? I go the same speed regardless, I strive for
smooth cuts. Fast feed rates result in a cut that is less smooth than
slower feed rates.


>
> I'm guessing some engineer, scientist figured out the optimal cut
> speed, feed rate, bit size, teeth number, etc. some time ago for
> router bits, saw blades, etc.
>

Yes and I doubt any would agree with your thoughts. While your comments
make sense to some degree. The results yield less than the best outcome.

sS

[email protected] (Scott Lurndal)

in reply to Electric Comet on 18/01/2017 12:49 PM

30/01/2017 7:17 PM

Electric Comet <[email protected]> writes:
>On Wed, 18 Jan 2017 16:54:14 -0800 (PST)
>"[email protected]" <[email protected]> wrote:
>
>> I'm guessing some engineer, scientist figured out the optimal cut
>> speed, feed rate, bit size, teeth number, etc. some time ago for
>> router bits, saw blades, etc.
>
>maybe everyone assumes that but in fact no one really questioned it

Highly doubtful. Just because you don't understand it doesn't mean
that it isn't well understood.

>
>my routers are single speed so the bit size does not change the speed
>the router

And your point is?

http://www.harborfreight.com/router-speed-control-43060.html

>
>so the router speed should be based on the bit dimensions from what you
>say

Try spinning this in your handheld router at full speed (just don't do it
where there is anyone you care about in the vicinity):


https://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/raised_panel_router_bits1.html

>
>
>my lathe tops out at 3000 rpm and i have no problem turning half inch
>spindles

Apples are not the same as Oranges.

Your router spins at more than 5 times that speed.

http://www.rockler.com/how-to/router-bit-speed/


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