Recent Topics
Thoughts on the GM strike?
by Vern_in_IL - 09/19/19 09:37 PM
tropical storm imelda blows up everynight?
by motor_oil_madman - 09/19/19 09:12 PM
2017 Corvette / Mobil 1 ESP 0w40 / 5.2k mi
by dparm - 09/19/19 08:57 PM
2019 Lexus UX 250h
by Direct_Rejection - 09/19/19 08:56 PM
Gas theft
by tahoe_hybrid - 09/19/19 08:04 PM
Aisin 09G transmission fluid?
by sloinker - 09/19/19 07:44 PM
Oil for 2005 BMW X3
by Nyquist - 09/19/19 07:34 PM
Golden Eagles Take Down Deer and Wolves
by buster - 09/19/19 07:31 PM
P21S Windshield Washer Booster
by mclasser - 09/19/19 06:30 PM
Why warm up oil before a UOA sample is taken?
by paulri - 09/19/19 06:21 PM
Selling the 97 Camry V6 again
by PandaBear - 09/19/19 05:15 PM
FRAM Orange Cans
by KevGuy - 09/19/19 05:13 PM
Hill billy down spout
by P10crew - 09/19/19 05:04 PM
Colt Ceases Civilian AR-15 Production
by billt460 - 09/19/19 04:50 PM
Amsoil “synthetic technology”
by spiderbypass - 09/19/19 03:15 PM
Oil Change Special @ Firestone
by Mad_Hatter - 09/19/19 01:05 PM
Newest Members
Srfridd, V1313, Ecan89, ProBest, Zolton
69333 Registered Users
Who's Online Now
83 registered members (ACC, 330indy, 4WD, AdditiveOCD, 2002 Maxima SE, 10 invisible), 1,714 guests, and 21 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics294,799
Posts5,066,829
Members69,333
Most Online3,532
Jul 30th, 2019
Donate to BITOG
Print Thread
Hop To
Page 2 of 3 1 2 3
Re: Chainsaw Tooth Velocity [Re: MolaKule] #4707864 03/26/18 08:13 PM
Joined: Dec 2005
Posts: 813
C
cpayne5 Offline
Offline
C
Joined: Dec 2005
Posts: 813
(2*pi*1.5)x(4300/60)

first part is circumference
second is revolutions per second

full revolutions x circumference = inches traveled per second
divide by 12 to get feet

Last edited by cpayne5; 03/26/18 08:14 PM.
Re: Chainsaw Tooth Velocity [Re: jhellwig] #4707868 03/26/18 08:15 PM
Joined: Dec 2016
Posts: 9,438
L
Linctex Offline
Offline
L
Joined: Dec 2016
Posts: 9,438
Originally Posted By: jhellwig


Edit 3 I didn't do it right at all. 3377 ft per second.


3,300 feet per second is way faster than the speed of sound

that's high velocity rifle bullet speed


"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."
Re: Chainsaw Tooth Velocity [Re: A_Harman] #4707871 03/26/18 08:16 PM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
Originally Posted By: A_Harman
What's the trick here? Are you going to nitpick about how tall the teeth are, which would change the tangential velocity.
How long is the bar? What is the radius of the drive sprocket?

Am I biting on your hook?


No trick just simple calcs and units conversions to get to: How far will anyone tooth travel in one second?

Sprocket radius was given as R = 1.5" and I stated that the tooth velocity (for all practical purposes) is approximately equal to the tangential velocity of the sprocket.

Bar length is immaterial.

The linear velocity of the chain, which carries the teeth and links, is the key.

Last edited by MolaKule; 03/26/18 08:19 PM.

The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: MolaKule] #4707879 03/26/18 08:24 PM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
A_Harmon and JimPghPA showed the correct calculations so we're going to give each a set of virtual BITOG Piston Cup Cufflinks. thumbsup

Mr cpayne5 will receive a virtual BITOG coffee stirrer. thumbsup

Last edited by MolaKule; 03/26/18 08:27 PM.

The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: MolaKule] #4707919 03/26/18 09:06 PM
Joined: Mar 2004
Posts: 22,803
D
Donald Offline
Offline
D
Joined: Mar 2004
Posts: 22,803
The teeth will travel far enough in one second to rip your skin apart big time.


2015 Subaru Forester 2.5 engine/CVT
2015 Ford F250 w/Powerstroke
2016 Subaru Crosstrek CVT (wife's)
Re: Chainsaw Tooth Velocity [Re: Linctex] #4707937 03/26/18 09:26 PM
Joined: Jul 2013
Posts: 1,902
J
jhellwig Offline
Offline
J
Joined: Jul 2013
Posts: 1,902
Originally Posted By: Linctex
Originally Posted By: jhellwig


Edit 3 I didn't do it right at all. 3377 ft per second.


3,300 feet per second is way faster than the speed of sound

that's high velocity rifle bullet speed


Eh. I forgot to devide by 60. The first time for some dumb reason I calculated 1.5 like it was a quarter of the circumference.

Last edited by jhellwig; 03/26/18 09:28 PM.

Sparks fly from my fingers.

1995 Chevy K2500 Suburban lt 5.7
2014 Toyota Sienna
1983 Chevy K5 350
Re: Chainsaw Tooth Velocity [Re: MolaKule] #4707958 03/26/18 09:53 PM
Joined: Mar 2016
Posts: 2,346
C
CR94 Offline
Offline
C
Joined: Mar 2016
Posts: 2,346
Why such an easy question? A more accurate answer would require knowing the chain pitch (per link) and the number of teeth on the sprocket. Or you'd have to define sprocket effective radius in a particular way.


2011 Toyota Prius now at 102K
1981 Mazda GLC (323) retired at 606K
1972 Subaru DL retired at 190K
1954 Chevrolet retired at 121K
Re: Chainsaw Tooth Velocity [Re: Donald] #4708242 03/27/18 08:29 AM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
Originally Posted By: Donald
The teeth will travel far enough in one second to rip your skin apart big time.


This sprocket speed was my old Homelight Chainsaw's speed.

Some chainsaws have a rotational sprocket velocity of 7000 rpm.


The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: CR94] #4708251 03/27/18 08:34 AM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
Originally Posted By: CR94
Why such an easy question? A more accurate answer would require knowing the chain pitch (per link) and the number of teeth on the sprocket. Or you'd have to define sprocket effective radius in a particular way.


Apparently it wasn't that easy for everyone.


Not sure I understand your comment.

The sprocket rotates such that its Tangential Velocity is the equal to the chain's linear velocity, which is the same velocity for any tooth or link in the chain no matter where on the bar that tooth or link might be.


The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: JimPghPA] #4708253 03/27/18 08:37 AM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
Originally Posted By: JimPghPA
4300 RPM/60 seconds per minute = 71.66 revolutions per second.

The circumference of a circle = pi X Diameter or pi X 2 X Radius

Circumference of a 3 inch diameter circle is 3 X 3.14 = 9.42 inches

71.66 revolutions X 9.42 inches circumference = 675.0372 inches per second.

Divide by 12 to get feet per second.

675.0372/12 = 56.2531 feet per second


and

Originally Posted By: JimPghPa
4300 rev/min x 2*pi radians/rev x 1 min/60 sec x 1.5 in x 1 ft/12 in = 56.28 ft/sec, or about 38 mph.


Quite a few responders had done the calculations properly but for some reason I could not get a simple answer to:

How many feet will any one tooth travel in 1 second?

If the chain's linear velocity is 56.25 ft/sec then the distance a tooth will travel in one second is;
56.25 ft/sec X 1 sec = 56.25 feet.

Last edited by MolaKule; 03/27/18 08:48 AM.

The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: MolaKule] #4708276 03/27/18 09:10 AM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
Another way of approaching the problem is:

Data: Sprocket RPM is 4300, Sprocket Radius is 1.5".


Anything touching the outer portion of the sprocket will by necessity have to attain a velocity equal to the Tangential Velocity of the sprocket.

The chain effectively "translates" the rotational motion to Linear Motion.


Vt = w*R, where Omega w is in radians/sec, R is in inches.

There are 9.55 RPM/Radian. (One radian is 57.3 degrees of rotation of a full circle, or 0.1592 of a circle).

1/0.1592 = 6.28; 6.28 is 2*Pi.

w = 4300 RPM / (9.55 RPM/Radian) = 450.3 Radians/sec.

Vt = w*R = (450.3 Radians/sec) * 1.5" = 675.5 Inches/Sec.

(675.5 Inches/sec) / 12 inches per foot = 56.28 Feet/Sec.

56.28 Feet/sec. X 1 sec. = 56.28 feet.








Last edited by MolaKule; 03/27/18 09:25 AM.

The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: MolaKule] #5208441 09/09/19 11:50 AM
Joined: Dec 2012
Posts: 663
J
jakewells Offline
Offline
J
Joined: Dec 2012
Posts: 663
How many pins are on the rim? That would determine the speed of the chain instead of just noting the size of the rim it comes in either 6, 7, 8, 9, 10, pin.

Also i prefer using a non tacky oil in any chainsaw.


1996 Chevy 1500 W/T 4.3 V6. Harvest King All Fleet 5W40 With Fram XG3980


Re: Chainsaw Tooth Velocity [Re: jakewells] #5208689 09/09/19 06:42 PM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
Originally Posted by jakewells
How many pins are on the rim? That would determine the speed of the chain instead of just noting the size of the rim it comes in either 6, 7, 8, 9, 10, pin.

Also i prefer using a non tacky oil in any chainsaw.



It doesn't matter, as the linear velocity of the chain is a function of the Tangential Velocity of the sprocket. Put a red paint dot on any one tooth and find out how far it will travel in one second. If any one tooth is moving at a linear velocity of 56.28 Feet/sec. then in 1 second it will travel. = 56.28 feet.

Quote
Data: Sprocket RPM is 4300, Sprocket Radius is 1.5".

Anything touching the outer portion of the sprocket will by necessity have to attain a velocity equal to the Tangential Velocity of the sprocket.

The chain effectively "translates" the rotational motion to Linear Motion.

Vt = w*R, where Omega w is in radians/sec, R is in inches.

There are 9.55 RPM/Radian. (One radian is 57.3 degrees of rotation of a full circle, or 0.1592 of a circle).

1/0.1592 = 6.28; 6.28 is 2*Pi.

w = 4300 RPM / (9.55 RPM/Radian) = 450.3 Radians/sec.

Vt = w*R = (450.3 Radians/sec) * 1.5" = 675.5 Inches/Sec.

(675.5 Inches/sec) / 12 inches per foot = 56.28 Feet/Sec.

56.28 Feet/sec. X 1 sec. = 56.28 feet.

Last edited by MolaKule; 09/09/19 06:44 PM.

The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Re: Chainsaw Tooth Velocity [Re: MolaKule] #5208845 09/09/19 10:27 PM
Joined: Mar 2016
Posts: 2,346
C
CR94 Offline
Offline
C
Joined: Mar 2016
Posts: 2,346
Originally Posted by MolaKule
[quote=jakewells]How many pins are on the rim? That would determine the speed of the chain instead of just noting the size of the rim it comes in either 6, 7, 8, 9, 10, pin.

It doesn't matter, as the linear velocity of the chain is a function of the Tangential Velocity of the sprocket. ...
Quote
It does matter, because the most relevant tangential velocity (that equals the chain speed) is that at the effective pitch radius of the sprocket, not at its overall outer radius.


Small difference, perhaps, but significant.


2011 Toyota Prius now at 102K
1981 Mazda GLC (323) retired at 606K
1972 Subaru DL retired at 190K
1954 Chevrolet retired at 121K
Re: Chainsaw Tooth Velocity [Re: MolaKule] #5209419 09/10/19 04:54 PM
Joined: Jun 2002
Posts: 20,361
MolaKule Offline OP
Global Moderator
OP Offline
Global Moderator
Joined: Jun 2002
Posts: 20,361
I think the difference is going to be very small:

For a sprocket (from the rim toward the center of the bore) you have an Outside (or Outer) Diameter, a Pitch Diameter, and a Bottom Diameter.

See Page 3 of:
Martin Sprocket Engineering

You made me open up my old HomeLite Timberman ChainSaw but hey, it needed cleaning anyway. I put the sprocket measurements and calculations into MatLab and here are the Results:

Here are the measurements of the ChainSaw drive sprocket:

OD = 1.25"
BD = 0.75"
PD = 1.125"
Sprocket RPM = 9000

Linear Velocity using
OD = 1.25"
Sprocket RPM = 9000

49.1 ft./sec = 49.1 feet linear travel in 1 second;


Linear Velocity using
PD = 1.125"
Sprocket RPM = 9000

44.2 ft./ sec. = 44.2 feet linear travel in 1 sec.

A difference of 10%.


You still need those safety Chaps and HD Gloves! cool

BTW, I need to sharpen the chain on this puppy as well. fence

Last edited by MolaKule; 09/11/19 11:00 AM.

The value of a scientific theory is its ability to prompt further study, not that it has any relation to the established facts of scientific reality.
Page 2 of 3 1 2 3
Previous Thread
Index
Next Thread

BOB IS THE OIL GUY® Powered by UBB.threads™