• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
  • PLEASE: Read the FORUM RULES BEFORE registering!

4

Using Large Flat Belt Pulleys With V-belts

3
Like what you see?
Click here to donate to this forum and upgrade your account!
10

markba633csi

Active Member
Active Member
Joined
Apr 30, 2015
Messages
1,318
Likes
526
#1
I see this is commonly done on machinery which (I think) was originally run from a master line-shaft system. I'm enclosing a picture of Wildo's 9A restoration as an example; my Diamond mill has a similar setup. How does the belt stay on if the large pulley isn't crowned? Would a serpentine or leather flat belt be a better choice, and the motor pulley changed over to a flat one (with a crown)?
Mark S. wildos9Adrive1a.jpg
 

Wreck™Wreck

Active User
H-M Supporter-Premium Member
Joined
Sep 29, 2014
Messages
1,918
Likes
1,463
#2
The belt is positioned by the driving V-belt sheave, flat belts do not require crowned sheaves, alignment is important however.

Klaatu barada nikto
 

12bolts

Global Moderator
Staff member
Active Member
Joined
Apr 23, 2011
Messages
1,929
Likes
368
#3
My shaper has a large flat driven pulley. From what I have seen when the 2 pulleys are in close proximity tracking is not a problem as the smaller V pulley keeps it positioned

cheers Phil
 

markba633csi

Active Member
Active Member
Joined
Apr 30, 2015
Messages
1,318
Likes
526
#4
I just wondered cause the v-belt is not really designed to run on its inside surface, but it seems to work anyhow. A simple solution and cheap. The best kind.
Mark
 
M

Mister Ed

Guest
#5
This was standard on Logan lathes, for the belt from the motor to the jackshaft. It makes changing pulleys (speeds) very easy with just a little release of tension. I have never seen a tracking or tension issue. Jackshaft to spindle is/was flat belt.
 

12bolts

Global Moderator
Staff member
Active Member
Joined
Apr 23, 2011
Messages
1,929
Likes
368
#6
I just wondered cause the v-belt is not really designed to run on its inside surface, but it seems to work anyhow.
I think you will find it mostly occurs when the flat pulley is of a quite large diameter. Consequently the massive surface area of the belt on the large pulley really negates the issue of the v belt running on its inside face

Cheers Phil
 

benmychree

John York
H-M Supporter-Premium Member
Joined
Jun 7, 2013
Messages
998
Likes
565
#7
The belt is positioned by the driving V-belt sheave, flat belts do not require crowned sheaves, alignment is important however.

Klaatu barada nikto
I beg to differ, flat belts are always run on crowned pulleys. Perhaps you meant to say that in a vee/flat drive, the vee belt does not need to be running on a crowned pulley.
 

benmychree

John York
H-M Supporter-Premium Member
Joined
Jun 7, 2013
Messages
998
Likes
565
#8
I ran a line shaft in my shop many years ago and used a vee/flat drive with a two grooved sheave on the motor about 4" diameter using belts approximately 7/8" wide running on a 30" diameter pulley on the line shaft that was crowned; the belts nestled up against each other , and it worked fine and slippage was not a problem with a 3HP motor driving.
 

Ulma Doctor

Infinitely Curious
Active Member
Joined
Feb 2, 2013
Messages
4,297
Likes
3,495
#9
my SB11" lathe has a similar drive , the motor pulley has a v pulley- the rest of the drive is done with flat pulleys.
 
6
5 7