I am building a saw bench for firewood that runs off my tractor's PTO. What
is the ideal cutting speed for the blade, it is 29" in dia. My gearbox (on
the saw bench) is 2:1 and I was going to use 1:1 for the gearbox to spindle
sheaves. So basically my blade will be 1/2 the speed of my pto. Is this good
or should I alter the sheaves ratio.

habbi wrote:
I am building a saw bench for firewood that runs off my tractor's PTO. What
is the ideal cutting speed for the blade, it is 29" in dia. My gearbox (on
the saw bench) is 2:1 and I was going to use 1:1 for the gearbox to spindle
sheaves. So basically my blade will be 1/2 the speed of my pto. Is this good
or should I alter the sheaves ratio.

If the blade is new, I'd ask the manufacturer. Good blades are
tensioned to run true at a predetermined speed.

John Martin

habbi wrote:
I am building a saw bench for firewood that runs off my tractor's PTO. What
is the ideal cutting speed for the blade, it is 29" in dia. My gearbox (on
the saw bench) is 2:1 and I was going to use 1:1 for the gearbox to spindle
sheaves. So basically my blade will be 1/2 the speed of my pto. Is this good
or should I alter the sheaves ratio.


I run mine right off the PTO . I think it might be nicer if it was 50%
faster . Twice as fast I think would be too much on mine . Trying to
remember the blade D . Close to yours , if you want I will hike out and
measure it . No way I would want mine running slower . Bearings now run
just warm to the touch after hours of saw time . Luck
Ken Cutt

Which PTO speed do you have (540 or 1050)? Suspect that your shaft
speed will be too slow even with the higher speed PTO

habbi wrote:
I am building a saw bench for firewood that runs off my tractor's PTO. What
is the ideal cutting speed for the blade, it is 29" in dia. My gearbox (on
the saw bench) is 2:1 and I was going to use 1:1 for the gearbox to spindle
sheaves. So basically my blade will be 1/2 the speed of my pto. Is this good
or should I alter the sheaves ratio.

Unless your saw is very thing (less than 0.125") the go for a rim speed
of about 6000-8000 ft/minute. (790 rpm - 1050 rpm).

Bruce Lehmann
TKT Engineering
www.thinkerf.com

I have both speeds, I tried it today and at the high pto speed and the 2 :1
gearbox it seemed slow. Tractor 2000, PTO ~1000 blade ~500rpm.
"RoyJ" wrote in message
nk.net...
Which PTO speed do you have (540 or 1050)? Suspect that your shaft
speed will be too slow even with the higher speed PTO

habbi wrote:
I am building a saw bench for firewood that runs off my tractor's PTO.
What
is the ideal cutting speed for the blade, it is 29" in dia. My gearbox
(on
the saw bench) is 2:1 and I was going to use 1:1 for the gearbox to
spindle
sheaves. So basically my blade will be 1/2 the speed of my pto. Is this
good
or should I alter the sheaves ratio.

Thanks, I have it set-up for 500 rpm and it seems slow, I will change the
spindle sheave to a smaller one to give me a speed in your recommended
range.

"sawdoc" wrote in message
oups.com...
Unless your saw is very thing (less than 0.125") the go for a rim speed
of about 6000-8000 ft/minute. (790 rpm - 1050 rpm).

Bruce Lehmann
TKT Engineering
www.thinkerf.com

habbi wrote:
Thanks, I have it set-up for 500 rpm and it seems slow, I will change the
spindle sheave to a smaller one to give me a speed in your recommended
range.

"sawdoc" wrote in message
oups.com...

Unless your saw is very thing (less than 0.125") the go for a rim speed
of about 6000-8000 ft/minute. (790 rpm - 1050 rpm).

Bruce Lehmann
TKT Engineering
www.thinkerf.com




Keep a watch on you bearing temps . Some old mandrels just will not
handle high speed for long . You sure do not want to wipe one out with a
29 inch blade spinning right close to you . Luck
Ken Cutt

The bearings I have are old brass sleeve bearings with grease nipples, the
shaft is 1.5". The bearings are hefty and about 3" long. Do you think they
will be fine? How true should they be to the shaft. when everything is loose
the bearings spin freely on the shaft but once I tighten the bearing blocks
down to the framework there is a bit of drag. This is do to the slight
warping of the framework after welding. I can still easily turn the shaft
with one hand on the shaft though.

"Ken Cutt" wrote in message
...
habbi wrote:
Thanks, I have it set-up for 500 rpm and it seems slow, I will change
the
spindle sheave to a smaller one to give me a speed in your recommended
range.

"sawdoc" wrote in message
oups.com...

Unless your saw is very thing (less than 0.125") the go for a rim speed
of about 6000-8000 ft/minute. (790 rpm - 1050 rpm).

Bruce Lehmann
TKT Engineering
www.thinkerf.com




Keep a watch on you bearing temps . Some old mandrels just will not
handle high speed for long . You sure do not want to wipe one out with a
29 inch blade spinning right close to you . Luck
Ken Cutt

habbi wrote:
The bearings I have are old brass sleeve bearings with grease nipples, the
shaft is 1.5". The bearings are hefty and about 3" long. Do you think they
will be fine? How true should they be to the shaft. when everything is loose
the bearings spin freely on the shaft but once I tighten the bearing blocks
down to the framework there is a bit of drag. This is do to the slight
warping of the framework after welding. I can still easily turn the shaft
with one hand on the shaft though.

"Ken Cutt" wrote in message
...

habbi wrote:

Thanks, I have it set-up for 500 rpm and it seems slow, I will change

the

spindle sheave to a smaller one to give me a speed in your recommended
range.

"sawdoc" wrote in message
egroups.com...


Unless your saw is very thing (less than 0.125") the go for a rim speed
of about 6000-8000 ft/minute. (790 rpm - 1050 rpm).

Bruce Lehmann
TKT Engineering
www.thinkerf.com




Keep a watch on you bearing temps . Some old mandrels just will not
handle high speed for long . You sure do not want to wipe one out with a
29 inch blade spinning right close to you . Luck
Ken Cutt



I go by feel on old style bearings . In fact that was what I saw my
Grandfather do while I was growing up . Warm is safe , hot is not .
Bronze bushings should be fine . Slight drag , well I would think that
would accelerate wear to one side . Shim the blocks or clamp the frame
enough to release the tension and weld a bar to hold it in its free
position . Cutting with a buzz saw always feels too slow at the start
and to fast towards the end . Also small stuff the saw seems too slow ,
big stuff too fast . Do a few hours of actual cutting and then see if
you think it needs to spin faster . Or if the bearings are running hot .
Likely you will not start out at the ideal speed but over the long haul
you will be happy enough with the size of the pile . Luck
Ken Cutt

Ends up the slight drag is only when I tighten the belts. So bearings will
heat up if going too slow? I thought it would be the other way around.


"Ken Cutt" wrote in message
...
habbi wrote:
The bearings I have are old brass sleeve bearings with grease nipples,
the
shaft is 1.5". The bearings are hefty and about 3" long. Do you think
they
will be fine? How true should they be to the shaft. when everything is
loose
the bearings spin freely on the shaft but once I tighten the bearing
blocks
down to the framework there is a bit of drag. This is do to the slight
warping of the framework after welding. I can still easily turn the
shaft
with one hand on the shaft though.

"Ken Cutt" wrote in message
...

habbi wrote:

Thanks, I have it set-up for 500 rpm and it seems slow, I will change

the

spindle sheave to a smaller one to give me a speed in your recommended
range.

"sawdoc" wrote in message
egroups.com...


Unless your saw is very thing (less than 0.125") the go for a rim
speed
of about 6000-8000 ft/minute. (790 rpm - 1050 rpm).

Bruce Lehmann
TKT Engineering
www.thinkerf.com




Keep a watch on you bearing temps . Some old mandrels just will not
handle high speed for long . You sure do not want to wipe one out with a
29 inch blade spinning right close to you . Luck
Ken Cutt



I go by feel on old style bearings . In fact that was what I saw my
Grandfather do while I was growing up . Warm is safe , hot is not .
Bronze bushings should be fine . Slight drag , well I would think that
would accelerate wear to one side . Shim the blocks or clamp the frame
enough to release the tension and weld a bar to hold it in its free
position . Cutting with a buzz saw always feels too slow at the start
and to fast towards the end . Also small stuff the saw seems too slow ,
big stuff too fast . Do a few hours of actual cutting and then see if
you think it needs to spin faster . Or if the bearings are running hot .
Likely you will not start out at the ideal speed but over the long haul
you will be happy enough with the size of the pile . Luck
Ken Cutt

habbi wrote:
Ends up the slight drag is only when I tighten the belts. So bearings will
heat up if going too slow? I thought it would be the other way around.


No the bearings will heat up if they are binding . Luck
Ken Cutt