I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob

On 01/03/2015 9:20 AM, Bob Engelhardt wrote:
I have a self-propelled leaf blower/vac. The wheels are driven by a belt
that goes down from the horizontal shaft of the engine, turns horizontal
to go under the deck, and turns vertical again to drive the axle. All
that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At first
I thought that I had gotten something oriented wrong, but I've ruled
that out (most parts only go one way and I have a parts diagram that
agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt wants
to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Not seen that particular one before, but all pieces of gear have
seen/had that used such an arrangement had some additional guides to
restrict the belt from side movement.

I notice some holes in the above bracket at about the right position;
wonder if there aren't some missing such pieces here...

--

On 1/3/2015 9:20 AM, Bob Engelhardt wrote:
I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob

Two things I think I see in the picture.

1) The pulley on the left side is wider than the one on the right side.
Swap them and see if the problem moves with the pulley.

2) The pulley on the right side seems to have a slightly different
angle than the left side. Not perpendicular with the frame.

3) On the axle, can you slide the assembly with pulley and sprocket
to the right a bit? You will need to move the sprocket at the other end
to.
Mikek


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

Bob Engelhardt wrote:
I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob


The right hand pulley needs to be angled in at the bottom so the belt
enters straight.

--
Steve W.

"Bob Engelhardt" wrote in message ...

I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob


What direction is the geared shaft supposed to turn?

"Rick" wrote in message
...



"Bob Engelhardt" wrote in message ...

I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob


What direction is the geared shaft supposed to turn?

Sorry, meant "sprocket".........

On Sat, 3 Jan 2015 15:52:14 -0500, "Rick" wrote:



"Bob Engelhardt" wrote in message ...

I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

It appears to have two different width pulleys, so I'm wondering if
the righthand pulley had been replaced at some point (or originally)
with the narrow one, causing the problem. One fix I can think of,
having dealt with quite a few mower deck pulleys myself, is to add a
1/4" or 3/8" rod guide. It would keep the belt from trying to hop the
left sheave. You have 4 existing holes to mount it between.
http://manuals.deere.com/cceomview/O...2793_H4a18.jpg


What direction is the geared shaft supposed to turn?

Yes.

Um, what direction is the belt moving? My guess is that the righthand
side moves up toward the pulley it tries to jump, correct? In that
case, the geared shaft moves thattaway! (counterclockwise if looking
from the end the gear is on) I love these quick quizzes based on a
single, incomplete picture of a complex mechanism, where entire drive
and driven mechanisms are hidden! Do post more.

--
All I want is a warm bed,
a kind word, and
U N L I M I T E D P O W E R !
--anon

"Rick" wrote in message
...


Here is a picture of the underside. The arrow points to the spot on
a pulley where the belt "enters" it at an angle. Of course, the
belt wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it
by changing something. But this is the way that it came from the
factory and it should work. What am I missing?

Thanks,
Bob


What direction is the geared shaft supposed to turn?

Perhaps you have the belt running backwards on the drive pulley?

On 1/3/2015 10:50 AM, dpb wrote:
Not seen that particular one before, but all pieces of gear have
seen/had that used such an arrangement had some additional guides to
restrict the belt from side movement.

I notice some holes in the above bracket at about the right position;
wonder if there aren't some missing such pieces here...

Those holes are for the motor bolts. And the parts diagram doesn't show
belt guides. But it's a good idea - I was considering changing the
pulley orientation, but I think that a guide would be easier.

Thanks,
Bob

On 1/3/2015 11:14 AM, amdx wrote:

Two things I think I see in the picture.

1) The pulley on the left side is wider than the one on the right side.
Swap them and see if the problem moves with the pulley.

One of the first things that I tried was swapping the pulleys. But one
is a flat pulley, riding on the back of the belt & the other a vee.
Swapping them and keeping the front-back right didn't work.


2) The pulley on the right side seems to have a slightly different
angle than the left side. Not perpendicular with the frame.

The angles are slightly different & the right one is nearly
perpendicular, but needs to be "tilted" quite a bit (clockwise). If it
pointed in the direction that the belt was coming from, it would work.
That's the big question in my mind: why doesn't it point that way?


3) On the axle, can you slide the assembly with pulley and sprocket
to the right a bit? You will need to move the sprocket at the other
end to.

The unseen sprocket is welded to a shaft and that determines the
alignment of the rest. I thought of an end-over-end swap, but the belt
pulley is centered & swapping wouldn't change anything.

Thanks,
Bob

On 1/3/2015 2:51 PM, Steve W. wrote:
The right hand pulley needs to be angled in at the bottom so the belt
enters straight.


It does. I was about to change it so that it would when I thought I
might be missing something and posted.

I still can't answer why it was made that way. And it's not been
damaged so that the alignment has changed.

Thanks,
Bob

On 1/3/2015 3:53 PM, Rick wrote:

What direction is the geared shaft supposed to turn?

Sorry, meant "sprocket".........


Such that the chain and belt sections in the foreground move upward.
Given CCW engine rotation and forward movement of wheels.

On 1/3/2015 5:13 PM, Larry Jaques wrote:

It appears to have two different width pulleys, so I'm wondering if
the righthand pulley had been replaced at some point (or originally)
with the narrow one, causing the problem. One fix I can think of,
having dealt with quite a few mower deck pulleys myself, is to add a
1/4" or 3/8" rod guide. It would keep the belt from trying to hop the
left sheave. You have 4 existing holes to mount it between.
http://manuals.deere.com/cceomview/O...2793_H4a18.jpg

The pulleys are as shown on the parts diagram. And were the same on
both of the donor machines. So I think they're OK.

"dpb" mentioned a guide, but your picture of the Deere arrangement
convinces me that it's the way to fix it.

Um, what direction is the belt moving? My guess is that the righthand
side moves up toward the pulley it tries to jump, correct? ...

Yes. It is the critical point. The belt is entering the pulley under
tension and wants to climb the side. All other points are either
aligned properly, or the belt is exiting a pulley, or it is entering
"slack" (return path).

I love these quick quizzes based on a
single, incomplete picture of a complex mechanism, where entire drive
and driven mechanisms are hidden! Do post more.

Well, the engine is off, so there's nothing to show there. The chain
goes to sprocket - that's no help. There's really nothing to add.


Thanks,
Bob

On 1/3/2015 6:25 PM, Jim Wilkins wrote:
Perhaps you have the belt running backwards on the drive pulley?

No - the direction of the wheel rotation determines the direction of the
sprocket, hence belt. And the direction of rotation of the engine
determines how the belt rides on it's pulley. The belt could ride in
reverse on the left-right pulleys and the cross over itself going to the
engine, but, seriously!

Bob

Bob Engelhardt wrote:
On 1/3/2015 2:51 PM, Steve W. wrote:
The right hand pulley needs to be angled in at the bottom so the belt
enters straight.


It does. I was about to change it so that it would when I thought I
might be missing something and posted.

I still can't answer why it was made that way. And it's not been
damaged so that the alignment has changed.

Thanks,
Bob

Some of the outdoor stuff I have worked on defies logic. Bending that
into alignment will decrease the belt wear as well as keep the belt on.

One of my old Power King mower decks will make you scratch your head. It
uses a LONG belt. Comes off the engine back to the deck, then wraps
around and goes over itself to drive one spindle then back across to
drive the two on the other side. Sort of looks like those W shaped paper
clips!


--
Steve W.

I'm thinking that this was much ado about nothing!

I went to the cellar to put a guide on the belt. I took the pulley
bracket off & thought "Why don't I try to bend it?". Well, it bent
really easily, much to my surprise! Here's the fixed pulley (the full
picture for you, Larry :-)
http://home.comcast.net/~bobengelhardt/DSCF1184.jpg

The pulley is held by an L-shaped bracket & I just twisted the upright
leg. Now I'm thinking that it might have been damaged, given how easy
it was to twist and how little twist it took.

Bob

On Sat, 3 Jan 2015 18:25:45 -0500, "Jim Wilkins"
wrote:

"Rick" wrote in message
...


Here is a picture of the underside. The arrow points to the spot on
a pulley where the belt "enters" it at an angle. Of course, the
belt wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it
by changing something. But this is the way that it came from the
factory and it should work. What am I missing?

Thanks,
Bob


What direction is the geared shaft supposed to turn?

Perhaps you have the belt running backwards on the drive pulley?

(Palm hits forehead) Yeah, flip the belt at the chain end and it will
track the other way, running just fine onto the wider pulley. I'm sure
that's how it was designed, if no pulleys have been changed.

(That said, how could it have worked the opposite direction?)

--
All I want is a warm bed,
a kind word, and
U N L I M I T E D P O W E R !
--anon

"Larry Jaques" wrote in message
...
On Sat, 3 Jan 2015 18:25:45 -0500, "Jim Wilkins"
wrote:

"Rick" wrote in message
...


Here is a picture of the underside. The arrow points to the spot
on
a pulley where the belt "enters" it at an angle. Of course, the
belt wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it
by changing something. But this is the way that it came from the
factory and it should work. What am I missing?

Thanks,
Bob


What direction is the geared shaft supposed to turn?

Perhaps you have the belt running backwards on the drive pulley?

(Palm hits forehead) Yeah, flip the belt at the chain end and it
will
track the other way, running just fine onto the wider pulley. I'm
sure
that's how it was designed, if no pulleys have been changed.

(That said, how could it have worked the opposite direction?)

I helped rebuild an old riding mower for a community park committee
which had a convoluted belt arrangement that could easily be routed
incorrectly. It may have been discarded after being reassembled wrong
in a previous repair.

The blades spin backwards just fine, but they don't cut very well.
-jsw

On Sun, 4 Jan 2015 07:28:39 -0500, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Sat, 3 Jan 2015 18:25:45 -0500, "Jim Wilkins"
wrote:

"Rick" wrote in message
...


Here is a picture of the underside. The arrow points to the spot
on
a pulley where the belt "enters" it at an angle. Of course, the
belt wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it
by changing something. But this is the way that it came from the
factory and it should work. What am I missing?

Thanks,
Bob


What direction is the geared shaft supposed to turn?

Perhaps you have the belt running backwards on the drive pulley?

(Palm hits forehead) Yeah, flip the belt at the chain end and it
will
track the other way, running just fine onto the wider pulley. I'm
sure
that's how it was designed, if no pulleys have been changed.

(That said, how could it have worked the opposite direction?)

I helped rebuild an old riding mower for a community park committee
which had a convoluted belt arrangement that could easily be routed
incorrectly. It may have been discarded after being reassembled wrong
in a previous repair.

Ditto those great stories. My $5-fix golf cart was my best repair.
I've cleaned plugged-up vacuum cleaners found in the junk pile at
garage sales and they worked perfectly; it sold for $10 at my next
gar(b)age sale.


The blades spin backwards just fine, but they don't cut very well.

Funny how that works.

--
All I want is a warm bed,
a kind word, and
U N L I M I T E D P O W E R !
--anon

I see that you have the problem fixed, but just in case, here's another thought:
I have several old Cub Cadet garden tractors that turn a belt 90 degrees to move power from the horizontal engine shaft to vertical driven pulley on the mower deck. Most of the time when a belt comes off it's because the belt itself is bad. Sometimes I have to look closely to find the defect.
I have learned over the years that all vee belts are not created equal, by a long shot. Especially when subjected to this kind of twisting. Some of them take a permanent or semi-permanent set when sitting for a long time. Not a problem in "normal" service, but not good here.

(There ARE other belt-retention problems with these old Cub Cadets, which I detail at:
http://www.spaco.org/CubCadet/MowerBeltComeOff.htm


Pete Stanaitis
---------------

wrote in message
...
I see that you have the problem fixed, but just in case, here's
another thought:
I have several old Cub Cadet garden tractors that turn a belt 90
degrees to move power from the horizontal engine shaft to vertical
driven pulley on the mower deck. Most of the time when a belt comes
off it's because the belt itself is bad. Sometimes I have to look
closely to find the defect.
---------------

I overloaded the vee belt that drives the hydraulic pump I added to my
tractor and broke the internal cords on one side. The belt still
looked the same and ran straight without a load, but any loading made
it instantly roll ~90 degrees and then slip.

The only evidence is that the broken side stretches freely when the
belt is bent sideways.

The fix was a new pump of 2/3 the displacement, spinning faster.

-jsw

wrote:
I see that you have the problem fixed, but just in case, here's another thought:
I have several old Cub Cadet garden tractors that turn a belt 90 degrees to move power from the horizontal engine shaft to vertical driven pulley on the mower deck. Most of the time when a belt comes off it's because the belt itself is bad. Sometimes I have to look closely to find the defect.
I have learned over the years that all vee belts are not created equal, by a long shot. Especially when subjected to this kind of twisting. Some of them take a permanent or semi-permanent set when sitting for a long time. Not a problem in "normal" service, but not good here.

(There ARE other belt-retention problems with these old Cub Cadets, which I detail at:
http://www.spaco.org/CubCadet/MowerBeltComeOff.htm


Pete Stanaitis
---------------

Ever visited www.cubcadetcollectors.com/forum/
It was at one time the IH Registry

--
Steve W.

On 1/3/2015 9:20 AM, Bob Engelhardt wrote:
I have a self-propelled leaf blower/vac. The wheels are driven by a
belt that goes down from the horizontal shaft of the engine, turns
horizontal to go under the deck, and turns vertical again to drive the
axle. All that turning is problematic and the belt keeps coming off.

This is a blower that I reconstructed from the parts of 2 scrapped ones.
Same model, so no fabrication involved, just bolting together. At
first I thought that I had gotten something oriented wrong, but I've
ruled that out (most parts only go one way and I have a parts diagram
that agrees).

Here is a picture of the underside. The arrow points to the spot on a
pulley where the belt "enters" it at an angle. Of course, the belt
wants to climb up the side of the pulley and come off.
http://home.comcast.net/~bobengelhardt/DSCF1179.jpg

I just don't get how this can work. My first impulse is to fix it by
changing something. But this is the way that it came from the factory
and it should work. What am I missing?

Thanks,
Bob
My large mowers have 1/8" hard wire bolted to the chassis and over the
belt - keeping the belt between the loop of the wire on both sides.
As pressure on the belt (from motor or wheels) the belt tends to shorten
on one end and lengthen on the other for the start up. Belt jerks are
common. These loops are then more like 7 or a z where the bottom bolts
on and the vertical section goes over the height of the pulley and the
wire bends over the pulley. keeps the belt with some slack on the
pulley. And so on.

Martin