I was vacuuming leaves the other day when the "6.5 hp" Harbor
Freight-powered vac let out a terrible bam-bam-bam... and started
slowing quickly. Quickly shut off and locked tight. Oh, crap! Up to
my ass in leaves and a broken vac!

It had to be the engine, of course, but when I got it in the shop, I
found this:
http://home.comcast.net/~bobengelhardt/DSCF1165.JPG

When the blade failed, its backing plate bent and the blade tip started
hitting bolt heads in the case. All the blades had real cracks - one is
circled - and were not far from failure. I can think of no other reason
than centrifugal force. The blades are about 3/16" thick - pretty
surprising that they would crack like that.

Now, here's the best part: I had a spare impeller in the shed! Who
keeps spare impellers? Impellers don't fail, why would anyone have a
spare? You're looking at him, as they say.

Fixed in a flash and back to the leaves. Very satisfying.

Bob

On 2014-11-15, Bob Engelhardt wrote:
I was vacuuming leaves the other day when the "6.5 hp" Harbor
Freight-powered vac let out a terrible bam-bam-bam... and started
slowing quickly. Quickly shut off and locked tight. Oh, crap! Up to
my ass in leaves and a broken vac!

It had to be the engine, of course, but when I got it in the shop, I
found this:
http://home.comcast.net/~bobengelhardt/DSCF1165.JPG

When the blade failed, its backing plate bent and the blade tip started
hitting bolt heads in the case. All the blades had real cracks - one is
circled - and were not far from failure. I can think of no other reason
than centrifugal force. The blades are about 3/16" thick - pretty
surprising that they would crack like that.

Now, here's the best part: I had a spare impeller in the shed! Who
keeps spare impellers? Impellers don't fail, why would anyone have a
spare? You're looking at him, as they say.

Fixed in a flash and back to the leaves. Very satisfying.

Bob

Bob, my best guess is that the steel used was substandard (ie perhaps
too much sulphur), and welded in a way that left some residual
stress.

On 11/15/2014 10:14 AM, Bob Engelhardt wrote:
I was vacuuming leaves the other day when the "6.5 hp" Harbor
Freight-powered vac let out a terrible bam-bam-bam... and started
slowing quickly. Quickly shut off and locked tight. Oh, crap! Up to
my ass in leaves and a broken vac!

It had to be the engine, of course, but when I got it in the shop, I
found this:
http://home.comcast.net/~bobengelhardt/DSCF1165.JPG

When the blade failed, its backing plate bent and the blade tip started
hitting bolt heads in the case. All the blades had real cracks - one is
circled - and were not far from failure. I can think of no other reason
than centrifugal force. The blades are about 3/16" thick - pretty
surprising that they would crack like that.

Now, here's the best part: I had a spare impeller in the shed! Who
keeps spare impellers? Impellers don't fail, why would anyone have a
spare? You're looking at him, as they say.

Fixed in a flash and back to the leaves. Very satisfying.

Bob


You'll pay for that...later.

On Sat, 15 Nov 2014 10:14:21 -0500, Bob Engelhardt
wrote:

I was vacuuming leaves the other day when the "6.5 hp" Harbor
Freight-powered vac let out a terrible bam-bam-bam... and started
slowing quickly. Quickly shut off and locked tight. Oh, crap! Up to
my ass in leaves and a broken vac!

It had to be the engine, of course, but when I got it in the shop, I
found this:
http://home.comcast.net/~bobengelhardt/DSCF1165.JPG

When the blade failed, its backing plate bent and the blade tip started
hitting bolt heads in the case. All the blades had real cracks - one is
circled - and were not far from failure. I can think of no other reason
than centrifugal force. The blades are about 3/16" thick - pretty
surprising that they would crack like that.

Now, here's the best part: I had a spare impeller in the shed! Who
keeps spare impellers? Impellers don't fail, why would anyone have a
spare? You're looking at him, as they say.

Fixed in a flash and back to the leaves. Very satisfying.

Bob

Ugh. FWIW, the centrifugal force is unlikely to have done it. Without
a macro-level photo of the break, it's hard to tell, but it probably
is fatigue, possibly on weakened areas that, as Iggy says, could have
been bad welds.

When a fan or turbine spins, unless it's precision-balanced, it will
vibrate. Ekven a balanced one can vibrate if the air currents are
"noisy" from preceding blades. That can put a lot of stress on fan
blades.

--
Ed Huntress

On 11/15/2014 10:34 AM, Ed Huntress wrote:

... but it probably is fatigue, ...

When a fan or turbine spins, ... it will
vibrate. ...

That makes a lot of sense. More so when you consider that it's being
driven by a 1-cylinder gas engine, hardly a smooth power source.

Maybe I should grind stress relief at the top of the blades where they
meet the hub. Like so (engage imagination):

/
____ /
U
|
|

Bob

On Sat, 15 Nov 2014 11:37:33 -0500, Bob Engelhardt
wrote:

On 11/15/2014 10:34 AM, Ed Huntress wrote:

... but it probably is fatigue, ...

When a fan or turbine spins, ... it will
vibrate. ...

That makes a lot of sense. More so when you consider that it's being
driven by a 1-cylinder gas engine, hardly a smooth power source.

Maybe I should grind stress relief at the top of the blades where they
meet the hub. Like so (engage imagination):

/
____ /
U
|
|

Bob

I can't help you there. If it's fatigue, it's very dependent upon two
things: the number of cycles it goes through, and the percentage of
yield strength that the load applies.

Steel has a very long fatigue life unless it's stressed close to the
yield limit. (Aluminum, for the record, has much less resistance to
fatigue.) If you reduce the thickness or length to which the load is
applied, by grinding in relief, the result could be worse than just
leaving it alone.

That depends on whether you're starting off with microcracks at or
near the surface of the welds. If there are microcracks, they're
starting points for fatigue.

Unless you're making parts for an aircraft turbine, trying to
calculate these things is not worth it. Just go with your sense of how
metal behaves and be thankful your fan isn't made out of some
expensive superalloy. d8-)

BTW, look closely at the breaks. If some part of the break area is
shiny, you're dealing with fatigue. It could be a ring around the
break, or some area across the break. When metal fatigues it "frets,"
or rubs against itself, before it fails. That usually leaves a small
shiny area. As the break progresses, the area to which the load is
applied gets smaller, until the metal breaks from being overstressed.
That part of the break is likely to be dull or crystalline in
appearance.

But it's not so cut-and-dried. Sometimes it's hard to tell.

--
Ed Huntress

On 11/15/2014 7:14 AM, Bob Engelhardt wrote:
I was vacuuming leaves the other day when the "6.5 hp" Harbor
Freight-powered vac let out a terrible bam-bam-bam... and started
slowing quickly. Quickly shut off and locked tight. Oh, crap! Up to
my ass in leaves and a broken vac!

It had to be the engine, of course, but when I got it in the shop, I
found this:
http://home.comcast.net/~bobengelhardt/DSCF1165.JPG

When the blade failed, its backing plate bent and the blade tip started
hitting bolt heads in the case. All the blades had real cracks - one is
circled - and were not far from failure. I can think of no other reason
than centrifugal force. The blades are about 3/16" thick - pretty
surprising that they would crack like that.

Now, here's the best part: I had a spare impeller in the shed! Who
keeps spare impellers? Impellers don't fail, why would anyone have a
spare? You're looking at him, as they say.

Fixed in a flash and back to the leaves. Very satisfying.

Bob
Bob, are you sure you didn't vacuum something other than leaves? Like a
rock or piece of metal lying in the leaves?

Paul

On Sat, 15 Nov 2014 09:26:19 -0600, Ignoramus30301
wrote:

On 2014-11-15, Bob Engelhardt wrote:
I was vacuuming leaves the other day when the "6.5 hp" Harbor
Freight-powered vac let out a terrible bam-bam-bam... and started
slowing quickly. Quickly shut off and locked tight. Oh, crap! Up to
my ass in leaves and a broken vac!

It had to be the engine, of course, but when I got it in the shop, I
found this:
http://home.comcast.net/~bobengelhardt/DSCF1165.JPG

When the blade failed, its backing plate bent and the blade tip started
hitting bolt heads in the case. All the blades had real cracks - one is
circled - and were not far from failure. I can think of no other reason
than centrifugal force. The blades are about 3/16" thick - pretty
surprising that they would crack like that.

Now, here's the best part: I had a spare impeller in the shed! Who
keeps spare impellers? Impellers don't fail, why would anyone have a
spare? You're looking at him, as they say.

Fixed in a flash and back to the leaves. Very satisfying.

Bob

Bob, my best guess is that the steel used was substandard (ie perhaps
too much sulphur), and welded in a way that left some residual
stress.
AKA Made in China

On Sat, 15 Nov 2014 09:02:50 -0800
Paul Drahn wrote:

snip
Bob, are you sure you didn't vacuum something other than leaves? Like a
rock or piece of metal lying in the leaves?

Paul

That would be my guess too. It doesn't take long, just a few seconds to
make a mess that looks like it took many hours to create. The offending
piece/part could have easily been thrown out and is many feet away.

The "hammers" used in tub grinders have been known to break and get
thrown. They have gone through roofs and walls many blocks away from
where the grinder was operating...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On 11/15/2014 12:02 PM, Paul Drahn wrote:
Bob, are you sure you didn't vacuum something other than leaves? Like a
rock or piece of metal lying in the leaves?

I'm pretty sure that I have, over the years of using it. But I don't
think that was a rock: there isn't a dent in the blade. And all the
blades are cracked - a single rock would only be hit by a single blade
before being ejected. It might be that the accumulated impacts of
pebbles over the years was what caused the fatigue.

Bob

On 11/15/2014 1:43 PM, Leon Fisk wrote:
That would be my guess too. It doesn't take long, just a few seconds to
make a mess that looks like it took many hours to create. The offending
piece/part could have easily been thrown out and is many feet away.
....

When I do suck up something larger than sand, I know it. There is a
single whang when a blade hits it and it's ejected.

Bob

BTW - the leaf vac is a set up of my power wagon. See page 9 he
http://www.mwdropbox.com/dropbox/PowerWagon.pdf

On Sat, 15 Nov 2014 19:53:03 -0500
Bob Engelhardt wrote:

On 11/15/2014 1:43 PM, Leon Fisk wrote:
That would be my guess too. It doesn't take long, just a few seconds to
make a mess that looks like it took many hours to create. The offending
piece/part could have easily been thrown out and is many feet away.
...

When I do suck up something larger than sand, I know it. There is a
single whang when a blade hits it and it's ejected.

That's usually the problem. What got sucked up didn't get thrown out
right away. I remember something similar happening years ago but I
can't remember it clearly enough. Been bugging me ever since you posted
this. Anyway... it happened so fast and looked so bad it was hard to
believe all the damage done in just a few seconds. It was probably when
I worked on a farm ~40 years ago... I do remember pulling odds & ends
out of the grinder-mixer. It could bring a 50hp tractor to a stall if
you pushed the input too hard. Typical hammer-mill with different
sized screens for determining how coarse the output feed would be. You
would have to shut down and remove the screen to find the foreign noise
maker. A lot of times you really couldn't tell what the offending beat
up piece of metal taken out once was...

BTW - the leaf vac is a set up of my power wagon. See page 9 he
http://www.mwdropbox.com/dropbox/PowerWagon.pdf

I like it, nice write up. I have a similar version in my mind but I
still need the exercise. Also agree that the DR version costs way too
much. If I live long enough though, there will come a day...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On 11/15/2014 11:51 AM, Ed Huntress wrote:
...
BTW, look closely at the breaks. If some part of the break area is
shiny, you're dealing with fatigue. ...

I had taken the impeller to the dump yesterday. I went back today,
intending to retrieve it, cut out a sample of a crack, and examine it
for signs of fatigue. It was gone! Who would want an old, really beat
up, impeller?

"Bob Engelhardt" wrote in message
...
On 11/15/2014 11:51 AM, Ed Huntress wrote:
...
BTW, look closely at the breaks. If some part of the break area is
shiny, you're dealing with fatigue. ...

I had taken the impeller to the dump yesterday. I went back today,
intending to retrieve it, cut out a sample of a crack, and examine
it for signs of fatigue. It was gone! Who would want an old,
really beat up, impeller?

I bartered some cast iron for a rusty wagon front axle with an old man
who picks up -any- scrap metal to sell to the junkyard.

I was hoping it might be wrought iron, but a little cleaning showed
that the rust pattern isn't directional.

On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:

On 11/15/2014 11:51 AM, Ed Huntress wrote:
...
BTW, look closely at the breaks. If some part of the break area is
shiny, you're dealing with fatigue. ...

I had taken the impeller to the dump yesterday. I went back today,
intending to retrieve it, cut out a sample of a crack, and examine it
for signs of fatigue. It was gone! Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)

--
Ed Huntress

On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to use
that with. "Oh, honey, my squeegee is broken - I can't do the windows
today."

On Sun, 16 Nov 2014 18:57:24 -0500, Bob Engelhardt
wrote:

On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to use
that with. "Oh, honey, my squeegee is broken - I can't do the windows
today."

In my house, I could get multi-season use out of it. "Sorry, hon, but
the lawnmower blade is broken." "Oh, sorry, babe, but the fan for the
weed-wacker just took a dive." "Omigosh, the snow blower compressor
just broke into pieces."

My wife is not a machinery type. d8-)

--
Ed Huntress

Ed Huntress wrote:
On Sun, 16 Nov 2014 18:57:24 -0500, Bob Engelhardt
wrote:

On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to
use that with. "Oh, honey, my squeegee is broken - I can't do the
windows today."

In my house, I could get multi-season use out of it. "Sorry, hon, but
the lawnmower blade is broken." "Oh, sorry, babe, but the fan for the
weed-wacker just took a dive." "Omigosh, the snow blower compressor
just broke into pieces."

My wife is not a machinery type. d8-)

My wife would just give me "the look" and tell me "You've got a machine
shop . Either fix it or make a new one . " .
Sometimes a blessing is also a curse .
--
Snag

On Sun, 16 Nov 2014 18:32:11 -0600, "Terry Coombs"
wrote:

Ed Huntress wrote:
On Sun, 16 Nov 2014 18:57:24 -0500, Bob Engelhardt
wrote:

On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to
use that with. "Oh, honey, my squeegee is broken - I can't do the
windows today."

In my house, I could get multi-season use out of it. "Sorry, hon, but
the lawnmower blade is broken." "Oh, sorry, babe, but the fan for the
weed-wacker just took a dive." "Omigosh, the snow blower compressor
just broke into pieces."

My wife is not a machinery type. d8-)

My wife would just give me "the look" and tell me "You've got a machine
shop . Either fix it or make a new one . " .
Sometimes a blessing is also a curse .
At least THAT would give you an excuse and permission to go out to
the shop and work on something (else)

"Bob Engelhardt" wrote in message
...
On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to
use that with. "Oh, honey, my squeegee is broken - I can't do the
windows today."


In Mensa we made a game of trying to fit a previously chosen odd word
or phrase smoothly into a dinner conversation. I'm going to see how
long it takes to use "My squeegee is broken".

wrote:
On Sun, 16 Nov 2014 18:32:11 -0600, "Terry Coombs"
wrote:

Ed Huntress wrote:
On Sun, 16 Nov 2014 18:57:24 -0500, Bob Engelhardt
wrote:

On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to
use that with. "Oh, honey, my squeegee is broken - I can't do the
windows today."

In my house, I could get multi-season use out of it. "Sorry, hon,
but the lawnmower blade is broken." "Oh, sorry, babe, but the fan
for the weed-wacker just took a dive." "Omigosh, the snow blower
compressor just broke into pieces."

My wife is not a machinery type. d8-)

My wife would just give me "the look" and tell me "You've got a
machine shop . Either fix it or make a new one . " .
Sometimes a blessing is also a curse .
At least THAT would give you an excuse and permission to go out to
the shop and work on something (else)

Good point ! Out of sight , out of mind ...

--
Snag

On Sun, 16 Nov 2014 18:32:11 -0600, "Terry Coombs"
wrote:

Ed Huntress wrote:
On Sun, 16 Nov 2014 18:57:24 -0500, Bob Engelhardt
wrote:

On 11/16/2014 5:55 PM, Ed Huntress wrote:
On Sun, 16 Nov 2014 16:47:17 -0500, Bob Engelhardt
wrote:
... Who would want an old, really beat
up, impeller?

Hmm...somebody who wants an excuse to give to his wife for not
gathering up the leaves? d8-)


That's good! I'm going to have to stockpile a few broken parts to
use that with. "Oh, honey, my squeegee is broken - I can't do the
windows today."

In my house, I could get multi-season use out of it. "Sorry, hon, but
the lawnmower blade is broken." "Oh, sorry, babe, but the fan for the
weed-wacker just took a dive." "Omigosh, the snow blower compressor
just broke into pieces."

My wife is not a machinery type. d8-)

My wife would just give me "the look" and tell me "You've got a machine
shop . Either fix it or make a new one . " .
Sometimes a blessing is also a curse .

Use logic, Terry.

"Honey, for only $1,732, I can buy 'billet' g and make the parts and
fix it myself in about 2 months. Or, for $283, I can buy a bolt-on
replacement and have it fixed the day after it arrives. What would you
suggest I do?" Then give _her_ The Look.

--
I started out with nothing and
I still have most of it left!
--anon

I was back at the leaves yesterday, with the freshly repaired vac. At
the end of the day, and the end of the leaves (almost), this happened:
http://home.comcast.net/~bobengelhardt/DSCF1170.JPG

In case it isn't obvious, that is the end of the HF engine crankshaft!
It was quite an alarming event: a heavy steel impeller, running 3000
rpm, coming off and bouncing around inside its housing!

The engine was only $100, but it also only ran 10 - 15 hours before
falling apart. Unfortunately, those hours were over a 3 year period and
I'm SOL on any warranty.

I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Sigh

Bob

On Mon, 17 Nov 2014 12:36:24 -0500
Bob Engelhardt wrote:

snip
I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Seems like you said it was the horizontal 6.5hp. If so they are still
selling them for $99 with coupon (ask if you need one). I bought one a
couple years ago for that, thinking I would never see that price
again. There has been coupons and parking lot sales with that price
ever since...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On Mon, 17 Nov 2014 12:36:24 -0500, Bob Engelhardt
wrote:

I was back at the leaves yesterday, with the freshly repaired vac. At
the end of the day, and the end of the leaves (almost), this happened:
http://home.comcast.net/~bobengelhardt/DSCF1170.JPG

In case it isn't obvious, that is the end of the HF engine crankshaft!
It was quite an alarming event: a heavy steel impeller, running 3000
rpm, coming off and bouncing around inside its housing!

The engine was only $100, but it also only ran 10 - 15 hours before
falling apart. Unfortunately, those hours were over a 3 year period and
I'm SOL on any warranty.

I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Sigh

Bob
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine - but
it does save the engine - and you can make all the other failure prone
parts!!!

On 11/17/2014 12:45 PM, Leon Fisk wrote:
Seems like you said it was the horizontal 6.5hp. If so they are still
selling them for $99 with coupon (ask if you need one). ...

That's the one. $120 now, less 20% would be $96. But given my
experience with this one, I would probably get a used B&S or Honda.
Failed-pump pressure washers seem to be a good source for horizontal
shaft engines. Here's one:
http://boston.craigslist.org/nos/grd/4730588264.htm

Bob

On 11/17/2014 12:46 PM, wrote:
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine - but
it does save the engine - and you can make all the other failure prone
parts!!!

That would be a much better approach.

What is a "back tensioned", anyway?

Bob Engelhardt wrote:
I was back at the leaves yesterday, with the freshly repaired vac. At
the end of the day, and the end of the leaves (almost), this happened:
http://home.comcast.net/~bobengelhardt/DSCF1170.JPG

In case it isn't obvious, that is the end of the HF engine crankshaft!
It was quite an alarming event: a heavy steel impeller, running 3000
rpm, coming off and bouncing around inside its housing!

The engine was only $100, but it also only ran 10 - 15 hours before
falling apart. Unfortunately, those hours were over a 3 year period and
I'm SOL on any warranty.

I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Sigh

Bob

Check around for a Honda motor of the same size. A lot of folks in the
cart world have been interchanging the parts as bolt ons. Crank, rod,
piston are supposedly direct interchange.

--
Steve W.

wrote:
On Mon, 17 Nov 2014 12:36:24 -0500, Bob Engelhardt
wrote:

I was back at the leaves yesterday, with the freshly repaired vac. At
the end of the day, and the end of the leaves (almost), this happened:
http://home.comcast.net/~bobengelhardt/DSCF1170.JPG

In case it isn't obvious, that is the end of the HF engine crankshaft!
It was quite an alarming event: a heavy steel impeller, running 3000
rpm, coming off and bouncing around inside its housing!

The engine was only $100, but it also only ran 10 - 15 hours before
falling apart. Unfortunately, those hours were over a 3 year period and
I'm SOL on any warranty.

I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Sigh

Bob
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine - but
it does save the engine - and you can make all the other failure prone
parts!!!


Wonder if you could cut the crankshaft a bit short, then install a stub
shaft out to a carrier bearing mounted on the other side to help carry
the load?

--
Steve W.

"Bob Engelhardt" wrote in message
...
On 11/17/2014 12:46 PM, wrote:
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back
tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine -
but
it does save the engine - and you can make all the other failure
prone
parts!!!

That would be a much better approach.

What is a "back tensioned", anyway?

It goes on opposite a front tensioner.

Speaking of which, this seems to work decently, or at least
repeatably:
http://www.amazon.com/Gates-91132-Be.../dp/B000CRDLZM

I haven't rigged up a calibration load yet.

On Mon, 17 Nov 2014 13:15:20 -0500
Bob Engelhardt wrote:

On 11/17/2014 12:45 PM, Leon Fisk wrote:
Seems like you said it was the horizontal 6.5hp. If so they are still
selling them for $99 with coupon (ask if you need one). ...

That's the one. $120 now, less 20% would be $96. But given my
experience with this one, I would probably get a used B&S or Honda.
Failed-pump pressure washers seem to be a good source for horizontal
shaft engines. Here's one:
http://boston.craigslist.org/nos/grd/4730588264.htm

Read the fine print on your 20% off coupon. I don't think it will work
on "Predator" stuff... Here is one of the $99 coupons:

http://widgets.harborfreight.com/wsw...tm_source=1031

Both Honda and B&S have different quality lines. The cheap stuff may be
no better than HF nowadays. Make sure you research the model
numbers/prices first...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

On 11/17/2014 1:59 PM, Steve W. wrote:
Check around for a Honda motor of the same size. A lot of folks in the
cart world have been interchanging the parts as bolt ons. Crank, rod,
piston are supposedly direct interchange.

Good to know. Thanks.

On 11/17/2014 2:14 PM, Jim Wilkins wrote:
"Bob Engelhardt" wrote in message
....
What is a "back tensioned", anyway?

It goes on opposite a front tensioner.

Jim!

Wait a minute ... a belt travels onto a pulley at its front and exits
the pulley at the back, yes? If so, I got it. If not, not.


Speaking of which, this seems to work decently, or at least
repeatably:
http://www.amazon.com/Gates-91132-Be.../dp/B000CRDLZM

Years ago I wanted to check the belt tension on my compressor and didn't
see anything like what you referenced. So I made my own:
http://www.mwdropbox.com/dropbox/BeltTensionGauge.pdf

Bob

"Bob Engelhardt" wrote in message
...
On 11/17/2014 2:14 PM, Jim Wilkins wrote:
"Bob Engelhardt" wrote in message
...
What is a "back tensioned", anyway?

It goes on opposite a front tensioner.

Jim!

Wait a minute ... a belt travels onto a pulley at its front and
exits the pulley at the back, yes? If so, I got it. If not, not.


Speaking of which, this seems to work decently, or at least
repeatably:
http://www.amazon.com/Gates-91132-Be.../dp/B000CRDLZM

Years ago I wanted to check the belt tension on my compressor and
didn't see anything like what you referenced. So I made my own:
http://www.mwdropbox.com/dropbox/BeltTensionGauge.pdf

Bob

You did a very nice job on it.

This past weekend while I was digging through tool boxes for something
to extract a spark plug boot from its secret hideaway behind the
intake manifold I found a pencil-type tension gauge that appears to
work on the same principle, if I would just cut out the radiator
support to view it from the proper angle. The Krikit has the
advantages of signalling the correct application force by feel and
sound, and holding its reading until reset. It agreed reasonably
closely to the quarter-turn test which is how the dealership mechanics
set belts.

I asked a service manager about the proper tool and suffered through a
runaround that everyone was too busy to help me. On the way out I
found them clustered around the Snap-On truck and got the real answer.
-jsw

"Bob Engelhardt" wrote in message
...
On 11/17/2014 2:14 PM, Jim Wilkins wrote:
"Bob Engelhardt" wrote in message
...
What is a "back tensioned", anyway?

It goes on opposite a front tensioner.

Jim!

Wait a minute ... a belt travels onto a pulley at its front and
exits the pulley at the back, yes? If so, I got it. If not, not.

Seriously, the force a belt transmits appears as the difference
between the tensions on the pulled and the return sides, so a
tensioner on the back or return side suffers less abuse.
-jsw

On Mon, 17 Nov 2014 13:21:26 -0500, Bob Engelhardt
wrote:

On 11/17/2014 12:46 PM, wrote:
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine - but
it does save the engine - and you can make all the other failure prone
parts!!!

That would be a much better approach.

What is a "back tensioned", anyway?



Tensioner running on the flat of the belt- back tensioning increases
the wrap around the pully where a regular tensioner would reduce the
wrap. Back tensioner goes on the slack side of the belt. (also the
most common way of tensioning a belt other than some equipment that
pivots the motor mount or slides the motor on the mount for a fixed
tension)

On Mon, 17 Nov 2014 14:02:54 -0500, "Steve W."
wrote:

wrote:
On Mon, 17 Nov 2014 12:36:24 -0500, Bob Engelhardt
wrote:

I was back at the leaves yesterday, with the freshly repaired vac. At
the end of the day, and the end of the leaves (almost), this happened:
http://home.comcast.net/~bobengelhardt/DSCF1170.JPG

In case it isn't obvious, that is the end of the HF engine crankshaft!
It was quite an alarming event: a heavy steel impeller, running 3000
rpm, coming off and bouncing around inside its housing!

The engine was only $100, but it also only ran 10 - 15 hours before
falling apart. Unfortunately, those hours were over a 3 year period and
I'm SOL on any warranty.

I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Sigh

Bob
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine - but
it does save the engine - and you can make all the other failure prone
parts!!!


Wonder if you could cut the crankshaft a bit short, then install a stub
shaft out to a carrier bearing mounted on the other side to help carry
the load?
and beat the heck out of a Lovejoy coupler every 10 hours or so - - -

wrote:
On Mon, 17 Nov 2014 14:02:54 -0500, "Steve W."
wrote:

wrote:
On Mon, 17 Nov 2014 12:36:24 -0500, Bob Engelhardt
wrote:

I was back at the leaves yesterday, with the freshly repaired vac. At
the end of the day, and the end of the leaves (almost), this happened:
http://home.comcast.net/~bobengelhardt/DSCF1170.JPG

In case it isn't obvious, that is the end of the HF engine crankshaft!
It was quite an alarming event: a heavy steel impeller, running 3000
rpm, coming off and bouncing around inside its housing!

The engine was only $100, but it also only ran 10 - 15 hours before
falling apart. Unfortunately, those hours were over a 3 year period and
I'm SOL on any warranty.

I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

Sigh

Bob
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. But on a 3 gang pulley with a back tensioner
and all the stress is taken off the "expensive bits" I know, it
doubles the cost of the project, beyond the price of the engine - but
it does save the engine - and you can make all the other failure prone
parts!!!

Wonder if you could cut the crankshaft a bit short, then install a stub
shaft out to a carrier bearing mounted on the other side to help carry
the load?
and beat the heck out of a Lovejoy coupler every 10 hours or so - - -


The stub would go into the hub of the impeller and simply extend the
crankshaft out to the bearing.
If the shaft is threaded inside, the extension could be machined to
thread into place to make it more secure.


--
Steve W.

On 11/17/2014 12:46 PM, wrote:
One good reason to have the impeller on a "spindle" shaft and belt
drive it off the motor. ...

And ... an outboard bearing on the engine shaft to take the radial stress.

On 11/17/2014 12:36 PM, Bob Engelhardt wrote:
...
I've emailed HF Customer Service for the part and even if it has to ship
from China, I'll be glad for it. But I'm not optimistic about it being
available.

HF: "Part not available"

But a guy on eBay parts out "freight damaged" HF engines. Crankshaft is
$42 shipped.

I have 3 alternatives:

1. A new crank: $42 delivered. Several hours to R&R. It's still HF.

2. A used Honda engine: $70, 2 hrs to pick up. May require some fitting
to the vac. It's _used_.

3. A new HF engine: $114 delivered. Bolt on. I'd have the old for
spare parts. It's _HF_.

What to do, what to do?

Bob