Leaf Blower

[peter lena 8,610]

@JoeM  used pillow block bearings on all of our , vertical  belt  / bucket conveyors  , also on  bush vacuum pumps , ran 24/7 , that belt tensioner , pulley should also have  BEARING CLEAN OUT / RE GREASE .LUCAS  H/D OR MARINE  GREASE . on that spring tensioner , if its drawn with a TURNBUCKLE , you can dial in a perfect  tension . @Racinbob  like stated , make improvements as you go , think you will be surprised . at how easily rotational equipment  can function . pete

[JoeM 7,873]

I was just more or less thinking of the running environment. Those oiled bushings run in a mostly clean filtered air. The pillow blocks are sealed and grease-able. It doesn't take a lot of dust to wear that bushing and or shaft.

 

As far the air outlet. That fan is air pump and when choked to a certain point it will go into a stall. And that is it and you can't no more.

If you going to put effort in a custom sheet metal work and fabrication, why not make it so you get maximum air flow that is direct able. If you want less cfm reduce the rpm. 

 

 

[Ed Kennell 38,138]

2 hours ago, Racinbob said:

 

I'm not necessarily looking for max volume for what I'm doing. To move leaves (and apparently sidewalks and cats) I'm thinking a sweet spot of volume and velocity. Choking down an outlet on a whole house system basically redirects the air to another opening rather than increasing the velocity. Does that sound even partially right @WHX?? The guys do have me convinced to go 8" instead of 6".

I originally had mine swing mounted using the weight of the blower to maintain belt tension.    The I didn't like the bouncing blower on my front end, so I switched to a rigid mount and added one idler tensioner pulley.   That worked much better.   Just be sure to put the tensioner on the bottom loop of the drive belt.   I had an 8" adjustable 90 ell on mine that allowed me to adjust the angle and height of the discharge.

Even with the large pulley on my blower I only ran the engine at 1800 and I had plenty of velocity to move leaves.    My blower was probably cranking around 1K.

 

 

 

[Racinbob 11,050]

16 minutes ago, Ed Kennell said:

I originally had mine swing mounted using the weight of the blower to maintain belt tension.    The I didn't like the bouncing blower on my front end, so I switched to a rigid mount and added one idler tensioner pulley.   That worked much better.   Just be sure to put the tensioner on the bottom loop of the drive belt.   I had an 8" adjustable 90 ell on mine that allowed me to adjust the angle and height of the discharge.

Even with the large pulley on my blower I only ran the engine at 1800 and I had plenty of velocity to move leaves.    My blower was probably cranking around 1K

 

That's my first choice of tensioner Ed. Clean and simple. I like what I'm hearing on the rpm of both the engine and blower. I'd prefer slowing the engine down a bit. Jim said I should hold the max rpm of this blower to about 1800. With the pulley I have that would be max engine rpm. Backing it down a bit would be great. 

[87 416-8 horse 420]

I had the exact same blower on mine. I had a little smaller pulley that I put on it and that was a bad idea. The drum ended up in pieces. Also make sure you have a big enough outlet because I only had a 6 inch 90 and that didn't help. For the tensioner I used the weight of the blower and I had no wobble.

[jay bee 896]

I’m thinking of using this method!!!

[Racinbob 11,050]

I'm really happy with the way it's coming together. I changed my mind about using angle to extend the frame and used the flat plate that was on the frame. This thing is heavy. To make things easier I added casters, two fixed under the blower and one go-roundy in the rear. The idler is going to be duck soup. A rope measurement tells me that 68" is a good start. I have a trip to town scheduled for Friday to pick up a few things. Since you guys talked me into an 8" discharge making a custom piece will be less beneficial so I might just pick up over the counter tinwork for it. I'll pick up an 8" to 6" reducer just to experiment. 

 

[Racinbob 11,050]

Got her done! A 72" belt was perfect without a tensioner. There's about 1/2" adjustment available where the pillow blocks mount to the frame. I really couldn't give it a good test because the leaves are drenched. I'm glad I started with 8" but I'm sure I'll want to take it to 6" (second pic) to increase velocity and I'll experiment with 4". Based on pulley sizes at wot it should be spinning at about 1800 rpm. It moves a lot of air but it also seems to be loafing. As heavily built as this is I think I could safely get more. I'll experiment with the velocity first. 

 

[8ntruck 6,998]

On 3/28/2024 at 2:04 PM, jay bee said:

I’m thinking of using this method!!!

Somebody here said that they had one of those 2 cycle Toro snow blowers, mostly to make noise and annoy the neighborhood.  That 'leaf blower' has it all over the 2 cycle Toro in the noise making and annoying the neighbors department!

Edited April 12 by 8ntruck

[953 nut 55,189]

5 hours ago, Racinbob said:

I'm glad I started with 8" but I'm sure I'll want to take it to 6" (second pic) to increase velocity and I'll experiment with 4"

         I don't think the velocity will make up for the volume of air that won't be moved. I think that type of fan will be inefficient with a smaller duct size. @WHX??, what can you add on this subject?

[Handy Don 12,213]

5 hours ago, Racinbob said:

I'll experiment with the velocity first.

Eye and ear protection, please!

[Racinbob 11,050]

40 minutes ago, 953 nut said:

         I don't think the velocity will make up for the volume of air that won't be moved. I think that type of fan will be inefficient with a smaller duct size. @WHX??, what can you add on this subject?

 

I don't know Richard. Could likely be. All the more reason I'm glad you guys convinced me to start with 8". Once things dry up I'll see what happens and report back 

[Racinbob 11,050]

42 minutes ago, Handy Don said:

Eye and ear protection, please!

Noise certainly isn't a problem. I can't hear it run over the engine noise. 

[WHX?? 48,814]

2 hours ago, 953 nut said:

         I don't think the velocity will make up for the volume of air that won't be moved. I think that type of fan will be inefficient with a smaller duct size. @WHX??, what can you add on this subject?

No it won't ... velocity will be greater with restriction but greater load on the prime mover. For an electric motor that means higher amps that might damage the motor. No worry like that with a gasser but fan efficiency is definitely decreased.

[Racinbob 11,050]

Here's the verdict. I had to go to the edge of the woods to get to enough leaves which made them somewhat harder to move. I ran a pass with the three options, 8", 6" and 4". The clear winner was the 6". Actually by quite a bit. My theory. Leaf blowers are rated by MPH and CFM. I have two and both of them have nozzles that will give them more 'power' by reducing down and increasing the velocity. But they are designed from the ground up to be leaf blowers. This tractor blower isn't designed to be a leaf blower. My thinking is that a squirrel cage blower isn't designed for high velocity. It's designed to move air through a home system with minimal restriction. I'm thinking it needed to be a compromise. Starting with the style sheetmetal fitting with the 8" outlet I used I believe I picked up about all the volume that the blower offered. Reducing it to 6" definitely increased the velocity and it didn't seem to hurt the volume all that much. Going down to 4" really choked things up. 

I'm going to go ahead and swap the 8" pulley for a 6". That will let me experiment with a higher blower rpm as well as allowing me to reduce the engine rpm some. 

[Handy Don 12,213]

12 minutes ago, Racinbob said:

This tractor blower isn't designed to be a leaf blower. My thinking is that a squirrel cage blower isn't designed for high velocity. It's designed to move air through a home system with minimal restriction

Your assessment is completely correct on this. HVAC typically uses volume over velocity for more efficient heat transfer and to limit noise from airflow.