Silo blower converted to leaf blower

[tommu56]

Just wondering if anyone has any ideas about pully sizes to use with 540? i got mine built and now it wont blow leaves very well. I dont think its over spinning it, i dont think i got enough speed. I got a 12" pull on the pto side(540 pto) and a 4" on the fan. So i figured it should be turning it 1-3 and at pto speed should give me about 1500 rpm(aprox). I built a duct to dirrect air but it didnt seem to help much. Any input would help as im lost now.

Just guessing most fans run faster than that but it is all in the blade design.
That fan might be for high volume and you might need high pressure.
A smaller nozzle might give you the pressure but again the fan design curve dictates what you can get out of it.

my friends woods belly mower has like a 20" pto wheel and 4 or 5' on the spindle to get the mower blades at the correct speed.

tom

 

[GE222]

Keep in mind that a furnace blower, while it can have a relatively high volume is designed for low velocity to keep the noise at a minimum. A silage blower has high volume, but also has high pressure for moving heavy material up to the top of the silo.

 

[204saskman]

No one has an idea about the pully sizes?

Thanks

 

[cmhyland]

I think you can determine pulley size by finding out what the original power was for the blower. If the original power was an engine, then I think you can assume 3000 to 3500 RPM.
If that is the case your running half the speed. 12 inch drive pulley to 4 inch driven pulley is 3 to 1 so the driven shaft is running 1620 RPM. My guess is your running your blower at half or less than it's intended input shaft speed. Sounds like you need a 24 inch drive pulley.

Regards,
Chris

 

[204saskman]

I think you can determine pulley size by finding out what the original power was for the blower. If the original power was an engine, then I think you can assume 3000 to 3500 RPM.
If that is the case your running half the speed. 12 inch drive pulley to 4 inch driven pulley is 3 to 1 so the driven shaft is running 1620 RPM. My guess is your running your blower at half or less than it's intended input shaft speed. Sounds like you need a 24 inch drive pulley.

Regards,
Chris

Thats what i was trying to figure out Well now i had an idea. So i have a 12" main pully can i got down to a doubloe pully say a 4" with a second 12" back down to a 4" That would double the speed would it not. I would just go to one size bigger pully on the main but my main drive pully is welded to the shaft as i got it off an old pto driven grain auger. Im going out to the scrap yard tonite to look and see if i can find a 20" or bigger pully. But if not i might have to just try my idea. My leaves are starting to fall like crazy now so i would like to try and get this thing working.

 

[leonz]

About your leaf blower:

The formulae for deterimining the pulleys needed are the following:


Driven R.P.M. = Motor pulley diameter divided by driven pulley diameter times motor R.P.M.

Motor R.P.M.=Driven pulley diameter divided by motor pulley diameter times driven R.P.M.


Motor pulley diameter=driven R.P.M. divided by motor R.P.M. times driven pulley diameter.


Driven pulley diameter=motor R.P.M. divided by driven R.P.M. times motor pulley diameter.

You want very small identical pulleys on both the PTO shaft stub of the silage blower and the tractor stub to accomplish this.

So if you used a six inch pulley on the P.T.O., stub of the tractor and a six inch pulley on the silage blower in the example.


6 inches divided by 6 inches times 540 r.p.m., equals 540 rpm at the silage blower PTO stub.

As long as you can find or buy the identical size V belt pulleys with the 540 R.P.M., female splines you will be fine.


Also please remember the roller bearings on the silage blower are not high speed bearings. I do not want you to have a surprise bearing explosion.

 

[204saskman]

About your leaf blower:

The formulae for deterimining the pulleys needed are the following:


Driven R.P.M. = Motor pulley diameter divided by driven pulley diameter times motor R.P.M.

Motor R.P.M.=Driven pulley diameter divided by motor pulley diameter times driven R.P.M.


Motor pulley diameter=driven R.P.M. divided by motor R.P.M. times driven pulley diameter.


Driven pulley diameter=motor R.P.M. divided by driven R.P.M. times motor pulley diameter.

You want very small identical pulleys on both the PTO shaft stub of the silage blower and the tractor stub to accomplish this.

So if you used a six inch pulley on the P.T.O., stub of the tractor and a six inch pulley on the silage blower in the example.


6 inches divided by 6 inches times 540 r.p.m., equals 540 rpm at the silage blower PTO stub.

As long as you can find or buy the identical size V belt pulleys with the 540 R.P.M., female splines you will be fine.


Also please remember the roller bearings on the silage blower are not high speed bearings. I do not want you to have a surprise bearing explosion.

Im using a furnace blower not the silo blower. I was gonna build a silo blower but i couldnt find a 540 one.

 

[204saskman]

So got my blower all weled up. It was working good, just one issue. I think the old furnace blower i bought was in a flooded basement cause the cage blew off the shaft. So now i need to find one that has a bigger shaft and a stronger fan. Before it blew up, it sure was blowing the dirt chunks in my shop floor around. It was pretty impressive.

 

[medic1050]

I know this is kinda like a thread hijack but one of the flail mower converts. Yesterday I used my flail mower while reversing to blow the maple leaves from my lawn. It has rained steady for 2 weeks and only been dry for 2 days with rain again for today. It mower easily blew the top layer of dry leaves and picked up, mulched and blew out the compacting wet leaves. I blew all the mulched leaves into windrows at the edge of the bush line then ran over them with the mower going forward.

While I am never ceased to be amazed by the ingenuity and the technical expertise of my fellow TBNers I wanted to potentially save someone like me some fabrication time if they already had a flail mower.

 

[Cantoo]

I've bought real leaf blowers at auctions before for less than $100. I also have a 16hp leaf vac loader that I paid $500 for, like new.