# Impeller rpm



## JAYJAY (Nov 8, 2017)

hey guys 

does anyone knows how fast can you make a old noma impeller turn as rpm by changing the pulley? 
original is 3 inch from motor and 8 inch on impeller.

thanks


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## e.fisher26 (Nov 6, 2016)

Now that is one awesome rig


——————————————
Noma 10/29
Cub cadet 5/26 conv to 8/26
Toro 8/24
Husqvarna st230p


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## RedOctobyr (Mar 2, 2014)

What are you asking? The max achievable impeller RPM? That just depends on how big an engine pulley you want to buy. You could also change the pulley at the impeller, but I expect the engine pulley would be easier to change, since crankshaft-mount-style pulleys are likely more common.


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## JAYJAY (Nov 8, 2017)

well i have 2 belt, one from the motor that is 17.5 hp going to a straight shaft with a 3 inch pulley the same size as the crankshaft on the motor then on the same shaft i have another 3 inch pulley with a belt that goes on both 8 inch pulley for the impeller. my question is if i change the pulley size on the shaft from 3 inch to ex... 5 inch that will make the impeller on both blower turn faster will the blower hold the rpm? because right now if the calculation is right with the 3 inch pulley i should have around 1300 rpm at the impeller. if i put a 5 inch i should get 2100 rpm. is this to much or should i stay with a 3 inch. if i was able to upload a video you will see exactly my setup.


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## e.fisher26 (Nov 6, 2016)

More speed less power


——————————————
Noma 10/29
Cub cadet 5/26 conv to 8/26
Toro 8/24
Husqvarna st230p


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## leonz (Dec 12, 2014)

If you can use a digital non contact tachometer that will help you a lot as you would want 540 RPM with your set up as long as you have plenty of torque to transmit through the V belt drive. 

The transmission of any engine power through V belts is only improved with the use of a flywheel using the disc type wood chipper as the best example. 

SO its going to be a case of trying the beast in real world conditions and then take it back to the garage laboratory.


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## RedOctobyr (Mar 2, 2014)

For context, most Ariens blowers are around 1100-1200 RPM. With their impeller diameter, that's one point of comparison. 

Unless your impeller diameter is much smaller, then 1300 already sounds somewhat high, to me. 2000+ seems like too much, in my opinion. 

You have a powerful engine, but it's driving 2 blowers (what width are they?). Granted, it's not also powering a drive system, but still, I'm not sure that you just have tons of extra power "to burn".

A larger pulley from the engine will transmit less torque to the impeller/auger. 

leonz, where are you getting 540 RPM? Without a bit more info, at least, that sounds rather arbitrary, and quite low, for an impeller speed.


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## leonz (Dec 12, 2014)

Hello RedOctober,

I am using the rear 540 RPM power take off speed of subcompact and compact tractors in the example. In this case either 540 RPM or 1000 RPM is used for rear mounted tractor snow blowers, The bloody front mounts have to use the mid mount PTO set up and either a belt drive or propeller shaft to a reversing gearbox to make them work.

He is using a long V belt drive with snubber and V belt guide pulleys and his motor may not be large enough to provide the torque needed as is. 

If he can spend some time visiting the electric motor web sites to determine the needed pulley sizes for the required speeds he will spend less time and money.


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## JAYJAY (Nov 8, 2017)

RedOctobyr said:


> For context, most Ariens blowers are around 1100-1200 RPM. With their impeller diameter, that's one point of comparison.
> 
> Unless your impeller diameter is much smaller, then 1300 already sounds somewhat high, to me. 2000+ seems like too much, in my opinion.
> 
> ...


27 inch each


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## JAYJAY (Nov 8, 2017)

leonz said:


> If you can use a digital non contact tachometer that will help you a lot as you would want 540 RPM with your set up as long as you have plenty of torque to transmit through the V belt drive.
> 
> The transmission of any engine power through V belts is only improved with the use of a flywheel using the disc type wood chipper as the best example.
> 
> SO its going to be a case of trying the beast in real world conditions and then take it back to the garage laboratory.


yeah i know dont have one. how to a transmit more torque from the engine already have a 3 inch pulley on the crankshaft


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## JAYJAY (Nov 8, 2017)

leonz said:


> Hello RedOctober,
> 
> I am using the rear 540 RPM power take off speed of subcompact and compact tractors in the example. In this case either 540 RPM or 1000 RPM is used for rear mounted tractor snow blowers, The bloody front mounts have to use the mid mount PTO set up and either a belt drive or propeller shaft to a reversing gearbox to make them work.
> 
> ...


ive been try it out a few time but i have a belt slippering issue and i just found the problem still did fix it but in a few inch of snow it throw the snow at 1300 rpm but in more snow the belt slip so i still dont know how it will work


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## nwcove (Mar 2, 2015)

At 2100 rpm your impeller may become an imapler !


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## JAYJAY (Nov 8, 2017)

here's a picture with the straigth shaft with the 2 pulley for each belt the blue one come from the motor and the black one goes to the impeller they all 3 inch from the motor so technically should have to same rpm well roughly to the 3 inch pulley for the black belt.


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## JAYJAY (Nov 8, 2017)

nwcove said:


> At 2100 rpm your impeller may become an imapler !


sorry im french so i dont know what impaler means


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## JAYJAY (Nov 8, 2017)

leonz said:


> Hello RedOctober,
> 
> I am using the rear 540 RPM power take off speed of subcompact and compact tractors in the example. In this case either 540 RPM or 1000 RPM is used for rear mounted tractor snow blowers, The bloody front mounts have to use the mid mount PTO set up and either a belt drive or propeller shaft to a reversing gearbox to make them work.
> 
> ...


what's the address of the website so i can take a look


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## RedOctobyr (Mar 2, 2014)

leonz said:


> Hello RedOctober,
> 
> I am using the rear 540 RPM power take off speed of subcompact and compact tractors in the example.


I don't think those are a great comparison, unless: 
- those machines are turning their impellers directly at 540 or 1000 RPM 
- *and* their impellers are the same diameter as the ones on this setup

Barring better info, I'd argue that impeller tip speed is a better comparison than impeller RPM. I'm guessing a sub CUT or CUT blower impeller will be larger than a walk-behind impeller. 

A larger diameter impeller can turn more slowly, and still do its job, like throwing the snow a certain distance. Think of like a normal room fan for air, a larger diameter fan can turn more slowly, to move the same amount of air. 

Just comparing RPM, without also knowing/comparing impeller diameter, is not really a "fair" comparison, in my opinion. 



JAYJAY said:


> yeah i know dont have one. how to a transmit more torque from the engine already have a 3 inch pulley on the crankshaft


You can use 2 pulleys and two belts, as one example of how to transfer more torque. 



JAYJAY said:


> here's a picture with the straigth shaft with the 2 pulley for each belt the blue one come from the motor and the black one goes to the impeller they all 3 inch from the motor so technically should have to same rpm well roughly to the 3 inch pulley for the black belt.


I'm having a hard time understanding what's going on, from this picture. If you could post a few more, showing what the different pulleys and shafts are doing, that would help. If the pulleys are all the same size, why are there 2 shafts and 2 belts? With the same size pulleys, you're not changing RPM, so are you doing something like reversing the direction of rotation? 

I'm assuming that the obvious things are all correct, like making sure that your idler (tension) pulleys are not installed on the power-transmitting side of the belt (the side of the belt that is under tension, between the engine and the load).


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## JAYJAY (Nov 8, 2017)

RedOctobyr said:


> I don't think those are a great comparison, unless:
> - those machines are turning their impellers directly at 540 or 1000 RPM
> - *and* their impellers are the same diameter as the ones on this setup
> 
> ...


i have a video when its running but i guess i cannot upload it here.
the reason i did this setup its because the crank shaft of the motor is downward instead of being on the side like a 10hp.
so that's why i put a shaft with 2 pulley because i would have to put a belt about 200 inchs and i have to twist the belt some places because of the pulleys(maybe i could found another way but that was the result was).
so i keep the same pulley size from the engine and and the one on the shaft like it was a side crankshaft(talking about the last pulley with the black belt that is going to the impeller pulley. (in my head this settup should be the same rpm or close to the last 3 inch pulley like if it was a 10hp normal snowblower). if you could see the video you would understand right away


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## RedOctobyr (Mar 2, 2014)

Maybe you could upload the video to YouTube, or a service like imgur.com?


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## JAYJAY (Nov 8, 2017)

​


RedOctobyr said:


> Maybe you could upload the video to YouTube, or a service like imgur.com?


let me try on youtube


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## JAYJAY (Nov 8, 2017)

JAYJAY said:


> ​
> let me try on youtube


here it is


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## drmerdp (Feb 9, 2014)

You got a lot going on there. Getting power from the vertical shaft motor to 2 horizontal pulleys. As someone suggested, buy a cheap laser tachometer and check your actually impeller RPMs. 1300rpm is a very good number, 2100rpm is ridiculously fast. 

If your belts are slipping, then you may need to go to a double drive belt.


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## JAYJAY (Nov 8, 2017)

drmerdp said:


> You got a lot going on there. Getting power from the vertical shaft motor to 2 horizontal pulleys. As someone suggested, buy a cheap laser tachometer and check your actually impeller RPMs. 1300rpm is a very good number, 2100rpm is ridiculously fast.
> 
> If your belts are slipping, then you may need to go to a double drive belt.


im saying 1300 but that is a calculation with number if the motor turn at 3500 rmp. i probably loosing some rpm with all the pulleys.
so i should stick with a 3 inch pulley then.

for the belt the bracket i made for the 2 idler pulley in front of the motor was problably bending the pulley because last time i try with strong tension spring that i put the bracket of the idler bend because i put 1/8 inch steel. so thats what im fixing tonight with 1/4 inch steel for those 2 pulley


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## RedOctobyr (Mar 2, 2014)

JAYJAY said:


> here it is


OK. Wow! As drmerdp said, there is certainly a lot going on! Nice work on getting it all functioning! That is quite a setup. 

Please forgive my questions if I've misunderstood what is being shown. The video is definitely helpful, but it moves around a lot, and doesn't spend much time just viewing the pulleys from different angles, looking at the same view for 5-10 seconds  So I had to watch it several times and try to pause at views that showed what I was trying to see. I may have misinterpreted what it's doing. 

My first thought was that you're using a single pulley to drive *two* snowblowers. By contrast, some powerful Ariens blowers (but still smaller than this 17hp! engine) use 2 pulleys to drive a single snowblower. So you are putting a much, much larger load on this single belt. Making it more likely to break, in addition to slip. 

Putting 2 pulleys on each snowblower impeller might be difficult. But perhaps you could put 2 drive pulleys on your shaft, and use 2 belts to the blowers? That way, at least your output belt would only be driving 1 blower per belt. Your blue input belt from the engine would still be a challenge, though. 

I attached a few pictures. I'm still trying to make sure of where your spring-loaded idler pulleys are located along the path of the belts. The idler should usually be on the "loose" side of the belt. Not the side that is under tension, driving the load. 

If it's on the "loose" side, even as the load increases, the belt should not be making the idler pulley move (fighting the spring). And you want the idler to help keep the belt wrapped around the driving or driven pulleys, for more grip. If the spring-loaded idler is on the "tight" side, then the belt might un-wrap from the pulley, just as the load increases, which would only make the problem worse. 

In the first picture, the red arrow shows what direction your impeller belt is presumably spinning. The blue arrow shows what I'd expect to be the "loose" side of the belt. This is the belt area where I'd think you'd want your spring-loaded idler. 

In the second, I circled a blower idler pulley in blue, labeled A. Is this a spring-loaded idler? This area would be under tension, I think (the "tight" side of the belt). So under a load, if this idler is on a spring, it will move as the load increases. I think you'd want the moving idler to be located on the "loose" side of the belt. 

In the third, I circled a black engine idler pulley in blue, labeled B. I'm sorry, it is not a very good view in this picture. This one appears to be a spring-loaded idler, I think. Is that correct? It seems to me like this side of the belt would be under tension, as the "tight" side of the belt. Maybe I'm wrong. But if so, it does not seem like an ideal place for the spring-loaded idler, I would have expected you'd want it on the "loose" side of the belt. 

Again, forgive me if I have misunderstood how this is all working. And please don't take any of this as negative. I'm just trying to better understand the problem you're facing, and how it could be managed.


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## JAYJAY (Nov 8, 2017)

RedOctobyr said:


> JAYJAY said:
> 
> 
> > here it is
> ...


Tx for the comment and the info but I'm not sure if I understand the loose side. But I will post another video tonight just about the pulley and the belt. Your are right about all 3 picture. And don't worry I'm not taking this as a negativity. Don't forget I build this from scratch with just my brain lol. And I'm limited from where I can put the tensioner also. Because the belt is twisted from pulley to another pulley.


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## RedOctobyr (Mar 2, 2014)

About the idlers, I was trying to find some info/guidelines online about proper idler pulley locations, as a reference. I didn't find much, unfortunately, but I did find this: 

https://www.pooleyinc.com/pdf/PTP Installation Maintenance & Troubleshooting Guide.pdf

Take a look at page 15, "V-Belts Installation Guide". It at least shows some information on locations for idlers, along with size suggestions. 



I marked up one of their diagrams, to show the names that I was using, to relate my names for areas to an actual diagram. The idler pulley is the one in the middle, of course.


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## leonz (Dec 12, 2014)

JAYJAY said:


> what's the address of the website so i can take a look



Hello JAYJAY,


One site is Industrial Parts | Varidrive | US Motors | NIDEC, another is www. engineering toolbox.com


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## JAYJAY (Nov 8, 2017)

New video https://youtu.be/WJOn_7azcNA


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## JAYJAY (Nov 8, 2017)

https://youtu.be/WJOn_7azcNA


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