need math help

Leroy · Jan 2, 2018

drive gear of 33 teeth to driven gear of 12 teeth against drive gear of 30 teeth to driven of 15 teeth. I think the 33-12 tooth is faster on driven but not sure and how much faster is one over the other?

Steve@Advance · Jan 2, 2018

The 33-12 is 33/12= 2.75 to 1 ratio.

The 30-15 is 33/15= 2.2 to 1 ratio.

The 33-12 will drive the smaller gear slightly faster.

Steve@Advance · Jan 2, 2018

Lets try this again, sorry.

The 33-12 is 33/12= 2.75 to 1 ratio.

The 30-15 is 30/15= 2 to 1 ratio.

The 33-12 will drive the smaller gear slightly faster.

Andy Martin · Jan 2, 2018

You don't really need math here. 33/12, whatever the output is, if you only change the input 30/12 will be slower output than 33/12. So 30/15 is a lot slower.

If you want to calculate output speed you divide the input by the output, that's 2.75, so the output is 2.75 times the input. If it were 30/12 the output would be 2.5 times the input. 30/15 is easy, 2 to one. Even 30/11 is still slower than 33/12, output is 2.73 times input.

Leroy · Jan 2, 2018

Thanks. Considering putting a Deere rake 4 bar real in a 3 bar frame, the 3 bar frame is high steel wheels, and the 33-12 is what is in the 3 bar with the 30-15 the 4 bar so real would run slighter faster doing that than factory but I don't think it would be too much faster to make trouble. 3 bar rakes just do not sell and 4 bar on low rubber the same but take the 4 bar on low rubber real and put it in the 3 bar frame you would have the model that does sell but without changing out gears as well the real would just run a bit faster but in heavy hay I don't think it would make trouble. A 4 bar rake on steel is what sells and they are getting very hard to find.

guido · Jan 2, 2018

Hello Leroy,

Also torque will be in proportion of the ratio. The lower the ratio, smaller driven year, the higher the torque on that gear. I don't know if that would be an issue in your case?

Guido.

Leroy · Jan 2, 2018

Just want to make sure the bars are not spinning too fast to beet the hay too much while raking but are spinning fast enough to do the job.

guido · Jan 2, 2018

Hello Leroy,

Having sheer pins in the system was my concern. Sounds like all is well,

Guido.

Leroy · Jan 2, 2018

The hay rakes of the 30's, 40's & 50's did not come with shear pins. The rakes up to 47 were 3 bar on steel wheels and after that 4 bar on steel or a low wheel rubber tired version. We have several 3 bar versions that do not sell and may have real problems. I have bought 2 of the rubber tired versions that I can put the reals into the frame of a 3 bar rake and have the version that the Amish want. My only consern was will I have to tear down the gear box to change the gears as well or will the slightly different real speeds work OK as in not being either too slow or too fast.

ed will · Jan 2, 2018

Hi, iirc. Speed ? diameter of drive gear = s ? diameter of the driven gear. Quite easy. Ed Will Oliver BC

need math help

Leroy

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Steve@Advance

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Steve@Advance

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Andy Martin

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Leroy

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guido

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Leroy

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guido

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Leroy

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ed will

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