sickle mower mid mount on Super A

crlndy · Feb 13, 2013

I managed to find a Kosch sickle mower (belly mount) for my Super A, but am missing the belt pulley that goes on the PTO shaft. I contacted Kosch and was told they still manufacture the pulley, but it is 12 3/4" in diameter. Because the Super A is off centred, the PTO shaft is only about 4" from the rear left fender, which means I need a pulley no more than 8" diameter. Can anyone confirm what diameter the belt pulley is on their mowers?

William Eccles - Jardine · Feb 13, 2013

You have just said that you need to have a smaller driver pulley you may also need to reduce the size of the driven pulley to keep the same speed ratio. Just a note to consider. check belt pulley and gear tables for ratio and speed functions. Machinery hand dook ant the library.

edward will · Feb 13, 2013

Hello
As I remember: SD = sd Where speed x dia of large = speed x dia of small. so if you switch to an 8 in driver you have to increase driven pulley by 1/3. just my thoughts. Ed Will

edward will · Feb 13, 2013

Hi I made an error in saying to increase the size of driven pulley which should be decrease. so dia are in ratio. sorry Ed Will

Dave Sherburne NY · Feb 13, 2013

This site will figure the diameter of the pulleys you need. I would be afraid that you might have to make the driven pulley so small that the pulley wouldn't have enough surface area and the belt would slip. If you can shift down a gear or two maybe you can leave the driven pulley alone. OR go to chain drive.
Pulley and belt info

Dave Sherburne NY · Feb 13, 2013

Can you take that PTO shield off the tractor and get a larger pulley on the tractor. Then you could fabricate a guard to cover the pulleys and belt

mkirsch · Feb 13, 2013

Judging by the size of that driven pulley in the picture, a 12-3/4" diameter drive pulley would have the sickle moving at LIGHT SPEED.

The driven pulley on my International A-22 belly mount sickle mower is about the same size. The drive pulley isn't more than 8" in diameter.

I think Kosch people were looking at the wrong parts book. Unfortunately it appears that they do not have their parts books online.

crlndy · Feb 13, 2013

My understanding is that the IH A-22 driven pulley is about 5" and the drive pulley about 8". The Kosch mower driven pulley is about 7 1/2", so I figure the drive pulley should be about 10+" but I am not sure even that would fit! Can I ask how close your pulley is to your rear fender? Do you think a larger pulley would even fit?

LMack · Feb 13, 2013

Circumference of a pulley = Pi x dia. Speed = Distance over time. If the large pulley is 10" the circumference is 10pi. If the smaller pulley is 5" the circumference is 5Pi and time is the same for both. So the speed difference between the large pulley is 10Pi/5Pi or 2 in this case. The smaller pulley turns twice as fast as the larger for this example. Put the diameter of the large pulley over the diameter of the smaller pulley and you will have the speed ratio as long as there is no slippage.

gene bender · Feb 14, 2013

Can they tell you what the input shaft on the mower is supposed have in RPMs for the mower to operate good. That set-up will not have a large pulley on the PTO as there just isnt enough room. Does the input shaft go to a gear box and whats its ratio of the input to the out put. If the out-put is greater than the input you sure dont need a huge pulley on the PTO

sickle mower mid mount on Super A

crlndy

New User

William Eccles - Jardine

Member

edward will

Member

edward will

Member

Dave Sherburne NY

Well-known Member

Dave Sherburne NY

Well-known Member

mkirsch

Well-known Member

crlndy

New User

LMack

Member

gene bender

Well-known Member

Similar threads