Just some help of hyd motor pick. I got a old sickle moewer from the amish guy on the hill and going to adapit to the Bobby. The sickle mower is a 6 ft mower I need help in picking a good hyd motor for it. I have a 763 pump flow is rated at 15 +. and the second question would you direct connect or use a shaft.
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TriHonu
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- Apr 15, 2007
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Last month, my brother converted a sickle mower to attach to a skidsteer. I spec'd the hydraulics for him.
First, you have to know what gearing is in your sickle. We converted a John Deere Model 50. It has a wobulator head (no pitman) and was originally belt driven from a 540 rpm pto. The original belt drive turned the wobulator at 1080 rpm. The wobulator was geared to move the sickle out and back for each revolution. This gives you 2160 strokes per minute. Assuming the sickle can handle 2 inches of forward movement on each stroke (insuring a complete cut) that calculates to a max forward travel speed of 4 MPH.
We originally wanted to direct drive the wobulator but could not find a motor that would handle the flow and pressure from CAT skidsteer that would produce 1080 rpm. We decided on a Eaton Charlynn 2000 series. It will handle 20 gal/min at 3000 psi, and 908 rpm continuous. The smallest displacement motor in this series is 4.9 cubic inch. It has a bearing on the output shaft to allow side loads so you can mount a pulley or gear drive. We used a belt drive to a jack shaft to gear up the motor speed to our desired rpm.
The down side is the motor has a case drain. I spoke to a Eaton Engineer and he stated you can not exceed 1000 psi case pressure. The CAT machine does not have a case drain line. So we plumbed the motor case drain to a 1000 psi pressure relief valve that dumps to the top of the sickle bar if the motor case pressure spikes. If you plug the case drain and the pressure goes over 1000 psi you will blow the motor seals. You can not just vent the case drain since this motor is designed to flow oil to the case drain during normal operation.
What I am telling you is:
1. You will need to determine what RPM your sickle is designed to run at.
2. You have to find a motor that will handle the 15 gal per minute at the 3000+ psi that your auxiliary circuit puts out.
The smallest displacement in the Charlynn 2000 series is 4.9 cubic inch. With the 15 gal per minute flow on your machine that will translate to just over 600 rpm at full throttle. The next size up is 5.5 cubic inch which would give you about 550 rpm at full throttle.
We purchased our parts from https://www.surpluscenter.com. Our conversion included both a hydraulic motor and hydraulic lift for the sickle bar. The customer primarily wanted to use the sickle with the bar pointed at the sky. He is using it trim the brush and limbs along the sides of the 5 miles of trails through the woods on his property.
We had over $1500 USD in parts for our conversion. (Motor, motor mount, pulleys, belts, 12v selector valve, pressure relief valve, fittings, hoses, flat face couplers, QuickTach plate and steel for the frame).
First, you have to know what gearing is in your sickle. We converted a John Deere Model 50. It has a wobulator head (no pitman) and was originally belt driven from a 540 rpm pto. The original belt drive turned the wobulator at 1080 rpm. The wobulator was geared to move the sickle out and back for each revolution. This gives you 2160 strokes per minute. Assuming the sickle can handle 2 inches of forward movement on each stroke (insuring a complete cut) that calculates to a max forward travel speed of 4 MPH.
We originally wanted to direct drive the wobulator but could not find a motor that would handle the flow and pressure from CAT skidsteer that would produce 1080 rpm. We decided on a Eaton Charlynn 2000 series. It will handle 20 gal/min at 3000 psi, and 908 rpm continuous. The smallest displacement motor in this series is 4.9 cubic inch. It has a bearing on the output shaft to allow side loads so you can mount a pulley or gear drive. We used a belt drive to a jack shaft to gear up the motor speed to our desired rpm.
The down side is the motor has a case drain. I spoke to a Eaton Engineer and he stated you can not exceed 1000 psi case pressure. The CAT machine does not have a case drain line. So we plumbed the motor case drain to a 1000 psi pressure relief valve that dumps to the top of the sickle bar if the motor case pressure spikes. If you plug the case drain and the pressure goes over 1000 psi you will blow the motor seals. You can not just vent the case drain since this motor is designed to flow oil to the case drain during normal operation.
What I am telling you is:
1. You will need to determine what RPM your sickle is designed to run at.
2. You have to find a motor that will handle the 15 gal per minute at the 3000+ psi that your auxiliary circuit puts out.
The smallest displacement in the Charlynn 2000 series is 4.9 cubic inch. With the 15 gal per minute flow on your machine that will translate to just over 600 rpm at full throttle. The next size up is 5.5 cubic inch which would give you about 550 rpm at full throttle.
We purchased our parts from https://www.surpluscenter.com. Our conversion included both a hydraulic motor and hydraulic lift for the sickle bar. The customer primarily wanted to use the sickle with the bar pointed at the sky. He is using it trim the brush and limbs along the sides of the 5 miles of trails through the woods on his property.
We had over $1500 USD in parts for our conversion. (Motor, motor mount, pulleys, belts, 12v selector valve, pressure relief valve, fittings, hoses, flat face couplers, QuickTach plate and steel for the frame).
