Hi all, glad to see everyone is keeping this forum in good shape. I’d like to continue a discussion I started a while ago, now that I have a better Cub understanding from the info on this forum. I’m still interested in using my ‘49 Cub as a small low weight capacity rough terrain forklift capable of lifting 500-700 lbs six feet high. Or, if I could lift 1000 lbs., only 12 inches off the ground and move it that would be good too. I’ve read a lot here and have since become more familiar with the drawbacks that the Cub has for this use. I searched the internet for ideas and types of lifts and have gotten more familiar with what is available.
As some suggested, I’ve looked into using a used 4wd Kubota with a loader or separately putting a lift on it. A used compact all terrain forklift by other brands or even a used ‘power trac’ would be about the same price, and I admit may be a better solution. I realize that just the materials cost to fabricate a lift on a Cub might be about the same or more. I’d sure like to make use of the cub that I have. So, I thought I’d run a few thoughts by those that are adventurous enough to see if this is possible. This is what I’ve come up with so far.
Putting a lift on the front would put too much weight on the front axle and affect steering. Plus a rear counterweight would add to overall weight, which has to be watched with the cub’s limitations. 3800lbs seems to be the forum’s agreeable maximum. Even so, flotation turf tires would be used in front, along with welded gussets to strengthen the front axle.
Mounting a lift at the rear is counterbalanced by the engine plus additional weight. Here the rear final drive is fragile but can be strengthened as was done for the later model Woods mower and Rick Prentiss backhoe. To this type of bracket I imagine attaching an aluminum 12â€x12†heavy duty box truss, similar to http://www.showsolutions.com/pro_series_12_trusses.php ,
as a sub frame that reinforces the cub structure. It would run under the belly of the tractor, also fixed to both sides of the torque tube at the center mounting plate, and to both sides of the receiver at front steering housing. The rear end of the beam is extended beyond the cub and a lightweight forklift is attached to it. This lightweight gusseted box truss will distribute the lift, motion and torque loads evenly, up down and sideways, through the cub’s mounting points, so not to stress one particular area. A post in this forum discussed the deflection forces of the span and sizes and weights involved for a steel ‘I’ beam sub frame running under the cub belly as it extended working weight - like lifting a bale spear or snow blower, I believe. But now I can’t find it. From the numbers that were given I calculated that the aluminum box truss meets that discussion’s requirements. The truss can also be extended beyond the front of the cub and hold counterweights. The cub’s rear rocker arm can be used to tilt the forklift fore and aft. This truss beam would also aid in turning the forklift into a non permanent attachment by easily driving over it then hoist up and mount into position. A steel box truss would be easier to attach, to weld to, and could take a beating but the weight would take away from the overall load capacity of the Cub and forklift. Aside from making one, they are hard to find. What do I need to understand about attaching aluminum to steel, specifically the aluminum box truss to steel brackets and the cub itself?
Operating the lift could be done several ways. The existing TC can lift 400lb loader bucket so should be able to operate a 400lb lift. I have not worked out the details but for 400 lbs I imagine a “carry-all†concept that uses TC to raise the load in 12 inch increments, like an extension ladder. Each 12 inch raise is caught and held by a trip mechanism. The rocker arm is lowered while the load stays in place. The arm catches a new “rung†or chain link type catch, and then raises the load another 12 inches and so on. A simpler version would be to manually set holding pins at 12 inch incremental heights. This may be all the cub forklift can do.
Here is an idea I kept stumbling over: can the force of the rocker arm be used to work a pump jack that results in lifting more than the 400lb lift capacity of the TC? Just like a human can pump a jack to lift a car what would be the resulting weight lifted if a cub with 400 lbs of pressure in the rocker arm pumped a jack? What type of hydraulic jack?
If a separate hydraulic system was run off the Cub pto to operate a forklift you would run into the problem of disengaging the pto in order to move the tractor. Would this affect holding the load in raised position while moving into position? The cub pto has to run at high engine idle to get max hydraulic flow while picking up a load. Would the Cub have to run continuously at a high idle to keep the lift positioned, while maneuvering the load?
But to lift a heavier weight than 400lbs a different method than the TC is needed, I’m guessing.
A battery operated hydraulic pump system seems like a good idea but I don’t know if they can lift high enough to get my load to six feet high. They run off 12 volt battery, my ’49 cub is a six volt system so how could I keep a 12 volt battery charged from the cub engine?
Another way to operate the lift could be done by a portable hydraulic power unit powered by a separate 8 hp engine to power the unit http://www.fostermfgcorp.com/hydraulicp ... %20Gas.htm. Both would become counterweights attached to the beam. This way the cub idle doesn’t have to stay high while operating the clutch for movement.
I also wondered if an air compressor could be used to operate a lift. I imagine the compressor could be mounted on the beam and powered off the cub engine by belt and extra pulley or the pto. http://www.vanair.com/products.php?product-id=42 http://www.vanair.com/products.php?product-id=44 . The compressed air tank would operate the lift’s piston in separate relation to using the clutch and high idle in order to move the cub. I have also seen that an air compressor gear can be directly attached to engine gears at the block but wonder if it could be done to a cub?
Another idea is to use a ‘Forkster’ http://www.forkster.com/products/mini.asp . A similar smaller idea is the Avant lift attachment http://www.avanttecno.com/www/index.php ... s=1&pid=12 (but the Avant attachment was never available in the US and seems impossible to find even overseas, if it was ever made). This type would have to be operated by a hydraulic power unit and separate 8hp engine. This would take the problem of weight off of the cub itself. It would be attached to a reinforced final drive and or to the box truss beam. I imagine that by using the truss beam the ‘Forkster’ could attach to the front. Whether rear or front attachment I wonder if the ‘Forkster’ would produce too much side torque on the cub when making that initial move to go to the left or right thus forcing the outrigger wheels to change direction?
I saw recently here on the forum an ebay advert for a used lowboy with rear mounted forklift. The lift looked heavy duty. The lowboy rear end is obviously strong enough to carry the lift, so how large is the hydraulic system? Is it an internal hydraulics or separate unit from the engine like was done on the cub?
After all this my conclusion has become that the breaks may be the biggest problem, unless someone knows how to improve the rear brakes. With a lot of design work I imagine some motorcycle type disc brake system could be mounted to the front wheels to aid the braking problem. Another thought, with obvious cost and newbie misconceptions, could hydraulically-powered independent wheel motors be attached to each cub’s front wheels to solve braking and add drive? (Maybe electrically powered wheel motors in a few years.)
So, this is as far as I got, a bunch of newbie ideas. I’d sure like to make more use of the cub that I have, so it would be great to have some more of this forum’s feedback and knowledge so I can continue thinking about it.
Arnold
As some suggested, I’ve looked into using a used 4wd Kubota with a loader or separately putting a lift on it. A used compact all terrain forklift by other brands or even a used ‘power trac’ would be about the same price, and I admit may be a better solution. I realize that just the materials cost to fabricate a lift on a Cub might be about the same or more. I’d sure like to make use of the cub that I have. So, I thought I’d run a few thoughts by those that are adventurous enough to see if this is possible. This is what I’ve come up with so far.
Putting a lift on the front would put too much weight on the front axle and affect steering. Plus a rear counterweight would add to overall weight, which has to be watched with the cub’s limitations. 3800lbs seems to be the forum’s agreeable maximum. Even so, flotation turf tires would be used in front, along with welded gussets to strengthen the front axle.
Mounting a lift at the rear is counterbalanced by the engine plus additional weight. Here the rear final drive is fragile but can be strengthened as was done for the later model Woods mower and Rick Prentiss backhoe. To this type of bracket I imagine attaching an aluminum 12â€x12†heavy duty box truss, similar to http://www.showsolutions.com/pro_series_12_trusses.php ,
as a sub frame that reinforces the cub structure. It would run under the belly of the tractor, also fixed to both sides of the torque tube at the center mounting plate, and to both sides of the receiver at front steering housing. The rear end of the beam is extended beyond the cub and a lightweight forklift is attached to it. This lightweight gusseted box truss will distribute the lift, motion and torque loads evenly, up down and sideways, through the cub’s mounting points, so not to stress one particular area. A post in this forum discussed the deflection forces of the span and sizes and weights involved for a steel ‘I’ beam sub frame running under the cub belly as it extended working weight - like lifting a bale spear or snow blower, I believe. But now I can’t find it. From the numbers that were given I calculated that the aluminum box truss meets that discussion’s requirements. The truss can also be extended beyond the front of the cub and hold counterweights. The cub’s rear rocker arm can be used to tilt the forklift fore and aft. This truss beam would also aid in turning the forklift into a non permanent attachment by easily driving over it then hoist up and mount into position. A steel box truss would be easier to attach, to weld to, and could take a beating but the weight would take away from the overall load capacity of the Cub and forklift. Aside from making one, they are hard to find. What do I need to understand about attaching aluminum to steel, specifically the aluminum box truss to steel brackets and the cub itself?
Operating the lift could be done several ways. The existing TC can lift 400lb loader bucket so should be able to operate a 400lb lift. I have not worked out the details but for 400 lbs I imagine a “carry-all†concept that uses TC to raise the load in 12 inch increments, like an extension ladder. Each 12 inch raise is caught and held by a trip mechanism. The rocker arm is lowered while the load stays in place. The arm catches a new “rung†or chain link type catch, and then raises the load another 12 inches and so on. A simpler version would be to manually set holding pins at 12 inch incremental heights. This may be all the cub forklift can do.
Here is an idea I kept stumbling over: can the force of the rocker arm be used to work a pump jack that results in lifting more than the 400lb lift capacity of the TC? Just like a human can pump a jack to lift a car what would be the resulting weight lifted if a cub with 400 lbs of pressure in the rocker arm pumped a jack? What type of hydraulic jack?
If a separate hydraulic system was run off the Cub pto to operate a forklift you would run into the problem of disengaging the pto in order to move the tractor. Would this affect holding the load in raised position while moving into position? The cub pto has to run at high engine idle to get max hydraulic flow while picking up a load. Would the Cub have to run continuously at a high idle to keep the lift positioned, while maneuvering the load?
But to lift a heavier weight than 400lbs a different method than the TC is needed, I’m guessing.
A battery operated hydraulic pump system seems like a good idea but I don’t know if they can lift high enough to get my load to six feet high. They run off 12 volt battery, my ’49 cub is a six volt system so how could I keep a 12 volt battery charged from the cub engine?
Another way to operate the lift could be done by a portable hydraulic power unit powered by a separate 8 hp engine to power the unit http://www.fostermfgcorp.com/hydraulicp ... %20Gas.htm. Both would become counterweights attached to the beam. This way the cub idle doesn’t have to stay high while operating the clutch for movement.
I also wondered if an air compressor could be used to operate a lift. I imagine the compressor could be mounted on the beam and powered off the cub engine by belt and extra pulley or the pto. http://www.vanair.com/products.php?product-id=42 http://www.vanair.com/products.php?product-id=44 . The compressed air tank would operate the lift’s piston in separate relation to using the clutch and high idle in order to move the cub. I have also seen that an air compressor gear can be directly attached to engine gears at the block but wonder if it could be done to a cub?
Another idea is to use a ‘Forkster’ http://www.forkster.com/products/mini.asp . A similar smaller idea is the Avant lift attachment http://www.avanttecno.com/www/index.php ... s=1&pid=12 (but the Avant attachment was never available in the US and seems impossible to find even overseas, if it was ever made). This type would have to be operated by a hydraulic power unit and separate 8hp engine. This would take the problem of weight off of the cub itself. It would be attached to a reinforced final drive and or to the box truss beam. I imagine that by using the truss beam the ‘Forkster’ could attach to the front. Whether rear or front attachment I wonder if the ‘Forkster’ would produce too much side torque on the cub when making that initial move to go to the left or right thus forcing the outrigger wheels to change direction?
I saw recently here on the forum an ebay advert for a used lowboy with rear mounted forklift. The lift looked heavy duty. The lowboy rear end is obviously strong enough to carry the lift, so how large is the hydraulic system? Is it an internal hydraulics or separate unit from the engine like was done on the cub?
After all this my conclusion has become that the breaks may be the biggest problem, unless someone knows how to improve the rear brakes. With a lot of design work I imagine some motorcycle type disc brake system could be mounted to the front wheels to aid the braking problem. Another thought, with obvious cost and newbie misconceptions, could hydraulically-powered independent wheel motors be attached to each cub’s front wheels to solve braking and add drive? (Maybe electrically powered wheel motors in a few years.)
So, this is as far as I got, a bunch of newbie ideas. I’d sure like to make more use of the cub that I have, so it would be great to have some more of this forum’s feedback and knowledge so I can continue thinking about it.
Arnold