Trying to build a 42" Rotatary Mower

[J_J]

FlyC17s ,

I really don't you have enough juice to run a 42 in blade with enough torque to do a credible job.

For example.

Using your 11 GPM, and maybe a 3 cu in motor, that will power the hyd motor to about 847 rpm.

Now, as far as the torque. 3 cu in, and 3000 psi, will provide about 1433 in lbs, or 120 ft lbs

If you go with a smaller cu in motor, you decrease the torque, but gain rpm.

 

[J_J]

FlyC17s,

If you stick with the 3000 rpm, , and 11 GPM, the cu in of the hyd motor would be about .847.

The torque using .847 cu in and 3000 psi = 405 in lbs or 44 ft lbs.

Here are some pic of a hyd blade attachment. Don't know all the particulars.

 

[tmc_31]

J.J, what kind of torque should we be looking for for an application like this. 42" blade? 72" blade? Or does the blade length even matter? It seems like I saw a torque spec that some manufacturer published for a brushcutter but I can't seem to find it.

Tim

 

[aczlan]

J.J, what kind of torque should we be looking for for an application like this. 42" blade? 72" blade? Or does the blade length even matter? It seems like I saw a torque spec that some manufacturer published for a brushcutter but I can't seem to find it.

General rule of thumb is 5hp/foot, so you would need ~17.5 HP to drive it. Hydraulics are ~80% efficient, so you would need to start with ~22HP used on the engine to get ~17.5HP at the deck.

Aaron Z