PTO Speed?

[Steve23240]

I am a complete newcomer to tractors and to this forum. I am a great fan of fora such as this as there are always kind people willing to share their expertise!
I have recently bought a Kubota L1500 (15HP) and a SICMA 95cm flail mower. I am a tad confused about the speed at which the mower should be used; on the PTO housing on the mower itself is a little notice that says 540 rpm, however literature on the SICMA website suggests 2040 rpm. Having cut a little bit of the orchard 540 rpm feels a little slow but I'm afraid to run it at 2040 rpm as it sounds rather too fast. Your advice would be very welcome.
many thanks, Steve

 

[LD1]

I am a complete newcomer to tractors and to this forum. I am a great fan of fora such as this as there are always kind people willing to share their expertise!
I have recently bought a Kubota L1500 (15HP) and a SICMA 95cm flail mower. I am a tad confused about the speed at which the mower should be used; on the PTO housing on the mower itself is a little notice that says 540 rpm, however literature on the SICMA website suggests 2040 rpm. Having cut a little bit of the orchard 540 rpm feels a little slow but I'm afraid to run it at 2040 rpm as it sounds rather too fast. Your advice would be very welcome.
many thanks, Steve

It sounds like the mower needs to be ran at 540 PTO rpm NOT 540 tractor RPM (if the tractor will even go that low)

Most tractors have a standard 540 PTO and a few nave a 1000rpm PTO. But the splines are usually different.

To obtain 540 PTO rpm your tractor needs to be ran somewhere arond 2500RPM. (It should have a mark on your tach that references 540 PTO)

The 2040 is probabally refering to the rpm in which the mower actually runs if given 540 rpm @ the PTO. which would give the mower just under a 4:1 box.

I dont know a lot about flail mowers so this is just a guess. I'm sure others will be along to chime in.

 

[johnrex62]

I could be wrong, but I think it is likely that the SICMA documentation probably refers to the flail rpm, not the PTO rpm. The drum or cylinder on the mower probably turns at 2040 rpm when the PTO is running at 540 rpm.

There is another thread on here discussing PTO speeds for your tractor and the following information is for another model which is similar to yours.

PTO 1 requires 2430 engine RPM for 540 PTO RPM. PTO 2 requires 1876 RPM for 540 PTO RPM. At the engine speed you specified for PTO 3, the gearbox was turning about 950 RPM. The correct engine speed for 540 PTO RPMs in PTO 3 is 1300, which puts too much strain on the engine.

http://www.tractorbynet.com/forums/grey-market-tractors/58350-kubota-l1500-l175-power-take.html

You will probably be happier running the engine at a higher rpm in PTO 1 to maintain the PTO 540 rpms when using this mower.

 

[Steve23240]

Thank you both, that is very helpful and makes sense to me.

 

[Steve23240]

Another question, if I may? Does the high/low ratio affect both PTO and gearbox or does the PTO turn at the same speed regardless of whether its in high or low ratio?

 

[leonz]

Another question, if I may? Does the high/low ratio affect both PTO and gearbox or does the PTO turn at the same speed regardless of whether its in high or low ratio?

A lower engine speed puts more loading on the tractor which translates to bad for your tractor.

If you have the No.6 spline on your PTO stub shaft you need to run the tractor at the engine speed required for the 540 R.P.M. Power Take off speed all the time to maintain maximum power delivery to the mower gearbox and flail motor rotor.

 

[bp fick]

I have a finish mower, by Sicma.

My little Kubota tractor needs to spin at 2900 RPM to achieve 540 at the rear PTO. I am inclined to believe your L series would be around 2500 RPM on the tractor, but look for an index on your tachometer of some kind.

Yes, the gearbox on the mower will indeed spin at over 2300 rpm due to its own gearing.
Hi/Lo has no effect on PTO

 

[easygo]

Another question, if I may? Does the high/low ratio affect both PTO and gearbox or does the PTO turn at the same speed regardless of whether its in high or low ratio?

The PTO RPM is only changed by the engine RPM regardless of the traveling speed of the tractor. Hi/Low only changes the wheel RPM it has no effect on the PTO.

 

[Steve23240]

Brilliant - thank you very much!

 

[jlsmith]

I have a finish mower, by Sicma.

My little Kubota tractor needs to spin at 2900 RPM to achieve 540 at the rear PTO. I am inclined to believe your L series would be around 2500 RPM on the tractor, but look for an index on your tachometer of some kind.

Yes, the gearbox on the mower will indeed spin at over 2300 rpm due to its own gearing.
Hi/Lo has no effect on PTO

Thats why i like my MF 1800 to 2000 RPMs and im at my 540 mark. saving the fuel.