Measuring/calculating PTO speed (not PTO speed = Machine speed / implement speed)

[OldNick]

I DAGS and searched the forum for PTO speed etc.

So. I have a Hinomoto N279 32HP tractor. Maybe I bought badly as it does not even have its own section here

However.. The N279 has a 4 gear/speed PTO. I know the flail mower I have bought requires a 540 RPM PTO speed. But I do not know for the N279 what PTO speed results from what engine speed in each PTO gear. The Tacho has no indication of PTO speed for each PTO gear.

So how do I measure the PTO speed? I tried writing on a spline with liquid paper. But 540 RPM is what.... 9 per second. Try counting that.

To add to that, the 4 PTO gears do not make sense to me: they do not go 1=slowest 2=a bit faster...etc. They seem to duck and dive, based purely on non-measure obs.

Or do I just wing it, going as high-gear as I can without labouring, running at 1500 RPM of the 200RPM of the N279, and yet getting a decent thrashing?

I understand that the whole thing revolves around also looking at Forward Movement Speed and is all a balancing trick. But I would like to know the figures as a starting point.

 

[mikester]

https://www.princessauto.com/en/digital-laser-tachometer/product/PA0008714933

 

[sea2summit]

https://www.princessauto.com/en/digital-laser-tachometer/product/PA0008714933

That or similar^

Just don't get anywhere close to that spinning shaft, especially at 540. I'd probably mount it somehow to take some measurements, no way I'd hold it close to the shaft.

 

[oosik]

Geeze - that makes life easy. Not really that expensive either.

 

[LD1]

^^^^Yup.....get a tach if you dont have an owners manual.

But an unfamiliar machine to you....I'd do some web searching and see if you can find an operators manual

 

[ruffdog]

The tachometer should have an indicator that shows what engine speed is needed for 540 pto rpm. This one is at 2500 engine rpm:

 

[ptsg]

The tachometer should have an indicator that shows what engine speed is needed for 540 pto rpm. This one is at 2500 engine rpm:

View attachment 783570

In this case, it doesn't have any marks. It may be written on a sticker somewhere though.

Hinomoto N279 Dash

 

[ruffdog]

One site said rated power was at 2600rpm and governed speed was 2800rpm. I'm thinking that 540 pto speed will be near 2500 rpm.

 

[OldNick]

OK. That laser thingy looks cheap enough to give a go without killing my bank balance. Even at the USD Aud exchange rate, I have a couple of jobs for it, right now. Thank you

 

[OldNick]

One site said rated power was at 2600rpm and governed speed was 2800rpm. I'm thinking that 540 pto speed will be near 2500 rpm.

Well I certainly do not want to run my engine at 2500! Anyway does that have anything to do with a 4-speed PTO, or refer to my question?

 

[OldNick]

In this case, it doesn't have any marks. It may be written on a sticker somewhere though.

Hinomoto N279 Dash

View attachment 783571

Well if it has markings elsewhere, I can't find them

 

[OldNick]

Y

The tachometer should have an indicator that shows what engine speed is needed for 540 pto rpm. This one is at 2500 engine rpm:

View attachment 783570

es but in what PTO gear? Anyway I see no such markings on my Tach

 

[OldNick]

^^^^Yup.....get a tach if you dont have an owners manual.

But an unfamiliar machine to you....I'd do some web searching and see if you can find an operators manual

HAH! You reckon I have not tried? I am currently not being replied to by tomanuals.com, because they are they the only ones who even offer a manual.

 

[ptsg]

Y

es but in what PTO gear? Anyway I see no such markings on my Tach

It's very common for these smaller Japanese tractors to have 4 PTO speeds. Something like 540 - 750 - 860 - 1000. All achieved at the rated RPM, probably in the 2500 engine RPM range like Ruffdog says.

It's also common to use the 750 RPM with less engine RPM to achieve 540 PTO RPM with less engine RPM, also known as 540E (E for economy).

 

[OldNick]

That or similar^

Just don't get anywhere close to that spinning shaft, especially at 540. I'd probably mount it somehow to take some measurements, no way I'd hold it close to the shaft.

But isn't that why you use a laser? I know caution is needed, but try table saws and other stuff. "Stay away" is just common sense.

I have to admit that the proliferation of techno solutions does produce a loss of awareness. And that farming is still up there as the most dangerous job.

 

[ruffdog]

It's very common for these smaller Japanese tractors to have 4 PTO speeds. Something like 540 - 750 - 860 - 1000. All achieved at the rated RPM, probably in the 2500 engine RPM range like Ruffdog says.

It's also common to use the 750 RPM with less engine RPM to achieve 540 PTO RPM with less engine RPM, also known as 540E (E for economy).

It should be noted that running a higher pto gear at a lower engine speed will greatly reduce available HP.

 

[WranglerX]

OK. That laser thingy looks cheap enough to give a go without killing my bank balance. Even at the USD Aud exchange rate, I have a couple of jobs for it, right now. Thank you

Check to see if there is a optical tachometer app for a cell phone .....

 

[ruffdog]

I have an old mechanical tachometer for reading rpms of the end of shafts. The new mechanical ones cost more than the electrical ones.

 

[WranglerX]

I have an old mechanical tachometer for reading rpms of the end of shafts. The new mechanical ones cost more than the electrical ones.

Like this?..

 

[5030]

I use a Stewart Warner direct contact tachometer to measure pto speeds.