TP200 TPO chipper: a question

[Andrew L]

Attended a chipper training course today, mainly to tick the H&S box.

We were training on a brand new TP 200 which was attached to a Valtra forestry tractor '07 plate but I don't know what model, apologies.

 

In the practical session, the chipper was very impressive, dealing very easily with the supplied brash and blowing it 2 or 3 times further than my TP155 could manage.  But then I was asked to go into the cab and set the TPO etc.  After engaging the soft start TPO, I upped the engine revs to get the TPO spinning to ~1020 rpm as instructed and saw the engine tacho get to ~2400: almost maxed out!

There was a lot of engine noise and I asked about fuel consumption and was told it was very poor.  The TP counter was showing 1040 rpm.  I know very little about tractors but TP says the TP200 should be attached to a tractor with an output of 40-85hp.  I think I was told the Valtra makes 150hp. 

I was thinking of maybe getting one of these chippers maybe in the future but now I am confused by what I saw ie was the impressive performance because the tractor used was massively overpowering the chipper?  Can anyone enlighten me?

Cheers

A

 

[Johny Walker]

Tp run best at 1000rpm @ 540 it's worse than a green mech 😁

[monkeybusiness]

It sounds like the pto possibly wasn’t in 1000 speed - maybe 540 eco so the tractor had to rev hard to reach the correct shaft speed.

If the tractor has a 1000 speed pto (I’d be amazed if it didn’t) then it would need selecting/changing into etc, and the engine would deliver 1000rpm at the pto at more economical revs.
I’m disappointed (but not surprised!) that the ‘instructor/assessor’ didn’t know how to operate it properly!

(I was ‘assessed’ for my NPTC chipper ticket by a bloke that had never used one - he had been trained up to help give ‘naughty boys’ a vocation). 

[Andrew L]

Bear with me: no tractor expert but the PTO lever had a 540 or 1000 option and it was set for the latter, so it seems weird that it had to work so hard to spin up the chipper?!

[ESS]

Something not quite right here . On older tractors 540 pto speed was achieved at around 1700 rpm.

[PeteB]

I got to lash back agin Jonny Walker, it is my job after all.  GreenMech tractor powered stuff is good, even better when used on a decent tractor and by folk who know what to do! I had an 8" GreenMech on a Unimog back in the day and it was/is a blinding piece of kit! 

 

With ours, the "No Stress" kicks in when the tractor reaches the correct rpm, no matter what gear you are in. If you have a load of HP available, stick the tractor in 1000 speed and rev to a high tickover and it will work. If you overspeed it, an experienced chipper operator will hear that it is too fast !

[Andrew L]

Right, there was a "no stress" system in place but tbh, I don't think it kicked in,,,, (!)

Trying to get my head around this:

My TP 155 diesel makes about 24hp and spins the disc at ~1400 or so, if I shove anything bigger than about 3-4 ins diameter into it, the "no stress" kicks in but it deals with it albeit a touch slowly.

Is the 150 or whatever hp being wasted but there is no other way of doing it more economically given that is his tractor?

Will powering the chipper like that damage it at all or does it just mean that the "no stress" will be needed less often since the torque of the big tractor will be able to deal with the extra work of bigger lumps of timber without the disc slowing down?

 

Sorry if I am being dense

A

[s o c]

My 10inch  Jensen runs fine at 900rpm pto speed on a 95 horsepower Valtra or 100 horsepower Claas.

might go to 950 for big material or can run as low as 750 for small.

parameters on the no stress can be set at whatever rpm you want on Jensen, I don’t know about other makes

[woody paul]

My fendt 304 has 3 pto settling 540 750/540e 1000, to get the speed in each you need 2000rpm so when on chipper stick it in 750/540e at lower rpms and it will chipper all day on about 7 litres. 

Have ran it in 1000 with low revs so pto at 540 but tractor struggles to much. 

Edited March 6, 2021 by woody paul

[Paddy1000111]

Sounds like we need to know the exact model of the tractor, pull up the manual and see about pto speeds?