Stumpgrinder rate of return

[aspenarb]

21 hours ago, jmac said:

What hp is in that big rayco bob? I have a slightly smaller grinder with v4 Wisconsin on it, think its 35hp.

 

Its not big on HP but at a very useable and calm 1800rpm knocks out about the same torque as four of those 25/30hp Kholers do at 3000rpm, add in the huge weight of all the pulleys,flywheel,engine mass and it takes some stopping.

 

Bob

[donnk]

wouldnt a micro digger be a much better option even if you had to run the head off a beaver pack ?

 

grinder is 1 trick pony and a micro could get all the same places plus its a digger ?

[doobin]

25 minutes ago, donnk said:

wouldnt a micro digger be a much better option even if you had to run the head off a beaver pack ?

 

grinder is 1 trick pony and a micro could get all the same places plus its a digger ?

A beaver pack won’t run any reasonable size stump grinder. Your biggest beaver pack is a 13hp petrol engine. The basic pedestrian machines are all 13hp, with no hydraulic losses. 
 

 I’m going down the route you suggest, but with an auxiliary petrol engine on the head- it’s the only feasible way. 30hp loncin should do nicely!

[Dan Maynard]

A beaver pack won’t run any reasonable size stump grinder. Your biggest beaver pack is a 13hp petrol engine. The basic pedestrian machines are all 13hp, with no hydraulic losses. 
 
 I’m going down the route you suggest, but with an auxiliary petrol engine on the head- it’s the only feasible way. 30hp loncin should do nicely!

I'm sure I've seen a picture of such a machine on here from a while ago? Think may have been an early Greenmech machine but might be making that up.

[donnk]

58 minutes ago, doobin said:

A beaver pack won’t run any reasonable size stump grinder. Your biggest beaver pack is a 13hp petrol engine. The basic pedestrian machines are all 13hp, with no hydraulic losses. 
 

 I’m going down the route you suggest, but with an auxiliary petrol engine on the head- it’s the only feasible way. 30hp loncin should do nicely!

they do a diesel one as well, more flow.

 

but, how about forget another engine and run it off PTO from the pickup, just long hoses ?

Edited December 26, 2021 by donnk

[doobin]

2 hours ago, donnk said:

they do a diesel one as well, more flow.

 

but, how about forget another engine and run it off PTO from the pickup, just long hoses ?

Way more hassle than an engine directly mounted. 13hp petrol will give you 30l/min. You’d need a much bigger diesel engine to give you the same, and they are a lot more money too. 30hp petrol Loncin is around 1.2k plus vat. 

[donnk]

17 hours ago, doobin said:

Way more hassle than an engine directly mounted. 13hp petrol will give you 30l/min. You’d need a much bigger diesel engine to give you the same, and they are a lot more money too. 30hp petrol Loncin is around 1.2k plus vat. 

pickup PTO + long hose!

[doobin]

4 hours ago, donnk said:

pickup PTO + long hose!

How much flow rate do you think a pickup PTO actually puts out?? Let alone running the hoses around. You'd better budget for a massive oil cooler on the pickup somewhere also.

 

Direct drive is the most efficient drive posible, and a petrol 30hp engine is so much cheaper than all the above.

[donnk]

the hose length would be the cooler. tickover on a 2L diesel plenty of horses.

[aspenarb]

20 hours ago, doobin said:

How much flow rate do you think a pickup PTO actually puts out?? Let alone running the hoses around. You'd better budget for a massive oil cooler on the pickup somewhere also.

 

Direct drive is the most efficient drive posible, and a petrol 30hp engine is so much cheaper than all the above.

 

We built a large grinder with a direct drive motor for a big excavator and it was uncontrollable because slewing was far too erratic, on a small machine using the offset slew I would have thought it entirely feasible and workable. There is an old Rayco in the corner of the yard that would make a good donor for the bits so I may get in the workshop and cobble one together for our small Kubota. Thinking third service to operate a clutch.

 

Bob