Which cutter head rotation ?

[Eagleview]

Im planing on building a tracked mulcher using a 10 ton excavator base . It will have a shaft driven cutter head via a twin disc clutch on a 265hp Nissan Diesel . In my mind the drum should rotate bottom forward like my flail mowers so it will shred going forward and should not need to go over the area in reverse . But they are mainly made to rotate top forward , why ? My machine will look a little like a PT400 Gator only smaller . With my flail mowers when you strike a piece of steel or a hard rock it just throws them forward and gives me time to stop . Rotating top forward in the same situation the cutters would grab the object instantly and probably break something . My mowers are useless in reverse but cut like a lawn tractor going forward , does this not apply to mulchers ?

 

[diyDave]

Why not set it up to go both ways? That way, if you have double sided cutting tips, you can run it till one side gets dull, then reverse direction, to give you more time between service intervals. I made a small 4' cutter for my ASV RC30, and used double sided bush hog blades, as they were available, and you don't need a vacuum wing on the back side of the blade, anyway!

 

[rutwad]

Im planing on building a tracked mulcher using a 10 ton excavator base . It will have a shaft driven cutter head via a twin disc clutch on a 265hp Nissan Diesel . In my mind the drum should rotate bottom forward like my flail mowers so it will shred going forward and should not need to go over the area in reverse . But they are mainly made to rotate top forward , why ? My machine will look a little like a PT400 Gator only smaller . With my flail mowers when you strike a piece of steel or a hard rock it just throws them forward and gives me time to stop . Rotating top forward in the same situation the cutters would grab the object instantly and probably break something . My mowers are useless in reverse but cut like a lawn tractor going forward , does this not apply to mulchers ?

For the skidsteer mulchers, forward is backward and backward is forward.

 

[Robbie Hegwood]

The timberax is the only head that runs "backwards". I personally liked it's direction of rotation for is didn't throw debri at the tractor and controlled debri out the front.
The reason they cannot run both ways is the motors on the heads. It will run backwards but has no torque.

 

[Eagleview]

Why not set it up to go both ways? That way, if you have double sided cutting tips, you can run it till one side gets dull, then reverse direction, to give you more time between service intervals. I made a small 4' cutter for my ASV RC30, and used double sided bush hog blades, as they were available, and you don't need a vacuum wing on the back side of the blade, anyway!

You think like me . I was thinking of doing that and having the best of both worlds . As it is shaft driven through a gearbox and not hydraulic driven i could do that . But would you not need another set of tooth holders mounted in reverse ? Because the motor and box came from a truck with cruise control im going to use the truck speedo as well . First i'll have to find out what speed on the gauge 540 and 1000 PTO RPM'S is and set the cruise control at that speed . When the head starts to load up the cruise will stomp on the loud pedal a bit harder and stop it from bogging down .

 

[McCaskey]

Please post pictures while you build this. A lot of would be very interested in seeing the machine under construction.

 

[rutwad]

You think like me . I was thinking of doing that and having the best of both worlds . As it is shaft driven through a gearbox and not hydraulic driven i could do that . But would you not need another set of tooth holders mounted in reverse ? Because the motor and box came from a truck with cruise control im going to use the truck speedo as well . First i'll have to find out what speed on the gauge 540 and 1000 PTO RPM'S is and set the cruise control at that speed . When the head starts to load up the cruise will stomp on the loud pedal a bit harder and stop it from bogging down .

Why not set the RPM's to the maximum torque? Most cruise controls will disengage after a certain speed reduction, and it won't have time to react to the sudden "bog".

 

[Eagleview]

It would be set at the engines max torque which is 1800rpm . I would have to select the appropriate gear which would give me a shaft speed of 540 or 1000rpm @ 1800revs then mark the speedo at both points for future reference . If the speedo was reading say , 40 kilometres per hour @ 1800revs in fourth gear thats what ide set the cruise at . In easy going i may be able to use sixth gear @ 1400revs to save fuel . I just got the price on a new Gator PT400 $690,000 . So this machine is a go . Im having trouble sourcing a new excavator track frame though .

 

[Robbie Hegwood]

If your going to buy an excavator frame to construct the mulcher why not purchase a tractor that meets your needs without modification.
New holland makes a 165 hp bi-directional tractor that can run mulchers with a pto. I ran a 145 hp version that was very nice and decently strong. The package was 180k. I would think the 165 should be under 200k
The price for the PT seems a little high. Geography class, where is Orstraya?

 

[Eagleview]

Slang for Australia . I was thinking of what you said but i want steel tracks and a low profile cab . I use a New Holland tractor now and find that i have to drive though branches to reach the tree trunk . I'm also wanting to fit remote control so i can work the machine in dangerous places without me in it , ive given one other machine an oil change the hard way and im not going to go with another one .

 

[Eagleview]

Is there no one out there that can tell me why most of the cutter drums spin top forward and not bottom forward ?

 

[Digdeep]

Is there no one out there that can tell me why most of the cutter drums spin top forward and not bottom forward ?

I would guess that it is because it would be difficult to mulch small trees that you had knocked down. With the mulcher spinning "top down" it would seem to pull the small tree toward the machine and into the mulcher. With the mulcher spinning "bottom forward" it would seem to push the small tree away from the mulcher.

 

[Eagleview]

What should happen is it would lift the cut ends mechanicaly and aided by vacuum draw the material into the top of the chamber where it is pulverised against the secondary cutters in the chamber the same as a flail mower . Engineers have proven that using the ground as an anvil as in top forward rotors does not work , thats why you have to back over the material again using the back of the rotor . As when your going backwards the drum is spinning bottom forward (with your reverse travel) . So why do they persist in building them this way ? Have any of you guys backed over virgin scrub with a top forward mulcher ? Does it completely shred the material in one pass ?

 

[alchemysa]

I know absolutely nothing about this, but out of interest I watched a youtube video of the Gator 400 at work. It would seem to me that by rotating 'top forward' it safely pushes large logs UNDER the drum so no real harm is done if you hit a big one too fast. On the other hand if the drum was rotating 'top backwards' and you drove too fast into a log you would have an almighty explosion as the a log was 'sucked' into the mulcher head faster than it can be shredded. (Sorta like trying to force a baseball bat through a keyhole)

 

[alchemysa]

I know absolutely nothing about this, but out of interest I watched a youtube video of the Gator 400 at work. It would seem to me that by rotating 'top forward' it safely pushes large logs UNDER the drum so no real harm is done if you hit a big one too fast. On the other hand if the drum was rotating 'top backwards' and you drove too fast into a log you would have an almighty explosion as the a log was 'sucked' into the mulcher head faster than it can be shredded. (Sorta like trying to force a baseball bat through a keyhole)

I see this one DOES rotate 'top backwards'...
Loftness >TimberAx > Specifications

But not this one...
Carbide Cutter, forestry products by Loftness, tree brush cutter

I'll go away now. This is not my field at all.

 

[Eagleview]

Thank you for your effort in supplying the link . That is what i think is the best way to rotate a cutter . Yesterday i cleared 5 acres of dense regrowth up to about an inch thick with my 100hp tractor and flail mower . Being able to mow this material in one pass is definately the way to go . If i can source a new excavator base i will fit a TimberAx/type head to it . Im sure the technique would work on the larger scale .

 

[Eagleview]

Well in my search for an excavator track base to build a mulcher i found a new 23ton excavator at the right price . So i paid the man and it will turn up tomorrow night , i'll leave it as is . It has 2 digging buckets and a mud bucket . Now all i need to do is buy a land clearing rake for it , a vertical tree extraction grab , a rock grapple and a mulcher and something to carry it around........ ah well it's only money What is the best , a drum shredder or a disc shredder like the Slashbuster ? I'll be doing creek bank mowing of saplings up to around 8 inches and woody weeds and some right of way work . We have the FAE , Berti and Ahwi(which is your Fecon i think) in OZ . Some of you manufacturers should think about sending some gear too our little island .

 

[cbturf]

IH,

On the track or tire type mulchers you are better on the top down rotation because you have to work backwards to create a smooth and level finished product. When you are working forward you are piling the debris up in front of your machine. As you backdrag the processed material is picked up run through the head and deposited fairly uniformly out in front. On the other hand if the bottom down design really was better it seems like more than one manufacturer would jump on board. Usually if there is an earth shattering innovation like this would be EVERY other manufacturer would jump on board to get a piece of the pie.

 

[Landwise]

Iron Horse,

Loftness makes a Timber Axe now that fits an excavator. It is not advertised yet, but it can be purchased. I run one on a Kubota 080, but it is really way too heavy for this machine. It would be awesome on one as large as you bought. It weighs #1600 lbs, and I am running it with ~26 GPM. Very satisfied.

 

[Eagleview]

This site used to have very good diagrams of what they are talking about but i can only open the cached version at the moment but it is a very good read . This engineer says that it is very ineficient to have a mulcher chop down against the ground as the ground is not a good anvil . I do'nt know if they are correct , but it sounds feasable to me and the other makers just stick with the same "O" design . My flails do not throw material forward , they cut at the bottom while the material is bent forward and then lift it up to strike the first and second set of anvils to further reduce it's size and then throw it out the back with the huge air stream created by the rotor . I never have too go over ground a second time , scrub turns to lawn in one pass . I have attached a couple of pics of it mowing Lantana and braken but it does bigger stuff just as well .Weed Removals : Weed Removal : Weed Handling : Australia