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Forestry mulcher help

Started by davidn3, May 01, 2019, 06:24:17 PM

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davidn3

Just purchased a bobcat 60" forestry mulcher.  Was excited to try it out and wasn't impressed.   Running it on a bobcat 2013 s750 (85hp)  with grouser tracks.  It seemed to bog and stop spinning way more than expected.   Espesualy with stumps (pine).  I was running at 1700 rpm, which is more than I normally run it.  The carbide teeth seem to be pretty dull but none broken.  Do I need new teeth?  $80 a tooth kind of sucks right off the get go.  Run more rpm?  Nowhere does bobcat state what rpm I get that 85hp at.  Also the pressure gauge on the front isn't working.  Is it worth my time fixing it?  For the most part it runs.  Just want more optimal use out of the 18k I just spent.

nativewolf

Sorry but not surprised to hear.  85 HP is just not enough power and that s750 hydraulic flow rate and pressure is not super high.  To be effective you'll need to do some research to see what RPM keeps hydraulic flow highest, keep hydraulics cool, stop and clean that radiator with a blower, watch temps because a mulcher is a good way to burn up a skidsteer.  

Carbide teeth getting dull already?  was this a new mulcher head?  You shouldn't be getting dull teeth right away if they are carbides unless you've been playing in dirt.  Might be easier to start with good old knives that you can sharpen.  

In the future I'd suggest getting an FAE head on a purpose built carrier, like a CMI 175 or a Fecon 150.  These machines will have 50-70GPM and 5000psi, more weight and better ergonomics for mulching.  
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ohiowoodchuck

My buddy brought a new cat 299 and a mulcher out to my place back last fall. Definitely not impressed. The skidsteer had the hp and the flow but the head couldn't hold up to the mulching. It kept breaking the bolts on the hub that held the bearing and drum shaft in. After 3 sets of bolts in four hours we quit. 
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davidn3

The hp and flow are in the specified range for the mulcher.  The mulcher is used. A 2013 model I believe.   Fecon type head sold by bobcat.  The planer type teeth look like they would do better but there are a lot of rocks in the area.  Wasn't having any issues with broken teeth,  or temp.  But it was only 40 degrees out. Just the drum would stop with less force than I thought.  Had to let it spin back up to speed quite often.

barbender

You should be running full throttle with that mulcher attachment. 
Too many irons in the fire

AnvilRW

Do you have high flow hydraulics?  You have to have high flow.  I run a Fecon 74SD HDT style with the double carbide teeth on my 2015 Bobcat T770 (92-hp).  I run it through mixed gambel oaks from 2" to 8" diameter and pines bigger than that.  I run my engine at full rpm, which is about 2,400.  I have lots of rocks, too.  I'm on my third set of tracks and third set of teeth.  The machine hydraulics will get hot in summer months when running it hard so I end up with about 45-minutes out of an hour of productivity.  If I'm working flat ground, it never gets too hot.  Most of the work I do is steep terrain at around 7K altitude.  I run my machine in crawl/snail mode, normally about 55-57% speed.  I run the cutter a few inches off the ground going in, and then mulch going back.  If you're not mulching on flat ground, mulch when you're backing downhill.  If what you're mulching is big/tall, top them first.  It's like anything else, you learn by doing and you have to listen to how the machine is handling the load and adjust your travel speed accordingly.  I've never had my head stop spinning unless I jammed a log/stump in it.  There's pics in my gallery so you can judge the terrain and what I'm mulching.
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davidn3

Thanks.   I saw kubota has rpm ratings on there machines.   2200-2400 rpm.  Bobcat doesn't state anywhere in the owners manual,  1000+ page service manual,  or website about recommended rpm.

davidn3

Yes I have high flow.  I think its 36gpm on Bobcats.

davidn3

Anvilrw,  could you post a picture of what dull carbides look like?  I'm running double carbides.  None are broken, but they are rounded.   It was chipping.   Just not as smooth as hoped.  What do you look at for you hydraulic temp?  Engine temp go up with it?  I'm on pretty flat terrain. 

davidn3

Also....where do you buy teeth? Bobcat sells them for $150 per carbide tooth.  Extreme wear products sells them for around $85 per double carbide.  Any other suggestions?

AnvilRW

Quote from: davidn3 on May 02, 2019, 01:08:46 AM
Anvilrw,  could you post a picture of what dull carbides look like?  I'm running double carbides.  None are broken, but they are rounded.   It was chipping.   Just not as smooth as hoped.  What do you look at for you hydraulic temp?  Engine temp go up with it?  I'm on pretty flat terrain.
I'll see if I have a pic, but I don't really go by how they look, but rather how they cut.  The teeth will start rounding over as soon as you start using them, but once the carbide rolls back into the steel cutter body, they're toast on hardwoods.  My machine alarms when the hydraulic temps get above 220F or so, IIRC.  The engine itself never gets hot, only the hydro fluid temps.  IME, mulching with a skid steer isn't like mowing a lawn, you have to pick at it.  More like mowing an overgrown field with your push lawn mower.  Here's a pic of what new teeth look like:


  
"A man with any character at all must have enemies and places he is not welcome—in the end we are not only defined by our friends, but also those aligned against us."

AnvilRW

Quote from: davidn3 on May 02, 2019, 01:21:09 AM
Also....where do you buy teeth? Bobcat sells them for $150 per carbide tooth.  Extreme wear products sells them for around $85 per double carbide.  Any other suggestions?
$85 a tooth is cheaper than I've ever seen them.  I think my last set was more like $120 each with the bolt and nut.  Changing those teeth is a job if you're doing it in the field.  Best to have someone help you.
"A man with any character at all must have enemies and places he is not welcome—in the end we are not only defined by our friends, but also those aligned against us."

Riwaka

Do the Fecon parts fit the Bobcat mulcher? 

Fecon have slip-teeth for rocky ground. 
Bull Hog for Skid Steers | FECON    (50 inch)

Supertrak run 140 horsepower for the fae 72 inch mulcher. (Similar power/ width to running a 44 inch wide mulcher on the bobcat 85hp)
FAE have a 53inch mulcher.

Yes fix the pressure gauge.

davidn3

Fecon teeth wont fit a bobcat.  I believe that's one of the only differences between the 2.  Along with the hydraulic pump.

nativewolf

Well, fix pressure gauge, get pressure as high as possible, take a small slice and it will bog down, immediately back out/lift up let it get back to speed, then lower head again and take another slice.  As others said you just can bury that head.  

Lastly, what they say works as far as GPM and Pressure is not nearly what is required for any continuous use.  

I had a massive 200+hp tractor and pto powered mulcher and could easily stop the whole head on a stump if I left it buried.  

Why did you buy it?

My feeling is that the heads are just too abusive for skidsteers, they will cause so much stress/wear on the machine that you'll be lucky to break even doing any work.  I mean lucky.  99% of people that have tried mulching with a skid steer have gone out of business.  However, you can easily rent a Fecon or similar machine if you have 5-10 acres to do and have a month of evenings. 
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davidn3

Purchased for brush cleanup mostly from trees being cut down.  Pine stumps on my trails.  Not trying to clear land.  It will probably get 50-100hrs of use a year.  But will need it here and there so it doesn't make sense to rent a machine or purchase something that is 100k+

nativewolf

Gotcha.  Well good luck with the project.  In your shoes I would sell the mulching head and once a year hire someone with a really powerful mulcher, pay them $3000 for a day and see what gets accomplished.  I am selling my own and getting a purpose built carrier.  I've hired 3 companies to do mulching in the last year and spent many thousands but it was still cheaper than doing myself.

The thing that I have to caution you on is that mulching heads ..are extremely demanding and will damage a non purpose built carrier.  Secondly, your skidsteer is just not powerful enough.  They are meant to be run on something like a T870 bobcat or the like.  Machines with lexan windows, more cooling, better sealing, etc.  

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davidn3

I believe a 770 Bobcat is 92hp and a 870 is 98hp.  My 750 is 85hp.  This isn't very far from 92.  The 7hp is probably negligible.   I will probably trade it in some day for an S870. But a mulcher this size should have no problem using 85hp. 3k per year seems excessive. 

Southside

I know nothing about mulchers, but I know plenty about making and using hay.  We used to sell around 30K square bales and probably another 2K round bales in addition to our own use each year.  It was a part time gig - decent size, but still part time.  I always "knew" we were saving money doing it that way, but I never really crunched the numbers.  Capitalization, land, seed, depreciation, maintenance, fuel, repairs, wages - including my own.  Well, eventually I was forced to crunch the numbers and you know what I came to realize - I was actually loosing money on each and every bale.  So now our hay shows up via tractor trailer, in the quality and quantity that I want, I spend 45 minutes each load getting it off and under cover, then I go back to making money.  

My point is that with any equipment intensive endeavor you just can't go by "seems", you need to dive deep into the weeds to know if you are getting the best value for your dollars.  Just curious, what does a hydraulic pump cost for your skid steer if you cook it due to the mulcher head being too much for it?  Oh - and be sure to calculate in the cost of getting any metal out of the entire hydraulic system should the pump die and FOD the whole thing.  Those are the kinds of moments you have to look at when deciding if you are betting against the house.    
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mike_belben

Quote from: barbender on May 02, 2019, 12:49:44 AM
You should be running full throttle with that mulcher attachment.
This.  Hydrostatic machines use low pressure charge pumps to feed the high pressure drive pump.  Theyre built to run at rated rpm, all of it. 
Rpm will make more gpm [more power flowing into the head to work really] which will shorten your recovery times from bogging.  Cut quality is gonna be a function of cutter tooth condition,  cutter speed and mass of the head. 
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pine

Quote from: nativewolf on May 02, 2019, 06:42:22 AM
My feeling is that the heads are just too abusive for skidsteers, they will cause so much stress/wear on the machine that you'll be lucky to break even doing any work.  I mean lucky.  99% of people that have tried mulching with a skid steer have gone out of business.  
There are many things that nativewolf has said that I agree with but some that are just plain inaccurate.
It is absolutely true that if you are working large areas and mulching those area full time that a dedicated unit is the best that you can have.  They do have downsides.  While their power and speed is unmatched, they are not to be used in tight areas and can not be used easily unless you are doing a complete mulch of an area.   They are fantastic for doing ROW work and post mulching of a clear cut.  Working around leave trees and doing "surgical" work in tight constrained areas they are not the best option.  

Having said all that if you are going to use a smaller machine (read non dedicated) then you still need power.  You can not use power that you don't pay for and don't have.  I will be the first to state that I have a predisposition against the Bobcat models for any mulching work as I have never talked to anyone that was really happy with the power that they get out of even the largest Bobcat.  Having said that the Bobcat is used by many folks for mulching and they get ok results (not good/great) but they are using a unit much, much larger than yours.  Hydraulic HP is what is is all about.  You don't have it.  Flow and PSI.
(FLOW x PSI)/1714 = Hyd HP
Now to state that 99% of folks that have tried mulching with a skid steer have gone out of business is just not true.  There are many folks that have a small fleet of mulchers that do well and have thriving businesses.  Now if you limit the description of a skid steer to the wheel only model I know of no one that is using a wheel model skid steer.  Smallest wheeled unit used that I know of is Barko 920 or 930.  Everyone is using a tracked skid steer (CTL).  Your statement that you have grouser tracks tells me that since you have a bobcat 2013 s750 which is a wheel model that you have a set of outside the wheel tracks for it.
Everyone that is successful with mulching with non-dedicated units use the largest machines they can find.  Smaller machines less than 100 hp are just not big enough in general.  
Now that is not to say that you can't do it with what you have.  You just have to learn how to use the equipment that you have and learn not to get too aggressive with it and bog it down.  All mulchers can be bogged down if they are asked to take too big a bite.  An experienced operator learns when to back off.  Double carbides are not "sharp" even when new.  Show us a picture of yours taken from the side and from the front.  The side view is very important to know how much carbide you have left.  Having said that you stated that you spent 18K for both head and SS.   That does raise the issue as to what may not be working correctly.  A good used Fecon head that is not worn out, is by itself worth about that price.  You have head and machine for that. Teeth are not cheap and if they are, that tells you something by itself.  
I am not that familiar with the Bobcat design head that is made for them.  What style rotor does it have?  Is it like a FGT, a HDT or a DCR style?
If your unit does not have side window guards and a Polycarbonate (bullet proof) front window I really do not recommend you use it until you have replaced/installed one.  It is a death trap and that is not hyperbole.  The first time something comes through that window and impales your body, you leave your family without their father/spouse.  It does not matter if it is wood steel or rock it will kill you.  There is a reason that the mulchers all state 300 feet danger area all directions.

nativewolf

@pine is absolutely correct..I am prone to hyperbole :D.  That said his particular bobcat model and mulching just seems a recipe for unhappiness.  @pine makes good points.  
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pine

Quote from: nativewolf on May 04, 2019, 06:57:20 PM
 That said his particular bobcat model and mulching just seems a recipe for unhappiness.
There is absolutely no disagreement in that statement. 
He (OP)will need to be very patient to get the work done with that combination even if all is working at the best of its tuned capability with the best knives.  The statement about using knives:  In general knives take less HP to run than do double carbides.  Finer product and you sharpen every day and maybe twice a day but they might help with the power that is available.

davidn3

Thanks for the help.  I didn't realize I needed full throttle.   Anyone know where to find a pressure gauge and line?  I'm sure bobcat could get me one at double the price.  But it looks generic enough to get elsewhere.   

nativewolf

I would talk to your bobcat dealer but my understanding is you should always be operating the skidsteers at close to max throttle.  That's the sweet spot for both hydraulics and diesels.  Now others may correct me on here but I would definitely ask your dealer about this.
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