predator st661 stump grinder

[treevolution]

Has anyone brought or used one.

 

Just after reviews as looking at an alternative to the Alpine Magnum grinder.

 

Thanks

[treevolution]

Bump

[Timbermcpherson]

I havent seen one of the predators in real life, but the chainsaw grinders look great in short vids but the reality is they require VERY sharp teeth design (as they lack weight or power like other grinders have) and blunt really fast on dirt, stones etc due to that design and the higher grinding wheel RPM from the saw, and the teeth tend to be expensive. 

They  are pretty hard on the operator, you certainly start to feel it after a couple hours.

 

Any idea how much the teeth are? your going to be changing and sharpening them a lot

Edited December 29, 2018 by Timbermcpherson

[Stumpzy]

Yes I too use an Alpine Magnum and when I saw the ST661 last year and I must admit it looked like a good replacement for my Magnum, lighter and more compact too. But having used one and talking to a couple of users we all seem to be complaining of the same issue and that is that there seems to be a fundamental problem with the "Bite". When you want to be grinding into the stump the wheel has little bite and likes to spin a lot making it unnecessarily hard work, something is not quite right with it yet. You do have to exert force and really push and force it in towards the stump and with no spike leg like the Magnum you have to have one foot firmly planted on the wheeled leg at the same time as exerting force, maybe just a different technique to learn but it does lack the bite without a doubt, and Predator seem to know but be in denial or at least the feedback has gone back to them and wasn't accepted.

 

Theres a 3 month old one for sale on eBay right now as the guy has given up with it and i believe Predator replaced the first one he had as it was faulty and he downgraded it but still not happy so he's put it up for sale and gone back to his previous machine. Maybe Predator will read this and take the feedback on board and refine the design, Im sure it could make all the difference if it could do the same workload as a Magnum at half the wight size and cost it could be a winner.... but in my opinion just not yet and I held back from buying one because of that.

Edited March 14, 2019 by Stumpzy

[marne]

Never used one, but have quite some hours spent with my Alpine. 

 

My first thought was, that it is incredible light, half a magnum, which definitely seems like a great thing. After thoroughly investigating the videos, it seemed like exactly what you described: the machine or at least the grinding head seems too light and needs to be pushed in the stump. An Alpine literally drops into the wood and with experience you learn how to use it with minimum to nearly no effort. Only dragging it up a steep incline, where the wheels can't be used is pita. AV gloves are a must. 

Maybe on the predator they should change the pivot-point's position more toward the engine. 

Edited March 15, 2019 by marne

[Høydeskrekk]

I've had one for a little more than a year.  Can't compare with the Alpine as I've never used one, and it was about twice the price of the Predator.

 

I had to send the unit back to Predator as it overheated and melted the sheave carriers.  Partially due to me being a bit careless about tightening the drive belt as I was breaking it in, and partially because, well, they were plastic carriers.  Predator replaced the sheave carriers with metal ones.  I've since developed the routine to regularly feel if the grinder head is getting warm.  If it is overheating, it's a sign of the belt slipping and time to tighten the drive belt a little more.  With the new bearing carriers, and proper belt tension, the unit has not given me much trouble since.

 

I haven't used it a lot, but it certainly has paid for itself and is great for those stumps that you just cannot access with heavier machinery.  The largest stump I've done with it was probably 60-70 cm diameter, and really a bit too much for this small machine.  But hey, it was good money and a good workout to boot

 

As others have mentioned, it really is important to keep those teeth sharp.  Last time I ordered new teeth, they were GBP 9.95 each.  The wheel is great for - well - wheeling the unit around.  Keeping your left foot on the support may get a little awkward if the stump is on a slope, but is generally not a problem and it isn't always strictly necessary to keep your foot in place, even though Predator says so.  The pivot point for the leg is just a clamp around the main shaft and can be easily adjusted.  One of the few things that bugs me a little is the bayonet style mounting for the leg.  The leg is mounted by angling the wheel all the way towards the engine, and when really reaching out with the grinder it may inadvertently come off.  It really isn't more than a minor nuisance, though.  The positive thing with the bayonet mount is that the unit is easy to put together without tools, and it has never really come out of control because of this and I have never felt that it has caused an unsafe situation.

 

 

 

 

Edited October 24, 2019 by Høydeskrekk