Stumper experts help the dim

[TimberMcPherson]

Right some basics of stumpgrinding. I have a couple of em (really just toys for most of you guys) but other than run em and read what I can on here. I have a few things I would like to know to understand how they really work. I would be interested in your guys input. I do understand different teeth system will changes the answers but lets assume we are talking about green, shanks, supers or simular teeth sets. (to complicated to factor in tornado, multitip etc)

First-is there an ideal cutter wheel speed?
I understand that we would usually measure wheel speed in RPM BUT different stumpers have different size wheels, so RPM would not be the only factor in figuring out the actual cutter speed at the tips. I have read that around 10,000 ft per second is about right. which equates to less than 1800rpm on your average grinder.

Second- Are more teeth better in general? obviously they would make for a smoother grind and woud eat some power, but is there an ideal distance between cutters or is it all contextual to HP?

Third. How do you match power to performance. is there a rough theory to match wheel size (or rather overall rotating tip diameter) to the power output? Should I mess with getting more HP out of the engine if its at the sacrifice of torque?

Forth. at what point does weight start being a factor?

My questions relate to getting a 25hp dosko or carlton or rayco walk behind and throwing a bigger (close to 40hp) engine on it and maybe changing the cutting head if it would help. (site access is a big issue here)

Then later I am looking at building a big grinder, something that will compete with tracked unit that I dont have the $100,000 for here.

Thanks in advance!

 

[jhg]

Second- Are more teeth better in general?

Forth. at what point does weight start being a factor?

My questions relate to getting a 25hp dosko or carlton or rayco walk behind and throwing a bigger (close to 40hp) engine on it and maybe changing the cutting head if it would help. (site access is a big issue here)

Not an expert, but I think momentum (weight) is what you want in a grinder wheel over speed. However, I noticed that the larger machines I have run had fewer teeth by far per area on the wheel as compared to smaller grinders. To remain competitive in material removal smaller grinders rely on more teeth taking smaller bites at a faster rate.
Even with a 25hp motor on a 252 you can over feed to the extent that it will TRY to walk up the stump rather than hold the wheel to it. Of course a stall is coming too, but you get my point.

Your limiting factor in performance regarding what you plan to do is the weight of the machine itself. You won't ever be able to take full advantage of that HP because the machine cannot hold it to the work, unless you use a wheel with a lot of teeth taking small bites- probably as fast as you can feed it.
I would say sharp teeth are important too, because dull teeth will ask the machine to hold them to the work which it can't do very well. So keep teeth that can cut, rather than bludgeon, the stump into mulch.

Joshua