Stump Grinder Build

Agent Blue · Oct 21, 2012

Looking to start collecting materials for a three point stump grinder build. Anyone have experience with this or know what works best for an arbor / disk to mount the carbide teeth on ? The frame looks relatively simple with the swival and I have a heavy duty angle gear box, pto shaft. A few researched details and it sounds like a cold february project.
Just off the top of my head I was thinking of a one ton truck front independant suspension drive shaft to hold the disk. The only drawback I can see is the machining of a disk to fit the wheel bolt pattern and of course cutter placement. It might be wise to start with a commercial 24" or so disk and build to fit it. Course the cost is a major factor as they might be pretty pricey.
There has to be at least one brave soul that went this route. I would like to participate in your learning curve.

muddstopper · Oct 21, 2012

I think I would forget the 1ton truck anything for mounting the cutter wheel. Shaft size just isnt big enough. Instead i would consider using two pillowblock bearing mounted on each side of the cutter wheel on about a 2inch shaft. You can machine a hub to weld to the shaft material to bolt the cutter wheel to. I would pull the cutter wheel using vbelts, B series, and probably three belts. Anything solid like gears or chains will break under the stress of the cutter teeth contacting the wood. If you already have the gearbox and tractor, your biggest cost will be in the plate material for the cutter wheel. I would want 3/4 to 1 inch minimum thickness for this plate. It needs to be strong enough to support the bolts that hold on the grinder teeth as well as to prevent flexing as it is worked side to side thru a stump. There are several different kinds of grinder teeth on the market, most common for the smaller grinders are the 1/2in keystock with the carbide tips. I havent bought any in a long time, but these used to be close to $10 each. The Rayco super teeth are much higher, but they wouldnt fit my little grinder so I never bought any of them.

I dont remember any of the tip speeds recommended for grinders, but I do know that the dia of the cutter wheel needs to be taken into account when choosing the proper gear ratio for turning the cutter head. I would highly recommend that you research the tip speeds of commercial grinders to determine pully size needed to pull your grinder at the proper rpms. Since your tractor pto and gear box are already pre-determined by using what you have, the pullies between the gear box and the cutter wheel will be the only way you can adjust your tip speed.

jimmysisson · Oct 21, 2012

Someone else posted in this topic recently. One suggestion was to make the head move side to side hydraulically and maybe fore and aft too so you don't have to keep moving the tractor a tiny amount.

Ductape · Oct 21, 2012

There have been a couple grinders made by TBN members in the past. Take a look here for ideas....

http://www.tractorbynet.com/forums/build-yourself/147454-stump-grinder-finished.html

Agent Blue · Oct 21, 2012

Ductape;
Thanks for the thread. I was looking through a bazillion posts when I tried to search for stump grinders. It brought up everything imaginable besides what I wanted.
I have viewed the grinder in the post and a short shaft with pillow block bearings is the simple and best solution. Most all the examples I have seen are hydraulic side to side cut moved by a cylinder. A verticle attached hydraulic cylinder provides good depth control and a solid mount. There is no question on the three point mounting structure. It is basic and very simple to build. The chain drive is looking like a winner. In this application belts in a short distance with small pulleys are not going to provide the constant torque needed to cut hard wood. I would feel better with a chain drive system. I want to stick with a 20 - 24" wheel. ( what I can find precut in a circle may also play a role in the final choice. ) Too small diameter means moving back to many times on a larger surface. Both machines are outstanding and should last a long time. Cutter teeth layout might take a bit of planning but that is a task left after the basic drive wheel is completed and attached. The PTO clutch is also a good idea.
Thanks for the post and information. My planning is leaps and bounds ahead with alot of new ideas to work out.

kruszert · Oct 22, 2012

You can get a lot of info by looking through the on line manuals for commercial three point hitch stump grinders - - Worksaver SG-26, Woods TSG 50 have parts diagrams. Chain is what they use. Teeth can be purchased from Green Mfg., Morneci, Mi. They can also help with proper tooth layout.

I have used mine a bunch. It works similar to a Vermeer SG 252. I ended up with about $1800 invested vs. $4000 - $5000 for a comercial one.

Reggie

Ductape · Oct 22, 2012

Just a little food for thought.......

Look at the Stumpster. No hydraulic swing, and no need for a 90* gearbox. Grinding wheel is driven directly by the PTO shaft. Just a different design that might be easier to copy.

Grinder 3000

Agent Blue · Oct 22, 2012

Not to knock the Stumpster technology but I like the orentation of the wheel in line with the tractor. I could see the advantage when they use a large diameter wheel... no moving the unit, just back and forth for a good size stump. The speed, where do they get 750 rpm with most tractors having 540 and larger units both 540 & 1000 rpm ? It is direct off the pto shaft so no increaser for speed.

I like the simple design Kruszert used in his build. Using a tried and true structure design, pillow block bearings for long life,hydraulic cylinders for direction control, and chain drive with an option of changing the rotation speed. Also with an additional wheel could be used for trenching, but I have a backhoe for that. I have a heavy duty angle gearbox in stock 1 to 1:50 which should work great....... I just have to locate my " wheel of fortune " and build around it. The search begins.
I just knew there were some good ideas here I could borrow.

brandoro · Oct 22, 2012

BaumaLight - Stump Grinders

I have one of these and am pleased with the operation. It really likes pine stumps and does well enough on fresh poplar stumps. Walks right through half rotten stumps. Not sure how handy it would be with a gear tractor but works nicely with the hst.
The one I have is the 1P/34. Not entirely clear where the link takes you. Simple design and cheapest by a significant margin. I don't have hundreds of stumps to grind so cheaper was important.

Tractor Seabee · Oct 22, 2012

I have considered building a stump grinder using a walk behind derilict and modifying to attach onto my BX 25 BH mount and use the BH hydraulic connections for a new valve array for up/down/left right, forward/back. A couple cylinders with feet on the front would allow attaching same way the BH does. Any thoughts out there or has someone already done this scheme. Been looking around and advertising on Craig's list for that used machine with a dead engine. 20-30 horse engine reeplacements tend to make an implement into scrap quickly.

Ron