Home made stump grinder build

[imalogger]

I just thought I'd share this for anyone else who has thought of doing the same thing.. Around 4 yrs ago I built a small walk behind grinder with a 13 hp motor. It works good on the smaller stuff and it definitely got my name around, but once ppl find out you grind stumps, stumps come at you in all sizes. I did a few 3 foot+ stumps with that just about killed my enthusiasm for grinding.. (and wrists & back) I just grind as a sideline so I couldn't really justify spending big bucks on a grinder that's not gonna get used every day. I rented a 1635 from the hardware store one time to do a bunch of big stumps I didn't feel like doing with my small one, but like most rental grinders, the teeth were horrendously dull and it was a pretty long day. I already owned a bobcat so I decided to build a grinder for it. I started on it over a yr ago then got busy with other things and it sat till about a 6 wks ago when I realized I just need to get this thing done. I have no idea how many pounds of welding rods I burned up, but it was a lot. Most of the metal came from auctions, the engine from Craigslist, and the teeth from Baileys. It's crude but I like being able to walk into the hardware store or deere dealer and get off the shelf bearings, belts, chains and sprockets, ect.. for it. I just ground out 3 stumps with it yesterday for the first time and it worked pretty well. Blew threw them like nobody's business ( at least compared to what I was used to) I know it's no 8018 or rg100 but given the amount I grind and I'm the only one running it I think it should do the job. Time will tell.

 

[MOE]

Looks good. Does it pivot or do you move the skidsteer side to side? I've always liked the idea of an independent motor for any kind of skid steer without high flow. The only suggestion is to fabricate some kind of belt guard so you aren't running the roller chain in the dirt or have a chunk of stump get in it and break or throw the chain.

 

[imalogger]

Yeah it's got a swing cyl, and a fairly wide sweep cuz the cutters are over 4 ft in front of the pivot point. I didn't want to tear up ppls grass more than I have to by pivoting. It is pretty heavy so that takes quite a bit of weight off the back of the Skidloader and doesn't mess the grass up too much. Yeah I thought about a guard on the chain, wanted to make sure the thing actually worked before I stuck any more time & $$$ into it. Ive got some customers breathing down my neck to do some big stumps so ill prolly run it like that til I can get a guard made. $40 for a roll of 60H chain is still way less than rent and a lot less than losing the customer and job. And a lot less than Polychain:hmm3grin2orange: Yeah a high flow skid loader was out of the question and the aux hyd on this machine at an idle puts out the perfect amount for running the swing cyl. It puts all 25 hp to the cutter without the drain of a hyd pump which is nice.

 

[third rail]

Hey that thing is way cool. I love American ingenuity. One question though, can you see what your grinding when your in the machine? It certainly has plenty of room for the chips! -Mark

 

[Mike from Maine]

I love it. But OSHA won't -- put some guards on it. Or you'll be saying you could have bought a new one for what you paid in fines.

 

[imalogger]

Alright guys, you asked for it, I built it - fabbed up a crude guard for it and ill see how it works tomorrow. Third rail- it's not too apparent in the pics but the beam is mounted 6" right of center. Makes it possible to see a little more than just the back of the engine, but it does take some getting used to grinding mainly by feel and just try not to get too greedy with the feed rate. View attachment 299025

 

[millbilly]

I don't wanna be a Debbie downer but how do you clear the path that the wheel sprocket travels? The older vermeers attached cutters to the bottom pulley( where your lower chain sprocket is), to remove the soil or what have you out of the way. Or you would need a much larger cutter wheel to get any depth

 

[imalogger]

Yeah a bigger wheel would be nice, but this is what I had to work with at the time. I made it with enough clearance so that I could put in a bigger wheel in the future if I wanted to. The cutters have maybe 5 inches or so below the bottom of the chain case. Clearing a path for the sprocket is pretty simple, when I get the stump down to ground level, ill drop down 4-5 inches so the cutters chewing the ground and the stump and the chain case is just clearing the ground when it sweeps. Since the machine has got so much swing, ill swing about a foot and a half past the right side of the stump, chewing out all the dirt, leaving an open spot for the chain case to swing into when I drop down another 4-5 inches. At this point the stump is 8-10 inches below grade. If I need to go deeper, ya just make your initial sweep wider, and the hole ends up with "steps" as it gets deeper and narrower. Might put on a vid of it working if I can figure out how to load it.

 

[Rookie1]

I like it! I like the fact that you made it. Youll get no Debbie downer comments from me. All I can say is put some paint on it so it looks a little more finished.

 

[MSgtBob66]

Awesome!

That thing is way too cool. Paint 'er up when you got time, awesomer!

This is why I got into stumpin'. I get to work on the equipment that I get to use.; Fabbin, maintenance, etc.

Stand by for my stumpin' trailer.

Semper Fi & Good Luck,

BOB

 

[LarryRFL]

Looks cool! Only negative I see is the grinding disk is chain driven. I'd go with a banded 5/8" belt (2 B belts banded together) instead. If your grinding wheel jams for any reason, there's more chance for damage. With a belt drive, your belt will slip or snap without much damage. If your chain breaks, lots could happen. Use the chain drive between the engine and the chain drive shaft.

Sorry. Too many years dealing with power transmission stuff selling industrial supplies. Still, way cool.

 

[imalogger]

Well I'm not an engineer, didn't go to collage or anything but I've spent pretty much my whole life running and fixing farm equipment. I like v belts a lot. More than chains really, but I didn't think this was the place for v belts on the final drive.. I'll explaine. Belts tend to do a lot better at high rpm applications and chains at slower speeds. Chains at high rpms wear pretty quickly unless their in an oil bath like a timing chain on a car or truck. Belts turning at slower speeds with high torque loads tend to slip badly unless your running really big pulleys for traction. By the time the power hits the jack shaft it's been geared down about 4 times. That's a lot of torque from a 25 hp engine and I suspect you would need some pretty large pulleys to keep the belts from slipping, and there isn't much room down there for big pulleys. I'm running a tripple pulley on the engine and with the belts reasonably tight, it will slip the belts if I happen to stick the grinder, which does happen now and then cause other old bobcat isn't the smoothest machine and being the grinder is pretty long it really amplifies your movements. Id say i got about the right amount of slip for a safety margin. I know I'm not running banded belts which really help cut the slip, but if I'm slipping a 3 3/4 tripple and slipping it occasionally, with 4x the torque I think I'd be slipping it an awful lot. The bottom chain sprocket does have 2 shear pins on it for if things really get ugly, but so far I haven't sheared them. I know what you mean about chains making a mess of things when they bust, I saw a busted timing chain cover on a Buick from when the chain broke. The outer skin of the guard fairly light gauge so when the chain breaks, it should give away instead of having no where to go and bending the gear or cutter head shaft. On most farm equip the final drives is made manly enough to handle whatever gets thrown at it and that's the last place you want slip. It's generally the input that will slip or bust. But like I said, I'm not an engineer..

 

[ritchie426kiwi]

Can we have some pictures of your stump grinder please

 

[superwrench]

I ran a search for home made stump grinder and brought up this thread, so I'll revive it. About 12 years ago I got motivated to build one, I'm going into my second year of using it. Immediately I've found things I want to change. Also figured out I'm no engineer nor hot dog welder. It still amazes me how much a stump grinder cost, for the only one purpose it has. This has been just a part time gig for me and will be for a while till I retire from my real job. I'm fortunate to have a good friend in a tree service to throw me some work to help me recoup the expenses from my hair brained idea of building one. I built it as a self propelled unit with a 35 hp vanguard powered engine with a New River 1 1/4" thick cutting wheel that's belt driven.

 

[MacAttack]

I gotta tell ya... that's pretty damn resourceful! That looks more rugged than the gutless turd portable Vermeer that I had to use with a crap-running Kohler when we had to do a stump in a backyard.

 

[superwrench]

Thanks Mac, I did go for durability & longevity, not sure about the engine. I had nothing to go from as far as dimensions, other than pictures & videos. From there,,, it was by guess & by gosh. More than likely I'll be upgrading the main hydraulic control valve and go wireless control. Right now I'm with a wire pendant control. But as you can see it's basically a clone from others,,,,, just heavy duty.

 

[MacAttack]

I'm more than a little impressed with that build, having run different stump grinders. There is no magic science behind it, if it has good power and the drive system can utilize the engine power without slipping, it will work!
Apologies if I missed this, but do you have a variable pressure / rate control knob on the hydraulic circuit for the left-right "sweep" control? In my opinion that's a critical thing on a stump grinder, to adjust that pressure so that you can apply steady pressure while making your sweeps across the stump without having to repeatedly go on and off with the hydraulic lever?
Again ...amazing work here.

 

[superwrench]

Mac,, I do have a adjustable orfice valve in that circuit for swing & for boom down. Unfortunately I went cheap on my main control valve bank, & now kicking myself. My hydraulic pump is a little on the big side, so as when you start to pinch down the flow to achieve your speed on swing, the remaining oil flow is going against the high pressure relief valve to get back to tank. That’s not good, as it takes some power from the cutting wheel, and is converted into unnecessary heat being put to the oil in tank. That’s why I want to change out the main valve bank I have now. Going to go with one that has a proportional PWM controlled flow cartridge valve assembly on the end of the valve stack. I have just the one in my mind that I’m going to go with, I had it on a crane on a mechanics service truck. Boy!! That was the best smoothest operating crane I’ve used. You could push any of the toggle switches & nothing would happen, until you squeeze the gun trigger that provides the current for the PWM oil flow valve. That valve is designed to send the extra oil not needed freely back to tank.

 

[superwrench]

Some more pictures.

 

[Kgw51gmc]

Where in the hell did those awesome tires come from!?