Tub vs. Horizontal Grinders

[coopers]

Curious if anyone has a lot of experience with the two and why would one be better than the other? I'm interested in grinders for grinding up green matter for composting. Since I have never had to use a grinder I'm curious to hear from those that have. The horizontal would be nice I would think because you can modify the feeding area and put a strong magnetic strip above the belt to take out any unwanted metals from the brush dropped off by customers before it get's ground up. Any and all thoughts and opinions is appreciated.

Thanks

[ksss]

Curious if anyone has a lot of experience with the two and why would one be better than the other? I'm interested in grinders for grinding up green matter for composting. Since I have never had to use a grinder I'm curious to hear from those that have. The horizontal would be nice I would think because you can modify the feeding area and put a strong magnetic strip above the belt to take out any unwanted metals from the brush dropped off by customers before it get's ground up. Any and all thoughts and opinions is appreciated.

Thanks


I think the Horizontal Grinders are more safe. You are restricted more in the size of material that you can grind. Tubgrinders are not as picky, but you often here about them launching material to the moon. I would think for the application you describe that a horizontal system would be best. I think the tub grinders are more suited for grinding out on in the "sticks".

[Gravel Rat]

A tub grinder can swallow pretty much anything except for metal and rocks of course. I worked with a horizontal grinder it was okay but definatly slower than a tub grinder. As KSSS said they are safer which is true you don't have stuff launching through the air like a tub grinder.

If your just grinding up green waste like trees and no stumps a horizontal grinder is a better option. If your doing stumps or large items then a tub grinder is better.

Tub grinders are expensive pigs to own and operate you really don't make much money with them because you are repairing them regulary.

[jefftb]

Tub grinders you can place material of just about any size in while horizontal grinders you will have pre-grinding size reduction in some instances, aka slice and dice something before it goes onto the conveyor.

Grinders are very expensive to own/operate and you had better be a high volume production grinding operation to make it come out in the end. Umm, so to speak.:rolleyes:

[Mr. Vern]

I own a Hogzilla tub grinder, and agree with everyone's assesments so far. Our machine is one of the largest made so it will grind just about anything, but at a very high price. There are a lot of tradeoffs in grinding, and it totally depends on your application, but a horizontal is orders of magnitude safer, but as was mentioned, more limited in what can be ground. Additionally, steel is the number one enemy of a grinder. Rocks are bad, but they will break up. Steel just keeps going around and around until it blows a hole large enough to get out, or in the case of a tub it might be ejected out the top. If you get steel into a horizontal, you can grenade the entire mill before you even know it is in there - this can happen in a tub as well, but it's more likely to happen in a horizontal. If you are near other businesses or where people and property can be damaged, horizontal is definitely safer. Everyone of our trucks has damage from flying debris that has come out of the tub. It is not uncommon for it to throw debris as high and far as 200 feet. It's awesome to watch, but it sucks when it hits your other equipment or the cab of the excavator or loader.
This one piece of advice I would give: if you can avoid owning a grinder and still make your business work, do it. We have been threatening to sell ours for the last 3 years because at the end of the day something always goes wrong and you don't make any money with it. You will also need to have a dedicated crew that can wrench and weld and fabricate if you get into this business.
Good luck!

[coopers]

Thanks guys. I've heard how much a pain these things are to own. I have a few companies that I can rent from to avoid owning. I'll probably just pile the brush up and when the time comes where I know I can get 4 plus windrows of compost I'll rent and grind the stuff up.

[jefftb]

As a followup to your rental statement, pay close attention to the terms of the rental. Generally there is a minimum and they require that grinder rental company provide the "operator". Here's the biggie in most agreements, you are responsible for all maintenance/repair of the machine while on your project. I have a serious problem with that given a possible scenario...the machine is three years old, 3000 hrs, the previous rental was for storm/hurricane damage for two straight months with good lord knows what shoved in it. It fails on the final day of your five day job and your responsible for the $15,000 repair bill. Check the consumables portion of the rental as well.

[Gravel Rat]

I forget the rate for a conctractor to bring in a grinder but the last I remember it was 1000 dollars per hour. They charge this rate because tub grinders are expensive to operate.

I don't think I would want to rent a grinder of any sort it is easier to have a contractor with one bring it in you load it the guy operates it.

[YellowDogSVC]

if you have the room, and want to grind to compost, just use a brush mulcher mower. I mix in the shreds from the mulcher with chips from a Vermeer bc2000 and get fairly rich material and I don't even try and compost for end product but rather ground cover and rock cover. there are a number of small machines that will do regrind and leave a good product. Vermeer has an ultra small horizontal grinder for regrind which may work well for what you are describing if you chip the bigger logs (> 12").

[AWJ Services]

You are better off just to store the material and then hire a company turn key to do the work.
If that will not work out finacially then owning a tub grinder is out of the question.

The Tub grinder players here send a 953 and a 20 ton excavator with a shear for grinders that have a loading crane.If they do not have a loading crane then 2 excavators and possibly a loader have to show up.

Companies here charge around 2500 an acre to clear land and haul the grindings away.Not much money for a million+ dollars of equipment and a bunch of man power.

[coopers]

YellowDog,

That is an interesting route I might consider. I'm all about avoiding this major pain of operating/renting/owning a grinder. A guy I used to work for when I was younger did just this. He'd use a mower/mulcher on a tractor (not sure what set up you use) and grind it down best he could. I don't want a mulch/bark coarseness to the material, it needs to be a fine compost (small small chips) for amending into the soil etc.

Jefftb,

If the rental agreements are going to have all those nice traps in the contract then it seems almost no different then owning one and just as much of a headache. Nonetheless I will look into the rentals, if they're not in my favor I'll scratch that and looking into something like YellowDog said or possibly have a guy come in and do the work for me. The biggest thing with compost is the timing. Don't want to run out before you've been able to compost and screen and I don't need the cost of grinding up the compost to be so high I can't keep up with selling the end product.

[jefftb]

YellowDog,

If the rental agreements are going to have all those nice traps in the contract then it seems almost no different then owning one and just as much of a headache. Nonetheless I will look into the rentals, if they're not in my favor I'll scratch that and looking into something like YellowDog said or possibly have a guy come in and do the work for me.

The rental agreements are most assuredly in their favor on grinder agreements. This is their transfer of risk and O/O costs on the machine to each rental-it effectively makes their cost of ownership almost nothing except the capital involved and its capital rate.

I had a project 2.5 years ago that I evaluated the cost of rental versus letting it go lock, stock and barrel to a sub-contractor. I could have made some money on the grinding portion but the perceived risk profile in my mind at the time did not cover the profit margin on that part of the project. FYI-the grinding would have cost $35,000 minimum for the rental.

My personal preference is always to pay someone I know money to do a job or work for me than someone I do not. The job went to a subcontractor:drinkup:

[Mr. Vern]

I can't imagine a rental yard ever renting a grinder of this nature to anyone without an operator coming with it. If you were to pick up a grinder from a rental company and try to run it on your own, you would be lucky to just destroy it, and far more likely to kill yourself or someone else. I don't say this to sound arrogant, but the learning curve on these is incredibly steep and there is no forgiveness in the process!
The reason there are damage waivers is because a $20 sledge hammer left in the pile can do tens of thousands in damage and possibly kill someone. My recommendation is to get someone in at a per ton price if you have an accurate way to measure tonnage, if not then just get a firm fixed price and go that way. Hourly can be a huge loser for you! I can spin my tub backwards and make you think I am going balls to the wall and only be putting out 20% of my capability. When doing hourly, you have no way of knowing what the guy is producing until it is too late.

[coopers]

Mr. Vern,

Thanks for that info. That's helpful and I'll remember that when outsourcing.

[AWJ Services]

Here the tub grinders usually just price it by the job.Very few work by the hour except maybe for special circumstances.

Oh and on a side note the tub grinders can absolutely throw a chunk of wood an amazing distance.

[ksss]

There was a guy years back that built his own tub grinder. He had a Cummins motor and truck transmission for a power plant. I had seen the grinder before, looked like crude as you would expect. He was grinding something that was stronger than his grinder, the grinder grenaded with him on it. He was DRT (dead right there). That was on a road project near Yellowstone.

[coopers]

There was a guy years back that built his own tub grinder. He had a Cummins motor and truck transmission for a power plant. I had seen the grinder before, looked like crude as you would expect. He was grinding something that was stronger than his grinder, the grinder grenaded with him on it. He was DRT (dead right there). That was on a road project near Yellowstone.

Sucks for him.

[mautz]

When hiring a grinder a good rule of thumb is $1 per horsepower per hour.

Here is a video of us grinding.

http://www.youtube.com/watch?v=qO_dDFne4IU