Most companies doing forestry mulching use drum mulchers for the excellent mulch they make but they charge more too. I am looking to cut prices using a disc mulcher. Diamond Mowers ads say they have belt drive two speed disc mulcher that spools up in only 13 seconds. They only offer a 60" deck size in it. Some companies (including Diamond) offer smaller size discs (CID has a 44" model). My questions for those who know about it: 1. Does the smaller diameter disc spool up any faster? How much? 2. Is it worth it to run a smaller disc mulcher for the faster spool up times? 3. Does a high flow system make any difference here? 4. Anybody tried the Diamond belt drive system disc mulcher yet?
answers: 1) There will be a mathematical equation that will give this answer if you know the center of gravity, the rotational mass and some other variables that I've forgotten over the past 35+ years. You should be able to write up a quick spreadsheet and enter variables for a quick comparison of different size disks for that equation. With today's internet, it should be easy to find this formula and make size to time comparisons adjusted to relative energy input and speed. 2) From my experience, if you stick with 3" material and smaller, you might make better time with the disc mulcher.......maybe. The job will not look clean but you might get it done faster than with a drum. (cheap-good-fast : you only get to pick 2 here) If you run a smaller disk, you have to run more passes -where does that save any time? If you don't cut the width of your tracks as a minimum, you might as well stick to the short bus for your transportation requirements. ALWAYS cut the outside width of your tracks/tires as a minimum. 3) High flow systems transfer more energy and will make a huge difference to performance. The higher the pressure, the higher the torque. The larger the displacement of the hyd motor, the higher the torque but higher flow rate required to turn the same speed. All of this is easily worked out through basic hydraulic engineering equations for a simple comparison. A variable displaceent motor is the most efficient energy transfer to any cutter, giving high torque at low speeds and full speed performance at full flow. 4) No. I still have a Davco 705 that I last used about 15 years ago. Unless I need to trim out under a fence line or cut grass, I have no use for a disk type cutter. Too limited, too dangerous and too slow for me to consider anymore. They have their place but not in my operations. My weakest machine is 45 gpm @ 5,100 psi at the cutterhead and it is painfully slow for me to operate. It's likely 5x or more slower than the 105 gpm @ 6,500 psi that I normally operate. I have not owned anything as small as a large skid steer for over 12+ years because efficiency matters to me. YMMV. My typical spool up speed from a dead stop at full throttle and 6,500 psi relief is well under 2 seconds. A 13 second spool up would be an eternity for me.
Smart reply. Thanks. Formula for hydraulic horsepower is HHP=Q*P/1714 so you've got 45*5100/1714 = 133hp and 105*6500/1714 = 398hp for your gear, so you're running high end gear. Yeah I am targeting the private home owner and small businesses who prefer small chip sizes for looks and rarely buy more than a days worth of mulching before they hit their limit. Thinking a 60" drum mulcher run on a Takeuchi TL12 (high flow) to keep costs down. I did a survey of my competition- they mostly run Takeuchi TL12s, John Deere 333Gs and Cat 299d3s charging about $175 an hour. I get the feeling they do not make a ton of money, but you got to start somewhere and there does seem to be a steady market for this. I run a backhoe/bobcat service and I am looking to expand into mulching.
My insurance bill just came in for my annual liability insurance. That is now at 150% of what it was last year. I have never had a claim in 30+ years of business. Don't forget to factor this into your rates. I might go up another 5% on the hourly rate to help offset this increase. Parts, fuel, service, insurance, vehicles and more.....everything has to be covered by that hourly rate.
I'm assuming you're looking at an excavator mounted unit? I have a flail mower, and rotary mulcher for my excavator, but do run a Davco rotary unit on my high flow skid steer. For sure go high flow. Night and day diff. My rotaty unit will do about 3 to 4" product, depending on what it is. You don't get a clean cut at the base is the only draw back. Anything bigger dia. sounds like it'll explode and is very time consuming.
"I'm assuming you're looking at an excavator mounted unit?" Yes I was, but I have decided 14gpm is just not enough power to do anything with. Even the midsize skids have 20gpm or so. I would not want to run a mulcher or a large brush cutter with less than 25gpm. The serious brush- cutting people have over 30gpm and up.
There is always a niche but you have to be able to find the clients who will pay for it.