Hydraulic Powered Mower for 1.5 ton mini-ex

[MossRoad]

Thanks for the responses. Mossroad, great having somebody with one of these chiming in so quickly. I had thought I had seen a hydraulic mower on an articulating tractor at some point and double checked the Ventrac but found that they are belt driven. I checked out your site and some of your videos. Very cool machine and it looks like the equivalent specs on your PowerTrac run the bush hog very well on vegetation up to and beyond what I'd be taking on with my machine.

I have thought about and considered some of the safety concerns. I would undoubtedly be curling the mower and am quite aware that curling it inwards with the blades facing me is not a good not just for blades but flying debris as well. My initial thought for a solution is to set up the mount to where the full curl inwards would still keep the mower parallel with the ground surface while allowing the outward curl to point the business end of the mower away from me and the machine. This would also hopefully leave a good stopping point to level the mower with the ground as well. Though I wouldn't plan on riding the mower on the ground all the time I have had some concerns about getting too much weight of the machine on the mower from time to time as well. So some re-engineering of the caster set up would possibly be in order as well.

The heat concern makes sense but is a bit beyond my rudimentary knowledge of hydraulics to know 100% if there would be a potential issue at this point. Like I said I know that there are some very expensive flail mowers that are supposed to work out of the box on my machine. I doubt that there is any type of auxiliary cooler involved with these mowers but there is a gear drive on those mowers and I do wonder if that lessens the heat load on the hydraulics. Also I was not 100% sure why the manufacturer of the rotary cutter said I'd need a case drain to run their mower with a direct drive setup. I thought it had something to do with foaming of the hydraulic fluid but perhaps foaming and heat build up concerns are one in the same thing.

But then again I am not sure I am not exactly understanding what the difference in heat load would be on a Powertrac vs my machine though. Spec-wise the tank capacity the tank capacity is listed at 5.5 gallons on my machine. With all the super long hydraulic lines I would assume an excavator may have the potential to radiate heat a bit better then a Powertrac, but then again I guess there's a possibility that constantly pushing the fluid through the extra length of lines has the potential to build up more heat as opposed to shorter lines on Powertrac as well. I guess we can see that I'm getting a bit over my skis as far as my level of understanding of hydraulics is concerned though.

I don't know much about case drains. There are no case drains on any of the hydraulic motors (both implement and wheel motors) on the PT425 series. But there are case drains on the motors on some of the larger Power Trac models and attachments, as I recall.

I think it has to do with returning any fluid that leaks past the seals in the motor case back to the hydraulic reservoir. Some types of motors have them and some don't. I do not know why or why not.

If you got a Power Trac brush cutter for the 400 series machines, you'd not have to install a case drain line. Just two hoses, pressure in and return. Other makers may require a case drain.

 

[muddstopper]

Dont forget the control valve must be a motor spool type valve to allow the cutter to coast to a stop. A simple cyl spool valve will cause the hyd motor to self destruct. I rigged up a hyd driven frail mower that came off a old Alamo long arm tractor mower on his small trackhoe. The guy wanted it plumbed to his thumb control. I warned him he could blow the hyd motor on the motor with the suddent stop of mower when he stopped the fluid with the thumb control. He wouldnt listen and blew out the motor in less than a week. He rebuilt the motor and blew it out again the next time he used it. Also the reason for needing a case drain to allow internal pressure to return to tank. You can purchase inline cushion valves to prevent this from happening.

 

[tommott77]

Dont forget the control valve must be a motor spool type valve to allow the cutter to coast to a stop. A simple cyl spool valve will cause the hyd motor to self destruct. I rigged up a hyd driven frail mower that came off a old Alamo long arm tractor mower on his small trackhoe. The guy wanted it plumbed to his thumb control. I warned him he could blow the hyd motor on the motor with the suddent stop of mower when he stopped the fluid with the thumb control. He wouldnt listen and blew out the motor in less than a week. He rebuilt the motor and blew it out again the next time he used it. Also the reason for needing a case drain to allow internal pressure to return to tank. You can purchase inline cushion valves to prevent this from happening.

Thank, had not considered that. This my first experience with mini excavators but I had assumed that most of these aux types implements (mowers, hammers, etc) would be plumbed up to the thumb lines. Is this not the case and if so where would you plumb a mower, a dedicated line/control?

 

[MossRoad]

Thank, had not considered that. This my first experience with mini excavators but I had assumed that most of these aux types implements (mowers, hammers, etc) would be plumbed up to the thumb lines. Is this not the case and if so where would you plumb a mower, a dedicated line/control?

Plan A: You could check and see if the existing valve bank has a power beyond port. If it does, just ad a motor spool valve at that point. If it doesn't, plan B. I don't know plan B, so hope plan A is available. :laughing:

 

[b7610hsd]

My Takeuchi TB125 mini excavator has a built in separate valve that you select for either a thumb operation or for a hammer/motor.

 

[D&Mmachine]

... I had assumed that most of these aux types implements (mowers, hammers, etc) would be plumbed up to the thumb lines. Is this not the case and if so where would you plumb a mower, a dedicated line/control?

You Cat dealer can help guide you in this process, all you need is likely already there (less the lines, control setup and possibly extra cooling). Further, The mower manufacturer may have options for matching the available flow on your CAT 301.7D to the desired RPM of the mower.

Some details: Your pressure and return lines should be sized appropriately for the mower's flow rate so even if the thumb circuit was configured properly it probably would't be sized properly. Flow/pressure aside, keep in mind that with a mower the excavator is often maxed out as a constant state, versus a hammer/thumb which is intermittent. Running 10GPM through a 5.5 gallon res doesn't leave the fluid much dwell time and running it like that all day is likely going to cause excessive fluid temp unless your stock cooling capacity is designed for it (unlikely as <1% of excavators are used with mowing attachments). Adding additional cooling capacity is relatively inexpensive and in addition to helping your system run more efficient it will extend the operating life of your equipment - as well as the interval between hydraulic fluid changes. You might get by until your ambient temperatures start to rise but don't rely on a high temperature alarm without knowing excactly how it operates and what its set points are.

As for a dedicated case drain line as others have said: for (all but a few) piston motors they are absolutely necessary and should be returned direct to tank unobstructed through a dedicated penetration, for other designs there may be less than "ideal" work arounds that work fine for your specific application in the "real" world.

IMPORTANT >> regardless of what mower you end up with be sure to budget for adequate operator protection, don't make the mistake of thinking a stock windscreen will help keep you safe!

...many other things to consider but for now I hope this helps

 

[Rustyiron]

Good stuff there D&M:thumbsup:

tommott, I have a "factory made" bush hog (Ambusher) on a 115hp SS with 30+ gpm available on the aux circuit, It's pretty good in the heavy stuff but I'd be real concerned at your stated gpm's and continue your homework before getting in to deep dollar wise. Not trying to discourage you, all I know about hyd. mowers is in the above sentence, just advising you to continue your research before you open the wallet.:thumbsup:

 

[tommott77]

Thanks for the continued input, that was some great info D&M. I'm learning a bit more as I continue to research this idea. My mini-ex does have an aux control switch to go from one way flow for a thumb to one way flow for a hammer or mower.

As of now I'm researching and considering a smaller hydraulic powered Sabre Samurai cutter, which in essence is a sickle bar mower designed to fit on a loader bucket on a smaller tractor. There's a good amount of info on them here but here is a link to their site for those unfamiliar.

SABRE SAMURAI CUTTER | Cutthat.com - Your Cutting Edge Technology Expert

Looks like it may solve a lot of the potential issues with some of the others mowers. It only needs 3 gpm to run properly to cut up to 1.5" material, which is about exactly as I'm looking for as it will primarily be used on grasses, weeds, and kudzu on steep slopes/roads in my mountain property/neighborhood. It may actually perform much better on kudzu as opposed to a rotary or flail mower where all the long vines wrap up on spindles and rotors very easily. The sickle bar setup will also alleviate a lot of the throw back and other safety concerns as well. I'm thinking that the low flow requirements would cancel out any overheating/taxing concerns of the hydraulics as well.

If I go this route I'd likely run it directly on the excavator bucket, only reversing the bucket on the excavator with the bucket facing out. Should give me good reach with the cutter and the entire unit only weighs 70lbs. So weight shouldn't be an issues as well. Probably ad a plate on the mounting bracket to allow to bolt the unit to bucket holes for the teeth as well.

Planning on touching base with them to run my scenario with them and get their take on it.

 

[MossRoad]

If you can get by with the 1.5" cutting, that would be a very good solution. As you mentioned, rotary cutter can throw cuttings and broken parts great distances with great force. This would be a lot safer for all the weird angles you could get into with it out on a boom.

 

[Diggin It]

You Cat dealer can help guide you in this process, ...

If that's a rotary cutter on the end of that trackhoe boom in your Avatar, I saw one of those in action the other day. State highway department was using it to mow brush on an embankment over a guardrail and down below the roadway.