Adding two hyd remotes to Kubota

[nealfris]

My layout now: L3000DT w/ LA 452s loader and Woods 7500 BH powered by PB from loader controls rather than PTO pump. It appears to me (not knowledgeable with hydraulics) the supply comes out of back top of trans., goes to loader in. PB to BH. Return from loader goes to left side of trans w/ return from BH connected to a block bolted over power steering block.
I would like to add two remotes, one for elec over hyd for front grapple and one for a home made boom mower with hydraulic motor or what ever else is attached to back, ie. hyd thumb. Can I simple T off something rather than the seemingly in depth remotes as scene in Everything Attachments video? Can I get separate components from Surplus rather than buy pricey bundled remotes?
I am very mechanically inclined, just not up to speed on hydraulics.

Now for the fun!!! Need help with boom mower math. I am using an old heavy duty 30" single blade JD mower deck w/ 28" blade attached to BH arm at bucket pins. Uses include grass and light brush only, reaching over banks and maintaining long drainage ditches.
My specific questions are: Is 6.9 gal min enough to run a hyd motor? What kind of valve do I need to run hyd motor? What model hyd motor would make all this work? I plan to mount the motor offset from blade pulley so as to work out rpm ratios and protect works with sacrificial belt. What is the math for figuring out hyd motor rpm all the way to blade tip speed. ie. pulley sizes, motor rpm etc.
Also should I put an extra filter in somewhere to prevent contamination.
Thanks and look forward to your input.

 

[kennyd]

Re: Another Hyd. remote question (sorry)

My layout now: L3000DT w/ LA 452s loader and Woods 7500 BH powered by PB from loader controls rather than PTO pump. It appears to me (not knowledgeable with hydraulics) the supply comes out of back top of trans., goes to loader in. PB to BH. Return from loader goes to left side of trans w/ return from BH connected to a block bolted over power steering block.
I would like to add two remotes, one for elec over hyd for front grapple and one for a home made boom mower with hydraulic motor or what ever else is attached to back, ie. hyd thumb. Can I simple T off something rather than the seemingly in depth remotes as scene in Everything Attachments video? Can I get separate components from Surplus rather than buy pricey bundled remotes?
I am very mechanically inclined, just not up to speed on hydraulics.

No, you cannot Tee into any high pressure lines, all valves must be added in series. The only line you can Tee is the low pressure return line (OUT line form the loader valve to the tranny)

You can get all the parts from the SC-no problem.

Now for the fun!!! Need help with boom mower math. I am using an old heavy duty 30" single blade JD mower deck w/ 28" blade attached to BH arm at bucket pins. Uses include grass and light brush only, reaching over banks and maintaining long drainage ditches.
My specific questions are: Is 6.9 gal min enough to run a hyd motor? What kind of valve do I need to run hyd motor? What model hyd motor would make all this work? I plan to mount the motor offset from blade pulley so as to work out rpm ratios and protect works with sacrificial belt. What is the math for figuring out hyd motor rpm all the way to blade tip speed. ie. pulley sizes, motor rpm etc.
Also should I put an extra filter in somewhere to prevent contamination.
Thanks and look forward to your input.

You will not be happy with the performance of the motor on a 30" mower with only 6.9 GPM.

 

[J_J]

Re: Another Hyd. remote question (sorry)

Kenny is right for the following reasons. To produce the 6.9 GPM's, at 3000 psi requires 14 HP. The pump will lose some HP due to efficiency, which brings that to 11.9 HP. The hyd motor also has an 85% efficiency. Now if you run those GPM's through a hyd motor, with 2 cu in displacement, the rpm of the hyd motor will be 797 rpm, and if you work out the ft per min on the 30 in bld tip, you will have about 4280 ft per min. No where near enough for efficient cutting. You need somewhere around 16,000 to 20,000 bld tip ft per min, for some efficient cutting.




Now if you provide that same motor with 20 GPM's, the rpm of the hyd motor goes to 2310, and that produces a bld tip speed of 12,358 ft per min. Still not good enough but will cut somewhat.

You need 41 HP to drive that 20 GPM pump.

To run a hyd motor, a motor spool valve will let you operate the hyd motor with free wheeling after valve is off. Could be a detent motor, or a variable speed valve like this.


https://www.surpluscenter.com/item.asp?item=9-064-38&catname=hydraulic

 

[nealfris]

Thanks guys. Trying to understand. I think my worst fears are coming to light. Manual says my tractor is 32.1 hp 2205 psi. Motor will be offset so I can multiply rpm to blade using different dia pulleys? Is torque the problem? The mower deck came off a mower with only 10 hp motor.

 

[J_J]

Yes, you will lose some torque. It takes about 11 HP to run your pump at 2205 psi. AS you go from from pump to motor, you lose HP So you would only be developing about 8 or 9 HP for the deck.

The take off deck on the JD mower was probably driven at engine speed of about 3600 rpm. That would give about 19,260 ft per min, which would cut as expected.

Why not use a 2 stroke small engine and mount it on a boom off the 3pt, and use another hyd valve to articulate the boom and tilt.

 

[nealfris]

Sorry to be slow on the uptake! Not getting the first part. Are you saying that my engine is 32 hp but only 11 hp @ my internal pump?
Also, can anybody enlighten me on the remotes scenario I mentioned???

 

[J_J]

Yes, it takes 11 HP to run that pump and when that energy is transferred to the hyd motor. It will produce less HP to the attachment.mower. Actually, you are only using that HP when you are using the hyd to the max. If you are not using any hyd, then the 32 HP will go to the drive, and/or provide about 30 HP to the PTO.

The remainder of the HP is used to drive the machine.

 

[nealfris]

Thanks JJ for your input and your patience!

 

[nealfris]

Just wondering, My pto is not being used with this configuration. Could I use a pto pump and get a better hyd output for the motor?

 

[kennyd]

Just wondering, My pto is not being used with this configuration. Could I use a pto pump and get a better hyd output for the motor?

Sure, but at quite a cost. Pumps are near $500, you would also need a tank ideally equal to the GPM of the pump, filter and large hoses also.

Also, can anybody enlighten me on the remotes scenario I mentioned???

I thought I did?

 

[Piston]

If you were going to get a PTO pump, where would you buy it from, and how do you size it to the pto? Is there a standard GPM flow that you go by? I have always been interested in doing that even though it's expensive/not neccessary

 

[J_J]

The answer about the remotes, is yes, you can do it. You can use a factory or after market kit, or gather all the components and do it your self.

The valve below is a solenoid selector valve and will give you a remote for the grapple or back side hyd. The curl hyd would connect to this valve, and side 1 would operate the curl normally. Side two would connect to the grapple, and your FEL levers would operate the grapple. If you installed QD's on side two, that can be your hyd supply for the front or rear, using some hoses. 6.9 GPM's does not provide a lot of hyd HP power.

You can run a hyd PTO pump at the rear, but it will get expensive. 25 to 30 hyd HP off the PTO pump will operate a lot of different attachments.

https://www.surpluscenter.com/item.asp?item=9-7852&catname=hydraulic

PTO pump--------$500
reservoir---------$80
valve-------------$150
hoses------------$200
fittings-----------$60

PTO pump

https://www.surpluscenter.com/item.asp?item=9-1047-1-C&catname=hydraulic

30 HP can provide about 20 GPM's at 2250 . That is with nothing else using the availiable tractor HP.

 

[Farmerford]

Piston and Nealfris:

I mounted a Bush Hog brand 48 squealer rotary mower on a FEL and drove it with the kind of PTO pump JJ recommends. I spent a bit more than he estimated for my reservoir, but otherwise he is right on. You can稚 do it for less than his $1,000 estimate and you could easily spend $1,300 or so with filters, relief valves, etc.

If it were me I would give it a try using your tractor hydraulics. You are going to install the remotes anyway, so the additional cost to give it a try will be a $250 hydraulic motor, $50 motor mount, $100 for pulleys and belt, and $100 for hoses and fittings. If it works you can add a separate motor valve to make starting and stopping easier, check valve to let the motor overrun the pump, and other refinements.

I think it might work. Say your hydraulic system pressure is 2250 psi. 6.9 gpm produces almost 9 horsepower. Even an 80% efficient motor will produce 7 hp at the shaft. There are lots of push type 21 rotary mowers that cut lawns and weeds just fine with a 4.5hp rated gasoline engine that is undoubtedly overrated. Your deck was driven with 10 hp, probably overrated, that also drove the wheels and carried a passenger. So 7 true hp should turn a 28 blade in grass and light brush..

It might not be able to keep up in heavy grass or weeds if it is being pushed fast, but you are not likely to do continuous cutting with the mower deck on a backhoe. If there is a continuous cut at all it will be very slow because you have to follow the contour of the ground with the boom and dipper stick. Most of us don稚 use the backhoe regularly enough to maintain the kind of skill to move the end of the stick very fast with that kind of precision. It will be much more put it down, let it cut, lift it, and put it down a couple of feet over. The blade should have plenty of time to recover speed while you are moving it over the grass.

I agree with JJ about blade speed for finish cuts on a lawn, but I assume you are not seeking a golf course cut. My Squealer with 48 cut has a blade tip speed of 13,000 feet per minute (4 x 3.14 x 540 x 1.92) and it cuts pasture grass and brush fine even when the blades are dull. And those blades are 3/8 thick. Blade sharpness obviously is important, but blade thickness also matters more than I would have thought. I have a 5 Bushhog with ｽ thick blades that takes quite a bit more power per foot in heavy grass than the Squealer with its 3/8 blades, and blade thickness seems to be the main difference.

Your 28 blade is probably ｼ thick and, with it so accessible you should have no problem keeping it sharp. It is only an educated guess, but I believe 7 true hp will spin a sharp ｼ thick 28 blade quite well in heavy grass, weeds, and brush under 1 diameter.

I would aim for a blade speed of say 15,000 fpm for another reason as well. You will not be able to shroud the blade fully and it will be tossing sticks and stones back your way. The slower the blade speed the slower those missiles will zing by your head; I know this from experience.

A 28 blade turning 2,000 rpm gives about 15,000 fpm at the blade tip. A 2 cu in motor will turn about 800 rpm, so a 2.5 step up from the motor pulley to the spindle pulley will produce 15,000 fpm.

If it turns out that your hydraulic system does not have the capacity, you can add a 15-20gpm pto pump and change the pulley sizes to keep the spindle at about 2000 rpm.

I think the biggest problem with using the tractor system would be hydraulic fluid temperature if you keep the mower in heavy cutting constantly, but you are not likely to do that.

Sounds like a neat project. Send pictures.

 

[nealfris]

Thanks JJ & Farmer Ford. I will try to post pics, never done it before & I have search hard for a help menu for my many forum questions. Particularly How do you put your equipment list under your post? Anyway. After giving the remotes some thought, I think what I'd like to do is remove BH feed from PB on loader control, Install a hyd/elec circuit (with its own PB) out of loader PB for grapple, split out of grapple PB to supply existing BH and extra remote for back. Is this do-able? Could some one please give me a list of parts I need should this be a suitable schematic. The hyd I intend on doing regardless of the boom project.

Regarding adding a pump and reservoir for mower, I found a new PTO pump for only $270.00 I was thinking that if I need that for extra GPM than it would not be a bad thing. While the boom is not being used I could use pump for the BH with QC. BH seams to be very whimpy using remotes. The relief squeals constantly. I have owned a small Terrimite with 18 hp Briggs connected direct to pump for 20 yrs. That little thing out digs the Kubota hands down!

The mower will have the out-shoot blocked, the deck angle is manual as you can see, the top will have a two pin plate weld just like on a bucket. the boom will attach were the bucket goes. my property is very steep in places and this rig will be great for reaching up and down (with counter weight of coarse) over banks. This thing is only tack welded as a prototype. My thinking is the arm works will out last the mower deck. If successful, I will make a more suitable deck out of heavier stock similar to a brush hog. It is very strong and surprising how little it weighs.

 

[J_J]

These are some of the hyd cutters from Power-Trac. The one on the green mower, is using 8 GPM's for the hyd motor.
The larger hyd cutter on the red machine, is using about 15 GPM's to run that one. It also has a counter weight. Both are fully articulated.


To add your equipment to the bottom of your post, select MY Home at top, then on left, select Edit Signature.

Copy and paste your equipment and attachments from your profile into your Signature

 

[nealfris]

Piston, check out
http://www.splitez.com/pto_hydraulic_pumps_tractor.html

 

[J_J]

Farmerford,

Recheck your bld tip figures figures for a 48 in cut. Circumference=2πr

2 x 3.14 x 24 in x 540 divided by 12 in = Bld tip speed in ft per min

 

[Farmerford]

RATS! Nothing starts Saturday like a reply pointing out the errors in your Friday post.

JJ, you are right about the formula for blade tip speed. I was not clear that my 48" mower has a 1:1.92 ratio step up gear box. That's why 13,000 fpm speed I gave seems too high. I think my 60" mower has about a 1:1.5 step up.