Loader pressure vs lifting gains - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information
John Deere Forum John Deere Garden Tractor talk

 
LinkBack Thread Tools Display Modes
post #1 of 8 Old 09-18-2019, 03:39 PM Thread Starter
MTF Member
 
Join Date: Aug 2019
Posts: 35
Loader pressure vs lifting gains

I've been searching for a while with no luck...

I remember seeing a basic calculation to determine the lifting capacity of a 40 loader at increased pressures, but can't seem to find it again.

Any help would be appreciated.

Thanks.

--Alex
alexo35 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 09-18-2019, 06:33 PM
20,000 Posts & Climbing
 
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Posts: 21,307
Re: Loader pressure vs lifting gains

It takes a specific amount of pressure to raise the empty bucket of a loader. Once that pressure is known, a ball park estimate of addition lifting force applied to the payload by the higher pressure can be calculated by using the leverage ratio based on the location of the 3 pins on the arm, or two pins on the arm and the center of the bucket.

Cylinder lifting force:

- Cylinder bore area X Pressure X The Sine of the angle between the cylinder centerline and the line between the cylinder pin on the arm and the post pin on the arm.

Leverage ratio:

- The horizontal distance between the post pin and the cylinder pin on the arm / the horizontal distance between the post pin and the bucket pin, or center of the bucket.

Measure the horizontal distances using a plumb bob dropped from the center of the pins to a length of lumber.

Discount the pressure for lifting the empty bucket from the anticipated pressure available and use the result for the force calculations. Keep in mind that the force calculations are for ONE cylinder. There are two cylinders on a loader. The result after doing the leverage calculations is the estimated payload that can be lifted.

Note that the calculations change as the load is lifted. They're only good for one lift position due to the changing angle between the arm and cylinder, and the changing leverage ratios.

The math is simple. Applying it, not so much.

Bob

Click for The Hydraulics Forum!

Sometimes you get on a roll, sometimes the roll gets on you.

In Service
MF GC2310, Husqvarna YTH20B42T

Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.
TUDOR is offline  
post #3 of 8 Old 09-19-2019, 04:12 PM Thread Starter
MTF Member
 
Join Date: Aug 2019
Posts: 35
Re: Loader pressure vs lifting gains

So if I understand you correctly, you're saying I should set it at 1450 and try it?

--Alex
alexo35 is offline  
Sponsored Links
Advertisement
 
post #4 of 8 Old 09-19-2019, 07:03 PM
20,000 Posts & Climbing
 
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Posts: 21,307
Re: Loader pressure vs lifting gains

Maximum pressure for a K92 auxiliary pump is 1502 psi. Anything below that is acceptable. Most who have added shins have set theirs at 1250-1400 psi.

Bob

Click for The Hydraulics Forum!

Sometimes you get on a roll, sometimes the roll gets on you.

In Service
MF GC2310, Husqvarna YTH20B42T

Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.
TUDOR is offline  
post #5 of 8 Old 09-20-2019, 08:58 AM Thread Starter
MTF Member
 
Join Date: Aug 2019
Posts: 35
Re: Loader pressure vs lifting gains

I checked my new to me 445 with the 40 loader and it is relieving at 1300 psi.

I am hitting the hydraulic limit of the loader on a regular basis. Mostly doing brush removal with the ratchet rake, or moving my spoil piles.

So the question was really, is it worth the effort to go from 1300 to 1450 psi. It sounds like the easy solution is just to re-shim the valve and see what she'll do.

To be honest, I'm really just disappointed that I missed out on that "oh wow" moment going from stock pressure to 1300. lol

--Alex
alexo35 is offline  
post #6 of 8 Old 09-20-2019, 07:24 PM
20,000 Posts & Climbing
 
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Posts: 21,307
Re: Loader pressure vs lifting gains

Quote:
Originally Posted by alexo35 View Post

To be honest, I'm really just disappointed that I missed out on that "oh wow" moment going from stock pressure to 1300. lol

--Alex
It might not be as big, but you'll still have an "Oh WOW!"

Bob

Click for The Hydraulics Forum!

Sometimes you get on a roll, sometimes the roll gets on you.

In Service
MF GC2310, Husqvarna YTH20B42T

Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.
TUDOR is offline  
post #7 of 8 Old 09-28-2019, 02:13 AM
MTF Member
 
sponfit's Avatar
 
Join Date: Apr 2016
Location: California
Posts: 37
Re: Loader pressure vs lifting gains

The 445 has the k91 not the k92. Not sure if the max pressure is any different though.
sponfit is offline  
post #8 of 8 Old 10-06-2019, 07:53 PM
Senior MTF Member
 
Join Date: Mar 2018
Posts: 382
Yeah go from 1300 to 1500, you'll get your own "oh wow." My x595 is set a bit higher than that even, and I got an oh wow from the guys whose van I lifted the back end of the other day so they could change a tire.
eKretz is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome