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Discussion Starter #101
I finally remembered to take the measurements:

Information request.

- The c-c distances between the 4 pin holes in the arms.

- A-B - Where A is the arm to post pin and B is the cylinder base pin on the post. 10.75" (could be up to 20" if I make a lower mount)

- A-C - Where C is the cylinder rod pin on the arm. 32.5"

- A-D - Where D is the bucket pin on the arm. 52.5"

- B-D 43.5"

And the retracted pin c-c distance on the cylinder - B-C. 26.75" with the bucket at rest on the ground, 25.875" with the cylinders fully retracted(front wheels a few inches off the ground)

There are two triangles, ABC and ABD
The cylinders are 1.5x18" for lift and 1.5" x16" for curl
I am using the hydro with the relieve valved shimmed to 1250.

I don't want to use a dedicated pump for a few reasons: 1.) Cost and complexity, 2.) ease of removal and attachment. With using the onboard circuits I can take the loader off in 5 minutes and install in about 7. I can also use the loader with the mower deck on which makes it really handy. This was a design requirement from the beginning.

From spending some time using it I have noticed that it is not good at multiple actions at the same time. For example it does not like to lift and curl at the same time. It also does not drive and lift as well as it lifts stationary. Nothing is free.

Tudor, if you share the formulas, I would be happy to do the math. I would even make a quick spreadsheet to run the numbers.
 

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Discussion Starter #102


A couple shots using it to move firewood around.


Sent from my iPhone using Tapatalk
 

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NICE SET-UP!! SURE BEATS A WHEEL BARROW!!!:tango_face_grin:
 

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I don't want to use a dedicated pump for a few reasons: 1.) Cost and complexity, 2.) ease of removal and attachment. With using the onboard circuits I can take the loader off in 5 minutes and install in about 7. I can also use the loader with the mower deck on which makes it really handy. This was a design requirement from the beginning.

From spending some time using it I have noticed that it is not good at multiple actions at the same time. For example it does not like to lift and curl at the same time. It also does not drive and lift as well as it lifts stationary. Nothing is free.

Tudor, if you share the formulas, I would be happy to do the math. I would even make a quick spreadsheet to run the numbers.
1.) Costly, yes. The complexity revolves around finding the real estate in which to mount the pump, string the lines, and install a reservoir. Most builds use one or both posts for the reservoir. There are only 3 lines involved.

2.) Ease of removal/attachment depends on where the loader valve set is installed with a separate pump. If it is part of the loader assembly which is detachable, pretty much everything has to come off. If it is attached to that portion of the loader that remains with the tractor, quick connects on the valve set ports simplify the detachment leaving the pump/reservoir/valve set in place on the tractor.

3.) Use of the loader while the mower deck is in place runs a significant possibility of mower deck damage. In general, GT buckets are usually 48" wide and some mower decks are considerably wider limiting how close to immovable, or (relatively) fragile, objects the bucket can be utilized.

I have a 54" bucket and a 60" back blade on my tractors. Clearing snow from beside a car can get dicey if I don't pay attention to where the back blade is in relation to the vehicle. The back blade can slip into a wheel well and cause expensive damage before the operator is even aware that contact has been made.

The control issues when operating lift and curl at the same time are due to the open circuit design of the hydraulic system. The fluid will follow the path of least resistance. Both can operate at the same time, but it takes a lot of time to develop the skill necessary to feather both valves at the same time in order to make it happen. Time is not saved during this process, but on occasion, it is a handy skill to have.

When the drive is involved, some of the flow goes to the hydro as make-up fluid to compensate for the normal internal leakage. As the hydro works harder, more fluid is diverted to compensate for the leakage that occurs at a higher rate due to the hydro pressure involved. Under extreme conditions, this can leave no flow available from the charge pump to operate a loader. With a separate pump, this becomes a non-issue as full pump flow is available for the loader at all times and is limited by engine speed alone, unless the relief valve pops.

Formulae

https://ostermiller.org/calc/triangle.html

Plug the lengths of the sides of triangle ABC into the diagram and click on Calculate. The result is the angles at each corner.

With a scientific calculator, enter the angle at C (Angle ACB) and press SIN. The result is the lifting force percentage of the force generated by the cylinder expressed as a decimal. (eg. Sine 24° = 0.4067, or 40.7% of the 3142 lb of force generated by a 2" bore cylinder at 1000 psi (1278 lb of lifting force).

For the leverage, drop a plumb bob from each of the pins on the arms, A, C, and D. Mark a long stick with the resulting positions and measure the distance between them for calculating the leverage available. Multiply the leverage with the cylinder lifting force available at point C. This is the lifting force available at the bucket pins on the arms. Don't forget that there are two arms involved and lifting force will be double.

Note that both the angle and the leverage change as the arm rises and the calculations need to be done for each height level that you have need to know. The least available lifting force is generally when the line joining points A and D is parallel to the ground (poorest leverage ratio), and is not a whole lot better at max height (poorest geometry).

Note also that the lifting forces available are theoretical and do not take the weight of the arms, cylinders or bucket into consideration. The leverage also changes when any position on the bucket is substituted for point D.

It's not all that complicated, but there is a bunch of number crunching involved and it takes a while before the vision of the changing geometry and leverage become locked into the mind.

The same type of calculations are also used for the bucket curl.
 

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Discussion Starter #105
Tudor, Thanks for the guidance. Next time I have the loader on, I will measure the positions to calculate the leverage.

My deck is 48" and so is my bucket. However I have a plfow that sticks out 6" on the right side and right now I have this huge tilt/dump MCS hanging off the back for collection of leaves. I can't wait to remove it. I don't plan to use the deck and the loader all the time together, but it sure is handy this time of year.

I get your point on distances and collisions. 20+ years of racing cars has taught me lots about spatial awareness and it's importance to avoid expensive trips to the body shop. Good news is that the tractor moves relatively slowly compared to my racecar. They are both fun. Practicing the nuances of bucket control will be fun for sure. I will be interested to see if small inputs on both controls will work better together.
 

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The deck cutting width may be 48", but the deck shell is closer to 50" wide. That doesn't sound like much, but it will scrape the paint if cutting down a side slope and run the risk of wedging the deck if cutting a trench more than 4" or so deep.
 

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Discussion Starter #107
I did some quick numbers. It looks like if I move the lift cylinder mount down about 8" it will change the sin of angle C from .30 to .55. All else remaining the same, it would mean a 1.8 x increase in lifting force available at pin C. (.55/.3= 1.8) Does that make sense? That seem huge and a no-brainer with the small expense of adding some additional plate with mounting holes to the uprights. I'll leave the original mounting point encase I ever need that little extra height (and it would be lots of grinding to remove the mounts!)
 
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