Front-End Loader Comfort Ride

[rScotty]

I've maxed out my FEL a few times moving stacks of lumber for a deck and more recently pallets of stone for a walkway that I had to take a few off to get them to lift. But my tractor is not an M59. This is not really scientific but I'm thinking of comparing max system pressure to charge pressure to determine a good setting but I don't even know if the relationship is linear and I'm assuming the type of accumulator would affect the settings as well.

I have a request for quote out for several different type of accumulators. would be nice to have one that is rebuildable but if it is three times the price I will bet on the non rebuildable one since I need two for the loader and one for the 3pt hitch.

Being a little bit scientific can save a lot of time. I'm know I'm just following along here, but if you are going to compare max system pressure, it will help to know how system pressure relates to the load in the bucket.

In your workshop manual there will be a table of loader lift versus height that will give you a feel for that relationship. It varies with lifter geometry; I'll copy one such below. By solving triangles and roughly approximating the cylinder surface area you can solve for pressure required to do that lift, and the graphed numbers can be used to check your figures.

I think what you will find is that working stationary pressures are not only lower than max, but often far lower. And you can see immediately that geometery has a huge effect. When the loader arms and cylinders are closer to parallel it takes a lot of hydraulic pressure to raise the arms at all.

Road bounce creates pressure spikes that are much higher and faster than the tractor pump's hyraulic system pressures. Measuring them with a fast-reading pressure gauge is far easier than calculating those little monsters. Remember, you are only trying to damp them... not eliminate them. The energy stays the same in the system; the idea is to spread it out over a longer period of time. Make it less abrupt.
luck, rScotty

 

[jonsstihl]

thanks for the extra info. it is much appreciate. my chart is actually in the loader manual and I just pulled it out this week to see if I could lift my pallets of stone. my lift capacity at ground level is around 3300 lbs which i'm assuming is at max system pressure but I understand what you are saying. is the TL1350 the M59 loader. Close to 50% more capacity than my LA854

those charts are max capacities at max system pressure. but I agree most of the time we are not maxing out the system. I have my tee actually installed in the system and capped. I just need to find the time to hook a gauge to it and measure system pressure with an empty bucket and with a loaded bucket.

 

[Smokeydog]

From little tractors to big tractors the pressure of hydraulic systems are about the same. What changes is surface area of the cylinders vs load and the volume of oil of the hydraulic pumps. The accumulators dampen by variable volume displacement changing their pressure from reaction to hydraulic pressure. Being able to displace adequate volume is more important than the pressure. Thumb size accumulator help you?probably not. Basket ball size? Probably too much give.

The two bulb McCormick accumulator system has two bulbs the same pressure for a smaller tractor.

Dolllars to donuts the manufacturers geniuses spent less time calculating than trying similar options to see what worked the cheapest.

Keep it simple. Have fun.

 

[npalen]

Do variable restrictors (flow control valves) have a place when plumbed in series with accumulators? Perhaps restricted in one direction (up) only?

 

[oldnslo]

Do variable restrictors (flow control valves) have a place when plumbed in series with accumulators? Perhaps restricted in one direction (up) only?

Flow controls or orifices can and are used to fine tune ride control. Free flow into the accumulator and meter out. This reduces or eliminates the pogo stick potential. Accumulator absorbs the spike and then slowly puts flow back into the circuit.

 

[npalen]

Walterscheid GmbH | NEW – hydraulic top link with shock absorber

Top links - NEW – hydraulic top link with shock absorber. Walterscheid GmbH

www.walterscheid.com

Ran across this as a first, for me at least, and thought it would be somewhat pertinent to this discussion on loader cushioning.

 

[Smokeydog]

Walterscheid GmbH | NEW – hydraulic top link with shock absorber

Top links - NEW – hydraulic top link with shock absorber. Walterscheid GmbH

www.walterscheid.com

Ran across this as a first, for me at least, and thought it would be somewhat pertinent to this discussion on loader cushioning.

Agree about the added traction from cushioning heavy loads on soft ground with a FEL.

Like to see a cat1/2 cushion top link. Might not be too hard to make or some how tie into the accumulator system when needed.

 

[jonsstihl]

Just got my pressure gauges hooked up on the loader and the three point hitch circuits. 3pt hitch hose is bspp #6 so I went with a T on the left side but you have to watch the linkages. atleast there is more room than the right side with the remote valves and linkages

loader stalls at 2400 psi
empty is at 500 psi
empty bucket 700
bucket full of wet dirt 1200psi
grapple 800
empty forks 600

3pt hitch
quick hitch is 100psi
my custom counterweight is 500psi
72 inch flaifl mower 500 psi
snow blower (weights 1200lbs) is at 900 psi

talked to a guy last week from a hydraulic place and he sounded really knowledgeable and was a reference from the multiple other places I tried.

 

[rScotty]

SNIP

Dolllars to donuts the manufacturers geniuses spent less time calculating than trying similar options to see what worked the cheapest.

Keep it simple. Have fun.

Are you saying that they try similar options by actually making a FEL and trying it? Or by modeling one on a CAD program?

If it's physically making one up - which I kind doubt these days - but if so I'll take that bet, and hope someday to collect.
It seems to me that there is no cheaper way to design than in CAD. Way less expensive than fabricating and testing.

What is surprising me is not yet seeing ads from people selling completed model files of common mechanical designs. It seems like a reasonable type of business. As an example, using a dynamic model file of something like our M59 FEL makes designing a new style of bucket much easier.
There are a number of makers of specialty attachments for tractors. I wonder what would be a fair price for a working model file like that? Or is every company making their own?
rScotty

Make mine donuts.

 

[rScotty]

Just got my pressure gauges hooked up on the loader and the three point hitch circuits. 3pt hitch hose is bspp #6 so I went with a T on the left side but you have to watch the linkages. atleast there is more room than the right side with the remote valves and linkages

loader stalls at 2400 psi
empty is at 500 psi
empty bucket 700
bucket full of wet dirt 1200psi
grapple 800
empty forks 600

3pt hitch
quick hitch is 100psi
my custom counterweight is 500psi
72 inch flaifl mower 500 psi
snow blower (weights 1200lbs) is at 900 psi

talked to a guy last week from a hydraulic place and he sounded really knowledgeable and was a reference from the multiple other places I tried.

Wonderful info! Were you as surprised as I was at how low the actual pressures are when lifting a load?

It's odd how many Japanese makers use British Standard threads - tapered and parallel both - for fluid connections in their otherwise metric world. I wonder how that happened.

rScotty