Loader Adding third function to swinger loader

   / Adding third function to swinger loader #1  

Loaderman22

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Hudson Valley, NY
Tractor
1947 Ford 2N, 75 MF 30B, 75 Swinger Loader, 1979 Cat D3


Loaderman22

Platinum Member​

I posted this in Construction Equipment and got no replies, so I thought I'd try here also.
I have a mid 70's Swinger 200 loader, it has come in quite handy around the property, but I am thinking it would be even more handy if it had a grapple. On the "dash" there is a 3rd cut out for a 3rd lever, so this must have been an option when new. One lever works arms, the other tilts bucket. The problem is, I really don't know much about hydraulics so I don't even know where to start. Maybe I should post in the hydraulics threads? I have heard/seen some guys add some sort of electrically switched unit to divert fluid to the 3rd function, but no one really shows the parts or how they did it. I have been looking at websites like Prince but it seems most are geared towards tractors where the valve body sits out in the open, whereas this one the valve is tucked up under the dash, and it would be ideal to keep it that way. I have no idea what kind of GPM this machine puts out, so I 'm afraid the grapple movement will be too slow if I get the wrong valve
 
   / Adding third function to swinger loader #2  
Well, im pretty new to hydraulics myself, but i know a little.

For one thing, the speed that the grapple operates at is not purely based on hydraulic flow. It's also based on geometry of the articulating linkage and the sizing of the cylinder or cylinders that will operate it. Any kind of hydraulic system can be made to move something quickly, but it is a tradeoff of speed vs power.

Power or strength may not be much of an issue with a grapple, depending on how you are going to use it. For example, in any case where the grapple can reach 'past' or around an object and then close, the grapple is just restricting the space by which the object could slip out, and doesn't really need to 'squeeze' very hard. Once you let off the controls, the grapple will be held in place with MUCH more strength than what it actually used to pinch down. However, if you are trying to grab something with smooth parallel surfaces like a big paver stone or something like that, the actual pinching/squeezing strength might come into play. If you are mostly using the grapple on brush/logs etc I would venture to say that the actual squeezing strength of the grapple is not very important and you can basically design it to attain your desired speed instead. Basically, if you are mostly holding something up with the floor of the bucket and just using the grapple to keep it from tipping/rolling out, strength won't matter. If you are trying to point your bucket straight down and keep a smooth object pinched between the grapple teeth and the floor of the bucket to keep it from falling out, strength will matter.

IF you divert your existing hydraulic flow from your bucket cylinders, for example, you don't need to know GPM because you can just figure out what you need from the size of the cylinders you already have and how long it takes to extend/retract those cylinders right now (preferably in the direction where it's dumping weight instead of lifting it, although the difference would be small). You can calculate the fluid volume of a hydraulic cylinder fairly accurately just by knowing the cylinder diameter and the rod diameter. Compare that to the internal volume of a different cylinder, and whatever percent smaller that volume is the percent faster it will operate, or vice versa, on your existing hydraulic circuit.

The valve you are talking about is called a hydraulic diverter valve, i believe. If you used a diverter valve that was electrically operated (easiest, most common i believe) you wouldn't actually install a 3rd hydraulic lever on your dash. You would probably just install a momentary switch on your bucket curl lever and whenever you were holding that button down the lever would operate the grapple instead of curling the bucket.
 
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   / Adding third function to swinger loader
  • Thread Starter
#3  
Thanks @Vigo327 very helpful insight!
 
   / Adding third function to swinger loader #4  
A couple more thoughts: The speed of the grapple can be throttled also, in addition to cylinder size, by a restrictor fitting in the plumbing and/or feathering the valve if it is manually operated.
 
   / Adding third function to swinger loader #5  
I used a standard lever controlled valve on my old tractor. I can easily feather the grapple.
My newer tractor has an electric valve and the lines have flow restrictor fittings as npalen said. They work very well.

FWIW here is a link to my valve addition project to my old tractor 10 years ago. At that time I probably new less than you about hydraulic stuff. I just read a lot on TBN and asked a lot of questions. If your loader is open center hydraulics you could do a similar installation.


gg
 
   / Adding third function to swinger loader
  • Thread Starter
#6  
At that time I probably new less than you about hydraulic stuff. I just read a lot on TBN and asked a lot of questions. If your loader is open center hydraulics you could do a similar installation.

gg
I wouldn't be so sure about that!!! I learn as I go, and haven't messed with hydraulics much, just enough to take off a leaky line and have a new one made up.

Thanks for the link, I will watch it.
 
 
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