FEL grapple 'close' is weak...help please

[Rip]

Re: FEL grapple \'close\' is weak...help please

Pat,

Sounds like you have found a workable arrangement regarding your diverter circuit.

It is one of my major frustrations in life to constantly come up against people who realy ought to know better (like your dealer) yet refuse to admit their ignorance and and ask a real authority. They then clearly display their lack of knowledge by spouting off with some really rediculous statements.

As I had mentioned, my Power Trac already had a front auxiliary circuit, but its control lever was under the dash in an awkward position for frequent use, so I did a fairly simple modification to place its control on top of the dash right next to the joy stick. Works well for me and my AnBo.

Living in the shadow of Mt Rainier must be beautiful, but it would make me nervous. Yet we live with the all too real threat of wildfire ourselves (had to evacuate 3 times in past 4 yrs). We do what we can... reduce fuels, 10K fire cistern, numerous portable and in-place fire suppression systems, etc.

Good Luck, Rip

 

[Patk]

Re: FEL grapple \'close\' is weak...help please

I'm positive the regenerative dump starts from center over to the right till you hit the detent, THEN it goes non-regenerative. I verified this by #1 putting a pressure guage inline on the rod side of the cylinder while extending the RAM (2400PSI), but goes to zip when you keep pushing right past the detent, and #2 the grapple grip gets strong after the detent.

Interesting, it sounds like the JD does the opposite...non-regen up to the detent, then regen beyond. If Kubota had that arrangement then locking/blocking out the stick motion beyond the detent would work fine.

I'm happy now with the grapple on the boom circuit and I love that AnBo grapple. Clearing brush, logs, and old stump debris for new walking trails through the woods.....It's too much fun to call it work. /forums/images/graemlins/laugh.gif

 

[Rip]

Re: FEL grapple \'close\' is weak...help please

The regen function on my NH TC-30 works like the JD, but I only use it sometimes. Now if they would reverse the Down and Float for the arms, I think I would like it better.

I know what you mean about the AnBo.... the guys I am working with are amazed at what it will do in conjunction with the low ground-impact and maneuverability of the PT 1845 on 20 to 35 deg hills. They keep saying "Awsome!" over and over.

Enjoy it while you can... I am sure you will get to some tasks that are less fun than playing "Jaws".

Rip

 

[Jim_Fisher]

Re: FEL grapple \'close\' is weak...help please

Patk,

</font><font color="blue" class="small">( I verified this by #1 putting a pressure guage inline on the rod side of the cylinder while extending the RAM (2400PSI), but goes to zip when you keep pushing right past the detent, and #2 the grapple grip gets strong after the detent. )</font>


I'm glad that you found a workaround.

I would expect the regenerative circuit to have a lower pressure since it's job is to supply a sufficient volume of oil to allow the weight of the load to dump the bucket. The only place from which that volume can be obtained is the return side of the system. If the pressure wasn't cut, it would pressurize both sides of the curl cylinders and cause the motion to stop.

With the grapple stronger at negligible pressure than it is at 2400 psi, there is obviously something at work here that we don't understand.

 

[Jim_Fisher]

Re: FEL grapple \'close\' is weak...help please

</font><font color="blue" class="small">( I verified this by #1 putting a pressure guage inline on the rod side of the cylinder while extending the RAM (2400PSI) )</font>

I just re-read this part. By the "rod side" do you mean "D" or "C" in your diagram? It almost sounds like you are checking the pressure on the return side of the circuit.

 

[Patk]

Re: FEL grapple \'close\' is weak...help please

In the diagram I initially checked pressure at C (the base end of the cylinder) to see what kind of pressure I had...it was 2400 PSI. I was confused by the weak closing force so I put the guage inline on the rod side ( D in the diagram) and was suprised to see ~2400PSI as well.

In my research into what the heck a regenerative circuit is, I found that the rod side discharge is pumped back into the base end circuit...but in doing so it see's nearly the same pressure as the base end. In this case you have nearly the same pressure on both sides of the cylinder, and it is only the large area of base side of the piston that allows the net force to extend the RAM. When I reversed the lines at the cylinders the RAM would only extend no matter which way the control stick was pushed, because the regen still applied pressure to both ends of the RAM, and in that case the base end wins and the RAM extends.

Yes, the boom circuit was the easiest route to make it all work as I 'expected' it to work.