This might be a stupid question to the old hands, but how do you curl the bucket and open the thumb at the same time? I ran a Hitachi 230 last nite and it was my first time with a thumb. The control was a rocker button on the right stick. I was loading demo debris into a truck. The bucket curl was slower then the thumb, so it would open the grip and drop the load. Also the thumb was stronger then the bucket curl, and i can't imagine it's good for anything to try to force it. If I tried to 'feather' the thumb it just looked jerky and unprofessional. Especially as I got near the end, and had to pick up up the remains with the bucket teeth downward, I couldn't smoothly curl the bucket up to swing it into the truck. Tips, tricks, hints? THANKS
All hydraulic thumbs that I have operated the bucket will "push thru" the thumb....... Allowing the material to remain pinched in the bucket. To roll out with material pinched in the bucket was forced out with the thumb and I controlled the speed with rolling the bucket out slowly. Please note mine are CATs and the thumb was on a floor pedal.
Probably the pressure relief is set wrong for the thumb, the bucket should always be able to overpower the thumb.
Well that's a relief!! At least it wasn't ALL me! CS
My EX60-5 thumb is pedal mount control as well. Nice thing is the variable pressure to move the thumb slow/fast etc. I'm assuming the thumb switch on the right stick is on/off and not variable?
Pressure relief on a thumb circuit is usually set to 2,100 PSI to allow the bucket to force the thumb in without damaging the cylinder or the linkage.
yes Art, on/off. No way to be smooth! I'm guessing the bucket ram is worn out or the thumb relief was set wrong. It is a rough hoe, it looks like they do as much demo with the counterweight and cab as the do with the bucket!!
On the 325BCat i run,thumb control is on the left joystick,elec./hyd.-switch,one speed.I find curling the bucket out,i can move both the same speed,and keep the load in nicely.However,when curling the bucket in,and using the thumb sw.the hyd's seem very slow but,i use the bucket to push the thumb cyl back....it seems to go in with very little hyd.load .
I have ran the electric operated and manual (foot operated) foot operated one lets you work thumb at variable speed where as the the electric one is on or off. I thought it was just me:drinkup