ointhead I have a Hitachi EX40UR- If a guy was to hook up a thumb to his offset boom control (electric switch from one to the other) would this work or would the pressure be too high? Any ideas? Has anyone else tried this? Also does anyone know what size of cylinder I would require for the thumb? (thinking of 1 1/2" rod size, approx. 28" overall)
Mini Excavator Thumb I am looking for some ideas...I have a Hitachi EX40 UR and I'm wanting to put a thumb on it but I need to know the cylinder size required (thinking 1 1/2" rod, 28" overall length) Also, if I hooked up the hydraulics (with an electric switch) between the offset and the thumb, as they are never used at the same time anyway, would it be too much pressure for the thumb?:Banghead
bunchdirt, I merged your 2 threads here. Please don't post duplicate threads in multiple forums.
I have see a EX50URG with the offset boom ram used for a thumb, they just put a link where the ram was on the offset. I have some pictures here some place. Do you have a manual for your machine?
Setting up a hyd thumb is a tricky thing as you need a relief valve in the circuit, set at 80%(from memory) of the bucket breakout force, so as not to damage the hydraulics. You may be best off to talk to a outfit that installs thumbs on machines. Have you goggled for thumbs? In the world of hydraulics just about everything is possible but costs money.
No I don't have a manual for my machiner, I've been told I can't get one here as it's a grey market. Can't anyone translate Japanese??I don't want to eliminate the offset, I just want to use the foot peddle for the offset and/or the thumb. I realize I have to put a relief in....I'm just wondering about a switch/valve to transfer hydraulic flow from offset to thumb cylinder.
I don't see any problems with setting this up, if you use a relief valve in the thumb circuit. Have you thought about a manual valve to save cost and complexity? You also have to consider how you are going to plumb it, are you going to have the valve up on the boom or down in the guts of the machine? My excavators have a manual valve to switch between back fill blade and track expansion, sure a electric valve would be easier but is not a big deal. Also my Kub has a two speed travel function which is controlled by an electric valve, so yeah valves to swap between functions in the the hydraulic system are quite common.
I am not a great fan of these thumbs that are mounted onto the bucket pivot pin, as they tend to get in the road a bit more. Not a drama if you use the thumb all the time but a proper dipper arm mounted thumb can be stowed out of the way, allowing a better view of the bucket.
That thumb hangs down for sure. i like mine stows tight and the price was right. i think in the future i could attach a ram and use the offset circuit. i just didn't have the time to set everthing up.
I just purchased a EX40UR where have you purchased replacement parts from? JIM
Sorry to hijack this thread but I do not have enough posts yet to start a new thread. I just bought a used Kubota kx71 excavator it has a side to side pivoting foot pedal to operate the thumb. When the pedal is depressed it stays down until you manually return it to center. I am new to this and wondering if that is how it is supposed to work or if the switch is sticking. Thanks in advance for any schooling you can provide this newbie!