Hi. My thumb is controlled by foot pedal and I’m looking to convert over to a Joystick toggle switch. I know what to do but can’t locate a D03 solenoid operated directional control valve that Meets the specs required. Machine details: 1995 Se210-2 Pilot pump: Flow rate 21 Lpm (5.5 gal) @ 470psi. Option spool for thumb: 30lpm (7.9 gal) @ 4979 psi. I have searched thoroughly and can only find valves with far greater max pressures & flow rates than what I need. Can anyone point me in the right direction in terms of where to buy or suggest a model to look for? cheers
You're not plumbing the thumb directly to this solenoid valve just replacing the pilot control correct? Does the foot pedal operate hydraulically or is it cable operated to the control valve?
Unless you can establish variable control, you're not going to like how it slams the thumb open and closed.
Good day You can convert a pedal operation to a toggle switch, the choice is also if you require to make it proportional or simple On/Off. Make your choice, the parts are freely available, then we can help you convert. We have published a lot of information on the website it is free and google safe, attached may answer some questions. Kind regards Uffex
Just because the valves are capable of handling higher pressures and flows doesn't mean that you can't use them. All the thumbs that I installed over the last thirty years were full on and off. I did have a way of reducing that by installing a subplate under the DO3 valve with a pressure reducing cartridge relief valve to drop the pressure spike when the pilot signals were sent to the main control valve. You didn't say in your original post if the pedal supplies oil directly to the thumb cylinder or it just supplies pilot pressure to a valve in the main control valve block. Your solenoid valve should be closed center with A/B ports and a drain. The ones I used to get are 1/4" porting for the pilot circuits. I was using the top rocker switch type handle the last time I installed these but most people now days want the trigger switches and buttons. Sure Grip makes a simple handle with a decent cost.
Do you have any more info on this subplate with relief?
Thanks for the feedback, I should of provided more info to make a few things clear. Current thumb works fine off a foot pedal which is Teed into the drive pedal pilot lines under the cab. Pilot pressure drives the thumb spool in the MCV. I would of thought a float centre valve would be the go so that the thumb spool can return to centre so I can stop the thumb mid-stroke? The idea I had was to use a spring centred toggle switch to achieve this, thus avoiding the thumb slamming open and shut, I decide when to stop it by pressure off the switch. Any finesse required to pick fragile object up can be achieved with the bucket. thanks in advance
Closed center indicates the supply line is closed off when the valve is in neutral. A and B ports are open to return. Open center valve would dump your pilot supply flow back to the tank all the time. The frequency of use of the thumb function usually means a robust switch that gets many cycles in a day of operation.
Here is the solenoid I used when I added solenoid control to my machine. https://www.ebay.com/itm/Hidraman-H...2349624.m46890.l49286&mkrid=711-127632-2357-0 I used a on-off-on spring centered switch and drove the solenoid with relays.
I’m trying to emulate what you’ve done precisely. Is that the exact valve you used, with the float centre?
The C4 is the one I used. The A and B ports flow to tank when the solenoid is in the off position. I'm not sure which one you would need. Mine gets it's pressure from a T into a pilot line.
Good day Folks May be this may of help, the specifications for the valve are attached along with sub plate drawing. Should you choose to install dampners for smoother operation company such as Hawe & Hydac have those. Kind regards Uffex
Like has been said before, DO3 valve, cylinder spool, A&B ports to tank with an aluminum sub plate, #4 or 6 ORB ports. As far as speed of thumb if it ends up being to fast you can always put a flow control valve in the cylinder line. I did many installs long before the proportional controls came out and had very little problems with speed. I'm assuming that since it's now foot controlled that you already have port reliefs installed. As far wiring goes, the only time I have seen it necessary to use relays is if you are running a rotating grapple in something like a logging operation where that DO3 is cycling continuously all day long. I have always wired directly from the handle to the valve and again have had little to no failures. Hope this helps.
Yes have port reliefs installed and flow control valves in the cylinder lines. Interesting that you haven’t used relays in the past, I’ve installed 12v diverter valves on tractors without relays and had no issues. Maybe I could run thicker wire and get away with it. I’m not wiring in a new joystick but modifying the original button which drove a rock breaker.
Good day May be I should explain relays when installed correctly can prevent ECU damage as well as burnt components please see attached, you can read the complete document by visiting the web site.I know that the Samsung machine has an ECU check out the availibity and replacement cost. Kind regards Uffex
Uffex. He's not planning on implementing the ECUat all. He wants to go straight from power to the joystick and out to an AB solenoid to control his pilot signal to option spool. No variable control, just on and off.
Good day Fun with F Yes that is how I understood the thread you do not need to connect the ECU to destroy the same, a good kick back can come from any coil be it relay or solenoid valve. My comment come from two customers who had additional solenoids installed and could not understand why the ECU hung out the white flag. Trying to save the guy from the same experience, I recall in the 1950's changing the headlight beam on cars was made from a pedal switch main cables run to the switch from the feed, most of the world has moved on from the 1950's. Nobody likes buying ECU's understanding the complexity is difficult, prevention is better than replacement. Keep smiling Uffex
Never had a ECU fail because of a thumb circuit. Link-Belt had problems in that the ECU would stop working after a sudden burst of multiple applications on the thumb buttons. Shut the machine down and restarted and all went back to normal. We installed diodes across the switches and never had another problem. Relays are an extra expense both in the part, installation labor and added complexity of the system. I have some Weldco Beales installs with an added relay box and no source of parts that I have had to modify to something simpler that would work over a longer time period.
I have to admit that I have not plumbed any machines newer that the Hitachi Zaxis dash 1 so with the "newer,better" systems I guess there is always the possibility of a spike blowing an ECM. Stranger things have happened. I had a customer who bought a Kobelco with a hydraulic thumb on it, it had a relief block mounted in line on the boom and they T'd the tank line into the tank line on top of the swing motor. Not sure what the operator did but it must have caused a tremendous pressure spike over relief because it cracked the top of the swing motor.
I'm guessing the problem was in the swing motor itself. The reliefs we used to put in on the boom only had a #4 drain line even on the big machines. Maybe they had two pump flow to the thumb?
Good day A final thought on omitting relays, should you make the work for revenue and a fire happens insurance company may well pursue a court action for substandard - negligent work. For peace of mind I prefer to stay within normal standards of workmanship. Kind regards Uffex
I've worked for many insurance companies and never met anyone working for them that knew anything about machinery. That's why they hired me. I've also never investigated or heard of a fire or electrical problem that caused damage on a machine where an insurance company denied coverage on. Fire is a named peril in the contract so is covered no matter the reason for it. I've also never heard of a subrogation on a loss for a supposed improper install on a machine. I've also never seen or heard of a problem caused from wiring up a thumb circuit directly to the solenoid the way it has been done in the northwest since I've been doing them. I started installing thumbs on Link-Belts back in 1980. I have had problems with micro switches lately on a machine that does have relays installed. For some reason the current flow going through the micro switch to the relay causes a spark inside the micro switch and when there are enough burn marks on the contacts the function they control will no longer work. That would indicate to me that the relays used require more current flow to close than the coil in the solenoid.
Uffex, I certainly appreciate all the information that you provide us on this forum and am in no way trying to insult you but you do have to realize that somethings are done differently in the US than over in the UK. I'm not sure when they began using hydraulic thumbs in the UK but in the US ,our area the Pacific Northwest was one of the first areas to use them and that was about the time that machines switched over from mechanical linkage to pilot operated systems. (late 1980s) John C., myself and many others in our area have been working on these machines since that day and like I said before, the only time I have seen relays is in the logging industry where that little DO3 was cycling every few seconds, all day long. And not using relays has worked great for all this time on a standard hydraulic thumb. Again, thank you for all you do on this site, it is certainly a top notch forum.
It is certainly possible John that the swing motor was the original issue, this one had a #12 hose coming from the thumb relief block down to the swing motor.
Evidently there are many decades of combined experience here so I’m wondering if you guys ever installed or observed some form of in-line shock valve on the cylinder extend line? Or is it just a matter relying on the port relief valve for those rough operators?
Most higher quality thumb installations had a cushioned cylinder installed. If you Google "cushioned hydraulic cylinder" it gives a pretty good explanation of it.
John, on that relief valve what would you set the pressure to if your pilot pressure would be 500psi? Or did you just dial it down until you had it where you wanted it? Could I just plumb in a relief to the pilot pressure side of my subplate or would that drop my entire system pilot pressure without a check valve?
I just dialed down to suit. Pressure was reduced down stream of the cartridge so you could put any kind of regulator in up stream of the sub plate.