Hi all, First post here as I cannot find the answer to my question anywhere! I have an attachment that I need to put onto a JCB 3cx, it is piped for hydraulic attachments. The attachment has a max operating pressure of 126 bar and max flow of 57/L per minute. How do I find the current pressure on the JCB's bi-directional attachment circuit and how do I adjust it? I don't own the JCB and don't have access to it until Saturday the 16th of March. It is a 2011 model 3CX Eco. Help needed ASAP. Thanks, Lewis Ferrari
from memory the aux switch has two settings to provide two different flows /pressure might be able to find out tomorrow cheers graham
That would be very helpful Graham. Any advice on how to actually operate the auxillary hydraulic circuit would be handy too. I'm only 17 and have used excavators but a 3cx only once before so basically a 3cx noob... It is an A level school project with a Superwinch hydraulic winch that I need to power up and I really don't want to break it as it costs 1500 quid! Thanks, Lewis
when you connect the auxilliary circuit you automatically get connec ted to a foot pedal next to the digging levers
sorry i did not manage to get to the yard today but will tomorrow for sure , as Robin has stated you use the pedal for the extender on the right hand side , but must pin the extender first you could always ring your nearest dealer for the info ,and also the machine will/should have the operators manual behind the seat will post up around the same time tomorrow cheers graham
Pretty sure you'll have to fit a separate relief valve, the easiest way would be to adjust you're circuit reliefs. But I'm pretty sure they aren't adjustable on that model, if they have them. I know on the boom/dipper circuits they are fixed. But saying that there are a couple of adjustable reliefs on those control valves, can't remember which spools off the top of my head. With regards to flow, hook up a flow meter. Most hydraulic workshops will have one, if you flick your Eco/Lo switch on the dash this should vary it a bit. This cuts certain pumps out, but will only work in the green zone on the tacho (been a while since I did the course on these so can't fully remember)
feed pressure is 207 bar , now you can change this via the ARV but will not be possible for you without the necessary gauges etc the best bet will be to switch from eco to low on the switch next to the ignition and leave the machine at tickover ,you do not need for it to run in the green band , this only applies to the eco side ,where the third pump kicks in while the revs are in the green hope this helps
Thank you Graham, Jock and Robin for the responses. I'm going to put the thing onto the JCB tommorow but knowing that the feed pressure is 207 bar I don't think I can risk connecting the hydraulics up. Ideally I'll see if I can borrow a relief valve for the short time it is needed for from the place that is supplying the hoses to me and have them plumb it up on connectors so it will work as a temporary measure. I will let you know how I get on! Thanks, Lewis
i run a hydraulic saw from the breaker circuit on mine ,and that is how we do it i would be interested to know what your doing and some pictures if its not too nosy
Went to test the attachment today, the day started badly.. and got worse. Got to the JCB, forgot keys to it, retrieved keys from home. Keys I'd been given were spares, immobiliser fob didn't work. After a delay the new keys came and we got going. Quick hitch had a slight taper to it, my tolerances were too tight and so it didn't fit! Took QH off, dipper width on the attachment was not wide enough by around 2mm so wouldn't fit. Think this is due to the distortion I encountered when welding the plates. For some reason the hydraulic place, so far, can't match the 3cx's female flat face couplings to male ones. So having delays with hydraulics too Going back sometime next week when hydraulics are sorted and I've re-machined pin bushings to fit the dipper. I have another question: Can the auxillary circuit's flow be reversed? E.g. can I rotate the winch drum in both directions? If so how? Thanks, Lewis
Here are some pictures of the 3cx and the attachment It is named the HoistmatePRO, manufactured solely by me (excluding the oxygen acetylene cutting of the 15mm plate) It essentially makes the 3CX or other excavators into a safer, more versatile crane and is powered by the auxillary hydraulic circuit. Oh and it is on a stand in the photos, it's not part of the attachment Lewis
Sounds like a bit of fun With regards to the aux circuit, if you have a picture of a hammer on your switch and the circuit is activated by a foot button on the LH side of the controls; then no not easily and cheaply. Just remembered as well the hammer switch in these is 3 position as well, off on (low flow) on (high flow) If its a 3 position switch with a picture of a hammer and shears (I think), that works as on off on then you will have 2 way flow; so yes it should reverse.
its not very common for backhoes to have the two way circuit in the uk my machine has the hammer circuit with an on /off switch as the high and low flow options are made by using the eco / low switch now ,the hammer/ bi directional should have a hammer and a ram with a double arrow ,where are you based as i know where there is a 3cx with bi directional i would say that is more suited to larger 360,s and telescopics where a similar setup is already available cheers graham
I live near Peterborough, Northamptonshire. As far as I can remember the switch didn't have a ram on it so I probrably out of luck with that. In terms of machines, I sort of had to restrict myself to something reasonably small as the project is big enough as it is. Also the avalability of the machine to test it on, 3cxs are common as muck around here. Does something like a JCB 8080 which uses 3cx bucket sizes have bi-direcional auxillary circuits? Thanks, Lewis
you would have more luck finding a smaller 360 5-8 ton with the aux circuit , most hirers should be able to tell you on the phone if its fitted really could you run a spool block using the hammer circuit as flow and return perhaps
Plant hire places was where I asked to test it first, the ones around me either: didn't have the correct equipment or were completely un-interested in investing their time in me. I explained the project to one plant hire place in Peterborough and without me asking for it he gave me his critical analysis of the project and told me it was basically useless and he wouldn't be prepared to help me out... I'm considering the spool block idea, the only disadvantage is the block and lever would have to be on the boom near the couplings, not easy to reach when the boom is at full height! I'm sure some string would solve it though! Regards, Lewis
Lewis, on the latest 3CX there is an option for bi directional flow for the breaker circuit, I would think one of these would be hard to find to hire. The way I get a double acting circuit is to put a double divertor 12 volt solenoid valve into the extending dipper circuit along with an extra set of pipe work to allow the attachment (jaw bucket in my case) to work with the dipper extended. If you were fitting the winch to the front some quick release couplers in the 4 in 1 circuit would be simple. Good luck. Ex tractor fan.
Lewis, the spool valve idea - you could use a 12 volt solenoid valve and run the cable along the backhoe to operate from the cab, the only way really as the breaker button/pedal is spring detented to the off position - safer than being near the winch/dipper arm and only needs one operator. Stay safe, Ex tractor fan
Thanks for the suggestions guys, Going to try and get it attached and operational on Friday this week. Have asked for a quote including a relief valve and electric solenoid valve so I'll have to wait and see what they come up with. Will update and post some pictures on Friday night. Thanks, Lewis
Well, I'm only a week late in posting back! I decided after some hefty quotes that connecting the winch hydraulically was too expensive for the duration it was going to be used for. However, the Winch has a manual freespool clutch and drag brake that can hold 1.5 tonnes. So I was still able to photograph items suspended in mid air etc. Here are some snaps from the testing day on Friday. Lewis