hello gentlemen, I recently ordered a much needed thumb for my 3cx. I few questions I have if anyone is familiar with this machine. I have a hammer circuit now that's plumbed up to the top of the main boom. I was thinking I could use this plumbing for the new thumb vs trying to route new hoses which would be a pain does it matter that they're 1/2 lines? And for the hammer circuit should I just loop it back to its self to seal the loop?
If you have a hammer circuit this is normally single acting so you get a feed and a return back to tank, You will need to have a double acting circuit for a thumb if not you will require putting a control valve / c top with releif valves on the hammer feed line as to make it a feed only into the block and able to split to open/close thumb and pipe the return from the new control block back into the hammer circuit return. These valves can be electric operated or bowden cable operated. If you have a extra dig on this machine you can use this circuit as well but need to still put a diverted control valve on.
Thanks Jeff, I was only thinking of using the plumbing going up the boom its maybe 1/2 or 3/4 not sure. I was thinking looping the Hammer circuit to its self and disconnect the switch. I didn't even think to use the hammer hydraulic supply to a new valve. I'm wondering if that would be cheaper than the diverter valve I bought to use the extra dig circuit as you suggested. The valve was 1k not counting lines and hoses.
Gday Steve, I played with these a fair bit back when I was doing my apprenticeship, few years ago now but. We used to do a lot of mods on the 3CXs tilt hitches, extra circuits, grabs etc. We did do a thumb, from memory we went the way jeff suggested and bolted a 6 port diverter to the top of the dipper and used the e-dig circuit. Only thing with doing this is to double check that circuit has adjustable circuits reliefs, you'll need to set the piston side relief at a lower setting to prevent damaging the thumb cylinder when your're crowding the bucket. You'll also need to fit the e-dig lock pin each time you plan on using the thumb to prevent it creeping or accidentally moving. The other option is ctop and use the hammer supply but ctop can be a bit jerky as it's on off unless you spend big and go for a proportional setup. Make sure you fit reliefs as well, the hammer circuit won't protect the cylinder from damage by the bucket as mentioned above I can't really see any dramas with using the hoses as you suggest, does your machine have powered sideshift? Not sure what model you have (gear or piston pump) but the valving underneath is pretty self explanatory, especially if it's gear pump. Cap it off, pull out the hammer switch and then supply your oil to the hammer hoses. Either by another slice in you control valve (exxy) or putting a 6 port diverter under the back of the machine and diverting one of the other rear end functions eg. powered sideshift. I did once get a bit sneaky and used one of the loader valve spools to supply a grab. Ctop with shuttle valves to work the pilot circuit and a 6 port diverter to divert from the loader lift spool (that was an expensive one though) A 6 port diverter on the e-dig circuit mounted on the top of the dipper would be by far the cheapest option though
I think the best bet for me not being experienced in hydraulics is the diverter valve. I wasn't aware that the extra dig had to be pinned. I was thinking I could switch back and forth and use both functions. I wanted to mount the valve under the machine as to not have hoses sticking out everywhere.
I'm really surprised that this machine doesn't have a spare valve somewhere.
So what does proportional mean? How does the thumb provide clamping force against the bucket with out pushing it back or vs verses. Does a relief valve operate when a certain pressure is reached and allowing the overage to go back to tank. Sorry for all the questions but I'm thinking of returning the diverter valve and getting a proportional foot valve and kit that's designed for the machine.
Finally got the thumb installed. Ami was great to deal with. Perfect fit
Looks good !!!
So I was working on the hydraulics today. My plan was to remove all the hammer circuit hoses and cap the feed and use the return as the return for the pressure relief return for the thumb. So I got everything from the hammer circuit removed, capped the feed and return and when I start the machine up I hear squealing from I think the front valve for the loader. And when I increased rpm it just didn't sound right. Hydraulic oil level reads fine and I operated every cylinder thinking it was air. Any input please share. Thank you
Here are the two caps
This is the hammer circuit I removed. The two 45 fittings that are next to each other went up the boom and where connected by a temp loop and the t fitting was the return and the 90 by its self was to the hoe block. I'm thinking I just need to connect the two caps in the previous picture together with a section of hose and I'm good. But I'm not sure if I can use it for a return for the thumbs pressure relief.
Steve 28 The first picture you got under the valve block i think the one you got capped is also a return from memory
What is your serial number i might be able to find the fitting instructions for the hammer circuit so you can back track.
Thanks Jeff here's the serial number jcb3cx4tk02015786. I think I need to connect them capped lines together and hopefully I can use it as a return. It goes right to the tank.
Steve, I haven't studied what you did too closely but check if the circuit for the hammer is double acting. I have installed a thumb on a JCB 212s (2cx in Europe) which has a factory hammer circuit. I was able to plumb right into that circuit. In my case the valve for the hammer is double acting, with one side unused. So I just caped the return line for the hammer that goes directly to the tank, and pumped the other side of the valve to the thumb. I have a very detailed video here which shows everything (hydraulics start at about 3:30 mark): Take a look and see if your valve looks similar.
Greg mine doesn't look the same. I don't have any spare controls ether. My foot pedal works the extend boom. I have a diverter valve and a pressure relief to add so I will toggle between extend hoe and thumb. now that I'm learning more im pretty sure the two capped lines need to be connected back together. I just don't understand how the hammer would operate if that was a return.
Jeff this looks like it
On the schematic the t's labeled 14 where piped up the boom and looped together.
These might help this machine is 2011 year correct.
Thank you Jeff. I'm going to work on it the rest of the week. Hooking up the diverter valve and pressure relief. Then I'll have to learn how to set the pressure relief. Ami suggested 1800 psi. I'm going to order a kit with gauges and adaptors. Should I add a tee inline with a port or just do it as gregs video shows, just unhook one line and hook gauge up then just reconnect. Thank you for your help and Greg thank you to. hydraulics are all new to me. This site has been a great tool. Happy thanksgiving
Yes Jeff pretty sure it's 2011
So I got some time this morning to work on the hydraulics. I reconnected the two capped lines and the machine is back to normal. And I was able to mount the new diverter valve and relief and do some hose work. I'm just waiting on two hoses from FedEx (their terrible) and I can get everything powered up. Here's some pictures. I'm going to replace the hose that jumps the block to the relief, it's to short and I'll get rid of two 90s.
Here's some more
If you connect the gauge straight to the end as discussed it will give you exact reading but make sure you vent the circuit before removal of the gauge and vent the tank as well.
I got everything done today and it don't work. This is starting to drive me crazy. The only thing I think it can be is the wrong schmactic for the diverter valve. I followed this schmactic thinking they're all the same. The only difference I made the thumb the primary and extend hoe secondary.
Maybe I need to reverse my input hoses
Here's a video you might want to check out. It's for the JCB 212S/2CX, but may give you some info needed. On his, the "aux" valve is double acting. He only capped the " return" line. I'm going to go his route this summer, too cold at this time of year here.
Thanks hook I've seen this video. Greg shared it a few days ago. My machine doesn't have this setup. After spending the night studying hydraulic valves I think I will get it right today. Just finishing my coffee then I'll get at it. Hopefully tonight I can show a video of it working.
Oh man, sorry...never even noticed it....lol
Greg, just thinking out loud here but.... I believe the hammer circuit puts out 19gpm, If I were to tap into this circuit via the couplers, and route the hose's to the front, this should be enough flow to power a hydraulic snow blower on the front. You could magiver a quick attach to the blower and some sort of lever for the foot control to start flow. I know these hydraulic blowers are expensive, but having a blower front mounted would be something. Whats your take on this?
Hookedondiesel, I started a new thread here , HeavyEquipmentForums for the snowblower idea.