I have a Cat 308E 2 CR that only had one AUX circuit. I have added a case drain for running a Hyd motor brush cutter. I want to add a Hyd Thumb. I have thumb control on one of my joy sticks for off set dig for shifting the boom over to dig closer to a wall. What control valve could I use to block off the hyd cylinder that goes to that function and tee into the lines to run my hyd thumb? It could be manual or electric control. What system pressure does the 308E have? Is 3/8 hyd hose big enough to run the hyd thumb?
you add quarter turn valve blocks and piping for a thumb coming off the existing AUX lines at the stick. I.e. to use the thumb you’d close off the blocks for the aux lines and open up the thumb valves then when you wanted to attach and use your brush cutter you’d close off the thumb valves and open up your aux valves after attaching your cutter and connecting your lines. I set up a 308 as described above several years ago for a customer. cat will have the parts necessary, get yourself a sharp counterman to find what you need for your machine configuration. This is the same kind of setup we install all the time on larger excavators as well.
Another option is 2 - 3 way valves on the boom. This is a listing on the type of valve I am talking about. https://www.surpluscenter.com/Hydra...y-Ball-Valve-Dynamic-DE3L-12-NPT-9-8595-8.axd I have one mounted on either side of the boom. This way I can run a mulcher or the thumb. Just be sure to shift both valve the right way. I took of the handles and put lock blocks on them so they don't shift accidently. Will try to get a couple of pics when I get out to where the machine is.
Thanks for the information
Can I leave the flow setting for the Aux the same to run cutter and thumb?
The issue you have is the thumb psi setting has to be low enough to allow the thumb to give against the bucket. This setting will not be ideal for running a mulcher. The higher the psi, the better the attachment performs. The result of the low psi setting is the attachment constantly going over relief. The ideal set up is to have a separate thumb circuit and aux. circuit that allow separate psi settings.
That's why I thought it was a lot better to share with the Hyd circuit under the excavator right side that shifts the boom over to left or right to dig close to walls. I know it would need two lines added. I already added a hose for case drain to the cutter motor that was a Cat Kit.
You change your tool/pressure profile in the monitor
OK
Can you change psi at the monitor or just GPM?
its been a while since I’ve been in the 308E2 monitor but I seem to recall different settings for the work tools but I couldn’t tell you further than that. The larger machines absolutely can change flow and psi in the monitor as well as a bunch of stuff. Like I said I had a customer that had a mulcher, bucket and thumb for his machine and we had it set up he could switch profiles when he switched tools. Thumb stayed on machine and he locked out aux and opened up thumb valves and switched to the thumb and bucket profile. The mulcher profile was specifically tuned to his mulcher in fact we flew in the setup tech from the factory to fine tune it as the Cat default settings under the mulcher profile were too much for it.