installing hydraulic thumb

[Uamauka]

Hi,

I am going to install a hydraulic thumb on an Ingersoll Rand backhoe. Hydraulics are open center. I have read several threads and I think I like the idea of using a solenoid diverter off of the bucket section with a momentary switch for the thumb. I am confused about which valve to use, single or double, how to wire the switch if using a double, or how to route the hoses if single. Also where should I install a relief valve for the thumb?

Also are my current hoses and fittings metric? If so what are my simplest cheapest solutions in that regard?

Thanks,

 

[J_J]

Here is a selector/diverter valve you can use.

SAE 8 15 GPM DOUBLE SELECTOR VALVE 12 VDC P15544-1

http://www.surpluscenter.com/_MoreSpecs/i9-5117.pdf

A SPDT-CO (Single Pole Double Throw Center O)
switch can be used to switch the solenoids.

It can be mountrd just about abywhere, even close to the cyl you are diverting.

 

[polarred21]

This looks like a good deal, have you had good luck with this vendor?

 

[Uamauka]

Thanks. Any suggestions as to what I should look for in a relief valve?

 

[J_J]

This should work.

1/2" NPT 30 GPM 1500-3000 PSI RELIEF VALVE RV-H4

http://www.surpluscenter.com/Hydrau...0-3000-PSI-RELIEF-VALVE-RV-H4-9-6135-50-H.axd

 

[Uamauka]

Thanks for the help. OK now it gets a little tricky. I have figured out that my machine's hydraulics are metric DIN. Where can I find adaptors to the SAE ports on the selector valve? Or alternatively selector valve and relief valve that are already metric? And where can I find reasonably priced metric hydraulic hose? I know I can get hoses made locally, but if I have to do a bunch of hose this will get expensive? Any ideas?

 

[J_J]

British (BSP) and Metric Fittings

 

[Uamauka]

hammer hydraulics 101 please



For installing the thumb, I have decided against mounting the valves out on the dipper, so I want to use the existing hoses that are plumbed for an accessory hammer. If I am to use these hoses, then I wonder if I should choose a solenoid control valve and run it to a rocker switch, rather than the selector valve run off the thumb valve as I had planned. Thing is, I don't understand enough about the routing and what is going on with the hammer hydraulics on my machine. So I have drawn a diagram of the routing of the hoses involved. Please school me on what is going on and my best options. I do not have or need a hammer for this machine, so keeping the one way accessory in the system is not required.

Thanks.

 

[J_J]

Re: hammer hydraulics 101 please

Is your hammer flow a steady flow or a pulsating flow?

If it is a steady flow, the just use the solenoid to feed the thumb. It will operate at full force, with no feathering. Just touch a momentary button to move the thumb.

Is the hammer spool the first or last spool in the system.

Do you know if you can use multiple at the same time? If they are in parallel, each spool operated will get part of the flow, making it fast or slow.

 

[Uamauka]

I am afraid I don't know the answer to these questions. I was hoping the diagram would shed light on what I have. I think the hammer is the last spool in the system. The machine's main relief valve is in the loader stack, and the lower of these hoses feeds the lower main valve of the backhoe stack, and the hammer hoses seem to be bypasses of the outlet section with the solenoid in between.

I was under the impression that this is an open center system, though I can operate more than one function at a time, for instance the boom and the dipper- in which case both are very slow.

I have no idea it if the hammer was a pulse or steady flow. I only know that it functions with a pushbutton switch on the joystick which has only 2 wires coming off switch.