Question on hydraulics for thumbs

[cschulz]

Hey Guys, Im looking to find if Im correct on my plan for hydro thumbs for both front bucket and BH bucket for my Kubota BX. I have the basic idea of adding fittings to a PB line and maybe split(T fitting) that line to go one front and one rear to solenoid valves. They will be a 4way 3 position, return to center with open center. Here Id be looking at installing the return lines to tank the same way. Also the valve is good for 5gpm which the tractor is 6gpm. Will this be a problem as a thumb?
Or should I run them separately? One off the FEL circuit and the other the BH circuit? I really don't think they will ever be used at the same time as they are at different ends of the tractor. I really don't want to add lines to my BH area and clutter that area up. Would like to make this look as clean as an install as I can. Keep it all tight and under the tractor. Id bend new lines if need be (BH). I may even look into the Flare less Compression fittings? Any concerns of these type fittings?
Im new to this and just wanted to get others opinions before I spend the money and or do some damage.
Here are some pics to look over.

Chris

 

[SSdoxie]

You cannot run Teed line to 2 open center valves. Oil always follows path of least resistance so when try to operate 1 valve all the oil would go through the other valve. Open center valves must be connected is series, not parallel.

 

[J_J]

If you want a selector valve for a thumb and control a front function, then install a two spool valve in series with your tractor flow.

It could be a two section 3rd function valve,or a two spool valve.

The valve should have PB.

 

[cschulz]

You cannot run Teed line to 2 open center valves. Oil always follows path of least resistance so when try to operate 1 valve all the oil would go through the other valve. Open center valves must be connected is series, not parallel.

Sorry it took me so long to reply but for some reason my computer at work will not allow this site. So Ill have to reply in the evenings.
The T-ing problem had crossed my mind but I tend to over think things and so thanks for the clarity. So I may just tie into one source and run through both controls in series. Have you had any experience with flareless connectors to splice into tubes?

Thanks Chris

 

[cschulz]

If you want a selector valve for a thumb and control a front function, then install a two spool valve in series with your tractor flow.

It could be a two section 3rd function valve,or a two spool valve.

The valve should have PB.

Thanks JJ, a 2 spool vavle is good idea but what I forgot to mention was that I would like to have just a finger tip control switch mounted on each hand control. One for the FEL and one for the BH. I had considered a manual single spool control valve mounted to the floor board and just add a pedal to work the front thumb. But with a BX space is limited.
Do you see and problem with the control from SC that I had a link to? Also do you have any exerience with the flareless connectors?
Here is a pic of the prince valve placed on a different tractor.But like I said Im prefering the simple switch idea in the last pic.

Chris

 

[J_J]

You should be able to use that valve or two valves.

The flow to the thumb will be full flow, no feathering.

You probably will want a relief valve across the thumb cyl in case the bucket cyl overrides the thumb cyl.

Here is another option. Two of these mounted on a subplate and a toggle switch mounted on the joystick handle.

12 VDC 10 GPM OC DA SOLENOID VALVE

2 STATION DO3 SERIES OC SUBPLATE

Valves can aso be operated manually.

You could also use a selector/diverter valve and have feather ability.

 

[cschulz]

Hey thanks JJ. I didnt realize that the valves I showed would work that way of full flow. And how does a relief vale and selector/diverter valves work with solenoid controls. I do like the simple set up of 2 solenoids and one manifold block Im just not sure where to mount on my very small BX. Please tell me more I have lots to learn.

Chris

 

[J_J]

A six port diverter valve will split one hyd circuit into two circuits, and each cyl is operated by a switch which will select each circuit.

Using a diverter valve on the BH, you could use a stabilizer hyd circuit for the thumb. Position 1 would be the stabilizer, and position 2 would be the thumb.

You need a relief valve on the thumb cyl to protect against the bucket overpowering the thumb cyl.

A diverter valve on the loader cross arms would operate the bucket or the grapple.

Solenoid controls provide full on and off.