Pneumatic system - Belt Changers

Hello.

I have a FADAL 3016 with the hi/lo belts and changers.

I am getting air escaping out of the manifold exhaust. When I change from lo to hi (or vice versa) the air escapes out of the other side of the exhaust manifold.

I don't think it is any leaking MAC Valve, but rather something in the belt actuators. Problem is that I cannot find any design or schematics on the belt change system.

I assume that air is directed through a Y system (there are additional manifold blocks on the top of the Z axis which this runs though) and as it pressurizes on actuator to engage, similarly it pressurizes the other side of the other actuator to disengage that one. I suspect that somewhere (likely in the actuator) air is leaking past the piston and therefore going out the exhaust, through the other circuit.

Problem is that I cannot find any explanation or diagrams of the belt change pneumatic to try to fault find this...

Can anyone help with either an explanation of how the belt change pneumatic a plumbed and work, or a drawing?
And wondering whether anyone has come across something like this before??

I ONLY EVER run in high belt mode, so even simplifying the system to lock out the low side would work for me, but again, I have no idea how the plumbing works in this system. Visually it seems somewhat complex, hence wondering whether there is a "Y" crossover to simultaneously extend one cylinder whilst retracting the other...

Thanks for any/all help!!!
Marty.

There are 2 hi/lo systems 1.Standard and 2. Air over Hydraulic used normally for a HighTorque machine.

the standard is very straight forward one Bimba cylinder to engage Hi and one bimba 2 engage Lo. sigle air lines

The air over hydraulic is basically using air to force the Hydraulic fluid in and a check valve from allowing it to escape. So as the belts stretch more fluid enters making it tighter and tighter. This is why when the machine makes a tool change it cycles the Hi/Lo cylinders to release the extreme pressure.

Here is a link for the drawings of the 2 systems. NEVER PAY FOR FADAL MANUALS THEY ARE ALWAYS FREE FROM MANY PARTS SUPPLIERS AS LONG AS THEY ARE AVAILABLE DOWNLOAD ALL THE FILES :)

GOTO page 296 in this manual https://flintmachine.com/images/uplo..._and_Motor.pdf

Goto pages 4 and 12 https://flintmachine.com/images/uplo...s/VMC_3016.pdf

Repair kit on page 4 for the Air over hydraulic

purchase the repair or doit yourself :) https://store.fivesmsi.com//product/...ELD-REPAIR-KIT

https://itscnc.com/catalogsearch/res...HYD-0018&cat=0

https://www.fadalcnc.com/index.php/hyd-0018.html

Thanks for all the detailed information Rodney, you've certainly gone to a lot of effort and I appreciate it!

I have read through the manuals and had a look at the repair kits, but the manuals do not touch upon this and so I am still uncertain about three things:

1. How are the hydraulic actuators plumbed, in other words, what tube goes where?
2. What do the hydraulic actuators do? In other words, I would imagine the system could simply be designed to apply pressure to the piston directly, so why does it run through a pair of these units on the way? Does their crossover plumbing serve as a sort of interconnect to ensure one piston will always retract when the other extends?
3. What goes on inside the hydraulic actuators? Outwardly they look like simple manifold blocks, but I suspect there are other things going on inside? Knowing this will help me understand how air can be bypassing somewhere and running back through the other system and leaking out the exhaust of the manifold block (past the opposite MAC valve) under the spindle cabinet.

Knowing this will help me understand the system and importantly (per point 1 above), will ensure that I reconnect the tubes in the correct manner. Again, from what I can garner from the manuals, there is not a great deal of background on this part of the pneumatics and why they are as they are.

On a side note, I have seem a great many posts and confusion surrounding refilling the oil in this system. The way the manuals describe the procedure, it refers to disconnecting the 1/4 line to the rear of the actuator then filling until the 5/32 line shows oil. Other recommend disconnecting the 1/4 at the hydraulic actuator block so that gravity helps when filling the 1/4 tube down to the actuator. Still others recommend doing the entire process using the tubes connected to the hydraulic actuator blocks. As you can see there is a degree of confusion out there. Again, I suspect a deal of this is lack of information about how the system is designed to work and plumbed...

Really appreciate all your insights!!


Thanks again!

Cheers,
Marty.

In a nut shell its a very basic system. Air comes in and splits and goes to the Extend of one and the retract of the other. I see you are in New Zealand i think so there is probably not alot of Fadals in the area. If i get a chance i will take a video of a Air over Hydralic working Shifting and post

Most of the systems are engraved into the main body with the connections like L/R meaning (Low / Retract or Return) etc. etc. You may need to remove the grim build up to see.

Attached is a photo Print it as large as you can and get 2 colored pencils and follow where the lines connect. You should be able to see where all the lines connect and also the actuator exploded vies with seals and check ball and spring. At least there are places to buy the repair kits if it is unable to be rebuilt.

OH also worst case senario if you give up on the repair route. You can elimate it altogether and just go with the original set-up which is simply replace the Bimba Air Cylinder with Single input for the extend using the spring in the air cylinder to retract.

Thanks for the reply and the detailed info.

With your information I should be able to get things moving forward from this point.

You are quite right, there are very few FADAL's in my area of the world, hence the reliance on the forum :)
Given this remoteness, and the exchange rate, the prime task will be to dissemble and replace seals in the air over hyd components.
If that is not successful, it will be best to simplify the system and go back to the original FADAL setup, replacing the cylinders with spring loaded ones as you've suggested, essentially deleting the complexity of the air over hydraulic components. As I only use the hi belt anyway, I may even simplify the system further to only include that. It is a rigid tap machine, but I have never had any trouble rigid tapping in hi.

I have attached a colorized version of the pneumatic diagram in the hope that it might help others here as well.

Thanks again!!

Cheers,
Marty.

Attachment 450198