Adding Bluetooth pressure transducers to cnc machines

[bill4807]

Look at Vektek.

They have wirless solutions for pressure sensors.
Use for rotating pallets or transfer machine stations.

 

[drbitboy]

Hey Bit, wrap your head around mechanical screw pump to create hydraulic pressure. Common...

That is something like what I thought it might be ("hydraulic clamp" was a clue), but OP only ever said stuff like "they screw/turn the nut [and that] clamps the parts." and I didn't want to assume.

Okay, so turning the nut runs the pump, that pump generates hydraulic pressure, that pressure drives the clamps, those clamps clamp the part.

That makes sense if there is no power to the table.

Sorry I am so slow/pedantic, but at least everyone is now (hopefully) unambiguously on the same page.

- drbitboy, DMD.

 

[plchris]

Thanks to everyone that has replied

Is there an API to the custom hydraulic clamp monitor on the Android? Because you can talk Modbus to the PLC e.g. see this link.

If stuff like API is greek to you, you will need to hire someone to code it, but yes, the solution should be simple.

Also, a minimal linux box (SBC or laptop with ethernet) should probably be able to do the same thing.

So yes, although this is a bit of a Rube Goldberg/Heath Robinson, it should be straightforward, but you should spend some time googling to see if someone else has already solved the same problem.

Thanks I'll look into this.

You said there is a small (battery powered?) hydraulic unit on the fixture clamps. How does the operator command it to clamp and unclamp?

Can you interlock the command to clamp with the permissive to drill? Maybe include a time delay to allow for the clamping action to take place. Admittedly not a perfect solution since it assumes the clamping action takes place on command.

It's manual. The operator uses an impact driver or drill with an impact socket attached to screw the nut and that generates hydraulic pressure on the clamp.

Thanks for the added detail; @PeterN usually checks out if the information flow is too slow, but he does like hydraulic problems.

But to me, "hydraulic clamp" is a new concept, so please use simple phrases and short words: does turning the nut actually tighten the clamp directly e.g. like the C clamps in my basement, or does turning the nut generate hydraulic pressure in these custom devices, and that hydraulic pressure exerts force on the clamping elements?

Turning the nut generates hydraulic pressure on the clamps.

Boy, this set has an LOL or two.



Sounds to me like you have a dual pallet tombstone. Difficult in that scenario with the indexing and the rotation.


I do have experience with that sensor you want to try. They do work, but very sporadic. Loose connection, have to try again and again, then a day is lost.


I did contact OEM, a couple of emails and phone calls. They told me to contact the place I bought it from, which was Mouser. They have no tech support for these items and neither does the OEM in China.


Yep, we want your money, and too bad if what you bought doesn't work.

Yup it's a dual pallet tombstone.
When you say loose connection do you mean the Bluetooth connection?

In this case we see nothing and information is being released a little at a time.

I really hate playing 20 questions.
The OP hasn't explained how the pump that rotates with the clamp gets power. The pump can't be powered by Bluetooth. Can't a parallel wire be run from the pressure switch back to the PLC then? The problem doesn't make sense.


In sawmills there are pantographs that run hydraulics and electric power to moving equipment. Obviously the hydraulic lines can't keep rotating the same direction for long.

The hydraulic clamp works by the operator turning a nut with an impact driver or drill with an impact socket attached.
We don't an issue with the hydraulic part. My question was about the best method of getting Bluetooth sensor data to a plc so we can prevent the cycle from starting if a sensor isn't up to setpoint.

Look at Vektek.

They have wireless solutions for pressure sensors.
Use for rotating pallets or transfer machine stations.

Thanks I'll look into this.

That is something like what I thought it might be ("hydraulic clamp" was a clue), but OP only ever said stuff like "they screw/turn the nut [and that] clamps the parts." and I didn't want to assume.

Okay, so turning the nut runs the pump, that pump generates hydraulic pressure, that pressure drives the clamps, those clamps clamp the part.

That makes sense if there is no power to the table.

Sorry I am so slow/pedantic, but at least everyone is now (hopefully) unambiguously on the same page.

- drbitboy, DMD.

Yeah I should have worded things better and maybe just left the machine part out completely . That part is fine. I'm wanting to get battery powered Bluetooth sensor data to a plc and use that to prevent the cycle from starting if a sensor isn't up to setpoint.

 

[padees]

Yup it's a dual pallet tombstone.
When you say loose connection do you mean the Bluetooth connection?

Yeah, it would drop Bluetooth connection all the time even just sitting on my desk. What you had to do to reset the sensor is pull the battery out, which is not ideal.

Boss wanted to monitor and data-log the purge pressure on a laser head. It would have been easy to hard wire in an analog sensor, but he wanted to use that unit.

We got the USB dongle and software for a laptop to do logging. When it worked it worked fine, but it didn't work more than it worked.

I didn't see anything on Vektek site. Was thinking something along the lines of a Banner wireless radio system. I see that Enerpac has a system, but looks like a rebranded Banner system.

If you have enough room on top of the tombstone and clearance, might be able to mount something up there. Run 4 pressure switches to the unit, shoot it to the receiver, then to PLC, or just use digital outputs to the CNC control.

 

[plchris]

Yeah, it would drop Bluetooth connection all the time even just sitting on my desk. What you had to do to reset the sensor is pull the battery out, which is not ideal.

Boss wanted to monitor and data-log the purge pressure on a laser head. It would have been easy to hard wire in an analog sensor, but he wanted to use that unit.

We got the USB dongle and software for a laptop to do logging. When it worked it worked fine, but it didn't work more than it worked.

I didn't see anything on Vektek site. Was thinking something along the lines of a Banner wireless radio system. I see that Enerpac has a system, but looks like a rebranded Banner system.

If you have enough room on top of the tombstone and clearance, might be able to mount something up there. Run 4 pressure switches to the unit, shoot it to the receiver, then to PLC, or just use digital outputs to the CNC control.

Thank you very much. Exactly the info I need. Since were gonna have 8 sensors total the chances of losing connection is gonna be too high for us to go with this sensor.

 

[RET]

I think this is exactly what you’re looking for.

https://www.vektek.com/Product.aspx?CategoryUid=464

 

[Steve Bailey]

Instead of Bluetooth how about a battery powered LED source on the fixture pointed at a receiver in a fixed location. Mount the LED source so that it gets exposed to the receiver (or simply turned on) when the clamps are properly tightened. Maybe you could use a pressure sensor with a mechanical indicator for that purpose. Interlock the signal from the LED with the permissive to start the spindle.

 

[bill4807]

I think this is exactly what you’re looking for.

https://www.vektek.com/Product.aspx?CategoryUid=464

Yes,
This is what i was refering to.

 

[padees]

Need power wires for that Vektek rig.

 

[plchris]

I think this is exactly what you’re looking for.

https://www.vektek.com/Product.aspx?CategoryUid=464

I found a manual online and this looks like it could work. Adjustable setpoints. Wireless. Built in relay outputs. Even has a unit with four pressure switches. Thank you very much.

 

[plchris]

Need power wires for that Vektek rig.

That's what I thought just reading the url posted. Then I thought why would it be wireless and need wires. So I searched for a manual. The wires are for the control box mounted outside and the sensors with the receiving unit are mounted inside.

 

[padees]

That's what I thought just reading the url posted. Then I thought why would it be wireless and need wires. So I searched for a manual. The wires are for the control box mounted outside and the sensors with the receiving unit are mounted inside.

It's the power wires... No Battery in these.




"Focused Field" Fixture Proximity Transmitters require no batteries, EVER! Nothing to replace. Wires into your supplied 10-36 VDC supply.

 

[plchris]

Instead of Bluetooth how about a battery powered LED source on the fixture pointed at a receiver in a fixed location. Mount the LED source so that it gets exposed to the receiver (or simply turned on) when the clamps are properly tightened. Maybe you could use a pressure sensor with a mechanical indicator for that purpose. Interlock the signal from the LED with the permissive to start the spindle.

That could possibly work and kind of similar to that vektek system.

Yes,
This is what I was referring to.

Thanks Bill, its my day off so I'm not gonna put too much time into researching but from reading several pages of the manual it may be what we use.

 

[padees]

Thanks Bill, its my day off so I'm not gonna put too much time into researching but from reading several pages of the manual it may be what we use.

Then you will need to externally supply 10-36VDC to the transmitters on each tombstone, index that in and rotate, so you have wires.

Good luck on your selection.

 

[tom_stalcup]

It looks like those Vektek sensors should do the job (as long as they actually work as advertised).

The presser sensors are connected(cable) to the transmitter(on the machine head somewhere).

The transmitter is passively powered through wireless from the receiver, which is wired back to the master control unit for power and machine interlocks.

https://www.vektek.com/Members/PartsLists/Documents/en-us/PL/PL3305.pdf