Engel Akula II Build Questions

[Oldus Fartus]

I'll set it up on the bench tomorrow and see if it is perhaps a LV Cutoff problem with the CTS.

I see there is an adjustment potentiometer for the low voltage cutoff but no information in the assembly manual about settings.

Also, what would I look for with the LEDs? (Nothing in the manual about the CTS LEDs either).

The wiring diagram shows three LEDs (yellow, red, green).

[JWLaRue]

Strange, you should have gotten a manual for the CTS module with your Akula kit. In any case, here's a link to it:

https://engel-modellbau.eu/shop/out/media/1584-CTS2_v10-17_E.pdf

-Jeff

[Oldus Fartus]

CTS 2 Manual

Strange, you should have gotten a manual for the CTS module with your Akula kit. In any case, here's a link to it:

https://engel-modellbau.eu/shop/out/media/1584-CTS2_v10-17_E.pdf

-Jeff

This should help me figure it out.

Thanks!

Pete

[Oldus Fartus]

Bench test results:

Green LED always on
(I think this is the transmitter signal integrity).

Red LED is always off
(I think this means that low voltage trigger has not been reached)

Yellow LED is always on and the piston remains in Bail (empty) position and piston will not Fill
(not sure exactly what the yellow LED indicates?)

[JWLaRue]

Okay....so assuming that you were able to successfully complete the initial set-up, the yellow LED in the 'on' state usually means that it is detecting one of the magnets. Is there a magnet next to the Hall effect sensor? What happens if you manually turn the gear so that magnet is not near the sensor?

Oh, how many magnets did you glue to the gear and did you verify that you have the correct alternating north-south-etc configuration? (it's easy to get wrong, we've done it at least once!)

Do you see any change in operation (or lack thereof) if you change the channel used on your receiver?

Can you provide a photo of the area of the piston showing the gear w/magnets and the sensor?

-Jeff

[Oldus Fartus]

Problems with CST 2

Okay....so assuming that you were able to successfully complete the initial set-up, the yellow LED in the 'on' state usually means that it is detecting one of the magnets. Is there a magnet next to the Hall effect sensor? What happens if you manually turn the gear so that magnet is not near the sensor?

Oh, how many magnets did you glue to the gear and did you verify that you have the correct alternating north-south-etc configuration? (it's easy to get wrong, we've done it at least once!)

Do you see any change in operation (or lack thereof) if you change the channel used on your receiver?

Can you provide a photo of the area of the piston showing the gear w/magnets and the sensor?

-Jeff

Yes, one of the magnets is near the Hall sensor.

Yes, I used a magnetic pole detector to alternate N and S (North is marked with orange paint).

Attached photos

Yes, I tried a new receiver on a different channel.

Update: After I left it turned off for about an hour and then plugged the battery back in, the piston cycles normally...very baffling?

[JWLaRue]

Definitely very weird.

Besides trying to run the system from a bench top power supply (instead of the battery), the next thing I'd be doing is to try putting the CTS through the initial set-up process again.....

-Jeff

[Oldus Fartus]

Further Testing

Definitely very weird.

Besides trying to run the system from a bench top power supply (instead of the battery), the next thing I'd be doing is to try putting the CTS through the initial set-up process again.....

-Jeff

Yes, for some reason it seems to fail when it is diving...it's pretty stable on the bench with either batteries or a power supply.

I'll run through the initial set-up again.

I'm using the linear mode rather than 80/20.

[JWLaRue]

I use linear mode as well.

-Jeff

[Oldus Fartus]

Engel was able to diagnose the problem.

Apparently the pressure switch also has an under-pressure capability as well as over-pressure.

I have been plagued with a small leak which produces an under-pressure when the sub is submerged. When that happens the pressure switch causes the CTS 2 to go into Bail (Empty) mode and brings the sub to the surface (nice addition safety feature I didn't know existed).

The reason I could't get the CTS 2 to fail on the bench was because the pressure switch was at ambient.

All is good...

[JWLaRue]

Good to hear that the problem has been resolved.

Apparently the pressure switch also has an under-pressure capability as well as over-pressure.

I don't believe that any of us knew that!

Can you share any details that Engel provided? Is the under pressure set point adjustable and if it is, how?

-tnx,
Jeff

[Ralph --- SSBN 598]

This makes sense.

If you turn on the system.
Cycle the piston and connect the hull halves while the piston is in the flooded position, it will put the inside of the hull at negative pressure when the piston is moved to empty (bail).

Someone has thought this system through.

[Oldus Fartus]

Good to hear that the problem has been resolved.


I don't believe that any of us knew that!

Can you share any details that Engel provided? Is the under pressure set point adjustable and if it is, how?

-tnx,
Jeff

Here is the email I received from Gregor Engel:

"Hello,

The pressure switch is definitely not faulty.

This can have 2 causes:
1.) Model loses pressure.
When tank is filled model submerges. Now it loses pressure. Then pressure switch detects an under-pressure and forces the tank to bail.
Did you check for possible leakages?

2.) Difference in temperature between water and air.
If air and water temperature differs strongly the air within the hull compresses as soon as the model is placed in water. This will cause an under-pressure and the pressure switch to activate the bail mode.

In both cases it will be difficult to open the hull as the under-pressure sucks the two hull parts together.
Opening the breather tube (attached to the main bulk head in the aft section of the hull) will equalize pressure.

It is really hard to identify the problem from a distance.
Please give me more specifics.

Best Regards

engel-modellbau

Gregor A. Engel"

[JWLaRue]

....hmmm.....have you tried to reproduce an under pressure condition to confirm?

-Jeff

[Ralph --- SSBN 598]

If the hull halves are hard to take apart, you can also move the piston to fill.
This movement needs to be very small and might need a couple of hits on the control.
This reverses the pressure from negative to positive.
Be careful opening the hull until you hear the pressure release.