Another ARKMODEL VII Build Blog

[redboat219]

Don't forget to cap the pump.

[rwtdiver]

Thanks David,

Coming from you that makes me feel like someday I might just really start understanding this hobby! I came into it being a little on the cocky side (well maybe a lot) but it did not take long for you guys that really know this hobby well to level me and put me in my place! It is a tuff hobby to learn, but when you take the time to listen, study, and siphon as much knowledge from those that really understand this hobby, there is no reason why you can not do!

On that note, I did stop complaining and just made it happen!



I managed to install the caps (spark suppression) and i also made the power connections to the motors while I was at it. The motors checked out, and counter rotation has been achieved.

Thanks for all the help with this process. Another lesson learned! Bob Martin has a good product here, but like everything with this hobby you need to adapt and adjust to when it's required.

Rob
"Firemen can stand the heat"

[He Who Shall Not Be Named]

I have taken the two motors out from the parts tray!



Now you have great access to the motors to install the caps and also the power connections to the motors as well! Like we have discussed on the Dive Tribe and in this forum many times, it's a good thing to get to know your WTC/ Sub drivers inside and out, so this little situation I have run into is offering up that opportunity to get to know these components!

Rob
"Firemen can stand the heat"

You are a 'glass half full' sort of guy, Rob. I like that. Know your turf! In no time flat you'll be the resident expert on that type WTC.

David

[rwtdiver]

I have taken the two motors out from the parts tray!



Now you have great access to the motors to install the caps and also the power connections to the motors as well! Like we have discussed on the Dive Tribe and in this forum many times, it's a good thing to get to know your WTC/ Sub drivers inside and out, so this little situation I have run into is offering up that opportunity to get to know these components!

Rob
"Firemen can stand the heat"

[rwtdiver]

I'm not the manufacturer of those cylinders, but based on what I've seen during that one cylinder setup I'm guessing those are just standard can motors with no noise suppression. Installation of the caps is quick and easy and does help mitigate any potential RF interference generated from the motors.

Bob

Bob,

To install the caps on the motors on the 80mm WTC is NOT a quick an easy installation! To try and solder the caps on with the motors inside the WTC (and do it right) is not an ideal situation! The motors need to come out. I understand fully that Nautilus Drydocks (Bob Martin) is not responsible for what some of his manufactures do, and if you are in this hobby (submarines) you better be ready for these type situations to pop up! I for one really appreciate the fact that we have Nautilus Drydocks and at one time David M. there for us to have all these products available to purchase!

Rob
"Firemen can stand the heat"

[rwtdiver]

any size will work, as long it is in the .01uF range of capacitance.

David

Thanks David. The 104's should work.

This is the motor that is in the 70mm and the 80mm WTC and there is no spark suppression on these motors!

https://duckduckgo.com/?q=mfa+como+drills+motors+719RE385+&t=crhs&ia=web

These manufacture should know that this motor was going into an RC type environment, and should have used the correct motor or at least installed the spark suppression before they installed the motor in the WTC! The motors will need to come out to do a good job of soldering, but you can solder on the power connections at the same time.

All the fun stuff to do in our hobby!!

Rob
"Firemen can stand the heat"

[He Who Shall Not Be Named]

any size will work, as long it is in the .01uF range of capacitance.

David

[rwtdiver]

I do have another question about caps?!



Could I use either one of these sizes for the caps?

Sorry for the poor quality photo!

Rob
"Firemen can stand the heat"

[rwtdiver]

OK! Thank you, David, for all your help and advice! Now that Bob has chimed in and the fact that he is not the manufacture, and the motors seem to be just the standard can motors. I am going to break out the soldering iron take the motors out and install the caps. I am going to install the caps on the 70mm WTC as well. Not sure but I was having a few glitches when running my Alfa sub, certainly could have been a spark suppression situation. I will keep you posted!

Thank you all again for your help and advice! "Still Learning"

Rob
"Firemen can stand the heat"

[RCSubGuy]

I'm not the manufacturer of those cylinders, but based on what I've seen during that one cylinder setup I'm guessing those are just standard can motors with no noise suppression. Installation of the caps is quick and easy and does help mitigate any potential RF interference generated from the motors.

Bob

[He Who Shall Not Be Named]

Thanks David, now I understand what you are talking about. I do not see any type wire coming out of the back plates at all. I am going to assume at this point that these motors do not have the spark suppression installed.

I am going to check with Bob and see if he can give me some more information on the motors that are installed in his 70mm and 80mm WTC!

David, if you do not have spark suppression caps on these brushed motors, could this cause radio interference or any overall interference in other components?

Thanks for all your help here David, I really do appreciate your help.

Rob
"Firemen can stand the heat"

Yes, check with Bob first.

If these brushed motors are not equipped with spark-suppressors then, yes, there will be a lot of 'electrical noise' running up and down the propulsion and control wiring.

That 'noise' (RF spikes of about 20mHz emanating at a cycle rate driven by motor speed and number of motor poles) is an artifact of the fundamental motor design; brushed motors employ a rotary mechanical switch (commutator) that turns the armature pole fields off/on as they rotate about the repelling magnets set within the motor case.

Though todays electronic devices are very well isolated from outside interference sources, its good practice to stop such electrical noise at the source than risk it degrading the performance of the other devices aboard your very expensive submarine play-toy.

David

[rwtdiver]

Two, sometimes three .01uF ceramic capacitors across the motor poles and ground (motor can).

If your motor has them pre-installed you'll see a wire coming out of the back-plate and wrapped around a pole -- if that's the case, spark-suppression is already in place. If not, you add your own as I've illustrated below. Same caps, same installation no matter the motor size. Only for brushed motors, I might add. Brushless motors don't need them.

Thanks David, now I understand what you are talking about. I do not see any type wire coming out of the back plates at all. I am going to assume at this point that these motors do not have the spark suppression installed.

I am going to check with Bob and see if he can give me some more information on the motors that are installed in his 70mm and 80mm WTC!

David, if you do not have spark suppression caps on these brushed motors, could this cause radio interference or any overall interference in other components?

Thanks for all your help here David, I really do appreciate your help.

Rob
"Firemen can stand the heat"

[He Who Shall Not Be Named]

Not sure on the spark-suppression David, could you enlighten me on spark suppression? I have not run into that term with RC type motors!

Rob
"Firemen can stand the heat"

Two, sometimes three .01uF ceramic capacitors across the motor terminals and ground (motor can).

If your motor has them pre-installed you'll see a wire coming out of the back-plate and wrapped around a pole -- if that's the case, spark-suppression is already in place. If not, you add your own as I've illustrated below. Same caps, same installation no matter the motor size. Only for brushed motors, I might add. Brushless motors don't need them.

[rwtdiver]

Two motors wired in parallel. Check. Polarity between the motors swapped. Check. You're good. Are the motors equipped with spark-suppression?

Not sure on the spark-suppression David, could you enlighten me on spark suppression? I have not run into that term with RC type motors!

Rob
"Firemen can stand the heat"

[He Who Shall Not Be Named]

Two motors wired in parallel. Check. Polarity between the motors swapped. Check. You're good. Are the motors equipped with spark-suppression?