Please help me diagnose an R/C problem.

[Tags]

I am a grandpa and I recently bought an NKOK USCG Island Class Cutter for my 8 year old grandson. It is a first experience for me, and second one for him.

The boat is made of plastic, has good detail and ran well for about an hour.

The controller has a Forward/Reverse speed stick and a Left/Right stick. Steering is done by pushing the L/R stick which reverses either the port or starboard motor when the speed stick is pushed. There is no rudder.

It ran well initially, but then matters went bad. Now when the speed stick is pushed forward only the port side motor runs. When reversed, both motors run as expected. Also, when the L/R stick is pushed left the port motor turns at full speed, without using the speed stick at all. This is not as it should be.

I replaced the controller 9 volt alkaline battery twice. And I replaced the 9.6 volt NiMH battery with a fully charged 9.6 volt NiCd battery. The symptoms changed ever so slightly. In forward the port side motor continues to run, and now the starboard motor turns very slowly.

Any ideas about how to understand and hopefully fix this boat will be greatly appreciated. My grandson is waiting patiently for grandpa to pull a rabbit out of the hat.

Thanks,
Tags

[Jerome Morris]

Tags, Sounds like your going to have to unscrew this boat and look inside.Perhaps and only perhaps some WD-40 could lubricate and dry out the electrics. This may help?
I saw one off these boats at the Maine ,boats ,homes and harbor show a year ago or so. I almost bought it 'cause it looked "Neat". I went back a hour later ---Gone. Ah well saved myself a few bucks.

[Kmot]

Tags, sorry to be the bearer of bad news to you. But the NKOK range as well as virtually all of the toy class boats from China have terribly poor quality electronics.

Try the WD-40 as Jerome suggested, but don't be surprised of the matter is not fixed.

Perhaps "grandpa's" rabbit in the hat is a "hobby class" boat as a replacement. If you have a hobby shop, as opposed to a toy store, near you then take a look at the boats available from "Aquacraft". It will require a larger investment because instead of throw away batteries you will need to buy a rechargeable battery and the charger. But the quality is a quantum leap and parts are readily available if needed. Something you can't get with the "toy class" boats.

BTW, I also have an NKOK boat. A smaller version but the same type of setup. After using it a couple times in my swimming pool it sat for a week inside my house. I went to ruyn it again and the motors would not turn over. I replaced the batteries. Motors would still not turn over. I then realized it had rusted up. I sprayed WD-40 on the motor shafts and they came back to life. This is something you should not have to worry about with your boat. Hobby class boats will not exhibit this type of poor quality.

[Ghost 2501]

hmm el cheapo bang bang types,

Kmot, you seem to have hit it there :)

[Tags]

Many thanks to Jerome Morris and Kmot. My feelings are not bruised by your response, and I will take it apart and try to dry things out. I will even consider upgrading the electronics in this same boat, if it can be done. The boat itself is good for kids. What do you think about upgrading?
By the way, Jerome, I spent a delightful day in Boothbay Hahbah last month. First time back in 30 years. Beautiful as ever.

[Aerominded]

Tags, if you like the way the boat looks, you can upgrade the electronics for not that much money-

estimates:

2 channel ground frequency radio @$40.00 (should include at least 1 std sized servo for rudder)
Electronic speed controller (for the motor) <$50.00

would probably be fine to convert this model to single motor with rudder-
you might be able to re use one of the motors that came with the kit or buy new (very inexpensive, depending on type <$10.00)

Propeller, shaft and stuffing tube, @ $15.00, max

Sounds like you have the battery covered...

Assorted brass stock and hardware and you have a fun 'winter project' which will only take a few evenings of enjoyable work!

nice thing about upgrading is when you out grow your first boat, you can move the radio, etc into your next project!

Do you have any model building experience? :) if not, lots of folks here will be happy to guide you through the process! :)

[Shaun Hendricks]

It's possible to 'upgrade' this model without much money spent. A basic 2 channel controller and receiver can be purchased for about $40 as said, however, you can keep this as a differential steered boat quite easily and not worry about rudders and servos. In fact, you can remove the mechanical steering servo.

Start with 2 speed controllers: $50 ( Waterproof ESCs (http://cgi.ebay.com/50A-100A-Max-Electronic-Speed-Controller-For-Boats_W0QQitemZ170038122532QQihZ007QQcategoryZ3405 8QQrdZ1QQcmdZViewItem) )

Add a V-Tail Mixer (splits the control signal to spin each engine as needed): $15 ( V-Tail Mixer (http://cgi.ebay.com/V-Tail-Mixer-for-R-C-Electric-Plane_W0QQitemZ130035764585QQihZ003QQcategoryZ2563 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) )

If the shafts are steel, switch to stainless steel or brass. If the sleeves are steel, it gets more complex. You can just add oilers to them and keep them oiled so they don't rust up. There's some small costs here, but nothing earth shattering. You could also just blow them out and lube them up after a run.

So, for about $100 you could have the same 'boat' you have now, but with upgraded electronics. No rudder, lose the servo and it will be more reliable with maintaining the prop shafts.

[Aerominded]

That sounds like a good solution Shaun! Tags wouldn't have to do any modification to the boat itself that way! :)

[Tags]

Shaun and Aerominded. You guys are terrific. I don't understand all the terminology, but will learn as I go along. When I get into this, I hope I can call for help. I have modelling experience from my childhood, but no R/C experience. Does a career in the data processing industry and a very old degree in physics count for anything?
Thanks again.

[more coffee]

nice thing about this hobby TAGS ,any background well help, everybody here well help you figure out what you cant get on your own ,at somepoint your background well be helping others.
its a win/win deal

[smart_racer]

Depending on your purchase date- return it to the vendor, they come with a warranty (can not remember NNOK policies )

[pompebled]

Hi Tags,

I also fell for the looks of the NKOK boats, I purchased a Pelican I, a smaller boat as yours, but with the same vector steering.

The problem are the pods that contain the motors, they all leak after some time due to the grease disappearing slowly.
As a result the tiny motors rust solid in a surprisingly short time.

I took off the pods and opened them, both motors were a single rusty clump.

Currently the boat is shelved untill I can find the time to build a 'traditional' propshaft, motor, servo and ESC into it.
My hull is much smaller so weight is an issue, but frankly I don't want to spend a small fortune on miniature parts to fit out a hull that's overweight to begin with and didn't cost much...

I'll see what I can cram into it.

Regards, Jan.

[Ghost 2501]

It's possible to 'upgrade' this model without much money spent. A basic 2 channel controller and receiver can be purchased for about $40 as said, however, you can keep this as a differential steered boat quite easily and not worry about rudders and servos. In fact, you can remove the mechanical steering servo.



well when i re did my southamptonm total cost £40 :) all up

[Aerominded]

You should be able to do it, Tags! bring any questions you have here and be sure to post pictures as you go along! :) We are all happy to help!

[Tags]

Thanks to all who have sent informative and encouraging responses. I am waiting for my daughter to return the boat to me. Hopefully, I will see it this next week. It's a long story. I'll let you all know how I progress.

[Shaun Hendricks]

well when i re did my southamptonm total cost £40 :) all up

Yeah, but how much of the stuff did you have just 'laying' about? How much was reused from other boats/projects. I could do this mod for free with all the junk I have but to start from scratch... :D Then again, my radio is capable of the proportional mixing... oi! :rolleyes:

I did like your Southhampton mod, looked great when you were done with it.

[Tachikaze]

The discription your provide of the problem does not suggest to me of a locked up motor, since you get reverse and forward on the motor, just at the wrong times.
These are basically a polarity change that drives the motors. When you throw the switches, it changes the polarity to move the boat forwards, backwards, left or right. From what you discribe, it appears as if your contacts are not working. I would suspect that you have some oxidation or corrosion on those contacts.

[Jerome Morris]

Tags, What brought ya' th' Boothbay Harba' ? Lobsta' or tourin' or family?
If ya' find ya' way to South Thomaston, look me up at ART OF THE SEA, I work there full time repairing ship models and would be happy to meet ya'

[pompebled]

Another possibility:

The "electrics" in these boats are shifty at best; the "speedcontroller' is a simple circuitboard with transistors doing the forward/reverse switching.
It is very wel possible one or more of these transistors have gone bad and need replacing.

Also open your remote and check if all the "switches" do still connect to their counterparts; no, or a bad connection, means no proper control.

Regards, Jan.

[Tags]

I disassembled the boat and got to the ESC/Receiver. It is a single board with all sorts of capacitors and other components that I am not experienced enough to identify. When I tested it, smoke wafted out of the enclosure the board is in. Motor enclosures looked well sealed and there did not seem to be any moisture around or on the board.
Took it to a local R/C hobby shop for his opinion and was advised that the board is quite unique. It is unique because the receiver and ESC are integrated on the single board. Likelihood of finding an over the counter replacement is very, very small. The shop owner suggested that I look for someone who can test components (capacitors, diodes). If I get lucky maybe the board can be repaired.
I still hold out hope that I can get the board repaired, and even get luckier by finding someone who has boards that will work with this boat. But I don't want to take the step of having NKOK repair it, as I have lost confidence that the replacement will be any more reliable. And they want almost the cost of a new boat to repair it.
Any one have any ideas about repairs, replacements or some other alternatives?

[Kmot]

It is not unique at all. It is commonplace in toys from China. They all use the integrated circuit board that has a combo Rx and ESC in it.

You are right. A replacement will be just as crappy as the one you have. I have smoked those circuit boards too.

They are not designed for adults. They are designed for kids who will either lose interest quickly and move on to another toy, or break it quickly and forget about it.

You can buy a complete hobby grade radio system on ebay for under $10 bucks. Usually brand new, removed from one of the bazillions of RTR cars/trucks. Tx, Rx, battery box, etc. An esc can be found for under $10 too for the size motor your NKOK has. My opinion is that trying to repair, or get a replacement board will just end up in the same situation sooner than later. If you actually want to keep this boat for some reason, then upgrade it to hobby class electronics. My $.02

[Kmot]

Here is just one example:

http://cgi.ebay.com/DuraTrax-2-Channel-Radio-Set-75-Mhz-by-Futaba_W0QQitemZ160044423256QQihZ006QQcategoryZ440 28QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/ESC-30A-50A-Max-RC-Brushed-Motor-Speed-Controller-US_W0QQitemZ190045344044QQihZ009QQcategoryZ34056QQ rdZ1QQcmdZViewItem

[Tags]

Thanks Kmot. I will visit the suggested sites. But not for this boat.
To my great surprise and relief, NKOK and eToys have told me that I will be taken care of. The boat is back in it's box and I am on my way to Denver tomorrow to deliver it to the Customer Service manager at eToys corporate. She responded to a letter I sent on October 20 in the most professional manner.
What I learned is to be more persistant with Customer Service representatives when I don't get an answer that I like, as I did last month.
I'll give a final report on my visit with eToys tomorrow.
Thanks to all again.

[smart_racer]

Happy to hear

[Tags]

Well, everything was cleaned up in the saga of the USCG cutter. I returned it to eToys.com and they credited my card for the full amount of the purchase. I feel fortunate, and speak highly of Gretchen Everhart, the customer service manager at eToys.
Now I am off to build an airboat from a kit and power it with a .09 Enya engine given to me by a friend. When that is complete, I will populate it with a decent entry level R/C system, play with it for a while and then give to my grandson. Hey, that is what grandpas do!
So for a few months I will be off the air, so if the Forum wants to archive me, please do so. Talk with you later. Thanks to all who provided information and encouragement.

[smart_racer]

As they say..."It all works out in the end"

[retoabcr]

I just skimmed thru this posting and ran across about using 9 volts rx batteries. Now if your servos were cheap or micro servos, that would cause almost all your problems. I found out the hard way in a Mutineer and it zig zagged and dropped 15 feet into a overflow. I recovered it and almost rebuilt the whole boat. I never used micro servos again. Oh yes,. the Mutineer run like a deer