Moebius Skipjack

[He Who Shall Not Be Named]

I'm late to this party, but thought I'd chime in as I don't think it's too late. That control shaft should be able to be popped out with a pair of pliers and 3.5 seconds of work. I don't think the shaft is notched, so just a bit of rotary pressure and it will snap free of the resin. Pull it free, run up a tube for your lighting, and you're done.

If it's being ornery, heat up the shaft tip with a torch and it will come free more easily.


Bob

No, that won't work in this case (I assume he's using my 1/72 SKIPJACK fittings kit).

Prior to casting the resin end of the rudder operating shafts they were peened from cylindrical to flat to prevent independent rotation or removal of the operating shaft from the rudder.

Removal will entail some rather ugly surgery and back-fill with a two-part filler.



David

[Ken_NJ]

Thanks Bob and David. I'm good with the light on the rudder.

Having an issue with electronics. I believe David said the motor on his SJ SD has capacitors built in. If I use a receiver battery or a power supply the motor runs smoothly. If I use a BEC the motor studders quite a bit. I tried 2 different BECs and both cause the motor to studder. Running everything I can as a load, the current draw stays below 500ma and the voltage stays steady at 5ish volts. Anyone have any ideas about this?

[Bob Gato]

Silly obvious question-and I know the answer...did you pull the red wire out of the ESC's plug where it gets signal from the receiver?

[Ken_NJ]

Yes I did Bob. And have the end shrink wrapped.

[Bob Gato]

Do you have all the grounds(regardless) of voltages connected together?

[Bob Gato]

I'll bet that you're running an Mtroniks ESC..a year back Capt CB on RCG chased a glitch on a twin...finally as suggestion from Mtroniks he installed an optical isolator and that finally cured the problem ..some might even come from the factory with an OI installed now-they can be very finicky with regard to feedback.

[Ken_NJ]

Yup, all grounds secured together. And yes Mtroniks. Not up on OI's use. Looks like a diode of sorts? On Digikey the look like 8 pin IC's. Sent an email off to Mtroniks as well.

[Ken_NJ]

Found the RCG thread. https://www.rcgroups.com/forums/show...Tronics-issues

[Bob Gato]

Ken I think its a light based transfer of information that has no electrical connection between the two components. Not unlike the optical kill system for magneto powered RC boats and aircraft. It keeps the very high voltage from the electronics.

[Ken_NJ]

Gotcha. This is the device they were talking about at the end of the RCG thread... https://www.mtroniks.net/prod/RC-Accessories/ZGM.htm

Hope I get an email from Mtroniks tomorrow.

[Bob Gato]

Wow Ken -10 pounds! you're gonna need more foam.. seriously it's a Scientific Wild Ars Guess...The engineers at Beechcraft used to call it an LDE..(last ditch effort)...Its worth a try...

[Bob Gato]

In the mean time.. do you have a spare brushed ESC-like a $15 hobby king 45amp crawler unit..to try and see if its an Mtroniks problem or something else?

[Ken_NJ]

I'll have to check the the spare parts box. I probably do.

[Ken_NJ]

Email from Paul at Mtroniks...

It sounds like the BEC you are trying to use is a switching BEC? These are very noisy electrically and could be causing a lot of interference with the control signals to the motors. Evidence for this is that the system works ok when running on batteries.

We would recommend you use the following, one on each speed controller. These opto-isolators cut all noise and leave a crisp signal for the speed controllers.

https://www.mtroniks.net/prod/RC-Accessories/ZGM.htm

In a quick search did not find that ZGM anywhere in the US. Cost with shipping from overseas is about $55. Not worth it. I'll keep looking for one here. In the meantime will look at what I have on hand for an ESC to try out and look for something other than the Mtroniks brand. Any other ideas?

[Bob Gato]

Oh pleeze! I have heard this from Mtroniks many times-Every body drinks the Kool-aid I don't know why anyone talks so highly of Mtroniks! All the other (cheap) ESCs can tolerate a noisey BEC!

It would be cheaper to buy a new ESC!!