BD3SX and Kosmik

[Puttputt maru]

Ok I know this has been asked before but the earliest thread I found is 2014.

So here it goes. I am contemplating going the Kosmik way for my next Triabolo intead of Jeti Mezon (still wondering with learning Jlog)

Is there a problem on powerup with the Kosmik ESC being plugged to the BD3SX?

From what I gattered you need to wire things differently to avoid the Kosmik not letting the BD3SX initialize properly.

Is this still true? if so, does anyone have a diagram to make it clearer than what I have read so far.

[jrwalte]

I had Kosmik Cool 160 at 7.4v a few months back and never had issue with 3sx booting.

[F1 Rocket]

Kosmik + BD + Jlog on all 4 of my big machines and never a problem.

[Puttputt maru]

Great thanks for clearing that up for me guys I guess I will be spending more money

[DEMONjoe]

The people running into issues with this combination were to be counted on one hand almost, so only very few. Why exactly this happens to only a few is unknown so far. I can only agree with Danny, as we could never reproduce this behavior here at our place, and we tested in a lot of different setup varieties. All simply worked, LV and HV.

What they experienced was some weird effect in the way the Kosmik boots up his BEC when the throttle signal is not seen right at power-on and the BEC is set to HV (never was present as far as I know with standard voltage setup). As we do not supply throttle output before the system is completely initialized (safety reason), what happens is that the Kosmik will not go up to full BEC voltage but remain in some very low voltage floating kind state, enough for the DEMON and Rx to work and initialize, but as soon as the servos draw power too (after initialization) this kills the whole circuit, starting from scratch. This may take place a couple of times only, or forever.
Solution, and this is what you can read in the Kosmik's manual, is to use a buffer pack (at least for initialization, added by me). A little 2S 450mA pack is sufficient here. At the same time this ensures control over all electronics in case the BEC fails. Some like this additional safety...I don't.

Btw: this does not only happen with BD systems! Just as a side note, as it is not the system that's responsible.

Hope to see you at IRCHA.

[Puttputt maru]

Thanks DEMONjoe for the explanation. Like I said it was an old thread and I have not seen more on it.

I don't like the buffer pack idea either but that is an other debate all together.

I am still a little on the fence between using a Mezon again or going Kontronik but unless Jeti comes up with a more powerful Mezon in the near futur, I think I will have to try a Kosmik just to find out what the "fuss" is all about.

[Grittner]

I have several 3sx pair with koby 40, Koby 70, Jive 100lv, helijive 120 helijive 120+, kosmik 160 (not the cool), and i never had a single problem, the only time it does not initialize correct is when I move the heli before 3sx is ready.

[Kiba]

Put me in the camp of the Kosmik + 3SX never booting-- it gets caught in an infinite reset loop. Without a buffer pack the Kosmik BEC starts and stays in the low voltage/amperage mode until the 3SX boots, then the initial "kick" of the servos when the 3SX initializes resets the Kosmik BEC because it's still in the initial low voltage/amperage mode as it hasn't seen a valid low throttle signal yet to go to full BEC voltage/amperage-- and then the process repeats over and over and over. Every time the 3SX tries to initialize it resets the Kosmik when the servos kick and the system gets stuck in a "boot loop." Kontronik was trying to be extra safe by making the Kosmik start the BEC in a low voltage / limited amperage output mode before switching to full voltage / amperage after seeing a valid low throttle signal but sometimes it causes problems. I've seen some Kosmik/3SX systems boot perfectly without a buffer pack where others like mine will never boot without a buffer pack.

A little 2S 450 buffer pack took care of it and gives some redundancy too-- provided you have a way to tell if the Kosmik BEC fails. As long as you have telemetry on your TX you can easily set an alarm to go off when the Kosmik BEC fails so you know to land ASAP. I have the Kosmik BEC set to 8.0V and my telemetry low RX voltage alarm set to 7.4V. If I try and power the heli from only the buffer pack wiggling the sticks will drop the buffer pack voltage to under 7.4V so the low voltage alarm triggers easily, even with a fully charged buffer pack. This will provide plenty of warning and time to land should the Kosmik BEC fail in flight. It will also alarm on the ground before takeoff if the Kosmik BEC fails to initialize as the low voltage alarm will go off while I'm wiggling the sticks to check servo response during my preflight.

New bootup process is connect the buffer pack, let the 3SX initialize, then connect the main pack to the Kosmik. Easy!

[crash at 42]

Im in the no boot camp also but, 1 out of 4 units all kosmik all BDsx. Easy to over come. I plug in a rx pack to initialize kosmik then unplug. I use r2 prototype capacitors for back up so I generally only plug in once for the day. The capacitors hold enough jigawatts till the next flight

[Puttputt maru]

Guys This is starting to make me wish even more that Jeti comes up with a Mezon 160.

It all sound easy if I hit one Kosmik that has that, but I like the ease of the Mezon.
Plug everything, put the heli on the flight pad, switch the Mezon on, walk to the flight line while everything initialize, flip the power on switch on my Jeti Tx and fly

[wadders248]

My three Kosimk and BD helis never have problems on initialising, though I use an Opti Ultra Guard on each, so I wonder if that acts as a buffer pack sometimes?

[ranchhand]

Are the guys with the startup problems using sats? The constant rebooting loop could be because the sat only, may need more voltage than the Kosmik's bec starts with, but once up and running, the bec is putting out enough voltage to keep the sats happy. Just a thought.

[Kiba]

No sats here, full Jeti RX.

The cause on my heli is the Kosmik BEC resetting when the 3SX initializes and "pulses" the servos, that sudden current spike resets the Kosmik as the Kosmik can't supply that much power when the BEC is in the initial low voltage / limited current mode prior to it switching to full power mode after receiving a valid low throttle signal. I've logged it on a scope, the voltage falls to <1V when the 3SX pulses the servos.

Either way, I'll stick with the buffer pack. A 2S 450 buffer pack is tiny and light with almost nothing to go wrong with it. I tried an Ultra Guard when I first built the heli but the UGs at that point where still fresh to the market and at that time they didn't have appropriate firmware for a Kosmik. With the early UG firmware the the UG would initialize at 5.1V (5.6V initial Kosmik voltage minus the 0.5V UG's programmed Vdrop when operating) while other times the UG would not initialize before the 3SX did which still caused the Kosmik to reset over and over.

A Scorpion BUG worked because I could manually switch it on, let the 3SX initialize, and then plug in the main packs but since the BUG is a LV backup device I didn't care much for it since I'm running HV servos. A 2S 450 lipo was lighter, simpler, and a true HV backup source.

[Steverin06]

I just recently started flying a new to me 700C with kosmik 200 and BD3SX.It would just get stuck rebooting over and over until I plugged in the optiguard. Now I know exactly what's happening. Thanks for this info!

Originally Posted by Kiba

Put me in the camp of the Kosmik + 3SX never booting-- it gets caught in an infinite reset loop. Without a buffer pack the Kosmik BEC starts and stays in the low voltage/amperage mode until the 3SX boots, then the initial "kick" of the servos when the 3SX initializes resets the Kosmik BEC because it's still in the initial low voltage/amperage mode as it hasn't seen a valid low throttle signal yet to go to full BEC voltage/amperage-- and then the process repeats over and over and over. Every time the 3SX tries to initialize it resets the Kosmik when the servos kick and the system gets stuck in a "boot loop." Kontronik was trying to be extra safe by making the Kosmik start the BEC in a low voltage / limited amperage output mode before switching to full voltage / amperage after seeing a valid low throttle signal but sometimes it causes problems. I've seen some Kosmik/3SX systems boot perfectly without a buffer pack where others like mine will never boot without a buffer pack.

A little 2S 450 buffer pack took care of it and gives some redundancy too-- provided you have a way to tell if the Kosmik BEC fails. As long as you have telemetry on your TX you can easily set an alarm to go off when the Kosmik BEC fails so you know to land ASAP. I have the Kosmik BEC set to 8.0V and my telemetry low RX voltage alarm set to 7.4V. If I try and power the heli from only the buffer pack wiggling the sticks will drop the buffer pack voltage to under 7.4V so the low voltage alarm triggers easily, even with a fully charged buffer pack. This will provide plenty of warning and time to land should the Kosmik BEC fail in flight. It will also alarm on the ground before takeoff if the Kosmik BEC fails to initialize as the low voltage alarm will go off while I'm wiggling the sticks to check servo response during my preflight.

New bootup process is connect the buffer pack, let the 3SX initialize, then connect the main pack to the Kosmik. Easy!

[crash at 42]

Originally Posted by Puttputt maru

Guys This is starting to make me wish even more that Jeti comes up with a Mezon 160.

It all sound easy if I hit one Kosmik that has that, but I like the ease of the Mezon.
Plug everything, put the heli on the flight pad, switch the Mezon on, walk to the flight line while everything initialize, flip the power on switch on my Jeti Tx and fly

You can do this with kosmik, like I said 3 of my 4 work no problem. The anomaly is the the 4th in my scenario the kosmik while booting is one tenth of a volt shy (5.6 vs 5.7v) of booting the BD.

[Seasick78]

Eric - I had several Kosmiks and the Optipower Ultra Guard worked a treat. No bootup issues.

[Puttputt maru]

Originally Posted by crash at 42

You can do this with kosmik, like I said 3 of my 4 work no problem. The anomaly is the the 4th in my scenario the kosmik while booting is one tenth of a volt shy (5.6 vs 5.7v) of booting the BD.

I guess I can take my chances or go that way then:

Originally Posted by Seasick78

Eric - I had several Kosmiks and the Optipower Ultra Guard worked a treat. No bootup issues.

Thanks Josh. I think if I decide to go Kosmik this is the solution.

[Seasick78]

The UG also saved me when I had a loose motor lead and the Kosmik went into protection mode and shut down completely, but the UG kept my servos and RX strong for a successful auto! That $45 investment saved untold hundreds $ that day!

(Btw I used the fuse and it also blew. That was another inexpensive part that saved an $800 ESC #Worth-It)

[Raptorapture]

I also experienced the rebooting constantly issue. Fortunately, I'm happy going the buffer pack route. Works like a charm. Protects heli from unplanned outage. Nice example re fuse. I've gone the simplicity route on that by omitting it.

[orthobird]

Add me to the group of not working!
I am using the following set up:
1. Kosmic 200 with a fan
2. BD 3sx
3. Jeti R3 rx
4. HV servos, Futaba BLS 157 HV on cyclic. Futaba HV tail servo.
5. Jlog


I have set BEC output from Cosmic to 8.0 volts. My telemetry reads it as being 7.9

It seems that the ESC does not initialize, unless i disconnect the fan, or disconnect the master/slave, and then reconnect.

SO what you are all saying is, i need to use a 2S lipo battery to power my 3SX/servos via the BD 3SX, just plug it in to "initialize" and I can disconnect and fly?