Safety Loop ??? Amps etc

[Drax21]

Ok so I really would like to get my Cyber Storm Ready to race for April. The rules state I need a safety loop. I know how to make one but I am wondering about the effects of having.
1.More Red Positive Wire (nearly 3 times more than black)
2.More Connectors

What sort of problems would this cause?
I have already shortened my esc wires to suit my previous set-up to run parallel batts. I use Multicore Silver solder on all connectors.
Rules also state a maximum of 5000mah to run 6.5mins..... So running a single.

I am using
1515 CC 2200kv Motor
180 SK ESC
M445 Prop
4s Lipo-TO BE DECIDED

Here are some pics of the wires and esc positioning.
DSC_1853.jpgDSC_1854.jpg

Thanks

[Drax21]

OK so I have got a little advice off the Astec Model Forum(UK).
I get with a set-up running 60 amps 4 inches of extra wire should be no problem.
I have done the connectors on the wires and I have about 6 inches when shortened properly.
DSC_1859.jpg
Picture show extra red wire (not in safety loop formation)

Need to know. What sort of amps I will be running? Anyone with a similar set-up?
Will this size boat even be a viable option to run 6.5mins on a 5000mah Lipo?

[JIM MARCUM]

Where in the NAMBA Electric rules require a "saftey loop"? JIM

[Drax21]

Where in the NAMBA Electric rules require a "saftey loop"? JIM

Not NAMBA, - SWAMBC. I'm in the UK, sadly....

[JIM MARCUM]

OOOOOOOOOOOOH. Still don't see why that's needed though. What's the purpose of saftey loop anyway? JIM

[Drax21]

OOOOOOOOOOOOH. Still don't see why that's needed though. What's the purpose of saftey loop anyway? JIM

Its meant to cut the power to the esc to save a meltdown of the motor or a runaway boat because of esc failure. A boat retriever will pull the loop. I think its a stupid rule. Same as only being allowed to run a max of 5000mah. Simply pathetic
Still, if I want to race I have to meet the rules.

[JIM MARCUM]

I think the problem is the rules are out of date. Those rules were for the FM crystal channel surface radios, and some early 2.4 gig RXes. Virtually everyone here has switched to 2.4 GIGA HZ TX/RX systems where the RX includes a failsafe. If signal is lost (or the TX turned off) the RX shuts down the ESC. You can buy a FlySky FS-GT3B with receiver for under $50 these days, so there is no valid excuse to not to buy one. I've got an expensive pile of air & surface FM TX/RX stuff - now just plain junk.

If I were you, I'd petition SWAMBC to update the rules to reflect what's happening todays R/C world. JIM

[iamandrew]

yeah im yet to see an electric boat go full power into the shore from a tx running out of batteries or somthing.
I do think that it MAY be possible for it to happen, but most ESCs would probably burn out and die instead of applying full power to the motor

[NativePaul]

It's not going to stop a runaway as you have to pull it out, its to decrease the risk to the rescue crew. As a byproduct for me it makes setting up boats less frustrating and race days a lot less stressful. I was against its introduction but now I have used them I have changed my mind and I am sure they are not going anywhere (even if ESCs came with a million pound guarantee to shut down on loss of contact or death) as being able to tape up ahead of time makes events run much smoother and no event organiser wants to make his job harder.

[CornelP]

The rule is quite good, as it helps rescue crews against stupid operators... if your boat is being rescued, you should not touch the Tx. Sadly, some forget about this and we had a close call with a guy revving the motor when his boat was in the rescuer's lap (the rescuer forgot to unplug the safety...).
As for amp draw, to get a 6.5min runtime, the average is 46A on a 5000mAh battery. If your rules are as per Naviga (or close) you could run a 5S around 4200mAh on a smaller prop. I tried it last season on two of my mono2 boats (Leopard motors, 1800 and 2000kv) and I found it's easier to find 5S batteries that will comply with the rules.

[TheShaughnessy]

amp draw

Not sure about exact numbers but i know a 2200 kv motor and an m445 will have a hard time (if at all) making 6.5 min. Im guessing you will see spikes in excess of 105 amps and 50-70 constant. My opinion is you need a lower kv if you want to finish.

[Drax21]

Not sure about exact numbers but i know a 2200 kv motor and an m445 will have a hard time (if at all) making 6.5 min. Im guessing you will see spikes in excess of 105 amps and 50-70 constant. My opinion is you need a lower kv if you want to finish.

As I thought, the rules will cripple how I want to run my boat. I noticed how the UK boats are quite small and in fairness don't look anything like a real boat. The Etti range seems to be a favourite so maybe an EVO2 is in my future if I wanna race. I notice a lot of small and high KV motors. I see 4S1P 4S2P or 6S2P.
So would 6S2P at 4600mah work better? If so how about a 4082 1600kv motor?

RULES


Formula 4
*!**(racing at 4 selected venues ONLY)
Motor: Open to any brushed or brushless motor
Drive: Any drive form may be used.
Hull: Any hull design or type.
Batteries: 4S1P or 4S2P LiPo, maximum capacity 5000mAh, minimum rating 20C,
*!** or 6S2P maximum capacity 4600mAh A123
*!** (as specified by the manufacture on the batteries)
Duration: 6 minutes plus a 10 second “Mill Time”
Course: Clockwise around the outside of the “M” course, or as the water permit
*!** or dictates.

[Drax21]

I think the problem is the rules are out of date. Those rules were for the FM crystal channel surface radios, and some early 2.4 gig RXes. Virtually everyone here has switched to 2.4 GIGA HZ TX/RX systems where the RX includes a failsafe. If signal is lost (or the TX turned off) the RX shuts down the ESC. You can buy a FlySky FS-GT3B with receiver for under $50 these days, so there is no valid excuse to not to buy one. I've got an expensive pile of air & surface FM TX/RX stuff - now just plain junk.

If I were you, I'd petition SWAMBC to update the rules to reflect what's happening todays R/C world. JIM

I use FLYSKY and it is a great TX/RX package. 10 model memory. Just make sure ABS is off. There are still a few boaters using the old 40MHZ and so on in the UK. Better range or something..

[properchopper]

The Safety Loop issue has been quietly simmering on a back burner in NAMBA, at least for a few moments last year. I've had several conversations with Lohring Miller, NAMBA's National Safety Director last year on the topic. Lohring's all for it, me not so much. It came up briefly last year in D19 when we started to race FE heats during Gas/Nitro events and a rescue boat operator had concerns. These concerns apparantly died down as there was no safety loop proposal at the last D19 annual meeting. Even so, regardless of the fact that fail-safes can shut down an unlinked Tx/Rx , a wet Rx or speed control can and has caused runaway props. I developed a simple safety loop configuration that's installer friendly. Rather than the conventional practice of drilling the hull and epoxying in connectors, my design just requires drilling a hole, dropping in the device, and tightening the nut underneath. The O-ring keps it watertight. Can be configured as male-male, male-female, or female-female. I like male-male since female connectors in the hull will trap water and could end up with corrosion inside the connector.

DSC02956.JPGDSC02957.JPG

[NativePaul]

I know a few Mono racers that are thinking of going back to 40mhz, on average 2.4ghz stuff is better on the surface (there are good and bad of both) but it just doesn't penetrate water, if a boat submarines with 40mhz you come off the throttle instantly but with 2.4ghz coming off the throttle underwater does nothing, your waiting for the failsafe to kick in which takes long enough that depending on the depth of the lake it may power down to the bottom of the lake and shove its nose in the mud, we have seen an increase in sunken monos since 2.4 became widespread.

There are 1 or 2 guys at the races I frequent that never switched to 2.4ghz, and why should they, good quality 40mhz radio with an IPD reciever, installed well has a good solid radio link, the only problems being carrying/swapping a bunch of Xtals to fit you in, and twits switching on in the pits without pegs, and both are non issues now everyone else is on 2.4.

6s2p 4600mAh would be better, as it offers about 40% more power than 4s 5000mAh, but not if you want to race as its 2s over the limit for SWAMBC and I have to doubt that it would be under the 560g limit the rest of the country has, and no-one wants to race someone with that sort of advantage over them, which is why the limits are there.

Note on the above: I wrote it thinking about LiPo but have just realised you are probably talking about A123 LiFePo4, which you are allowed 6s2p 4600mah of. They are lower voltage cells than LiPo and a lot bulkier and heavier too, I doubt you would fit 12 in an ETTI mono2 with flotation and get the CoG in the right place so it is one area where your bigger hull may be an advantage as well as on rough water. Despite the lower voltage A123s would still offer more power than LiPo for SWAMBC (no longer the case for the rest of the country), but the weight punishes you for the power to some extent and it depends on the boat and the conditions which will be faster, if you are thinking of getting an ETTI evo2 down the line having a big heavy powerful A123 deepV second boat for when it is very rough may be a good idea, though the ETTIs are pretty good in the rough so it would have to be pretty extreme conditions before you switched boats.