Safety Loops

[Grazacind]

A question for the vastly experienced mob on OSE. Does making the positive wire longer when using a safety loop hinder the performance ie. positive being longer than neutral. If you have to use safety loops as we do in Aus would it be better to lengthen the neutral to the same length or is it negligable.

My plan is to design and build an off the shelf item for use a safety loop rated to 200amps.

Cheers
Andrew

[nobbiworld]

The safety loop should be on the negitive side. Just keep all wiring as short as possible. The more wire you add will only add resistance. The number of joins( conectors ) will also add to this. As everybody has there own way of doing safety loops, it would be hard to do a off the shelf device. I have made one and nobody was interested. Which club do you run with? Steve

[lohring]

The problem I've had with safety loops is connector resistance. With currents much over 100 amps 5.5 or 6 mm connectors overheat and the solder connection fails. Bigger connectors like 8 mm bullets are too hard to disconnect. I'm currently exploring some other methods of building a safety loop because I believe they are a good idea.

Lohring Miller, NAMBA Safety Director

[properchopper]

The problem I've had with safety loops is connector resistance. With currents much over 100 amps 5.5 or 6 mm connectors overheat and the solder connection fails. Bigger connectors like 8 mm bullets are too hard to disconnect. I'm currently exploring some other methods of building a safety loop because I believe they are a good idea.

Lohring Miller, NAMBA Safety Director

Lohring, I haven't forgotten our conversation at the Nat's on this issue. I'm doing some thinking "outside the box" on ways to safely stall a runaway motor.

[Kris Flynn]

Why 'should' they be in the Positive side? If it is disconnected why does it matter?

Cheers
Kris

[Grazacind]

The safety loop should be on the negitive side. Just keep all wiring as short as possible. The more wire you add will only add resistance. The number of joins( conectors ) will also add to this. As everybody has there own way of doing safety loops, it would be hard to do a off the shelf device. I have made one and nobody was interested. Which club do you run with? Steve

Hi Steve I am not running with anyone at the moment. Just getting my driving sorted and having heaps of fun playing. I would like to run at Coomera as it is bit closer than the north side. I run at Springfield Lakes which is nice and big and flat. How about yourself.

With the safety loop I really like the idea of them. My idea is to make up the contacts with a plug to suit and test with 200amps on a ductor tester. Collect the data and keep doing that until I get a user friendly loop with very low resistance.

[nobbiworld]

Andrew, The problem with Coomera is salt water, very brackish anyway. As far as i know there is no electric run there, I could be wrong. I run with the Pine Rivers club. It is an electric only club. We run twice a month, one practise day and 1 race day. A normal race day is around 18-20 people with about 40 boats. Always something to see on the Lakeside track as well. You should come and have a look, PM me if you are interested. I live out Beaudesert way. Have a number of lakes to run on out here. Only drive to Lakeside once a month.
We should get together and I can show you the safty loops that I have moulded. Steve

[nobbiworld]

Kris, I was taught that DC power flows from negative to positive. If this is correct you should cut power on the source side. Hows is life going with new baby in the house? Steve

[JIM MARCUM]

If you are using 8 guage wire & 6mm connectors the delta resistance of the extra wire should be tiny. As to how to stop a runaway motor, I use receivers with auto shutdown if signal is lost. Turn the transmitter off & it will shutdown the motor automatically. And both AC & DC current flows to ground (negative). JIM

[lohring]

The new Hydra ICE controllers do shut down on loss of signal. It's a great safety feature, but I'm not sure I trust it in cases where, as an example, the receiver gets wet and starts acting up. I have two thoughts an a high amp connector. One involves toggling contacts together and the other involves Radsok connectors.
Radsok data sheet.pdf

Lohring Miller

[JIM MARCUM]

If you run a new Hydra ICE ESC & a failsafe receiver you got the RUNAWAY BOAT issue solved. JIM

[NativePaul]

If you race anywhere that is under Naviga rules or want to sell them to anyone who is, the safety loop has to break the positive side of the circuit, the loop has to be >25mm diameter for ease of pulling and has to be red for ease of visibility.

If you run a new Hydra ICE ESC & a failsafe receiver you got the RUNAWAY BOAT issue solved. JIM

Don't bet your boat on it, even if it works instantly on your radio and ESC it won't for everyone, there are plenty of radios and ESCs out there that take a loss of signal for up to 3 seconds to make them go into failsafe mode and stop, which on the lakes I run at would be long enough to see the boat crash if it happened anywhere apart from at the very start of the straight.

[rcboatmanwithkids2880]

Hi Guy's ,


Installing a Safety Loop at the moment on my "JPS " tunnel project , so what is the correct side for running the device ??

All the best in F/E R/C Boating ,
Brad

[properchopper]

As it turns out, the safety loop issue has surfaced here in L.A. where FE is starting to be raced during gas/nitro events. The retrieve boat operators have inquired about a means of disarming an electric boat. While a traditional on/off switch disconnecting the rx from the speed control or the rx from its power source coupled with a fail safe in the rx or even the SC can cover certain faults, a wet rx and/or speed control could bypass these safety features as Lohring points out. Water intrusion into these components is a very likely possibility on boats to be retrieved, since they most often have sat in the water upside down for several minutes and even the most perfectly taped boat may eventually let water in. I believe the handwriting is on the wall, at least here in L.A. regarding a safety-loop device. I have two different designs in mind which would make installation minimally invasive but without manufacturing abilities this is only a mind game. Thinking, thinking......

[Grazacind]

Hi Guy's ,


Installing a Safety Loop at the moment on my "JPS " tunnel project , so what is the correct side for running the device ??

All the best in F/E R/C Boating ,

Brad

For my opinion it should go in the positive side. Current flow is fron Neg to Pos in a DC system. This is of course just an opinion.