Safety Loop ??? Amps etc

[Drax21]

Tony those connectors look great although as rules state "the loop has to face backwards". Easier to pull out as the boat is going forward.

I was looking at 6s2p Lipo but I guess not that either. I think the A123s are way too expensive for what they are.
Looks like i will have to buy a EVO 2 or move to the USA

What really doesn't make sense to me is the restriction on MaH??? Its very low at 5000mah. If only I could have 8000mah....then I would definitely finish the race.

[properchopper]

........... 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. ...................

Well spoken. Happened to me running in first place in a P-Mono heat with 2.4 (still has mud hidden in some places inside)

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All better now, but a bit of work !

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[cuppa]

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.

I switched to 40mhz from 2.4GHZ for that very reason. I had an issue with 2.4GHZ where I think spray in the air formed a screen between the TX and RX. basically i lost confidence in 2.4.

[NativePaul]

There has to be a limit to batteries somewhere and although where I race it is done with weight, I believe a mAh limit to be a better method as long as you can trust your fellow racers not to re-label their packs, 5000mAh was chosen as it maintains some sort of parity with Nickle based sub C cells which are available up to 5000mAh, and also 5000 was the largest LiPo cell commonly available when the discussions whether or not to go LiPo and the rules for such were taking place.

You can finish with 5000mAh, propping down, reducing the blade area of your existing prop, running looser and reducing your KV will all lower your amp draw, increasing your run time. If you like fast balls to the wall speeds that you wont get your run time doing, there is no rule that says you have to finish, if you can do 30 laps in 4 minutes you still beat someone that does 29 laps in 6 minutes 3 seconds, its unlikely but you can have fun trying.

Those connectors would be fine for SWAMBC they have no rule about them facing backwards, probably OK for the rest of the country too if you fit them to a part of the hull that is sloping down towards the back so they pointing a little bit backwards, I have done that on a hull that I made Just big enough for my gear and then when I came to fit them realised the loop sockets would stop me getting it in if installed normally, I would expect to have to argue its case if I ever took it to the worlds and wouldn't be surprised if they didn't let me run it, but over here I don't think we have any racers/officilals that are officious enough to consider pulling a boat with an obviously serviceable safety loop.

[martin]

Paul is it because of the more efficencey that stepped hulls are used over v hulls with no step to help with lower amp draw & longer run times when racing. Martin.

[Drax21]

There has to be a limit to batteries somewhere and although where I race it is done with weight, I believe a mAh limit to be a better method as long as you can trust your fellow racers not to re-label their packs, 5000mAh was chosen as it maintains some sort of parity with Nickle based sub C cells which are available up to 5000mAh, and also 5000 was the largest LiPo cell commonly available when the discussions whether or not to go LiPo and the rules for such were taking place.

You can finish with 5000mAh, propping down, reducing the blade area of your existing prop, running looser and reducing your KV will all lower your amp draw, increasing your run time. If you like fast balls to the wall speeds that you wont get your run time doing, there is no rule that says you have to finish, if you can do 30 laps in 4 minutes you still beat someone that does 29 laps in 6 minutes 3 seconds, its unlikely but you can have fun trying.
.

Now I am gonna have to try 30 laps in 4 mins at Shaugh Lake.

[Drax21]

Well spoken. Happened to me running in first place in a P-Mono heat with 2.4 (still has mud hidden in some places inside)

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All better now, but a bit of work !

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Looks great Tony, Nice n Shiny

[Drax21]

Paul is it because of the more efficencey that stepped hulls are used over v hulls with no step to help with lower amp draw & longer run times when racing. Martin.

This is what I found http://www.navaldesign.co.za/article...s-%20Feb07.pdf

[NativePaul]

Yes, with limited power dictated by runtime and battery capacity, the only way to go faster is with more efficiency. Disregarding Aero lift an unstepped hull will be wet from the CoG to the transom, as drax's link points out its a low aspect ratio patch that leads to water bleeding up the side for a long distance lowering its efficiency. If you can take some weight on the prop it comes off the transom, not only will your contact patch/s be a better shape but will be smaller too , increasing efficiency again. While not a problem for cats, the tiny width of a fast unstepped monos wetted area isn't the most stable and can lead to chine walking.

[Drax21]

Yes, with limited power dictated by runtime and battery capacity, the only way to go faster is with more efficiency. Disregarding Aero lift an unstepped hull will be wet from the CoG to the transom, as drax's link points out its a low aspect ratio patch that leads to water bleeding up the side for a long distance lowering its efficiency. If you can take some weight on the prop it comes off the transom, not only will your contact patch/s be a better shape but will be smaller too , increasing efficiency again. While not a problem for cats, the tiny width of a fast unstepped monos wetted area isn't the most stable and can lead to chine walking.

I notice on that link it says a 10-15% increase in speed v unstepped hulls. What is the best speed you are seeing Paul?

[cuppa]

I may very well get shot down in flames for saying this but I don't think that winning races is all about flat out speed. I think it is more about having a boat that, given good driving, can negotiate a given course in the shortest possible time.

[Drax21]

I may very well get shot down in flames for saying this but I don't think that winning races is all about flat out speed. I think it is more about having a boat that, given good driving, can negotiate a given course in the shortest possible time.

That sounds about right. Need to hit top speed in the straights though and if you can keep it around the corners it helps. My practice lake is fairly long and suited to SAWs but my competitive lake is an Oval.

[martin]

The reason for the stepped hull over an unstepped hull is not to have a out & out faster boat but one thats fast but at a lower amp draw to give the required run time with the restrictions on what cells can be used.