Hi everyone !!

[Robbie1]

hello everyone im new from the uk , going to join "electra" for racing in 2017 , looking to do hydro 1 or 2 and mini hydro class , lots of purchasing coming soon , inc radio gear , hulls , hardware , motors etc etc have lots of questions , i used to race IC multi boats for years in the uk fast electric is fairly new to me , im a tool maker by trade , mechanical engineer and used to make all my own stuff , and fast electric will be no exception , i hope to modify and fully make parts inc coming soon carbon fibre parts via CNC from home to use in my racing , all very exciting so watch this space .

[gsbuickman]

Welcome to OSE , it sounds as though you'll fit right in here and I'm sure there are a number of guys that will have plenty of questions for you. I'm not here on the board everyday like I used to be but when I pop in from time to time it seems as though things have been a bit slow around here lately. However, I'm sure it won't be too long before some of the regulars stop by and say hi. Cheers

[Robbie1]

thanks

[srislash]

Welcome, I am sure you will enjoy FE. Good to have you on board. Technology has come a long way so it can seem daunting but just read a lot, don't be afraid of the 'search' button, and ask questions.

It has been a bit slow and not many cool builds as JIM said but a lot of us are here, Shawn

[Robbie1]

yer im picking it up < when i was racing was using multiplex radios and futaba , with crystals lol , the boats were just coming onto carbon fibre hulls , used to mix my own fuel to bring racing costs down used to do 20 gallons a season i only ran 10% nitro was quite a cost back then . but loved it , grew up racing these from little tiny park racers to 90s when i stopped met some great people and had really great times . hopefully is what will happen when i start racing again or i hope

[Robbie1]

So heres my first question on Offshore fast electrics ..............are you ready ?

So how do you guys select a prop for your hydro ? Obviously there will be a recommended prop for the hull you have purchased and type of motor , but do you guys experiment ? test ? get tthe revs up speed down or visa versa ?
Having trouble selecting props for my hulls as they a little bespoke ie , not a kit in a box.
Plus obviously being surface piercing and high cost i guess you guys dont buy these as a kit and swap them around ?
I understand octura numbers as regards to picth and diameter but means nothing to me ? without having alot to go try ?
your help on this
How did i do ?

[Robbie1]

It will be riggers in particular im intrested in .

funny aswell we used to laugh at people building and running with flexi shafts when i was racing , now im about to enter a world of wobblys

[Robbie1]

will be fantastic to go back to elmbridge aswell i used to do national events there when i was a lad , be quite tearful me thinks

[Robbie1]

Secound question regarding lipos ( used to be all nicads )

I want to be competitive , and matched with the right esc , but have found lipos for 400 euros , and lipos for £30 is there a differance only obvious thing to me is C rating , and contious current , would i give me an edge ?

[srislash]

Unfortunately I am no Hydro expert but I would look up the hydro of choice and see who's running what. You can get lifting props if you weight is too far back. Lower lift if further forward. It also depends on motor KV and size/brand.
What hydro are you contemplating Rob?

[NativePaul]

Welcome Robbie, I have raced with Electra since I returned to the sport in '07, I have just moved out of the area so wont be a regular next year, but I do plan to travel down at least once, so I look forward to meeting you.

Multiplex/Hitec (they are in bed now) and Futaba still make great radios and while I would recommend 2.4GHZ if you are buying a set, 27 and 40MHZ are way better than they used to be as most of the band's traffic has gone to 2.4 so if you are on a budget and still have your Multiplex set using it is a valid option.

First you have to choose your classes, the lap times of a Hydro2 are not that much lower than a Hydro1, but they are faster down the straights and take a lot more driving, it also costs near double the price to build one. Check out Greased Weasel Racing on Youtube, I have videos of all the Naviga surface drive classes there and they may help you get a handle on things. I would probably avoid Hydro2 on your rookie year even though you have raced in the past.

As for what batteries to buy, are you sitting comfortably? Then I will begin. Select your cell count, a Mini and Hydro1 can be either 2s or 3s and a Hydro2 can be from 4s to 6s, there are people running all counts and the energy is the same for either but I would recommend 3s and 6s for a slight efficiency gain from lower wire losses, and my talk about batteries hereafter will be based on 3/6. Do you have any intention to, or thoughts that you may compete internationally? Naviga (who set the rules internationally) just go by battery weight, you are allowed 110g for a mini, 280g for H1 and 560g for H2, there are basically only 2 competitive batteries for these weights and they are both quite fragile low "C" cells and quite high price, Tenshock and Redzone. Capacitys increase all the time, but last year those weights would net you 1700mAh for Mini, 4800mAh for the full size classes. The limited amount competitive batteries is not ideal and to help alleviate the issues the UK has legalised an alternative to the Naviga rules in that you can chose to run unmodified LiPos with a marked capacity of 1700mAh for minis or 4500mAh for the bigger classes instead of using the weight limit, 4500' sounds like less power than 4800mAh, but without the weight limit you can run a high "C" pack which will have a higher voltage under load and therefore a similar energy level. Likewise I think Redzone and Tenshock are the only people making 1700mAh, so if you go for capacity it will be 1600mAh. To compound the confusion Electra introduced the Mini Hydro class before Naviga did and as of last year (I missed the AGM so can't say about next year (are you on facebook? If so ask the electra page)) still hadn't got round to amending the Mini Hydro battery weight to the Naviga specs and was 140g. There is no need to pay e400 for a battery, expect to pay around £25 for a 110g, £55 for a 280g and £110 for a 560g race pack +postage, as you wont find competitive weight packs on shelves in UK. If you go for capacity there is a much bigger choice Overlanders are great and sold in many model shops, but are likely to cost a bit more, or Hobbyking Lipos are popular too and can be had for about half the price of Tenshock/Redzone.

Bespoke is the Norm for this game, I have only ever had 2 kits that suggested a prop, and in both cases I used something totally different as my electrics were different. The higher the motors KV is the smaller the prop has to be to get the runtime. In Naviga we tend to have smaller lighter boats than in USA so we don't need as big a prop to push them and our KVs tend to be a little higher, but both slow revving big props and fast revving small props can work. Generally a mini will use a 27-31mm prop, a Hydro1 34-36mm, and a Hydro2 37-42mm, suitable KVs will be 2700-3300 for minis, 3000-3500 for H1 and 1500-1800 for H2, a lot will depend on the hull, setup and weight as well as the KVs though, I would suggest using other people's experience to get you close before you get a handle on things. I have a box full of Octuras but for the effort that went into it I would probably go with 4mm threaded stub shafts now with Graupner carbon and Tenshock CNC props instead of dog drives and Octuras.

Is there anything specific that you are thinking of or want opinion on?

[srislash]

Ah, perfect Paul. I know nothing about racing especially in the U.K. And you are about the best contributor that I can think of on here.

Shawn

[SweetAccord]

Yes, Paul is super helpful and always very informative. He is correct with all he stated. One thing I suggest is get a bunch of varying sized plastic props and test which gives you what you are specifically looking for in speed vs. run time.

[Robbie1]

wow cool , yes after considerable amount of thinking im going to go with Hydro 1 and mini classes , then perhaps look to go to hydro 2 , im going to buy 4 hulls : 2 hydro 1 and 2 hydro minis , giving me 2 spare hulls , the hulls im thinking are mini mi , and doctor evil from hydro and marine , with some custom parts machined from CF at work then eventually at home on cnc , would this be a competitive hull ?
Plus yes i am thinking of getting (total Overkill !) duplex radio.
The lipos i were referring to are from MGM about 300 euros approx ?

Thinking of using the LMT lehner series in the mini and hydro 1 ?

What do you think ?

By the way thankyou

[Robbie1]

The mini will use the LMT lehner viper series ? (low diametre motor can get lower in hull keeping the shaft as straight as i can ? )
4mm shaft
2s 2200mah 45c 4150kv ?
Prop ? 3 blades ?

The hydro 1 again the lehner motor maybe typ 1920 ( 2650kv something near )
4mm shaft
4s (2x 3300 )
Prop ?

Keeping the mini and hydro 1 on esc 20% more than the motors are pulling ?

Very interested in doing national events and worlds :)