Economy brushless

[James_Simpson]

Hello GR8 to see a new FE forum here!

I would like to hear about any experiences anyone has has with the more economical B/L systems that are available now. Any one using Mega Brushless or Jeti Phasors? My local hobby store stocks jeti phasors and hacker/jeti controls. I am looking to power a 12 cell sport hydro. It is just for fun running not racing.

I particularly would like to know if I will see a noticeable Increase in run time, compared to a same speed brushed setup, due to increased efficiency?

 

[Andrewg]

James

I have now had a fair degree of experience using the megas in boats - they are excellent

they are best to date in monos and sport hydros

effectively the efficiency differences at high current levels are in minor and in a sport situation of negligible importance

For a 8 cell hydro try the 22/20/2 and for 12 cell the 22/30/2

the 30 series will go up to 18 cells before hitting maximum efficiency at around 88%

The Megas are especially easy to setup - or more precisely tolerate a poor setup well. However when optimised they are as fast as anything on the water.

Used with the tw setting jeti or the Master Navy controllers they are the bees knees

Despite what the esc manufacturer recommends the best efficiency for the megas is achieved running on the lowest advance level - more power at higher current as you increase the timing

In terms of runtime the benefits tend to be less than with planes due to the higher current draws in boats - so say a boat runs twice the amps of a plane the increase in runtime is 1/2 what it will be in a plane

Torque and peak power seem to be the main dfferences - The Megas haul thru turns and come out of them well.

Jeti motors however are not suitable for boats due to their unwrapped rotors

One area where the brushless motors have proven spectacular is the micro boats - with very little cell capacity runtimes are 7-8 minutes at 30 mph - a real bargain - and these thingsare so easily transported it isnt funny! see www.microhydros.com (that Forrester man and I lurk around there too - Trent Hare wons the site and it is excellent - full of enthusiasts and plans and vids and reports on the micros - in many ways not unlike intwaters - a true enthusiasts site)

Andrew Gilchrist

www.fastelectrics.comn

for fast electric boats!

 

[James_Simpson]

Thanks Andrew,

So then you think I'm just as well off with a 700 can motor setup for 4-5 min runtimes.

So the unwraped rotor makes them not good for boats huh, is that because the motor will over rev when the prop breaks free from the water?

P.S. there is a typo in your site link

 

[drobie]

I am looking to power a 12 cell sport hydro. It is just for fun running not racing.

Not to take any biz away from Andrew (I just bought two Mega brushless motors from him)......

By all means, James. If you are not going to be racing and just sport running, go with a 700 series motor. A neo if you want a little extra out of it.

Most will agree, that if you want to go with a 700 Neo, pick up one of Chris Fine's SS1. www.finedesignrc.com He's retooled the design with enhanced magnets and other tweaks that make it more durable and less prone to heat.

The ESC's of choice are by Andy Kunz at www.rc-hydros.com

If you really want to increase runtime, gear it.

On the other hand, a few guys are just starting to play with geared brushless setups. I think the verdict is still out in terms of runtime and speeds.

 

[Randy Naylor]

One area where the brushless motors have proven spectacular is the micro boats - with very little cell capacity runtimes are 7-8 minutes at 30 mph - a real bargain - and these thingsare so easily transported it isnt funny! see www.microhydros.com (that Forrester man and I lurk around there too - Trent Hare wons the site and it is excellent - full of enthusiasts and plans and vids and reports on the micros - in many ways not unlike intwaters - a true enthusiasts site)

Andrew Gilchrist

www.fastelectrics.comn

for fast electric boats!

Andrew Hi

Do you hve recemedation for a mega motor for a 15 inch Hydro to run 4 minutes. You know me I want it to be a rocket.

Randy

BBY Racing

 

[James_Simpson]

Thanks for all the posts!

The geardrive thing really confuses me ???

Some people say that if you have the right motor and prop, gears an not nesasary. So why are they always recomended for more runtime? Why not just run a motor with a higher number of winds?

 

[Andrewg]

Randy - Mega 16/5/3

James - Megas are fine as they have kevlar wrapping - tested to 114,000 rpm last I spoke to factory

Jetis are not as they have no Kevlar

The gearbox /direct is a perennial debate. Gerboxes originated when we had small ferrite motors with low torque in boats which were generally heavier.

Now with Neo magnets the motors have bags of torque, and much better efficiency and power curves.

The guys who now get most adantage are the F5B /pylon plane guys who use 26 cells to a small motor on 6.7:1+ ratios - the higher voltage gives better efficiency at high current but its a matter of a couple of percent to these guys ho are squeexzing every last percent out its important

for riggers run 2 pole brushless direct

for sport hydros and mono run 4 or 6 pole motors

You can use a gearbox but take a 8 cell motor for $90 add a gearbox $52 and run it on 12 cells and you are up for $142 with complexity but with a very flexible system in terms of runtime - longer runtimes still loose speed

Take a 12 cell motor $99 put it straight in and goes as fast with a more reliable system. There way to vary runtime is to vary prop pitch - you are more limited here as there are generally 1-3 pitch variations for any given prop diameter - but more most uses its the simple, reliable and effective way to go

For sport running I would definitely go with a direct brushless - they are in a different league to the 700's - totally

The brushed motors I run now are in there because they are very good ie the Neo 540 Neo 480 800BBX or because I use them for sport running eg the Mega Midi and 700BB

The brushless motors are more efficient, more powerful and have much better power curves especially in the top end where ferrities and the can motors drop off quickly

for price go for a 700 setup - but the 7008.4v use 16 cells - cheaper and faster than a 12 cell FDM or other motor $125 all up

the price goes up from here and the SS1, the 700bb 9.6v Neo, 820BB, 800BBX

the BBXon 16 or 20 cells is faster than the SS1 - in the offshore class it has seen off geared brushless setups - this is self promoting but I sell it because it has shown it has a niche where it is unbeatable value

Thats also why I stock Megas. Despite the hoo ha over lehners etc in mono and sport hydro they are a killer motor because they have more torque than the two pole motors and are less expensive

for speed and runtime go for a Mega brushless and 40 amp hacker $230 all up

either one will give you LOTS of fun

And if you want to build a rigger wait a few days we will soon have the worlds best looking brushless motor with efficiency up their with Hacker. And the price will be good too!!!

 

[drobie]

For sport running I would definitely go with a direct brushless - they are in a different league to the 700's - totally

I am tempted to disagree, not about the "different league" issue but about sport running. However, I guess I'll have to play with my Mega this summer to find out about that.

Right now, I go brushless for a speed fix, but I'd much rather sport run my boats with a 700.

The P Sport (brushless) hydro record was attained at average speeds of 29.9 over 5 laps. I can assure you there was nothing left at the end of those 5 laps and probably some VERY hot batteries. The LSH record (700 motor) was attained at average speeds of 23.4 mph over 10 laps.

LSH hydros look fast when not running with brushless setups and for sport running, I'd rather give up a little speed in exchange for runtime. And I think most sport runners would rather spend $150 for a motor/ESC than $230 on up.

That said, I'll have to play with props to see what it takes to attain LSH (or 700 equivelant) runtime and speed with a brushless setup.

 

[Andrewg]

Doug

what you should find is you save about 70g with the brushless motors

you have more torque

you have a very different shape in the power curve - not only is the spin up to maxium power markedly faster - whereas the can motors then drop about 25% between maxium power to max efficiency the brushless drop 10% so the top end holds up

One of the things holding down speeds on the electric oval is its size. I have seen video of 8 cell hydros using a chameleon 19T running an average of 38mph on a nitro oval

IMO its a pity we dont let the electrics stretch their legs a little more - in the late 70's nitro was running at speeds now obtained by electrics and they run on the large oval

 

[Steve Vasdekis]

You said Andrew!!!! We really need to stretch our "legs" for electrics. Not only will we go faster, but we will draw less amps and get more runtime. When I run my bandit shovel nose on 12 cells, x432, and hacker 9L it could really use an extra 100 feet or so because as soon as I come out of turn 2, i am right back getting into turn 3 just as the boat is parallel with the surface of the water and it looks awesome! Nothing but prop and rooster and rudder!

 

[Paul]

Hello Doug,

That said, I'll have to play with props to see what it takes to attain LSH (or 700 equivelant) runtime and speed with a brushless setup.

LMAO!!! WOOOOHOOOO! Bud, you bring your 700 powered boat to Batavia this year and run it hydro enduro. I, on the other hand, will be running a geared BL that will flat out eat a 700 alive. Keep this in mind, the record stands at 16 laps with Ed Hughey running a rigger and twin 05s, I was behind him with 14 laps running a 700 in a sport hydro.

I will take that record away from Ed this year.

Paul.

 

[Andrewg]

Paul

gee you could be near 534w output with that setup if it is what I am thinking it is

My estimate is you are up near /past 40 mph with that thing - thats fast

Nealry the same power sprint boats were pulling with 2000's

Andrew

www.fastelectrics.com

 

[Paul]

Hello Andrew,

gee you could be near 534w output with that setup if it is what I am thinking it is
My estimate is you are up near /past 40 mph with that thing - thats fast

LOL, your probably pretty close I find an excellent opportunity is rising with all the high zingers coming out lately. On top of that their inexpensive.

Paul.

 

[sjslhill]

That Hydro enduro could get real interesting with 3300 cells. 8) I'm thinking 20+ laps with the right combo. But Ed could also do better with more battery capacity.

It could be interesting indeed!

Steve

 

[drobie]

I am looking to power a 12 cell sport hydro. It is just for fun running not racing.

I particularly would like to know if I will see a noticeable Increase in run time, compared to a same speed brushed setup, due to increased efficiency?

by Paul: Bud, you bring your 700 powered boat to Batavia this year and run it hydro enduro. I, on the other hand, will be running a geared BL that will flat out eat a 700 alive.

Paul,

No doubt your geared brushless setup is good FOR YOU and YOUR objectives. My comments were responding to James original post that he wanted simple sport running on 12 cells. His goal was not to break Ed Hughey's record. His question was: Will I get more run time with a brushed setup.

My answer is still "no".

I wasn't even close to comparing a 700 to a geared brushless setup and I said if you really want to increase run time, gear it, meaning either of them.

 

[forresterace]

Thank you Doug R. for bringing this discussion back more in line with the original question.

Not that where it was going was not a valid subject in itself....

Might I suggest if you gentlemen wish to continue it, start a new thread.

 

[Andrewg]

One thing Pauls post did raise is the use of smaller brushless motors with gearboxes

There is a limit to how far one might go with this - the smaller brushless motor tend to have lower efficiency than the larger brushless while being much better than a brush motor of similar output.

A geared setup will give more runtime and an ability to choose a wider range of speed/runtime compromises. However it does this at the expense of simplicity and cost (by about $60 all up).

Andrew

fastelectrics.com

 

[David J]

I've been using a Mega 22/30/2 all winter in my Key West. Hacker 70, 12 cells and a 440. It has been an excellent sport boat with great runtimes and super performance. I would recommend them to anyone looking to get into brushless... However that being said I wouldn't recommend brushless to anyone who doesn't have a fair amount of brushed experience. Like I said my mega ran great many many times, that was until I tried to use it in my heavier and poorly setup sport hydro. Same prop and cells didn't even get it to plane, so I put the 645 prop back on that I had always used with my Plett and after two laps it stalled. When I got it back to shore I found a nice gooey mess and the wonderful smell of a melted esc.

 

[Andrewg]

David

Was the problem with the brushless motor or the setup of the hull and the prop used.

a x440 to an x645 is a huge jump and goes over at least two props which could have been used ie the x640 and x642

These motors are among the easiest to use I have found however the controller must be timed properly and the frequencyof operation must be setup for the motor in use.

Andrew

www.fastelectrics.com

 

[drobie]

James,

Is this what you are attempting to accomplish?

Not the best shot. My T-Plus, which not a very competitive hull so I don't race it, but at scale runs, it sure wows the crowd.

700 Neo.