700 BB OK on 14 cells?

[MikeC]

Is the Graupner 700 BB ok to run on 14 cells? Is it the same motor as Chris Fines 775 Ferrite motor? he advertises that as 8-16 cells.Thanks for any help

Mike C

[Paul]

Hello Mike,

No sweat, I've run my 700 8.4 and my Neo's on 16, it's a screamer.

Paul

[Ray Bidwell]

Yes mike the motors are the same. I have run mine on 16 cells and like Paul said it is a scream. I have seen videos of boats in europe running on 20 cells no guarantee on how long your motor will last but it is fast.

[MikeC]

I will stick with 14 for now.I am waiting for my new cells to come in and all I have left thats any good is a matched 2400 6 cell pack and two 4 cell 2000's.

[Allan]

There is no problem running any motor on any number of cells so long as......

1. You don't run it past it's top speed limit and it throws windings.

2. you do not exceed the current capacity - which really means that it all stays at a reasonable temperature

3. You don't overload it - see 2.

So the answer to you question is....

12 cells 450 prop 3 minutes max
20 cells 640 prop 30 seconds max 642 10 seconds before it burns

In between figure it out..... If you overload it the brush carriers soften and the brushes collapse.

If you want ultimate speed from one then break the fan blades off... UK boaters please not this mod is illegal for racing and will be picked up by scrutineering.

Hope this helps.

Allan

[Paul]

Hello Allan,


If you want ultimate speed from one then break the fan blades off...

Man, why didn't I think of that, their useless anyway. Thank you for that tip!

Paul.

[Jan-Nicolas]

Hi MikeC

...this is what Alan meant with "...the brush carriers soften and the brushes collapse."

http://www.rc-raceboats.de/images/tipsundtricks/verbrannt1.JPG
...You see a Neo9.6 ... roasted on 20 cells...

CU on WWW.RC-Raceboats.de
Jan-Nicolas

[Ray Bidwell]

Jan love that picture this must be your SAW motor right.

[MikeC]

So should I start with a 640 on 14 cells in my EV? I have a 442,645,637.

[Paul]

Hey Mike,

442.

Paul.

[MikeC]

Thanks Paul

[K.R.Joye]

Originally posted by MikeC
So should I start with a 640 on 14 cells in my EV? I have a 442,645,637.

Hey Mike my El Vee with 700BB D/D runs best spinning aluminum x642s.This was the El Vee to beat at BATAVIA last year.Make sure you have tabs and fins or you will spin out in the turns.Some of the Minnesota guys ran x645s.

[Paul]

Hello Ken,

Keep in mind Mike wants to up the cell count, pretty big difference between 12 and 14 cells.

Paul.

[K.R.Joye]

Originally posted by Paul
Hello Ken,

Keep in mind Mike wants to up the cell count, pretty big difference between 12 and 14 cells.

Paul.

Oops your right Paul,Pitch it down to the x442.

While were on the subject.Whats largest dia prop i'd swing on a 26"700BB LSH hull? I'm designing the hardware(flex not straight shaft)and want to make sure i have enough room.(x642?)

[Paul]

Hello Ken,

While were on the subject.Whats largest dia prop i'd swing on a 26"700BB LSH hull?

It depends on the 700, on my 700 Neo I was swinging a x642 no problem for 4 minutes but I have been playing with a x440/3 that's giving me outstanding performance but I haven't timed it yet. On a 9.6 700 I was running a x450 and on the 8.4 a x445. Really I just keep swapping and timing until I hit the "magic mark" so to speak.

Paul.

[K.R.Joye]

Paul, Thanks,45mm dia would probably be the largest.I'm assuming your referring to your BBY gun boat.Its alot larger than my hull.

[Jeff Wohlt]

My opinion only>>>I also run the 700 NEO with X642 on my RC Hydro. It seems to be the fastest and is on the edge for the motor. Now, if you run the 8.4 or 9.6 700 You can push it a bit harder without worying about the NEO mags getting too hot.

I think a 445 could also be a good prop for this motor/boat combo.

Here is a little info I have gathered along the way.

http://www.geocities.com/jwohlt5362/700motorinformation.html

The 642 is perfect for it but the boat needs to be trimmed correctly and make sure the tail is not dragging or the prop won't spin up like it needs to.

[K.R.Joye]

Jeff ,Thanks for the DATA. I planning on running the 700BB (DPI version) I think my hull will have a similiar ride and setup as the R/C Hydro.

Did you offset your motor and shaft.(flex or straight?)Mine are both offset 3/8"fr center.

[Jeff Wohlt]

Yep..offset it. Looking from the rear I moved it to the left but not that much. I did more like 3/16" or a bit more.

I am using flex and Fuller Hardware. You want the prop end to be about as deep as the front sponson bottom and a few degrees angle to push the rear end up.

Rides pads probably made the biggest difference on my RC Hydro. Just the back tips of the pads are riding on the water and the tail is clear of water drag.

DPI motors are the 8.4 volt version.

[Jeff Wohlt]

Here are some pics

[Jeff Wohlt]

Another

[avalentine]

Originally posted by K.R.Joye


Hey Mike my El Vee with 700BB D/D runs best spinning aluminum x642s.This was the El Vee to beat at BATAVIA last year.Make sure you have tabs and fins or you will spin out in the turns.Some of the Minnesota guys ran x645s.

...and it was beat ;)

Dan Proulx, Andy Valentine, Mark Anderson. All from EMYC. Dan running a Cat, and Mark and I running EV w/700bb. We'll be there again this year... to rock your world :D

We swing x645's w/8.4 700bb's every week. We run 8 lap races 2-3 times every Thursday. When there is open water of course!



All in fun Ken, see you this summer.

[MikeC]

I just ran my EV with the 645 on 12 cells and that is a very fun and pretty long running combo.I was impressed with the speed and it handles really well.

[K.R.Joye]

Originally posted by Jeff Wohlt
Yep..offset it. Looking from the rear I moved it to the left but not that much. I did more like 3/16" or a bit more.

DPI motors are the 8.4 volt version.



JEFF nice pics of your boat!What class is it set up for and motor are you running?I'll post some pics of my hull when its done.I thought Andy K.recomended a 3/8-1/2 offset in a thread a long time ago thats why i went that route.

ANDY VALANTINE! I thought i might snag one of you Minnesota boys on that boat to beat comment! Ha Ha .............
I'm looking forward to P spec Offshore too this year.I'm sure you'll have those El Vees glued to the water by then.

MIKE C. Looks like your fleet is growing.Cant wait to hear about your 800BBX wood Cat.Hows that coming?

[MikeC]

I hope to have the hull all finished this weekend and I should have the hardware on also.I started to make a motor mount and I need to have my flex hex drilled out.Hopefully I can test in in about a week or two.

[Allan]

Guys,

I have run a BB700 8.4 extensively over a number of years. My Volante raced 3 mins + 1 lap with a 450 on it for over two years, I still have the motor but a stone broke the fans so it became illegal. Same motor ran a 447/8 for 4 mins +1 lap. My closest competitor ran a 645 or 6? This was all on 1700's and the motor was at it's limit - i.e. it would not run much longer without burning.

The SWAMBC guys run 5 minute dead races so the count is e.g. 16.3 laps in 5 mins. and they run 445's

The BB700 seems to run best when it can unload and spin - I tried a 1250 but could only get it in plastic (octura) but that was fairly quick as well.

Allan

[Andrewg]

Allan

"My Volante raced 3 mins + 1 lap with a 450 on it for over two years, I still have the motor but a stone broke the fans so it became illegal. "


A stone!? or were you racing Onshore 12-cell?

[Allan]

Andrew - no - during a test session I put brought the boat in to make some adjustments - a small stone flew into the boat but could not be found - until power was applied!!

Allan

[Catman]

Originally posted by Allan



The BB700 seems to run best when it can unload and spin - I tried a 1250 but could only get it in plastic (octura) but that was fairly quick as well.

Allan

Sorry for replying to such an old thread, but i just got a ss1, climate boatworks matrix and a astro 207d , fullers FE hardware

I have a plastic 1250 and was thinking of trying it, did it provide much lift ? how quick was it, how would it compare to the prop im running ? currently im swinging a b230 prather, ive had 2 runs as i only finished the boat today, first i had a filed down b220, and bugger all strut angle, runtime was 7 mins and then some on 14 3000mah sport cells, motor and batteries cool. went to the 230 and a bit of angle as it dragged the back a lot to start. With a lifting prop hopefully i can get the strut angle flat again and get a bit more speed.

[Allan]

1250 is not a lifting prop and the pitch is only 1.2 rather than the 1.5 of the prather. I would suggest that you try 14 or 16 series. I never really got on with 16's so 17 is also an option.

[p1um1oco]

I'm looking forward to P spec Offshore too this year.I'm sure you'll have those El Vees glued to the water by then.


Glued to the water, that's not the way to make them run fast.:D

Dave