Jump to content



Help Support IntlWaters by donating using the link above.
Photo

1/8 Scale rules question


  • Please log in to reply
63 replies to this topic

#61 Don Ferrette

Don Ferrette

    World Racer

  • Admin
  • PipPipPipPipPip
  • 15,083 posts

Posted 12 May 2018 - 08:45 AM

 

You need 10s for the reasons Don explained.  Approximate watts out needed for a scale. Watts = volts X amps.  Less volts will generate more amps at the same watts.  The knee jerk is prop size limit.  Really?  With a prop anvil we can modify a prop such that the diameter becomes irrelevant.  Don's record is but one example.

 

It's always better to run higher voltage with lower current for the same power.  Just tell me where in the rule this lower current is required.  It will be determined by whether the motor or the ESC fails first.  The batteries have a lot higher capacity.

The first sentence is all that's needed. All the rest that I snipped off is based on formulas and calculations that take in no account for one critical always changing factor- the water. All that I have shared is based on REAL WORLD ON THE WATER testing, racing with PROVEN reliability. And "It will be determined by whether the motor or the ESC fails first" is absolutely laughable, ask Doug Smock how long he's been racing his 10S scale at full tilt with ZERO failures. Enough of this........





#62 Don Ferrette

Don Ferrette

    World Racer

  • Admin
  • PipPipPipPipPip
  • 15,083 posts

Posted 12 May 2018 - 09:28 AM

 

 

That's over 25 thousand watts, about TEN times what a 10S 1/8 scale will draw at full song. Not to mention who the hell wants to haul or even try to fit 6 pounds of batteries in a scale boat?? ( a typical 5S 5000mah pack weighs about 24oz)

 

You finally are beginning to understand the problem with the present electric rules that only limit voltage.  By the way, my 8S boat carried 4-5000 mah packs in heat race form.  We only needed 2 in series for two lap record trials.  As a nitro boat it weighed 14.9 pounds.  As an electric it weighed 18.3 pounds with 4.9 pounds of batteries.  The electric version was faster.  See the picture below.

 

If you look at the graph I posted, you can see the motor draws around 150 amps in the corners.  Something like that is reasonable and is set by the combination of motor KV, voltage, and prop diameter.  We could easily run a bigger prop, go faster, and draw more current.  What do you propose to set a reasonable current limit?

 

Lohring Miller

This motor/kv/prop limits debate is not worth any more key strokes and honestly I've now had 3 separate requests to block you from further posting on this thread. You got what you wanted in limiting FE scales in NAMBA, it should be apparent we are not interested in that approach in the IMPBA. With that being said and the complaints I'm receiving please refrain from any further posting on this IMPBA FE scale thread. I cannot block you from a thread, only suspend you entirely and you've certainly done nothing to deserve that extreme a treatment.





#63 Mikemalloy

Mikemalloy

    Newbie

  • Members
  • Pip
  • 72 posts

Posted 12 May 2018 - 10:25 AM

I understand everything everyone is saying, we (the guys that started FE in RCU)researched this and got feed back from a lot of you on IW. We initially started with 10s on our prototype in 2009/2010 with a castle 240 hv, NEU 1527 1.5Y 850kv 52mm prop. After further testing We decided a 8s setup would be better overall for racing in the club. So Neu 1527 1.5Y 8mm 859kv. and a 55mm props were what we started with, our 7 SURT 1/8 hulls weigh ready to race 13-15lbs. In 2011/12 we added the Turnigy and Typhoon 850kv motors and a max diameter 57mm prop. So over the last couple of years technology of batteries, Esc, motors as we all know have gotten better and worse. We have been running the Castle 240 and 200 HV Escs and Neu motors from 2011, so the comment made that the electronics wont last on 8s Well some of us are going on 7 years, with the same equipment. When the Castle escs finally give up we will probably go to the HW 180HV or the ZTW or what else is available. Dont get me wrong 10s is fun to race but IMO 7 boats in a Final doing 70+ mph could get really expensive.... But like it was stated the proposal passed so its moot at this point, I just thought I needed to say something. Im all for listening to anybody on what there thoughts are cuz everyone sees things differently and we can learn from one another.Attached File  C13F910C-86B1-49D5-A0E9-DDA0AB84828A.jpeg   121.78KB   5 downloads

Edited by Mikemalloy, 12 May 2018 - 10:34 AM.


#64 John Borden

John Borden

    Newbie

  • Members
  • Pip
  • 59 posts

Posted 15 May 2018 - 07:42 AM

I understand everything everyone is saying, we (the guys that started FE in RCU)researched this and got feed back from a lot of you on IW. We initially started with 10s on our prototype in 2009/2010 with a castle 240 hv, NEU 1527 1.5Y 850kv 52mm prop. After further testing We decided a 8s setup would be better overall for racing in the club. So Neu 1527 1.5Y 8mm 859kv. and a 55mm props were what we started with, our 7 SURT 1/8 hulls weigh ready to race 13-15lbs. In 2011/12 we added the Turnigy and Typhoon 850kv motors and a max diameter 57mm prop. So over the last couple of years technology of batteries, Esc, motors as we all know have gotten better and worse. We have been running the Castle 240 and 200 HV Escs and Neu motors from 2011, so the comment made that the electronics wont last on 8s Well some of us are going on 7 years, with the same equipment. When the Castle escs finally give up we will probably go to the HW 180HV or the ZTW or what else is available. Dont get me wrong 10s is fun to race but IMO 7 boats in a Final doing 70+ mph could get really expensive.... But like it was stated the proposal passed so its moot at this point, I just thought I needed to say something. Im all for listening to anybody on what there thoughts are cuz everyone sees things differently and we can learn from one another.attachicon.gifC13F910C-86B1-49D5-A0E9-DDA0AB84828A.jpeg

We started with 1 Scale in 2016.
In 2017 we have 10 with 5 that travel to most race.
The rule works.
We have good racing.
We all run with this as a base line and can help each other. Keep spear parts if needed
I support the new rule and it is a growing class.
If you our not A FE person you don’t know what to buy.
The rule help you with a good starting point and can race.
The trick is not to over do it.
I did last year. But now that I have got set up all is good.


I would be happy to talk to FE Scale boaters more if you would like.
Please PM me and I will send you my phone number.






Sent from my iPhone using Tapatalk


Edited by John Borden, 15 May 2018 - 07:43 AM.