Jump to content



Help Support IntlWaters by donating using the link above.
Photo

Electric Rules


  • Please log in to reply
127 replies to this topic

#1 LohringMiller

LohringMiller

    Beginner Boater

  • Members
  • Pip
  • 204 posts

Posted 13 May 2018 - 09:37 AM

As everyone knows electric motor input power in watts equals volts times amps.  The similar relationship in piston engines is power equals cylinder pressure times displacement times rpm.  Regulating the displacement in IC engines forced innovations that resulted in smaller engines with higher cylinder pressures operating at higher rpm to generate the same power.  Think the 1956 Chrysler 300 versus today's Honda Civic type R both with around 300 hp.  This pace was slow in both model and full size engines.  However a 1950s model engine like the McCoy 60 produced around 1 hp while today's similar size, tuned pipe engines can produce over 4 hp.

 

Today something is happening much more quickly in electric power.  Think golf carts versus the Tesla model S.  Lithium polymer batteries were a game changer.  Their very low internal resistance allows much higher currents than previous battery types.  Before this batteries were the limiting factor.  By only regulating input voltage with lithium polymer batteries we encourage innovation in motors and speed controls.  This innovation today allows close to 30 hp input power (600 amps times 37 volts) for short times like SAW runs.  With 1200 mah packs 400 amps will still give a 1.8 minute run time, enough for a standard heat race.  Commercially available speed controls can deliver over 300 amps when water cooled.

 

One solution has been the P limited classes.  By restricting the motor, it becomes the "fuse" limiting power.  If you restrict the ESC choice, that limits power as well with the ESC as the "fuse".  How expensive do you want this current limiting method to be?  Motors are getting inexpensive.  The fastest P limited racer in our club paid $27 for his motor.  Competition airplanes use a more elegant solution involving electronic controls that limit input power.  Simpler solutions that have been race tested involve limiting propeller diameter as well as motor KV and size. 

 

Another solution has been to limit hull length.  I watched Brian Buaas set two lap records in several voltage classes with the same small sport hydro.  It just got harder to drive at the higher power levels.  T class boats can be 60" long, the NAMBA maximum.  The most powerful IC engines in a twin configuration probably deliver around 10 to 15 hp.  Do we really want to allow electric power plants with more than twice that?  What are some other current limiting rule proposals?

 

Lohring Miller

 

PS: Engineering is done with numbers. Analysis without numbers is only an opinion.

 

 





#2 T.S.Davis

T.S.Davis

    Club Racer

  • Members
  • PipPipPip
  • 527 posts

Posted 14 May 2018 - 06:51 AM

I want one of these 600 amp controllers.  Why 600?  Why not 6000?  I've been doing this a long time.  I've yet to see this illusive controller that has been feared for 15+ years.  You say that engineering is done with numbers.  True.  However, engineering is also bound to reality too.  The answer to my "Why not 6000amps?" is obvious right?  Engineering that ignores reality is merely theory as proving it is not possible.

 

You want to re-write and flush everything we've been doing for a decade?  You go for it Lohring but keep that crap out of IMPBA please.





#3 Doug Smock

Doug Smock

    Club Racer

  • Members
  • PipPipPip
  • 928 posts

Posted 14 May 2018 - 08:33 AM

No worries Terry...🙄

#4 Ken Haines

Ken Haines

    Beginner Boater

  • Members
  • Pip
  • 83 posts

Posted 14 May 2018 - 01:59 PM

Lohring, here is the problem; those of us that race all over the country were not any part of this new scale rule.
You can theorize all you want and that is definitely opinion, but up until recently our current rule set worked. Additionally this 1/8th scale unlimited Hydra class was gaining popularity at some of the larger races with the original rule set. I actually very recently bought some of this equipment that now is illegal in NAMBA. So instead of setting up a limited rule set or actually new limited version class for the Northwest region clubs someone decided to just set the class on its head. It would be on par with the P-Ltd rule set being put in place for all the regular P Classes, and all the current P-Mono’s, P-Cat’s and P-Hydro’s then being illegal. Now you can debate here with all this technical jargon but most of the avid active racers in the rest of the country are upset. According to the way the rules can get passed someone that races very minimally or regionally at the most could in theory get a rule passed that limits many other classes across the country. My guess is that the NAMBA fuel guys voted yes because they thought with info that they had heard this was a good thing. This is why when a rule change that is not for electric, I simply abstain as it is really none of my business. I would hope in the future our electric rule votes would be respected in the same way.

On an older note weren’t you one of the crowd years ago arguing against hull limits and against 2p lipo set-ups. If I am wrong on that recollection I apologize, but that is what I seem to remember of the time that I visited your club at the 2007 Nat's. I believe we had a heated argument about that during my visit.....Kind of Ironic

Edited by Ken Haines, 14 May 2018 - 02:01 PM.


#5 Mike Hughes

Mike Hughes

    World Racer

  • Members
  • PipPipPipPipPip
  • 2,636 posts

Posted 14 May 2018 - 04:43 PM

Not all fuel guys vote for it. My son and I voted against. Not fair to limit the class that way. Now people with the 10S are illegal. 

Mike



#6 Bill Brandt

Bill Brandt

    World Racer

  • Members
  • PipPipPipPipPip
  • 1,729 posts

Posted 14 May 2018 - 07:10 PM

To propose a rule change, as I was told by our district director, a club has to run that rule for at least one year. RCU has been running this proposed rule for 3 years. My Texas friends reached out to me and together we proposed this change, although done through our District 8.
Once again the Namba Nats in Las Vegas were very lightly supported by 1/8 FE, in part because of the existing poor rule. Most areas that run 1/8 Scale FE run 8S. They run motors and escs that were readily available and new racers didn’t have to go through a steep and often expensive learning curve to race.
It appears that most dissenters of the rule change don’t themselves run the class. If they are advocates of 10S it’s usually because they’re from clubs that combine nitro and FE because they don’t have stand alone numbers.
If there aren’t enough motor choices then look for other 850 kv motors that will work and propose them down the road.
My customers across the US and in fact around the globe have applauded the change and the clarity it brings to 1/8 Scale FE.

#7 raptor347

raptor347

    Club Racer

  • Members
  • PipPipPip
  • 771 posts

Posted 14 May 2018 - 08:14 PM

Bill,

There are several groups that have been running FE 1/8 since it's inception around 2002. You've obsoleted their equipment. I know of 30+ boats in this situation.

 

The rule has issues that have been discussed in the past. I've said in the past writing club rules is different than writing national rules. The following is a copy of my post on OSE dealing with tech for the new rule set: 

 

"First off, unlike P-ltd and 1/10 scale, the new 1/8 scale rule doesn't state that the motors must be run as delivered from the factory, so modding is fair game. The factory markings constitute a legal motor and should remain visible for inspection. Missing or altered factory markings will constitute an illegal motor.

Definitive battery tech is pretty much impossible at the pond (and difficult in the shop), so all cells will require a factory label to verify capacity and discharge rate. Re-wrapped or unreadable labels will not be allowed for competition. The appropriate factory label and pre-heat voltage check will count for tech. 

Factory labels on ESC's will be required to verify they meet the requirements for rule 6.d.i.

Prop diameter should be checked each heat at the same time pre-heat battery voltage is checked. Should be an easy fixture to build/use.

That should cover tech inspection for the new FE 1/8 scale rules."



#8 T.S.Davis

T.S.Davis

    Club Racer

  • Members
  • PipPipPip
  • 527 posts

Posted 14 May 2018 - 08:55 PM

"Once again the Namba Nats in Las Vegas were very lightly supported by 1/8 FE, in part because of the existing poor rule." 

 

I call BS.  The numbers were down because the class list was limited and FE is fractured.  The class list was limited because there was only so much the gang could pull off in a week.  Guys didn't make the trip.  Having put together the largest FE event in US history I and having been CD for 3 nationals I'm not just speculating. 

 

The National FE chairman wasn't in favor of the rule change.  A multi time national 1/8 scale champion HATES it.  The guys that invented the class and wrote the original rule set are on the outside looking in with illegal boats.  You guys still think you got it right.  mmmkayy

 

Enjoy.

 

I was already up against this issue.  I HAD a NAMBA legal boat but wont be racing NAMBA.  So I needed to build new or try to convert it to something legal for IMPBA.  Now my boat has no home at all.



#9 Bill Brandt

Bill Brandt

    World Racer

  • Members
  • PipPipPipPipPip
  • 1,729 posts

Posted 14 May 2018 - 10:14 PM

Doing what I can to help the sport. Trying to give customers guidance. I wasn’t alone in this proposed change and that ain’t no “BS”. Otherwise it wouldn’t have passed. If people didn’t care enough to vote then they didn’t care.
The only good thing about this thread is we have toy boat racing in common. I gave an explanation and I get flack.
30 boats I made obsolete? That’s nuts. Just throw in an 8S setup that I bet you have more of than 10S and you’re running.
Come race with us. Last two races over 40 Scales entered in various Scale classes. We’re growing and we’ve been running this program now for 6 years in FE.

#10 Bill Brandt

Bill Brandt

    World Racer

  • Members
  • PipPipPipPipPip
  • 1,729 posts

Posted 14 May 2018 - 10:27 PM

"Once again the Namba Nats in Las Vegas were very lightly supported by 1/8 FE, in part because of the existing poor rule." 
 
I call BS.  The numbers were down because the class list was limited and FE is fractured.  The class list was limited because there was only so much the gang could pull off in a week.  Guys didn't make the trip.  Having put together the largest FE event in US history I and having been CD for 3 nationals I'm not just speculating. 
 
The National FE chairman wasn't in favor of the rule change.  A multi time national 1/8 scale champion HATES it.  The guys that invented the class and wrote the original rule set are on the outside looking in with illegal boats.  You guys still think you got it right.  mmmkayy
 
Enjoy.
 
I was already up against this issue.  I HAD a NAMBA legal boat but wont be racing NAMBA.  So I needed to build new or try to convert it to something legal for IMPBA.  Now my boat has no home at all.



The mere fact you acknowledge in your post that “FE is fractured” supports change. Club racers wanting guidance about what to buy to race don’t care about a National 1/8 Scale Champion. My son won Namba Scale Championship at his first National outing and he won’t have anything to do with FE. Won the only event he entered and referred to it as “plug and play” for those than can’t tune nitro or gas. I like it for the reasons he doesn’t. Enough soap box. Enjoy and I hope to race with you all someday.

#11 raptor347

raptor347

    Club Racer

  • Members
  • PipPipPip
  • 771 posts

Posted 14 May 2018 - 11:32 PM

At this point we have what we have. My part in this is how to tech the boats to be sure they conform to the rules as written at nationals and time trials.

 

My post above pretty much covers it.

 

The Turnigy and HET motors are going to need transparent water jackets so the factory markings/labels are visible for inspection.



#12 BrianTooms

BrianTooms

    Boater

  • Members
  • PipPip
  • 257 posts

Posted 15 May 2018 - 07:11 AM

Doing what I can to help the sport. Trying to give customers guidance. I wasn’t alone in this proposed change and that ain’t no “BS”. Otherwise it wouldn’t have passed. If people didn’t care enough to vote then they didn’t care.
The only good thing about this thread is we have toy boat racing in common. I gave an explanation and I get flack.
30 boats I made obsolete? That’s nuts. Just throw in an 8S setup that I bet you have more of than 10S and you’re running.
Come race with us. Last two races over 40 Scales entered in various Scale classes. We’re growing and we’ve been running this program now for 6 years in FE.


Well you made all my 70c batteries illegal too. 3 more boats here that won’t be running any time soon.


Sent from my iPhone using Tapatalk

#13 LohringMiller

LohringMiller

    Beginner Boater

  • Members
  • Pip
  • 204 posts

Posted 15 May 2018 - 07:50 AM

I am talking about electric rules in general, not just 1/8 scale.  I've been worried about current limits since lipos became generally available.  And Terry, the speed control in our full sized hydro was rated at 2000 amps on 144 volts.  We got close to 1000 amps through it.  I would have preferred to use lower currents at a higher voltage, but rules based on lead acid batteries limited us.  An engineer (Joerg) has already built a model size speed control that can handle 600 amps on 8S.  The design is not a secret.  Its 42 pcs IRFS7434-7P FETs with Schulze future 18.xx controller board. 

 

The 1/10 scale and P limited classes have successfully limited currents by using the motor as the current fuse.  Restricting the current in this way has allowed a single 5000 mah battery for heat racing.  I believe that this has done a lot to control the cost of racing at the entry level.  At the advanced level it has done a lot for prop design. P limited riggers and tunnels, as an example, are around 1/4 faster than in the beginning due to this.  Maybe the scale rules are over kill and/or need refined, but they also control currents very well. 

 

I'm looking for some other ideas short of actual or electronic fuses.  Maybe the type of current limiting that some ESCs have should be mandatory and checked at races.

 

Lohring Miller



#14 Mikemalloy

Mikemalloy

    Newbie

  • Members
  • Pip
  • 60 posts

Posted 15 May 2018 - 08:33 AM

Doing what I can to help the sport. Trying to give customers guidance. I wasn’t alone in this proposed change and that ain’t no “BS”. Otherwise it wouldn’t have passed. If people didn’t care enough to vote then they didn’t care.
The only good thing about this thread is we have toy boat racing in common. I gave an explanation and I get flack.
30 boats I made obsolete? That’s nuts. Just throw in an 8S setup that I bet you have more of than 10S and you’re running.
Come race with us. Last two races over 40 Scales entered in various Scale classes. We’re growing and we’ve been running this program now for 6 years in FE.


Well you made all my 70c batteries illegal too. 3 more boats here that won’t be running any time soon.
Sent from my iPhone using Tapatalk

Brian Tooms I’m curious on what brand of lipos you are using that are 70c?

#15 BrianTooms

BrianTooms

    Boater

  • Members
  • PipPip
  • 257 posts

Posted 15 May 2018 - 09:24 AM

Doing what I can to help the sport. Trying to give customers guidance. I wasn’t alone in this proposed change and that ain’t no “BS”. Otherwise it wouldn’t have passed. If people didn’t care enough to vote then they didn’t care.
The only good thing about this thread is we have toy boat racing in common. I gave an explanation and I get flack.
30 boats I made obsolete? That’s nuts. Just throw in an 8S setup that I bet you have more of than 10S and you’re running.
Come race with us. Last two races over 40 Scales entered in various Scale classes. We’re growing and we’ve been running this program now for 6 years in FE.

Well you made all my 70c batteries illegal too. 3 more boats here that won’t be running any time soon.
Sent from my iPhone using Tapatalk
Brian Tooms I’m curious on what brand of lipos you are using that are 70c?

I have 5s Revolectrix and Giant Power packs that are 70c.



Sent from my iPad using Tapatalk