Motor heat

[DPeterson]

Dan - good questions. And Darin - good info.

At the risk of being slammed - our focus in D4 is to continue to build on P-limited racing. NAMBA hung their hat on motors supplied by rtr manufacturers with certain technical parameters. This worked in theory and actually worked for a couple years in practice. There are many threads on here that explain the reasons there are many of us taking a different direction. We'll let that rest.

In D4 we have decided to take the technical approach in finding and approving motors for our racing. The main parameter is to find motors that can power a boat in the 45 to 50 mph range. Not burning premature will also be a plus. This is the speed range that makes the spec classes work. Our approved motors so far are the ones already running (the ProBoats and the Aquacrafts) and now the TP 3630. This spring we will also be testing a couple others from other vendors. The key here is that the motors have to meet our "on water requirements" to make our list.

So for Spec motors we will be staying within a certain can size and kv. By finding motors within this size that have more wire mass as Darin alluded to, we think we can build a list of approved motors that will have longevity. Besides more wire mass, better quality wire will be good.

Doug

[T.S.Davis]

NAMBA hung their hat on motors supplied by rtr manufacturers with certain technical parameters.

Splitting hairs but NAMBA didn't "hung their hat" on the RTR manufacturers. NAMBA responded to the parameters that were being run successfully in multiple locations, for multiple seasons, by multiple clubs. That's the on water proof we're both so fond of. The actual proposal itself was a collaboration between two clubs on opposite sides of the country that were running the spec and had experience with the rule proposal process. It was then proposed and voted on at the district level and then moved out for a national vote. So "NAMBA" didn't choose the RTR motors. The guys that were running it chose them.

By successful I mean that it put butts on the drivers stand.

I'm curious, why bother with "spec"at all Doug? Why not just move on to full P? There's maybe $40 difference between a 36mm TP and a 40mm 2100kv....ish TP motor. Seaking 180 is all you really need to run it. Those are cheap. 5000mah is enough for sprint if you don't go prop crazy. Mid 50's and the motors will out live both of us.

FE as a racing community is an itty bitty tiny little segment of RC. P limited as we know it is the largest segment of our tiny itty bitty piece of that RC pie. Aren't you at all concerned that you're going to split that segment into pieces further?

We're already looking at NAMBA P limited, IMPBA Limited (doesn't exist), and now D4 P Spec.

That club in OH with the Leopards, anybody know where they race?

[DPeterson]

Terry

collaboration between two clubs

then moved out for a national vote.

As we spoke of previously, 2 clubs that can garner enough votes to pass something Nationally does not mean it represents National interest. Especially so in such a small hobby. Time to get over the fact that you and NAMBA do not have the following you thought you had. Let it go and go race. It will be OK.

Splitting hairs but NAMBA didn't "hung their hat" on the RTR manufacturers.

I believe the NAMBA rule books says that the P-Limited motors must come from a rtr manufacturer. You know - the only one that is left. The one we both don't like. That there is hanging the hat on a mighty weak hat hanger IMO.


For the record - Our electric racing "Guidelines" are called IMPBA D4 P-Limited Super Stock. PLSS for short.

[T.S.Davis]

.....me and NAMBA?

Okay Doug. I guess we're done having intelligent conversations.

It's probably time for you to accept that the reason you can't get FE to expand in your parts isn't the boats.

[Doby]

Group hug time...

[DPeterson]

FYI - post 31 was to give Dan some more background into what and why IMPBA D4 is doing what we are doing. Dan runs in D4. Tried doing this while still aiming to stay on thread topic - motor mass versus heat control. Because my old club and now my new club started out using NAMBA rules it is hard to reference motors issues without the controversy.

If it wasn't for all the communications I have received through e-mail, phone calls, PM's and the TP motor orders supporting addressing the multiple motor vendor issue for P-Limited from all across the country I would keep my threads in the designated IMPBA section. Turns out the desire to improve upon the motor option is widely across both associations. So no choice for now.

I will pledge to keep the name NAMBA out of any future postings. It would be most appreciated if my postings would no longer be attacked.

Thanks - Doug

[keithbradley]

The outer can diameter or length can be misleading. It's the actual core that matters. More copper, more mass, better heat capacity, improved efficiency, etc.

^^^This is a solid piece of advice that gets missed by a lot of people.^^^ There's usually more credence in comparing the weight of two motors than there is in comparing size.

Doug I run 2260s in 8s and 10s boats. It's interesting to see you're running 4s with these!

[T.S.Davis]

P-Limited from all across the country I would keep my threads in the designated IMPBA section.

You should probably keep it in the D4 section since there is no IMPBA P Limited. Never has been. That's kind of a burden lifted. You can do anything you want since nobody has put any effort into defining it in that organization. I know some IMPBA pockets run it but they pull the rules from an illegitimate member driven organization that shall not be named.

I know I'm wasting my time since you don't respond to any of my questions anymore.

Why include the Aquacraft and Proboat motors in your spec if there is no existing rule set to concern yourself with? Make it a one motor class like the old LSH rules and be done with it. You achieve multiple desires. Reliable motors and AQ out of racing.

[DPeterson]

Really Terry. I pledged to stop posting anything on NAMBA and asked that my postings no longer be attacked. My goodness man. I am going to respond to you one more time and then I am going to figure out how to put you on my ignore list.

To understand what we are doing in D4 go back and read our 2015 Electric Guidelines. It is self explanatory.

If and when the IMPBA members feel the need to have P-Limited rules written in a formal rule book we'll figure it out. I can tell you that if I am involved the rules will not be based on unstable manufacturers and artificial numbers printed in their motor specifications. And if we decide to host a large electric race (I see no value in calling it a Nationals) it will not be a 5 day race covering 30 classes so 6 guy's can compete for a high point award while the rest of us running 6 classes can sit a watch. Oh - and spec classes will never run for records in IMPBA.

Ask me a question that does not involve dragging others names into our pissing match and I will answer it. This is highly unethical. I am surprised at your persistence here.

Here is an ethical question. Why are you and your club member constantly attacking my posts? What are you in fear of?

[DPeterson]

Back to topic

keithbradley - good points on the motor weight. You can clearly see this between the AQ2030 and the TP3630. There is a lot of air space in the AQ2030 versus the TP3630. Looking at the TP you wonder how they got all the wire in the can.

The 2260/5 is in my Titan 33 and was purpose built for P-Offshore. I wanted motor mass that could get me 4:00 of fast laps. After a run on a hot day I may get 100-110 degrees. My 10,000 Mah on board will be used up. My Hyperions have handled this so far. The trade off for more motor mass is weight. For me and my driving style (lack of consistent ability) weight is my friend.

Doug

[photohoward1]

^^^This is a solid piece of advice that gets missed by a lot of people.^^^ There's usually more credence in comparing the weight of two motors than there is in comparing size.

Doug I run 2260s in 8s and 10s boats. It's interesting to see you're running 4s with these!

Keith. I am in the same mind set as Doug. One thing to remember is we set-up our boats for Oval not SAW. They run from 2- 4 minutes all out. I may be off here but there is a difference in Oval and SAW when it comes to can size. Oval we like more mass to dissipate heat. SAW from my observations like high RPM. so smaller can size and low winds.

[photohoward1]

My 8s and 10s boats run 3040, 3060 and 3080 motors.

[ray schrauwen]

When you compare a NEU to A TP you can definitely see the difference in weight for the same can size and or similar winding length and stator length. Neu, Lehenr and some others just have the ability and want to do it better and you pay for that difference.

TP did do an incredible job on the one motor they made me for my Q-Sport. It's a one off though.

[T.S.Davis]

Here is an ethical question. Why are you and your club member constantly attacking my posts? What are you in fear of?

You make statements and/or implications that have no merit.

Examples:
NAMBA chose RTR motors. There were more than 2 clubs running the spec. Yourself included. It was run for multiple seasons before anyone even talked about making rules for it. AZ, MI, CA, CO, FL, WA, WI, OH, NJ and parts of Canada were running limited pretty close to what was proposed. Again, I know this because I looked into it. But your take on it is that Dave and I had the numbers and rammed it through. Didn't and doesn't happen that way but you typed that and if not disputed someone will just assume it must be correct.
A couple dozen runs on ice cold water is not "on water" testing. It certainly isn't enough to form a rule set. I can know this because I've formed rule sets umpteen times. That's not a discredit of your findings. It's just not enough findings.
This whole thread......a bigger motor with the same kv makes less heat. Well duh. Provided the space inside the motor is used for parts and not just air this is always true.

You and at least one of your club mates accused Dave and I of writing rules to protect racers on the west coast. More recently you've accused me personally of forming my opinions and protecting the rules based on loyalty to my sponsors. Neither of which is true and borders on slander. So you've assaulted my reputation and my integrity. Your the smartest guy in the room Doug, any idea why I might be watching for more BS from you?

What is true, is that I've spent 10 plus years helping promote FE in it's various incarnations. From 6 cell Nicd to Lipo spec. Been through it all. With that experience I can tell you that what you're doing will further divide FE into smaller pieces. That alone all by it's onsey is my fear. Nothing else. Getting people together to race is the ONLY thing that matters to me. It's the only thing that's ever mattered to me. If you knew me at all (I thought you did) you would know that to be the truth.

By all means, put me on your ignore list. I'll do the same for you. You're welcome.

[LuckyDuc]

Reading all of this makes me feel like a kid watching his parents go through a divorce

[keithbradley]

Keith. I am in the same mind set as Doug. One thing to remember is we set-up our boats for Oval not SAW. They run from 2- 4 minutes all out. I may be off here but there is a difference in Oval and SAW when it comes to can size. Oval we like more mass to dissipate heat. SAW from my observations like high RPM. so smaller can size and low winds.

Just to clarify, I wasn't implying that doug was doing anything wrong, just agreeing with him that he is indeed using large motors that are capable of far more than he demands, and I believe that is his intention.

I don't really agree with the assessment of SAW vs. oval, but either way I didn't mean to imply disagreement, just adding to the conversation.
For the record, I run all out too. Outside of sanctioned SAW events, I run hard. I'm not a one pass and bring it in guy.

[T.S.Davis]

For the record too, TP makes a great motor. Especially for the price.

Sean, sorry man. Feels that way too. Only one of us wont be moving into a van down by the river.

You know where we live. Stop by any time.

[DPeterson]

Interesting comparisons between SAW and OVAL. I too would lean toward small can high rpm for SAW and large can normal rpm for OVAL. I own a German SAW record and a US OVAL record. Both in the days of NIMH's. In those days the heat issue was with cells. Cooked a bran new expensive 12 cell nimh pack getting the OVAL record. Not much heat in the motor. Along came 2P Lipo and the heat instantly went towards the motor and esc. Had a couple multi thousand dollar days learning this.

Also interesting is that there is widespread knowledge that exists in the Hobby to control heat and or premature melt down of a motor and we don't utilize it.

Doug

[keithbradley]

My 8s and 10s boats run 3040, 3060 and 3080 motors.

That's not unreasonable, although I can't think of many situations where I would run a 3080 on 8s...doesn't mean it's not right for you, I just can't think of any application I would use it in. I set up my 73" 50lb Mystic with twin 3080s on 14s and if anything the 3080s were overkill, but an awesome display of power nonetheless.

It should be noted that I run almost exclusively twin powered boats. When I said I use 2260s in some 8-10s boats, this would only be for certain applications. I WOULD run one in a (smaller) 8-10s single motor boat too (If I for some reason wanted to build a single), but not in something large/heavy/wet. For example, the big, wide 40 something inch cats you guys would run in T-cat require a good amount of power to move and I wouldn't choose a single 2260 in one of those. My HPR 135 was I think an easier hull to push and I ran twin 3040s in that, although twin 2260s would be quite capable also.

So, I totally understand why you would run a 30 series motor in many HV applications.

[keithbradley]

Interesting comparisons between SAW and OVAL. I too would lean toward small can high rpm for SAW and large can normal rpm for OVAL. I own a German SAW record and a US OVAL record. Both in the days of NIMH's. In those days the heat issue was with cells. Cooked a bran new expensive 12 cell nimh pack getting the OVAL record. Not much heat in the motor. Along came 2P Lipo and the heat instantly went towards the motor and esc. Had a couple multi thousand dollar days learning this.

Also interesting is that there is widespread knowledge that exists in the Hobby to control heat and or premature melt down of a motor and we don't utilize it.

Doug

I understand your logic in using a larger motor than needed for oval, but I don't see what is to be gained by using a smaller can for a SAW application. Perhaps you won't see the same cumulative heat build up because runs are short, but you will see heat generated much faster, and in an overloaded motor current spikes possibly much higher than a proper motor would produce. In experimental setups I've seen well over 1000A spikes on MGM logs. These are very short spikes that occur between the poles when a motor is overloaded; short enough that most logging ESCs and loggers don't even pick them up. They are, however, still quite potentially damaging to both the motor and ESC.

It's almost an absolute that a SAW boat will run comparatively higher RPM, but again I don't see why this would lead you to run a smaller, less powerful motor. If anything I would suggest a larger motor as power demands will be substantially higher.

FYI... If you don't agree, that's fine; I'm interested in hearing why. I enjoy intelligent discussion and think everyone usually benefits from it.

**Also, I think the motor you choose has a noteworthy effect on the longevity of your ESC as well. There is a significant difference between running a 2-pole Lehner motor and a 4-6 pole TP motor, for example.

[Peter A]

**Also, I think the motor you choose has a noteworthy effect on the longevity of your ESC as well. There is a significant difference between running a 2-pole Lehner motor and a 4-6 pole TP motor, for example.

Can you explain, simply due to my lack of knowing here. Are you saying that 2 pole motors are better on esc's than 4 or 6, or Lehners generally and why?

[photohoward1]

Keith would you agree that 2 pole Motors are easier on the controllers?

[keithbradley]

Yes. I think a large portion of ESC failures with 4 pole/6 pole motors are a result of stress from inaccurate commutating due to weak BEMF and/or higher frequency.

[keithbradley]

Keith would you agree that 2 pole Motors are easier on the controllers?

I would agree that Lehner 2 pole motors are.
Feigao is however not on my friends list.

[ray schrauwen]

I would agree that Lehner 2 pole motors are.
Feigao is however not on my friends list.

You got burned by a Feigao huh? Or the Feigao got burned...

Did you put a pair in one of those little twin cats or something? I'm curious on this...

Hacker USA is gone, they were nice but, quite the price jump from Feigao. Might as well go Lehner then.

I forgot over time that 2 pole motors are easier on esc's. I got all goofy when all the cheap 4 pole motors came out.

[DPeterson]

Keith - The preference for a small can for saws would only be an assumption on my part today. I have put zero thought into it. I guess maybe because of the weight savings?

I took all my Lehners out of storage yesterday to look at them again. I miss them. Can't believe I am even remotely involved in those other ones.

It looks to me that any and all of the lower cost 4 poles are way better quality than any of the 6 poles. Is there such a thing as a 2 pole low cost motor?

I always wondered about the relationship between esc's and the various motor poles. More info here would be most beneficial.

Doug

[ray schrauwen]

1. It looks to me that any and all of the lower cost 4 poles are way better quality than any of the 6 poles. 2. Is there such a thing as a 2 pole low cost motor?


Doug

1. TFL makes a 6 pole motor. Are they not close to TP Power quality? I ran an SSS in my 40" mono and it never broke a sweat for 3rd in Q-mono and Q-offshore. Steve sold out dang quick on the SSS 4074 2200kv 6 pole motors....??

2. Cheapada chepo right here: http://www.hobbyking.com/hobbyking/s...er_2200kv.html

[Darin Jordan]

If you start mixing pole count, you might as well bag it and just run P... Definitely no longer "Limited".

And, just to be realistic about things, you've already created a one motor spec class. By your own admission and "on water testing", plus my own experience with FE motors, the current motors have been made obsolete with this new motor choice.

Might want to just keep it at the TP motor for now.

[ray schrauwen]

Lets just see what happens in the middle of summer. Heat does strange things...

If you start mixing pole count, you might as well bag it and just run P... Definitely no longer "Limited".

And, just to be realistic about things, you've already created a one motor spec class. By your own admission and "on water testing", plus my own experience with FE motors, the current motors have been made obsolete with this new motor choice.

Might want to just keep it at the TP motor for now.

[Jeff]

If you start mixing pole count, you might as well bag it and just run P... Definitely no longer "Limited".

And, just to be realistic about things, you've already created a one motor spec class. By your own admission and "on water testing", plus my own experience with FE motors, the current motors have been made obsolete with this new motor choice.

Might want to just keep it at the TP motor for now.

And yet another thread derailer. Thread is motor heat not spec motor rules. There is already a thread about that.

What is it with you guy's lately?