NAMBA's P Limited Rules.

[longballlumber]

I am just going to leave this here... It speaks volumes about length. The majority (not all, but most) are still racing competitively with the AquaCraft, Proboat, and ProMarine motors.

IMPBA Spec Motor Chart 2019-09-25.pdf

[HTVboats]

If the Records are any indication the S records are actually faster than the T records in six out of the ten records for SAW and 1/3rd oval for the five hull classes. Where the T classes are higher it is only by a very small margin (except T Mono SAW which Doug Smock put way up there).

https://nebula.wsimg.com/b0c815733fd8425ff24b779cff59f4a1?AccessKeyId=ACA7381D2BFC72351748&disposition=0&alloworigin=1

Is there really THAT much difference between 7/8 cell and 9/10 cell to warrant another 15 record classes? Wouldn't a 7-10 cell class do?

Why was FE 1/8 Scale brought in as S/T?

Yes there is a power difference between 8 and 10 cells (S & T) I can only speak for CAT ,OB and Mono where I have built record boats. When we run T, the limit of our times is the boat design that can't handle the power. A hull can only corner so fast and adding power may loose time in turns. When I started records for Cats the Q SAW was a hundred plus and the 2 lap 32 seconds. Now my Q Cat won't run 75mph but will run a 24 second two lap. Look at the SAW records and power will show speed differences.
Don is correct so few run records and there are classes that will never run in heats anywhere. Does it hurt anyone to have classes in the book? Should I never build a steam powered boat cause it won't be in the book anymore. Those obscure records give some of us tinkerers who want a challenge a format. Remember your records are meant to be broken that's why you are only a record holder. It is a different form of competition I hope will continue as it does advance technology that we all benefit from.
Mic

[HTVboats]

In the NAMBA rules S class has an asterisk - for records only. T class legal voltage is listed from 18.5 to 42.3 which essentially is Q,S, and T combined or effectively Open. I like IMPBA for things like bouy point deductions vs. a lap penalty and as far as FE rules NAMBA has an edge. I wish either group would just recognize what makes sense and copy where it advances the sport. Both organizations have some pretty sound and experienced minds.
Mic

[Terry Keeley]

That same "logic" could be said about E and F outboard tunnels, DEAD racing classes and even national levels BUT guys still run both at trials. Apples to oranges as less than one percent do record trials anyways...........

True. There's 31 classes for records in nitro x 3 = 93 records. Half of them should be archived IMHO.

Steam? Lol! I was there when he set it in '94.

And don't get me started on 1/4 mile...

[Terry Keeley]

I am just going to leave this here... It speaks volumes about length. The majority (not all, but most) are still racing competitively with the AquaCraft, Proboat, and ProMarine motors.

[ATTACH]166564[/ATTACH]

Why the variations in length for different motors of the same make? Are they different models or variations of the same model?

[dethow]

I am just going to leave this here... It speaks volumes about length. The majority (not all, but most) are still racing competitively with the AquaCraft, Proboat, and ProMarine motors.

[ATTACH]166564[/ATTACH]

You are correct Mr. Ball... it does speak volume about lengths. It shows that manufactures have variations in what they produce.

ProMarine SSS range from 55.6mm to 60.4mm. Over the 6 motors measured, 2 or 33.3% were over 58.0mm and 1 was over 60.0mm
TP Power range from 57.5mm to 59.0mm. Over the 6 motors measured, 2 or 33.3% were over 58.0mm.

Additionally... Over the several years of racing, the motors which measure between 58mm to 60mm have shown ZERO advantage.

Additionally... The 60mm length limit leaves room for manufacturing variations and in case any future RTR boats come out with slightly larger motors. We don't want people having to play games with suppliers by returning motors until they get one that fits the 58mm limit. And we don't want to force people to pull new motors out of brand new boats when nothing has shown that the additional 2mm will provide any significant advantage.

Additionally... There are many 60mm motors in the market that were not part of this study conducted. Leopard is a prime example of this. Leopard is a very popular motor and thus the scenario could exist that we could have a recreational sport boater who is approached to come to a race at a local club. This boated has leopard motors in his 2 boats that measure 60mm and now the only reason the club can't get him to come race is because he'd have to replace his motors. Now we all know those motors will not provide any advantage and most likely if he has a good time he'll choose on his own to upgrade his motor in order to be more competitive.

This has been debated already and the majority agree with 60mm length as evidenced by comments in this thread and the NAMBA membership vote. Mr. Terry Davis started in the last debate on this with your thought process of 57mm to 58mm and by the end of the thread he had conceded that 60mm makes more sense. I'm not sure Mr. Ball... but I think you may be the only one who is looking for under 60mm length. If others exist, I haven't seen them speak up in a while.

I (we) hear your concerns and as I've said... there is no silver bullet to answer all the questions you could bring up. If one tried there could be questions posed about almost every class... For example: How do we know the mAh labels are correct on batteries and how do we measure and tech that in a consistent method? Do we not allow batteries in the boats because there is no absolute answer to that question?

[dethow]

Why the variations in length for different motors of the same make? Are they different models or variations of the same model?

EXACTLY... Terry. They are variations of the same model.
This is the exact reason the 62mm was the original thought. But that turned out to be just a tick to much and made it possible to cut down larger motors to fit the 62mm length. Reduction to 60mm removes that possibility but still leaves room for manufacturing variations.

[Steven Vaccaro]

Over the last 20 years of selling motors, Ive seen many variations in motor length, can diameter and design drive us all nuts. Manufacturers don't tell us about changes, then one day we get a new batch of motors that are different. When questioned, the manufacture says "sorry or this is a new design". There needs to be a true +/- built into the rule. But Ive never seen a motor labeled 36 diameter come in at 37mm or a motor in the 50 or 55mm length size come in at 60mm plus.

The only people that will get caught breaking the rule, will be those trying to push the limits by buying 3660 motors or similar.

[dethow]

But Ive never seen a motor labeled 36 diameter come in at 37mm or a motor in the 50 or 55mm length size come in at 60mm plus.

I'm assuming you've seen a 36mm diameter come in at 36.1 to 36.5mm thou??? Which is why it was just rounded up to an even 37mm diameter limit.

Have you seen a 50mm or 55mm length come in at 58mm to 60mm? I'd assume that number would be VERY small if at all.
But have you seen a 55mm to 58mm motor come in at 58.1mm to 60mm? I'd imagine that number would be between 33% to 50%.

[Steven Vaccaro]

I'm assuming you've seen a 36mm diameter come in at 36.1 to 36.5mm thou??? Which is why it was just rounded up to an even 37mm diameter limit.

Have you seen a 50mm or 55mm length come in at 58mm to 60mm? I'd assume that number would be VERY small if at all.
But have you seen a 55mm to 58mm motor come in at 58mm to 60mm? I'd imagine that number would be between 33% to 50%.

Ive seen all of those, that's why I like the 37 x 60mm limit.

[Terry Keeley]

Ive seen all of those, that's why I like the 37 x 60mm limit.

Sounds like you guys got it right...

[Doby]

Lets open the can even further:

Better make sure that any measuring devices are calibrated to an acceptable standard. Then the calibration would need to be maintained on a scheduled basis and records kept.

Using some cheap plastic caliper vs a decent metal one will yield different results as well.

Perhaps both NAMBA and IMPBA could supply the devices and send them for use to wherever "Nats", "Trials"..or whatever are being run.

A defined measuring procedure should be standardized as well.

If my 60mm motor is measured and found to be a "hair" over by one of the "Terrys" at an event...and I'm not allowed to race, but I measured it and the manufacturer says its 60mm... you had better have your ducks in a row to prove how and what you measure it by and with.

(P.S...not picking on the "Terrys"....but you guys are generally the organizers of the biggest events around here and therefore have to deal with any potential headaches)

Are timing devices used calibrated? If so, how?
Voltmeters? If so, how?
Are hull lengths ever verified? If so, How?
Are other hull dimensions verified? If so, How?

If people going to be held to a certain specified requirement, better be able to accurately verify it.

How something is verified is just as important as the specification.

Careful when opening the can...sometimes the worms get out and create a mess.

[Terry Keeley]

Lets open the can even further:

Better make sure that any measuring devices are calibrated to an acceptable standard. Then the calibration would need to be maintained on a scheduled basis and records kept.

Using some cheap plastic caliper vs a decent metal one will yield different results as well.

Perhaps both NAMBA and IMPBA could supply the devices and send them for use to wherever "Nats", "Trials"..or whatever are being run.

A defined measuring procedure should standardized as well.

If my 60mm motor is measured and found to be a "hair" over by one of the "Terrys" at an event...and I'm not allowed to race, but I measured it and the manufacturer says its 60mm... you had better have your ducks in a row to prove how and what you measure it by and with.

(P.S...not picking on the "Terrys"....but you guys are generally the organizers of the biggest events around here and therefore have to deal with any potential headaches)

Are timing devices used calibrated? If so, how?
Voltmeters? If so, how?
Are hull lengths ever verified? If so, How?
Are other hull dimensions verified? If so, How?

If people going to be held to a certain specified requirement, better be able to accurately verify it.

How something is verified is just as important as the specification.

Careful when opening the can...sometimes the worms get out and create a mess.

I hear what you're saying (even misspoke when I talked about needing a "calibrated gram scale" to weigh spec motors) but if the limits are set high enough that they can be teched with "average" equipment (verniers in this case) it would be easy to do. In the case of weighing motors you would need a fairly expensive gram scale to tell the difference between a stock and modified wind, impractical and unnecessary as previously mentioned.

Mike and I had this conversation. He said technically we need a calibrated scale to make sure boats were making the 30 lb. limit. My reply was that we have a cheap fish scale and if a boat is so close to the limit we can't tell if it's legal or not the onus is put on the contestant to prove THEY'RE OWN legality.

It would be the same scenario if a fuel guy had a motor that was so close to the limit you could not say for sure using a pair of verniers if it was good or not. The onus would then be on the contestant to prove they're own legality by providing bore gauges, depth mics, even a climate controlled inspection room, lol!

Toy boats remember...

[Doby]

[QUOTE=

Toy boats remember...[/QUOTE]

And thats the phrase that is all to often forgotten about.

Perhaps the sarcasm didn't come across in my post..

Like Doug Shmuck says..Toy boats fellas!

[T.S.Davis]

When we thought that 62 was THE answer a buddy made gauges for me that had a 37mm opening on one end and a 62mm opening on the other out of stainless steel plate. Cake. I know where he lives........ haha