Motor RPM ???
10-06-2003, 07:21 PM
#31
on another side note, have you guys ever seen a machine spool thread?
Go pick some up and check it out, pretty neat for an in-accurate machine, and I would doubt if a machine built in the 80's did the same thing.
Go pick some up and check it out, pretty neat for an in-accurate machine, and I would doubt if a machine built in the 80's did the same thing.
10-06-2003, 07:23 PM
#32
Originally posted by sean
no ones whining about motors-just discussing a point yes- i am aware that smoe motors have adjustable timing. my question is of manufacturing standards. Losirob i realize my last post may have sounded a little harsh-no dis intended. the motor thing is trivial- but to say that if i plug my motor into one dyno and get a set of torque and rpm numbers and then plug the exact same motor into a different dyno and get different numbers,well that IS a problem.
no ones whining about motors-just discussing a point yes- i am aware that smoe motors have adjustable timing. my question is of manufacturing standards. Losirob i realize my last post may have sounded a little harsh-no dis intended. the motor thing is trivial- but to say that if i plug my motor into one dyno and get a set of torque and rpm numbers and then plug the exact same motor into a different dyno and get different numbers,well that IS a problem.
since they dont have any standards to comply with, I will just have it run off some html, java script magic 8 ball core engine.
that way it will just spit out random numbers with the rest of them.
anyone interested ? $300 + tax please
10-06-2003, 07:30 PM
#33
A machine winding a simple spool is an awful lot simpler action than winding an armature.
What do you guys expect from a cheap motor? The simple fact is, precision costs big bucks.
What do you guys expect from a cheap motor? The simple fact is, precision costs big bucks.
10-06-2003, 09:01 PM
#34
Nah, you didn't say anything that bothered me.
I do think it's naive to think that every motor should be be the same (or VERY close.) It doesn't happen in full sized cars and it doesn't happen in R/C either. I'd bet money, that if you took identical cars (anything, let's say a Honda Civic) and put it on a dyno, and then a different dyno, you would not get identical readings. Nor, would you get identical readings if you took 2 different cars of the same make and model to the same dyno.
Different dyno's use different equipment to get their readings. The Fantom dyno uses a flywheel while the CE, if I recall correctly, uses a slave motor. Those are going to produce different results. The difference in equipment is what causes the different results, not adding 2+2.
The issue, I think, is "relative closeness." How close can you get 2 manufactured motors to be? Unfortunately, there are too many variables for that to be realistic or economical, especially in a mass production situation. If the comm segments are unequal, the armature is out of balance, the magnets are misaligned, magnets are somehow damaged during manufacturing, brushes are never the same, is the soldering joint good or bad, etc... ALL of these things come into play when determining how a motor will perform.
Besides, it takes TIME to dyno each and every one of those motors. Time costs money. Ever wonder why matched batteries are so much more expensive than loose cells? It's because of the time and effort it takes to zap, cycle, and Turbomatch (or Lavco) those things.
Likewise with motors. Part of the reason those motors are so cheap, is because there's NOT an ultra-high level of quality control.
This discussion reminds me of the old saying, "There's correct, fast, and cheap. You can have any two of those qualities, but not all three."
Just my two cents.
Rob
I do think it's naive to think that every motor should be be the same (or VERY close.) It doesn't happen in full sized cars and it doesn't happen in R/C either. I'd bet money, that if you took identical cars (anything, let's say a Honda Civic) and put it on a dyno, and then a different dyno, you would not get identical readings. Nor, would you get identical readings if you took 2 different cars of the same make and model to the same dyno.
Different dyno's use different equipment to get their readings. The Fantom dyno uses a flywheel while the CE, if I recall correctly, uses a slave motor. Those are going to produce different results. The difference in equipment is what causes the different results, not adding 2+2.
The issue, I think, is "relative closeness." How close can you get 2 manufactured motors to be? Unfortunately, there are too many variables for that to be realistic or economical, especially in a mass production situation. If the comm segments are unequal, the armature is out of balance, the magnets are misaligned, magnets are somehow damaged during manufacturing, brushes are never the same, is the soldering joint good or bad, etc... ALL of these things come into play when determining how a motor will perform.
Besides, it takes TIME to dyno each and every one of those motors. Time costs money. Ever wonder why matched batteries are so much more expensive than loose cells? It's because of the time and effort it takes to zap, cycle, and Turbomatch (or Lavco) those things.
Likewise with motors. Part of the reason those motors are so cheap, is because there's NOT an ultra-high level of quality control.
This discussion reminds me of the old saying, "There's correct, fast, and cheap. You can have any two of those qualities, but not all three."
Just my two cents.
Rob
10-06-2003, 09:16 PM
#35
Originally posted by losirob
Nah, you didn't say anything that bothered me.
I do think it's naive to think that every motor should be be the same (or VERY close.) It doesn't happen in full sized cars and it doesn't happen in R/C either. I'd bet money, that if you took identical cars (anything, let's say a Honda Civic) and put it on a dyno, and then a different dyno, you would not get identical readings. Nor, would you get identical readings if you took 2 different cars of the same make and model to the same dyno.
Nah, you didn't say anything that bothered me.
I do think it's naive to think that every motor should be be the same (or VERY close.) It doesn't happen in full sized cars and it doesn't happen in R/C either. I'd bet money, that if you took identical cars (anything, let's say a Honda Civic) and put it on a dyno, and then a different dyno, you would not get identical readings. Nor, would you get identical readings if you took 2 different cars of the same make and model to the same dyno.
10-06-2003, 09:19 PM
#36
Originally posted by losirob
Likewise with motors. Part of the reason those motors are so cheap, is because there's NOT an ultra-high level of quality control.
This discussion reminds me of the old saying, "There's correct, fast, and cheap. You can have any two of those qualities, but not all three."
Just my two cents.
Rob
Likewise with motors. Part of the reason those motors are so cheap, is because there's NOT an ultra-high level of quality control.
This discussion reminds me of the old saying, "There's correct, fast, and cheap. You can have any two of those qualities, but not all three."
Just my two cents.
Rob
I was just using the rush as an example
whats the rpm on a D5 7 turn single or 15 turn double ?
a D5 is far from a cheap motor
10-06-2003, 11:42 PM
#37
I'd forget about trying to get them to undersdtand, Rob, we've already said it SEVERAL times, & it obviously hasn't sunk in, though I will add this....there is yet another factor that changes the performance of a motor & that's the LOAD being placed on it. You can bet that a motor that can hit 50,000rpm on a dyno(which is free-spinning rpm), will definitely NOT do that in a car on the ground. And how much of that fre-spinning rpm it can achive unde load depends on all those little factors we've already mentioned several times. About machine-wound motors, well, the fact is that the manufacturers aren't setting their winders up to be that accurate, they're setting them up to do it FAST, & while once in a great while that can produce a strong armature, that probably happens less than 1% of the time. That's why when I explain about different levels of stock motors to people I put it this way: because they're mass-produced as quickly as possible, there's ALWAYS a good number of motors that will be average, a few that are real gems, & some that are pure poop( believe me, a dog is a dog, & I've seen some real woofers that even a Mabuchi 540 motor could outrun). If you really think it should be that easy to make motors that consistent from one to another, then go build some motors & prove us all wrong....
10-07-2003, 08:22 AM
#38
no, i understand what your saying and i have learned alot from this thread, i am not arguing for the sake of being a jerk. i just like to see all sides of an issue. that makes sense-setting the machines to be fast,not accurate. i think it sucks, but i understand it. and like i said before i dont use those bargain motors myself, but i dont think its right that young kids and people who dont have much money cant get a decent motor because you have to pay that much for consistancy.but,it is what is. once again it all comes down to $$
10-07-2003, 08:33 AM
#39
It's the same in full sized autos as well. You've got cheap carburetors, and you've got performance carbs. Both will make your car go, but if you want your car to go as fast as it can, it costs money.
"Speed costs money. How fast do you want to go?"
Rob
"Speed costs money. How fast do you want to go?"
Rob
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