7.4 volt 162 gram Ferrari

[LBRC]

Two lithium ion's and a couple of 10 ohm resistors to fix the steering, triple FET stacks, and away you go.

[HammerZ]

Look's like an Iwaver packing some heat.

There is a new Iwaver section over on Mini-Zracer.com , check it out.

[viperdout]

Sweet. Wanna race my brushless xmod when it's done?

[LBRC]

The Ferrari is up for sale on ebay, it¡¦s a real sweet deal. I decided to keep my original test car I've become very fond of it. It¡¦s been through so much and is still running great so I ordered it a new chassis and some other cosmetic extras. But sure it loves to race, not the fastest I¡¦ve see but it will do 50 mph (81km/h) on the old speed checker and I¡¦ve finally geared it low enough so it doesn¡¦t just sit and spin when you hit the juice to fast, the li-on¡¦s give it a lower center of gravity and better balance so it handles much like a MR-02. With a 37 or 38 turn motor and large pinion gear the Ferrari would do the same, and it weighs less at only 162 grams.

A brushless motor would be nice no/low maintenance but they¡¦re still no competition for a good old fashion custom balanced low turn hand wound, with neo magnets and good precision bearings.

I call this car the Gump, the batteries look big but their still lighter than aaa¡¦s. So even with the ball differential it still weighs in less than a stock Iwaver or Mini-Z. In this picture it has a 14 tooth pinion and 42 tooth spur gear but there was still to much torque. So I¡¦m currently using a 16 tooth pinion gear with a 40 tooth spur gear. Note the motor is safety wired on but I've ordered it a PN racing modified motor mount that should take the bigger gears and not embarrass the poor little car so much. I¡¦ve also switched back to a plastic pinion gear since the metal one was a little to hard on the spur gear. Had it for breakfast actually.

[viperdout]

Originally posted by LBRC
The Ferrari is up for sale on ebay, it¡¦s a real sweet deal. I decided to keep my original test car I've become very fond of it. It¡¦s been through so much and is still running great so I ordered it a new chassis and some other cosmetic extras. But sure it loves to race, not the fastest I¡¦ve see but it will do 50 mph (81km/h) on the old speed checker and I¡¦ve finally geared it low enough so it doesn¡¦t just sit and spin when you hit the juice to fast, the li-on¡¦s give it a lower center of gravity and better balance so it handles much like a MR-02. With a 37 or 38 turn motor and large pinion gear the Ferrari would do the same, and it weighs less at only 162 grams.

A brushless motor would be nice no/low maintenance but they¡¦re still no competition for a good old fashion custom balanced low turn hand wound, with neo magnets and good precision bearings.

I call this car the Gump, the batteries look big but their still lighter than aaa¡¦s. So even with the ball differential it still weighs in less than a stock Iwaver or Mini-Z. In this picture it has a 14 tooth pinion and 42 tooth spur gear but there was still to much torque. So I¡¦m currently using a 16 tooth pinion gear with a 40 tooth spur gear. Note the motor is safety wired on but I've ordered it a PN racing modified motor mount that should take the bigger gears and not embarrass the poor little car so much. I¡¦ve also switched back to a plastic pinion gear since the metal one was a little to hard on the spur gear. Had it for breakfast actually.

Oh really? The setup I'm getting makes a Mini-T go 40 mph on the ground, and I will eventually get the Mamba 8000, which makes a T go 60 on the ground. BTW, I have MUCH less weight and a 1:1 ratio, which means I could top 70. Let me add one more thing: you can get a very low wind brushless and smoke any brushed motor.

[LBRC]

Then I am looking forward to seeing it when you are done. I like the idea of using 4wd if you get the power you are planning on you will need it. I would like to see actual specks (i.e. rpm and motor current drain) for the Castle Creations motors I haven¡¦t seen an impressive Mini-X yet, although I¡¦ve seen a very nice DTM-X4. Good luck.

[Jshwaa]

A brushless motor would be nice no/low maintenance but they¡¦re still no competition for a good old fashion custom balanced low turn hand wound, with neo magnets and good precision bearings.

Oh yes they are. Brushless motors to brushed motors is like jet engines to propellers. The technology in a brushless is suited for way better performance than brushed. More power and less heat.

[viperdout]

I just came back from my LHS. My Mamba should be in in about a week. I got a 5400, but I might get an 8000 just to have it uncontrollable. Muhahahaha.

[LBRC]

Oh yes they are. Brushless motors to brushed motors is like jet engines to propellers. The technology in a brushless is suited for way better performance than brushed. More power and less heat.

I¡¦ve been involved in extensive testing of brushless systems for 10th scale off road applications and for the sport class they¡¦re great but in the modified they just aren¡¦t quite making the grade. I will qualify that by adding a yet. Again for the Mini-T¡¦s I haven¡¦t seen the Castle Creations but the ones I have seen are good but still not noticeably better performance wise compared to the hot modifies that some people are using, including my slightly modified Team Orion Big Block. I have some experience using brushless motors as drivers for aircraft radar and other systems and am quite familiar with how they work, their advantages, and disadvantages. I believe they have great potential however expectations sometimes have a way of exceeding actual results.

That¡¦s why I am looking forward to seeing hard results from Viperdout¡¦s project and I sincerely hope it is a smashing success. But before everyone rushes out and pay¡¦s $140 for a brushless system (not a bad price at all) thinking it is going to give them a massive competitive edge, they might want to do a little more research.

Just like your jet engine example they have advantages but a jet engine is not necessarily better than a propeller especially for smaller aircraft, you might want to visit the Reno air races for a good practical explanation.

So Jshwaa I¡¦m willing to be convinced but for me the jury¡¦s still out.

Viperdout with any luck it will come in early, can't wait to see it.

[viperdout]

Originally posted by LBRC
I¡¦ve been involved in extensive testing of brushless systems for 10th scale off road applications and for the sport class they¡¦re great but in the modified they just aren¡¦t quite making the grade. I will qualify that by adding a yet. Again for the Mini-T¡¦s I haven¡¦t seen the Castle Creations but the ones I have seen are good but still not noticeably better performance wise compared to the hot modifies that some people are using, including my slightly modified Team Orion Big Block. I have some experience using brushless motors as drivers for aircraft radar and other systems and am quite familiar with how they work, their advantages, and disadvantages. I believe they have great potential however expectations sometimes have a way of exceeding actual results.

That¡¦s why I am looking forward to seeing hard results from Viperdout¡¦s project and I sincerely hope it is a smashing success. But before everyone rushes out and pay¡¦s $140 for a brushless system (not a bad price at all) thinking it is going to give them a massive competitive edge, they might want to do a little more research.

Just like your jet engine example they have advantages but a jet engine is not necessarily better than a propeller especially for smaller aircraft, you might want to visit the Reno air races for a good practical explanation.

So Jshwaa I¡¦m willing to be convinced but for me the jury¡¦s still out.

Viperdout with any luck it will come in early, can't wait to see it.

Can your Orion Big Block make a T go 60?

[Jshwaa]

I have some experience using brushless motors as drivers for aircraft radar and other systems and am quite familiar with how they work, their advantages, and disadvantages.

Then you'd know that the only disadvantage is the extra circuitry and cost while the advantage is way more power with less heat. If anyone can deal with their space and weight constraints to be able to apply a brushless, then there isn't any reason why you shouldn't. The price is another factor, but if you're just talking technical qualities then there is no comparison. You also have to take efficiency into consideration. If both motors are given the same amount of power, the brushless is going to be able to turn more of that electrical power into mechanical power, than the non-brushless motor.

The reason for that is inherant in the design of the brushless system. All of the switching, in a brushless, is done via power transistors that are remote to the motor, whereas with a brushed motor, all of the switching is done inside the motor. The brushes create a ton of heat with the arcing of the commutation. The arcs are literally lost power. You lose power in the form of heat and light. With a brushless, there are no such losses. There is some heat, but most is due to friction and field coils getting warm from their inductance.

So the way I see it.......

Brushed motor advantages: cheap, easy to control

Brushless motor advantages: less losses to heat and light, higher efficiency, more electrical to mechanical power conversion(which is the whole point)

Brushed motor disadvantages: a lot of loss to heat and light, brushes wear

Brushless motor disadvantages: cost, extra circuitry

Bottom line....if you can afford it, go with brushless.

And LBRC.....how you like those fatty CGR17500's? They put out a ton of current don't they? Check out the xmod with 3 of them.




*Also, LBRC* With the motors you were talking about being used as drivers for radar.....those motors are probably stepper motors, which use the same principle as brushless motors, but are designed to be able to stop and go on a dime, and every degree of the motor's rotation can be controlled. Steppers are used in hard drives and disk drives as well, for their ability to index to any point at the command of the control system. Stepper motors, and brushless R/C motors are a lot different.

[viperdout]

Originally posted by LBRC
Viperdout with any luck it will come in early, can't wait to see it.

I won't be at my dad's until Saturday, so I'll be picking it up then at the earliest.

[LBRC]

Yes stepper motors, but also simple DC motors due to reliability requirements almost all electric motors used for aircraft applications have to be brushless.

The strange disadvantage for RC car brushless motor applications is actually motor control not the physical motor, you do realize that it takes just about the same amount of energy to stop or slow down a brushless motor as it does to start or speed it up, for turn on and go all out applications no problem. But fast responsive precession control and breaks take power. Admittedly this is more of a problem for the larger heavier 1/10th scale cars than smaller ones.

I like the 17500's allot that¡¦s why out of the initial two Li-Ion Iwavers I made I decided to keep my test car over the cleaner, lighter and admittedly more race friendly Ferrari with the 14430's that this post was originally about.

The motor I'm running in it needs the 17500¡¦s greater capacity, it's fun but has fewer turns than truly practical and is wound with a wire that is unfortunately not mine to talk about but I can say it's not copper, not round, and the coating is not conventional. I spent a huge amount of time balancing the armature, the commutator cost $7 plus shipping from Japan, and the ceramic bearings would sell for about $20 each, then there's the neo magnets and brushes so L.O.L. a $140 brushless set-up would be much more cost effective. Control is my real problem, I took it out to a large freshly paved parking lot today to test the 16/40 gear combination unfortunately it still has too much torque for a controlled 2WD. What I can't believe is that the circuit board hasn¡¦t started smoking yet, I did toast the on/off switch though.

p.s. Jshwaa is that a optoisolator on your external FET board, how is it working performance wise?

[Jshwaa]

Jshwaa is that a optoisolator on your external FET board, how is it working?

How is it working, as in, how does the circuit function or how is it working as in how effective?

The effectiveness is great. I can't think of many other ways to do what the opto is doing. Anyone driving their FET's with the petty signal from IC1 is defeating their purpose.

For whatever it's worth....I toasted an S03 motor's comm and brushes doing an all-wheel-drive burnout into a stationary object for a few seconds. The weak link was the brushes and comm. I need a new motor(plasma dash?) This is why the brushless seems attractive. I just have to build an xmod receiver-to- brushless interface circuit(pipe dream).

As far as HOW the opto works.....well, just lemme know if you need to know......I'll explain if I really have to, but.....long story...but it is one effective circuit. It just hammers those FET's on and off.

[LBRC]

Yes I meant performance wise for the optoisolator.

Can your Orion Big Block make a T go 60?

My guess is yes, depending on the gearing. I rewound and tuned the motor and use the 17500's Li-Ion batteries with a LRP Quantum ESC. It would be interesting to take it with me to a track that has a reliable radar gun.