Jourduson

I have a Turbo Optima which I built up as a Javelin, an Ultima and a Tomahawk along side of a BBX, a Buggy Champ, a Fighting Buggy, a Wild One, a DT-03, and a RTR Sand Master for the Kids. All are runners. Now concerning my maintenance experience after running on dirt, gravel, sand I've found that these following three are easiest to clean and check for wear, damage and then servicing: Top of the list is the Tomahawk. Because there is no tray or protection whatsoever very little grub gets caught up. A vacuum cleaner and brush do the trick. Second the Buggy Champ, whereas I have not tried to make the box water tight, just dust tight. Third place the Fighting Buggy. All others have some sort of tray construction and collect stones and crud like dump trucks. I'm still shaking out little stones days later after the clean up and checkup/ servicing. With the Turbo Optima/Javelin I did some trial runs without the aluminium under guard and had much less to clean up afterwards, although then the lower belt box is not protected. My conclusion, the leaner and more open the chassis the easier the maintenance.

I think I've found a site that clears away the fog surrounding brushless motors and torque for me. Very nerdy in depth information without mentioning a brand or manufacturer. Some of you may already know about it, although it's mainly about planes and boats. It's homepage is: RadioControlInfo Yes, I'm a 69yo nerd who still uses a slide rule calculator with pencil and paper at times. Cheers!

Where are those independent testers. Most reviews on rc cars and accessories is pure advertisment.

True. That's why one would have to define the standard parameters of the test and test all motors the same way to make the results comparable. Just like the AES standards for measuring and testing audio equipment.

Thanks for the info. Perfect! All the important specs in one glance with the curves displayed. Note the torque/rpm curve. Define voltage, define rpm range, measure ampere across that rpm range and you would get the same kind of torque curve with a brushless motor without load. Now define a mechanical load with the same measurment procedure and then compare curves. The closer to one another the better. The 3650 looks as if it could be a hobbywing.

With brushed and brushless motors the choice is either speed (low turn no.) or power in the low rpm (high turn no) and everything in-between. So, whatever I'm building I make my choice. Two motors with the same torque but different rpm means, that the motor with the higher rpm usually is, but not in every last case, of better quality. Torque along with the efficiency in % says a lot about what is going on within the magnetic field (magnet strength, winding geometry and density, gap size). And every motor has a maximum torque, be it brushed or brushless like in the afore mentioned comment to Wooders28 with the Xerun V10. The data just has to be made public. I just wonder how many more motors than necessary have been sold because the customer bought two or more motors due to hype, insufficient or false data, until he or she had the right one for the build project.

Here is a calculation I did when a manufacturer publishes all necessary information except for torque using the link you supplied. It's not very polite to think your customers wouldn't be interested in the data.

Thanks for the information. Since I've only been using HobbyWing I knew about the the three phase rectangular puls modulation, yet they also claim that when you use a fully sensored motor/ESC system, they also include the rpm into the calculation in the algorithms.

The way I understand it, and please correct me if I'm wrong, is, given the brushless motor and the ESC are compatible, the torque is variable depending on the power requirement at any given rpm. The ESC will try to hold rpm according to the load, like going uphill for instance, by delivering more amps thus increasing the strength of the magnetic field. The result being more torque. This would explain, in my mind, the 'missing torque' with brushless motors. The same goes for the momentary battery voltage. The ESC acts as a voltage stabiliser to the motor (brushed and brushless) down to a certain voltage, so that the useful time of driving without too much loss is longer than when we had speed boxes with stepped resistors. If anybody knows more on what I've just written, he or she is very much welcome to correct and/or add to the subject.

High Kv, low turn count says nothing about the actual torque the motor is capable of.

Lego motors were never tunable, but the older ones had much more clout and no protective circuits. Now, due to third party damage regulations for toys, the present motors have at least a thermal resistor in them. After a couple of minutes the motor slows down. There are manufacturers like BuWizz that offer complete rc solutions for Lego. I have a small collection of old not 'castrated' motors for my Lego MOCs. 😁

It looks as if Tamiya is overachieving its specs to be on the safe side. I would like to see the numbers of brushed 540 motors produced, it must be phenomenal. When looking at the silver can I can just envision the raw sheet of steel being cut, the axel wire coming off the coil for straightening, cutting, first heating, second straightening, polishing ......

Hi alvinlwh Here's a link I found that might interest you. https://ibtinc.com/difference-between-brushed-brushless-motors/#:~:text=significantly better performance.-,Torque,torque versus brushed motor torque. Cheers!

That's exactly the point. The data is here to help one make a short list what motors might work with a specific car and what one wants to achieve. In the end it's personal preferences and gearing possibilities that make the decision. I decide on brushed or brushless depending on the buggy and what I want to achieve. My DT-03, Buggy Champ and Fighting Buggy are brushed because I wanted to keep them simple and fun. The SandMaster 2.0 is for the girls to play with: 1060 with Sport Tuned on Nimh. Whereas I went all out on my BBX, Ultima, and Optima Turbo/Javelin with Hobbywing brushless combos, and all three can handle the power. The Tomahawk is also a HobbyWing brushless combo, but less Kv. Because HobbyWing are generous with the data and the quality seems to be good, my begginer instincts went with them. Also they have ESCs and motors which the wiring can be individually soldered/taylored.

I truly admire the work and effort you put in to those listings. I suspect that torque is not specified for brushless motors, because of the close interaction with the ESC, especially when sensored. All depending on the type of ESC and it's settings the torque becomes a variable. One would have to set a testing standard with fixed parameters for comparability.