Clugh

Do u see the pm loss difference betweenthe two? This is hardly exhausted because there are none wound there. Execution is the key.

Clugh

...

Clugh

Lets look at the degradation of the magnetic field as a function of temperature.

But first consider the geometry used in these test results

Grade 45M Cylindrical Neo magnet
0.500″ OD x 0.500″ thick (M)
Work-piece 3/8″ thick 1018 mild steel
0.005″ gap between the magnet and work-piece


~ chart courtesy of Dura Magnetics~

So Stefan we see here the attractive force of the magnet, is proportional to 2 times the degradation of the Residual Induction (Br). This is a good first order estimate and it can be used, but should be validated empirically.

• Even though a selected grade of magnet does not experience an irreversible loss (i.e. permanent demagnetization) when heated up, it will still lose net magnetic field.

• For recoverable losses due to heating, a magnet will recover when cooled back down.

• Even though a magnet did not experience an irrecoverable loss, the recoverable loss may be such that the magnet fails to deliver adequate field at an elevated operating temperature.

• The Residual Induction Temperature Coefficient α (Br) can be used to estimate the degradation of the Br for a specified temperature range.

• The resulting percent decrease in attractive force or net field is proportional to 2 times the percent degradation of the Residual Induction (Br).

• Selecting a higher heat tolerance grade may not solve the problem of reversible field losses due to heat. A higher heat tolerance will mean that the magnet will not experience an irreversible loss at higher temperatures. This does not mean the percent loss of Br per degree C will be improved to the point the magnet will be successful in the application. The solution may be in the magnetic geometry design or changing alloys.

You see the magnetic field is a descending line as a function of the magnets temperature to demag. Are you sure this wind that drastically reduces this heat in the magnets does nothing you could feel. From here it should be apparent that the Energy Density (Grade) drops considerably as the magnet is heated up. The grade 45 essentially becomes a grade 38.7. This loss is reversible and the magnet will recover, but the application may be in jeopardy as the net field of the magnet degrades. What else is apparent is the magnet loses a full two pounds of attracting force when going from 20°C to 100°C.

So are you positively sure this wind that reduces the magnets temperature dramatically isn't something you could feel ? And how do you know what the next pilot would feel anyway since we are all unique in our sensory perception etc. Id think such a drastic reduction in magnetic pull definitely feel-able with good hands what do you think ?


The sun sets in the west and I'm done here for the evening.
Goodnight
Hubert

Clugh

ABB US corporate research center AKA NC state D.E.E.C.S.Tested this and in their test this was their conclusion.

The designed machine with their version of the shifted winding sets shows 1.25% increment in average torque, with 1.6% torque ripple, and 1.1% THD compared to conventional FSCW (torque ripple 5.3% and THD of 4.6%). The simultaneous cancellation of sub and super harmonics increases the power factor of the machine by 7% and improves the core loss performance by 15% compared to the DL FSCW. Most of the reported works on harmonic reduction can only reduce one particular harmonics with a sacrifice or no improvement in the average torque. However, the proposed concept has the advantage of cancelling most of the unwanted harmonics without sacrificing torque density of the machine. Torque ripple and THD reduction without pole shaping or skewing further reduces the manufacturing complexity. The proposed concept is equally applicable to reluctance machines and induction machines with either concentrated or distributed wound stator. Future work from this research will include experimental results.

Clugh

And again you can protect the pm and lower load amperage with semi metalic magnetic slot wedges. These questions have been answered long ago. It's only new to hobby.

Clugh

Micheal
Aloys is quite capable and can wind you the hybrid. He has the scribes from me. Including the 4 layer 12N10P . I still think a UETW cut with Delta LRK is worth the effort.

Clugh

I think Pavel Kirienko CEO of Zubax drives explains it all very well. Ralph is centered around resistance measurements od large wire but inductance is the key. What Pavel tells the modeler is that reliable and efficient operation of a sensor less drive is critically dependent on the correct modeling of the motor by the inverter. In Ralph case the motors are either known with a large degree of uncertainty or are not known at all. This would be dependent upon him but he only seems focused on resistance. For the YGE the most critical motor parameters are its phase resistance, direct/quadrature inductance , and the magnetic flux linkage. While the phase resistance and flux linkage are important they are fairly simple to measure automatically so from the standpoint of drive tuning they pose little interest while the d an q axis inductances can get complicated. In telega motor control the inductance is used in 2 key components: the motor state estimator and phase current controllers. The state estimator uses a variation of the standard PMSM model . It is usually expressed in the dq rotating frame. The thing to note is that the influence of inductance on the behavior of the motor is proportional to the current or its time gradient. Pavel knows the first piece of evidence that your inductance settings are incorrect is that the drive is stable under low load but exhibits issues such as stalling or high reactive power when q axis inductance is greater than zero or when the load is changed abruptly. What they call sync loss is a poorly tuned or inadequate inverter. The band width ratio is set incorrectly.

The bandwidth ratio is the d and q axis controller bandwidth to its update frequency which often equals the pwm frequency.

Ralph needs an LCR meter to determine his direct and quadrature inductaces in a rotating frame an tune his inverter correctly if possible. His options are the pwm settings line voltage and the current ramp.

Chris see how the UETW SL optimization works its way into this discussion ?

Regards
Hubert

Clugh

Ralph needs to measure the inductances himself. He has to rotate the motor very slowly and record the maximum and minimum inductance values. Pavel says he can excite the circuit at 1 kHz at 1 volt.

Clugh

Clugh

Clugh

Clugh

Hi Michael
Remmsemmel says that I cannot fly so for his type of test benches Im looking here. RC Planes aren't my main hobby but Ill buy and fly one if it pleases him.. This one I figure with low power would be more forgiving. For higher power in the bullish Im looking at a Cobra for a custom winding. Its 12N14P . In a dual layer Id simply wind the yy-Δ hybrid it should boost its torque output from the standard dual layer 2 or 3% but It will improve the power factor. I also have a pilot that can elevate my motors. This looks like a great beginners plane for state siders at 400 euros.

Clugh

Clugh

Clugh

Clugh

Clugh

Clugh

The audino like enviroment can use a FlexForce sensor for the load cell which will calibrate and measue up to 25 pounds. which is more than enough for something like this. With the 6 inch arm on center it should measure 12.5 ft pounds or 16.947724354 Nm. Thats good. Ill redo the arm in carbon fiber composite. Ill probably use the Parallax Prop chip for this project although basic stamp has basic plot. The basic code is here in the PDF. You don't have to have superior intellect. Just common sense and a little patience.

https://www.parallax.com/package/fle...kit-downloads/

Clugh

Clugh

Hallo Micheal,
Der Drehmomentarm kommt zusammen. Ich mache dieses, um mit dem Druckband zu arbeiten, aber ich habe eine TEDS-fähige Wägezelle gefunden. Ich kann das Joch und einen Achor dafür nachdrucken.Drucken Sie jetzt einfach die Halterung und eine Buchse aus, um den Kolben für den Druckschalter zu umschließen.

@ Ralph
Hi...

Danke,
Hubert

Clugh

Clugh

Wir sehen uns in 13 Stunden. Auf keinen Fall werden Sie alle Teile, die wir an einem Tag hergestellt haben, aus Aluminium einrichten und bearbeiten. Dies ist die Küchenlaborherstellung, die Modellbauern heute zur Verfügung steht. Carbon X kann eine Nylon-Kohlefaserqualität drucken, die so stark wie Metall ist, und kann auch Metall aus Ihren Dateien drucken. Aloys kann es aus den bedruckten Wachsstücken gießen und auf
seiner manuellen Ausrüstung veredeln. Ich habe eine sehr leistungsfähige Drehbank für diese Art von Dingen. Ich bin froh, dass ich es noch nicht benutzen musste. Ich werde es bald tun.Regards,
Hubert

Clugh

Clugh

The "scorpion knockers" | Page 9 | RC-Network.de

The "scorpion knockers" | Page 9 | RC-Network.de

"@FamZim Maybe there is already an "IEEE paper" for exactly the effect you described, with which your friend Hubert can help you!

Otherwise, as always: just try it out!
_____



My last (try-out) engine for 2022 is also ready and was measured in the "currently usual way".
It is a 12N10P HK4225 made of kit parts from Scorpion, wound with 6 turns 2.0mm wire, executed in single layer (PLC) and DD interconnected for approx. 2000/V. Whether this is now again a real scorpion "knocker", everyone can decide for themselves.

I see it as a pure feasibility study - practically it is definitely completely useless for me.
~powercroco~

Hi Ralph from this I know you are here.
Im glad that my forges spark your interest but their cuts are completely wrong for 2023 and in your case still also the Kv is still wrong.with less copper in the slot. I though you wer going to wind an align The winds you and audiosmith are on are good LRK's but the stators are surely exhausted as anything new or powerful. How could it be useless Michael? You could mount a reactionary torque mount in the nose of the plane and log it. He's crazy because knowing that and having a Gya-553 might help with high torque roll launches and moment of inertia..The new cuts increase the wind factor to 1. Thats a 7% increase in torque over your machine. Go bact to the flusperren which is a 14 poler. That seems to be the choice of drone racers 14 poles.

Why didn't you copy Torro's wind? So does "measured in the usual way" meanm no constant report.again? Plenty of loss with that one huh? The shorter stack make the tall windings heads mean more.

Danke,
Hubert

Clugh