Pyro 750 Comp

[Mercuriell]

Just about to put one into my TDR Speed so thought I'd have a peek inside ... Wind appears to be 4+5D 1.6

I guess it should be OK to do away with the circlip, keep the shim, as on the Scorps ?

[firemedic295]

10-4

[_Dekker]

With 1.6mm I do not get the gaps between the wires as in the picture, so I suspect it's 1.5mm wire (just short of 1.6mm OD)

[Mercuriell]

Originally Posted by _Dekker

With 1.6mm I do not get the gaps between the wires as in the picture, so I suspect it's 1.5mm wire (just short of 1.6mm OD)

You may well be correct - I tried measuring it with a vernier ! Often wondered if the OD spec refers to the bare copper or with the enamel coating - as I measured just under 1.6 I guess it refers to the uninsulated wire!

[_Dekker]

Originally Posted by Mercuriell

You may well be correct - I tried measuring it with a vernier ! Often wondered if the OD spec refers to the bare copper or with the enamel coating - as I measured just under 1.6 I guess it refers to the uninsulated wire!

Yes wire diameter is alway about the copper core diameter.
For comparison, this is the same wind with 1.6mm wire (1.68mm OD):

[belcom]

I noticed good quality wire usually adds about 0.8mm to OD of the wire. So Dekker's measurement is spot on.

[Raptorapture]

Originally Posted by belcom

I noticed good quality wire usually adds about 0.8mm to OD of the wire. So Dekker's measurement is spot on.

Thanks. Was having trouble confirming winding wire dia when measuring.

[swalko]

John, did you already tested your Pyro? I am curious about your results. I tested hand wound Pyro 750 5+5 YY 1.32 and i was not satisfied. It produced a lot more heat and power consumption was about 40% higher in a comparison to my Xera 4530. I expected same motor as Pyro 700 with higher performance, but it was not so and that Pyro 750 was noisy too.

[Vinger]

The 14 pole motors like to be Delta terminated and 1.32mm wire for your wind was way to thin, copper to stator ratio suffers and you get inefficiency like you experienced. 5 turn YY could easily be done at 1.5mm. What KV did you get?

[_Dekker]

Originally Posted by Vinger

The 14 pole motors like to be Delta terminated and 1.32mm wire for your wind was way to thin, copper to stator ratio suffers and you get inefficiency like you experienced. 5 turn YY could easily be done at 1.5mm. What KV did you get?

I don't agree. They (P750/P8xx) do do not have the Delta loop current in the amounts that other motors with delta winds show. Also the wave forms between YY and delta termination differ very little so nothing strange there.
The fill with 1.32mm (5+5) 10turns is actually 55% higher than the stock 750-45 so it should do just fine.

What esc is being used with it and with what settings?

[swalko]

It had about 560KV on Kosmik 200 in default settings.

[powercroco]

every 14P motor will generate 140% of iron losses at the same rpm compared to a 10P motor made from the same materials.

the positive effect of the lower copper losses (for the same rpm a 14P motor will need less turns) only will be feelable at very high loads.

as long as you use it in a normal load range, the negative effcts of the higher iron losses will overbalance.

also the max eff. of the 10P motor everytime will be the higher compared to the 14P motor.

all this is very old science and everyone can find these coherences into the standard works about electric motors. noone can change the physical basics behind this.

[swalko]

I agree Ralph. Even if i compare power consumption of stock Xera 4530 and stock Pyro 750-560, Pyro 750 still have higher power consumption than much powerfull Xera 4530. So what was the reason to develop 14 pole Pyros?

[powercroco]

a 14P has a special advantage.
it generates slightly more torque.
some very good pilots with powerhungry style can feel this and prefer this type of motor.
and at the right side of efficiency curve it has also higher efficiency.
unfortunally this is the region, where the crowd of normal pilots never flies - or only for small pieces of seconds.

[TommyBear]

Originally Posted by powercroco

a 14P has a special advantage.
it generates slightly more torque.
some very good pilots with powerhungry style can feel this and prefer this type of motor.
and at the right side of efficiency curve it has also higher efficiency.
unfortunally this is the region, where the crowd of normal pilots never flies - or only for small pieces of seconds.

So a 14P motor is a perfect candidate to power a speed heli ?

[powercroco]

May be.
In fact we havn't found the expected advantages in real life.
But I only can use the conclusions of my own side by side measurements and out of the flight logs of my test pilots.

[Vinger]

Originally Posted by _Dekker

I don't agree. They (P750/P8xx) do do not have the Delta loop current in the amounts that other motors with delta winds show. Also the wave forms between YY and delta termination differ very little so nothing strange there.
The fill with 1.32mm (5+5) 10turns is actually 55% higher than the stock 750-45 so it should do just fine.

What esc is being used with it and with what settings?

Thanks, so I learn something new again, humble to be in this company of motor gurus. Thanks again.

[Mercuriell]

Originally Posted by swalko

John, did you already tested your Pyro? I am curious about your results. I tested hand wound Pyro 750 5+5 YY 1.32 and i was not satisfied. It produced a lot more heat and power consumption was about 40% higher in a comparison to my Xera 4530. I expected same motor as Pyro 700 with higher performance, but it was not so and that Pyro 750 was noisy too.

I have been flying it in my SF2 TDR on 12 & 14S. On 12S it really doesn't seem much different from the 700. On 14S runs very hot, much more so than the 4535 in my Diabolo S. It does seem torquey judging by feel and HS holding. Have to say I feel more comfortable with the 10P 45 series. Have the 850 Comp to try to ....