350hz NSD Arrived. 9849 within 10 mins-do I have the high density one?

[SoulFireMage]

Hi guys,

I think I know the answer to this one but I'll ask anyway. Max score on 250hz model was 138xx (battery died in the end). I did leave it for months with only occasional use but the past week started again and got me this NSD one this morning. Heavier, quieter etc 9849 and harder workout all round. Is this the high density one? if so, is my score close on a par with previous achievement?

Thanks folks.

[Adrena1in]

1) Only the high density heavy "Stegosaur" rotor is available at the moment for the Metal 350Hz.

2) The first go for lots of people tends to be around the 9000 to 9500 mark. I know a 14.3k Powerballer who started on 9300ish, but he's now gone over 12000 with the Heavy Metal. I'm hovering around 13000 with the 250Hz and 11000 with the Metal...I think most people tend to show about a 2000 rpm difference, so you should soon get into the mid-11ks.

Tim.

[SoulFireMage]

Well I've just topped out at 10120 with the metal one, though I've no doubt I'll go higher today. Forearms nicely swollen now LOL.

Btw, have you read the translations in the manual that comes with it? I thought these were made in Ireland-seems not LOL. Funny as hell they are.
This 350hz business-does it mean in theory 18k is possible on the heavy one? I don't mean practically possible but if one were superhuman almost :-).

[donkapone]

it will be possible when you`ll put the lightweight rotor in which is going to come out pretty soon

[Adrena1in]

I've heard it said that the heavy rotor has been tested at 350Hz, but I'm not sure...no human would ever be able to do that anyway. Akis's record with it is 13700ish...not even 230Hz.

[Mark Nykamp]

I do 13300 with the 250hz and 11880 with the metal heavy rotor if that helps you at all.

[SoulFireMage]

I read on the powerballs site the 250hz ball can generate up to 40lbs of force. How about the heavy metal one? Is there anyone who's done a graph showing force over Rpm at all?

[Sayex]

I read on the powerballs site the 250hz ball can generate up to 40lbs of force. How about the heavy metal one? Is there anyone who's done a graph showing force over Rpm at all?

nope, but a graph between the lbs generates and the rpms its a good idea.
it should be a curve though... btw the metal rotor weight almost the double of the 250, so i guess.. and 250hertz the metal rotor should weight about 80lbs.
i think. am just guessing =D

[Adrena1in]

I've mentioned before that gyroscopic torque not only increases as the weight of the rotor increases, but also if more of the weight is distributed nearer the outer surface. The Metal is nearly twice as heavy, but it's also got a higher proportion of weight on the outer surface. This is because the surface is steel, where it's plastic with the 250Hz. I therefore believe, speed for speed, the Metal produces more like three or four times more torque.

But I'd love there to be a machine that can actually measure it. Perhaps there is. Perhaps whatever machine is used to computer balance the rotors also measures the torque??

[Dennis]

Hi Adrena1in,

I don't think the torque will be measured during balancing, as this torque will be generated by rotation of the rotor around its virtual axis (i.e. the "wobble" you feel when spinning your PowerBall). I assume that during balancing, the rotor's axle is fitted between a motor and bearing. The motor driving the rotor around its own axle. When speeding up the rotor, any wobble generated due to inaccurate weight distribution in the metal ring and yellow sphere can be detected and corrected by removing excess material (i.e. drilling holes in the metal ring of the rotor). This can be done until there is no detectable wobble when spinning the rotor at 250Hz.

Measuring the torque generated at certain speeds would require measuring the rotational speed of the rotor around its virtual axis at different revolutions. This can be calculated by measuring the diameter of the axle (to calculate the distance traveled in 1 revolution) and the length of the inner track (to determine the number of revolutions required to complete a full circle). Then the rotor has to be fitted in a clamp so that the axle is perpendicular to the rotation direction. By spinning the rotor (and the inner support ring to which the counter weight is attached) at different speeds, one can measure the torque resulting from the wobble thus generated. Go back to the calculations above and you can determine the torque generated at specific revolutions.

Naturally, you have to take into account the 'slipping' of the axle on the inner track, which will slightly reduce the number of revolutions around its steel axle with respect to its virtual axis.

Anyway, I'm not an expert, but this is what I can come up with. Feel free to correct me!

Kind regards,
Dennis