The Killacycle & Scotty Pollacheck 7.82 @ 168 MPH 10nov2

[Malcolm]

I was just reading the Zilla blog the other day. The 3-phase Zilla is in development, but he said not to expect anything soon.

 

[fechter]

OK, until the induction motor is developed, you could increase the resistance to arcing and flashover on the commutator by pressurizing the area around the commutator with sulfur hexafluoride gas.

SF6 is probably expensive and hard to come by, but CO2 may be substantially better than air, and is much easier to get ahold of.

We used to use SF6 to fill the waveguides on our linear accelerator to prevent arcing at high power levels.

If the gas leaked out, the waveguide would do a major meltdown.

Slightly rounding the edges of the commutator segments may reduce arcing also.

Gas/vacuum as Insulator

Air at atmospheric pressure is the most common gaseous insulation. The breakdown of air is of considerable practical importance to the design engineers of power transmission lines and power apparatus. Breakdown occurs in gases due to the process of collisional ionization.

Electrons get multiplied in an exponential manner, and if the applied voltage is sufficiently large, breakdown occurs. In some gases, free electrons are removed by attachment to neutral gas molecules; the breakdown strength of such gases is substantially large. An example of such a gas, with larger dielectric strength, is sulphur hexafluoride (SF6).

High pressure gas, provides a flexible and reliable medium for high voltage insulation using gases at high pressures, field gradients up to 25 MV/m have been realized. Nitrogen (N2) was the gas first used at high pressures because of its inertness and chemical stability, but its dielectric strength is the same as that of air. Other important practical insulating gases are carbon dioxide (CO2), dichlorodifluor9methane (CC12F2) (popularly known as Freon), and sulphur hexafluoride (SF6). The breakdown voltage at higher pressures in gases shows an increasing dependence on the nature and smoothness of the electrode material. It is relevant to point out that, of the gases examined to-date, SF6 has probably the most attractive overall dielectric and arc quenching properties for gas insulated high voltage systems.

 

[Malcolm]

Pack dry ice around the motor before a run...
...even if it doesn't reduce arcing it'll help keep the motor cool

They're all major greenhouse gases – coincidence?

EDIT: I guess motor heating is not really a concern if you're only running for 7 seconds

 

[Doctorbass]

Here is the best vid about the killacycle showing Bill amd the team at the drag race:

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[Doctorbass]

I found a text that show some special thing after the 7.82s run,

Back in the pits, after congratulations etc. for the crowd, Jim Ludiker and I were standing next to the bike discussing the run, and a VERY attractive (and well-endowed) young woman came up to me and said 'That was a terrific run you made. Let me show you my tits.' She then pulled down her already plunging neckline, flashed us both, smiled, and then casually walked away. We were all speechless.I wonder what will happen if we get the bike in the 6's? "

8)




Source: NEDRA

 

[Ypedal]

Lol.. hilarious.. incentive to get this beast going faster than ever !

( Tho 20 $ at the titty bar would be a heck of alot cheaper !! )

 

[TylerDurden]

That is funny. As if nerds don't already spend too much time & money on gadgets, if they find out they could possibly get laid...

 

[xyster]

Toadies of both sexes are attracted to power like fleas to a dog. Society's nerds have gone without either sex or power for so many generations now, I wonder for how long they'll (we'll ? ) remain goofy, benign nerds now that nerd-suited technology is all powerful and sexy.

 

[Jay64]

That is funny. As if nerds don't already spend too much time & money on gadgets, if they find out they could possibly get laid...

Isn't that the only reason to even GO racing??? :wink:

 

[KillaCycle]

Interesting thought, but the brushes require air to work properly. I've run brush motors in vacuum, helium, 1600 psi N2, and 1600 psi argon. The brushes fail quickly in all these different atmospheres, but work just fine in air.

OK, until the induction motor is developed, you could increase the resistance to arcing and flashover on the commutator by pressurizing the area around the commutator with sulfur hexafluoride gas.

SF6 is probably expensive and hard to come by, but CO2 may be substantially better than air, and is much easier to get ahold of.

We used to use SF6 to fill the waveguides on our linear accelerator to prevent arcing at high power levels.

If the gas leaked out, the waveguide would do a major meltdown.

Slightly rounding the edges of the commutator segments may reduce arcing also.

Gas/vacuum as Insulator

Air at atmospheric pressure is the most common gaseous insulation. The breakdown of air is of considerable practical importance to the design engineers of power transmission lines and power apparatus. Breakdown occurs in gases due to the process of collisional ionization.

Electrons get multiplied in an exponential manner, and if the applied voltage is sufficiently large, breakdown occurs. In some gases, free electrons are removed by attachment to neutral gas molecules; the breakdown strength of such gases is substantially large. An example of such a gas, with larger dielectric strength, is sulphur hexafluoride (SF6).

High pressure gas, provides a flexible and reliable medium for high voltage insulation using gases at high pressures, field gradients up to 25 MV/m have been realized. Nitrogen (N2) was the gas first used at high pressures because of its inertness and chemical stability, but its dielectric strength is the same as that of air. Other important practical insulating gases are carbon dioxide (CO2), dichlorodifluor9methane (CC12F2) (popularly known as Freon), and sulphur hexafluoride (SF6). The breakdown voltage at higher pressures in gases shows an increasing dependence on the nature and smoothness of the electrode material. It is relevant to point out that, of the gases examined to-date, SF6 has probably the most attractive overall dielectric and arc quenching properties for gas insulated high voltage systems.

 

[fechter]

Interesting. Well at least somebody tried it. I heard reports it has something to due with humidity. Add water?

OK, here's another crazy idea:

What if you installed some really strong magnets near the commutator to make a magnetic blowout?

I'd have to scratch my head a while to figure out how you could get enough flux across a really wide comm to actually blow out an arc, but at those currents, you can get quite a bit of force with good magnets.

Or, low tech approach: just make the commutator a larger diameter. Of course then it won't fit in the bike, but that's where the challenge is.
:wink:

 

[lawsonuw]

Interesting thought, but the brushes require air to work properly. I've run brush motors in vacuum, helium, 1600 psi N2, and 1600 psi argon. The brushes fail quickly in all these different atmospheres, but work just fine in air.

Interesting. I do notice one common factor of all these environments. They ALL lack Oxygen. Oxygen and the surface oxides that form on metal surfaces prevent metal surfaces from instantly welding when they contact each other. Did you try to introduce oxygen at a partial pressure of 5-10psi? (I'm aiming for about the same partial pressure of oxygen as air, don't know the value off the top of my head)

Marty

 

[TylerDurden]

I'm thinkin humidity too. Reid posted awhile back on the subject, that brushes go to sht in a heartbeat with dessicated air/gas.

I'm not sure I'd start feedin O2 in any quantity.

 

[fechter]

Oxygen, water, I'm not sure. Both concepts seem plausible.

Pure oxygen would be a bad idea.

 

[Stevil_Knevil]

BUMP..

Hey Bill, we need more of that Killacycle/A123 goodness to keep our chops up. Any news? Do you know of a BMS that we can use?

Best, -S