[Johnny_Revolver]

Rocket Scientists can spell laboratory, I`d wager.


Kidding btw...

[billy]

yeah but do they say it like lah bore a tory?
at least all the mad scientists i know do.

[samuel]

He sounds like a rocket scientist with no humor.I would rather read your scientific projects with humor.But I will read his old dull ones too. sam.

[billy]

B.T.W. during these kinda projects i be sure and say it
lah bore a tory!

[Clark]

This morning's project is not rocket science, it is how to start a jet engine.
I have made a torque control board driving the pulse width modulation for a permanent magnet motor/generator, but for a brushed motor, it is turned with a contractor [big relay like a solenoid]. Today I need to do a trade off in cost, weight, losses, transients, etc on a mechanical contractor vs one I make with 100 power field effect transistors placed source to source two in series and 50 pairs in parallel. This jet is to have series start, with two 28 Volt batteries in series for 56 Volts to the motor. I need a double pole single throw switch to pass 1000 Amps for a 60 second start. To get the heat out of the D squared pak surface mount transistors I will need to design the printed wiring board to act like a heat exchanger with 56 Volt layers and chassis layers interleaved. If the max junction temperature for the transistors is 175 degrees C, and I am dissipating 100 Watts steady state at 500 Amps generate, and the base plate is 100 degrees C at 100 Watts, then I will need a thermal path of less than 75 degrees C per Watt for each transistor minus derating.

I think I can invoice them for the effort of typing that.

[samuel]

Yeah!I call your 56volts and raise 35amps. sam.

[phoenix79]

You're talking some pretty heavy hardware. Is this a personal project or a work project. BTW, what material are you using for heatsinks? Cu is a bit expensive now. Is it worth it to switch to Al or maybe even Ag?

[Clark]

The air frame is the heat sink.
This jet, when it rolls out, will not be bought by the sort that buys CZ52s and thinks they are a well designed and well made firearm.
I think Rush Limbaugh has an older model.

[phoenix79]

A Gulfstream?

[FALPhil]

Back on topic.

Is anyone using AA#7 for their 7.62x25?

[phoenix79]

I use Red Dot

[Clark]

I like Power Pistol and 110 gr in 7.62x25mm.

If anyone can get more velocity a different way with that bullet from a Tokarev, I would like to hear about it.

I have worked up with LIL'GUN, H110, AA#5, AA#9, Enforcer, LONGSHOT, XMP5744, N110, and N105 until the brass failed or no more powder would fit.

And Power Pistol is the clear winner.

[modwerdna]

I am going to build a single shot bolt action pistol based on the ppsh41w barrel, the best of all worlds. Probably might see almost 2000 fps on that h110 max load and a 10 inch barrel - what do you think?-

When do you call it max load, just before the primers blow out?

[gandog56]

Like most of my non magnum pistols, I use Unique.
6 grains and an 85 grain HP.

[Dakoma]

6.6 grains of Unique .309, 90 grain XTP is suposed to get you 1,500 fps. Makarov.com Has alot of data.It's what I shoot,Starline brass Win.small pistol primers good load.

[blaster]

well, I have done a lot of loading for the 7.62x25 since I started this thread. (how do you guys find & resurect these ancient threads?) I settled on 12gr. of AA #9. this according to published data is supposed to send a 90gr jhp 1779fps. I recently got a new chronograph and guess what? the books lie like a politician. 1550 was as fast as they go. now back to square one, I'm gonna load up all the different powders and chrono them all in quest of the super Tork. about the only powder that I don't have on hand is Power Pistol. hope I can locate some in these dry times.

[gandog56]

I used AA#9 for my 10mm loads till I emptied the jug.

[blaster]

I like the AA#9, its really clean burning and meters good. I'll definatly use it up. I just wish the published velocieties would be done in the typical firearm that uses that caliber instead of a long test barrel. a chronograph is like a scale at the fish cleaning table, they both sort out the BS.