Author Topic: Crimping using pulsed power  (Read 1201 times)

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 281
  • Karma: +8/-0
  • Cedar Rapids, Iowa
    • View Profile
Crimping using pulsed power
« on: May 09, 2020, 10:02:16 PM »
I was playing around with my pulsed power machine a few days ago and decided to try something different. I took a 2 inch long piece of 0.875 inch diameter copper pipe and did a shrinking experiment. I placed the piece inside a 12-turn 12 AWG work coil and hit it with 7000 Joules. The result was an almost-perfect hourglass pinch. The work coil wasn't wound tightly against the pipe so I could have done the same thing with less energy with a tighter coil (better coupling) but I already had a few of these spare work coils made for quarter shrinking laying around.

This technique is actually used in industry where one piece has to be crimped on to another piece. Supposedly this method produces a better more uniform crimp than can be accomplished mechanically.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1180
  • Karma: +57/-0
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Crimping using pulsed power
« Reply #1 on: May 10, 2020, 03:35:31 AM »
Steve,

Nice crimping demo!  I'd done the same thing with my 3kV setup, but I think your pipe piece came out a bit more uniform.  Perhaps it helps to have some spacing.  I also crimped one onto a wood dowel. 
David Knierim

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 370
  • Karma: +11/-0
    • View Profile
Re: Crimping using pulsed power
« Reply #2 on: May 10, 2020, 05:57:35 AM »
Very nice.  Does the work coil get damaged?  Is it mechanically reinforced on the outside?

Long ago I thought of making very durable work coils in the style of flexible shaft couplings:
thick bushing with helical saw slot.


Offline johnf

  • High Voltage Technician
  • ***
  • Posts: 160
  • Karma: +5/-0
    • View Profile
Re: Crimping using pulsed power
« Reply #3 on: May 10, 2020, 11:57:40 PM »
Kludge
Woundnt you need to put some mica in the slots as the coil would compress Yes /No ?

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 281
  • Karma: +8/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Crimping using pulsed power
« Reply #4 on: May 11, 2020, 05:12:52 AM »
The work coil is completely sacrificial. Being sacrificial is actually good for the capacitor because the work coil disintegrates before any voltage reversals occur.  I had considered the idea of machining a heavy-duty G10 containment structure for the work coil just to hold it together a little longer to allow more work shrinkage.

I wonder what the re-usable work coil for the commercial pulse power crimpers looks like?
« Last Edit: May 11, 2020, 04:42:45 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline klugesmith

  • High Voltage Engineer
  • ****
  • Posts: 370
  • Karma: +11/-0
    • View Profile
Re: Crimping using pulsed power
« Reply #5 on: May 11, 2020, 05:33:55 PM »
I agree with John's point that the saw kerf (in shaft coupler) would tend to close up, and should be stuffed with insulator.
We might jokingly call the phenomenon magnetostriction.

Durable work coils might be a good application for copper alloys with high strength, in spite of electrical conductivity far below IACS.  I think they use something like that in world class resistive Bitter electromagnets, the kind that can continuously dissipate many kilowatts per cubic centimeter.

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 281
  • Karma: +8/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Crimping using pulsed power
« Reply #6 on: May 11, 2020, 09:37:31 PM »
Doing this little experiment made me think of the huge problems encountered during the WW2 plutonium bomb development. They had to determine a way to use explosives rather than magnetic fields to compress a plutonium core with practically perfect spherical symmetry. Its sort of a similar problem as crushing this copper cylinder with perfect symmetry minus one dimension, except that I didn't achieve perfect cylindrical symmetry by any means.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1180
  • Karma: +57/-0
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Crimping using pulsed power
« Reply #7 on: May 12, 2020, 04:56:00 AM »
I think Maxwell Magniform is the only company making magnetic forming machines commercially.  I heard somewhere that some of their coils us solid copper wire with a triangular cross-section, cast in epoxy.

Their most fascinating machines were made for Boeing, for taking dents out of airplane skins from the outside.  More complex control to get an attractive impulse!  Current needs to ramp up slowly, then suddenly drop in half.
David Knierim

High Voltage Forum

Re: Crimping using pulsed power
« Reply #7 on: May 12, 2020, 04:56:00 AM »

 


* Recent Topics and Posts

post ZVS long cable freq stabilization
[Transformer (Ferrite Core)]
kreasteve
Today at 02:56:13 AM
post Re: Exploding phones and electronics, a mini-series of 50kA discharges!
[Capacitor Banks]
Mads Barnkob
June 19, 2021, 05:30:28 PM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Mads Barnkob
June 18, 2021, 07:48:01 PM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Patrick
June 18, 2021, 02:48:57 AM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
June 18, 2021, 01:22:10 AM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
TMaxElectronics
June 18, 2021, 01:21:53 AM
post Exploding phones and electronics, a mini-series of 50kA discharges!
[Capacitor Banks]
Mads Barnkob
June 17, 2021, 08:27:10 PM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
Mads Barnkob
June 17, 2021, 08:23:57 PM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
Max
June 17, 2021, 02:51:45 PM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
Da_Stier
June 17, 2021, 02:01:23 PM
post LCR meter recommendation
[Sell / Buy / Trade]
the_anomaly
June 17, 2021, 01:58:48 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
Mads Barnkob
June 17, 2021, 12:42:03 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
haversin
June 17, 2021, 02:49:00 AM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
Mads Barnkob
June 16, 2021, 08:54:32 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
davekni
June 16, 2021, 08:00:50 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
haversin
June 16, 2021, 05:40:40 PM
post Demo Coil Protection
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
June 16, 2021, 05:39:14 PM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Twospoons
June 16, 2021, 10:20:30 AM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Patrick
June 16, 2021, 07:33:15 AM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
June 15, 2021, 01:21:38 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 15, 2021, 12:02:58 PM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 15, 2021, 06:52:56 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
thedoc298
June 15, 2021, 05:43:07 AM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
June 15, 2021, 05:26:34 AM
post The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
haversin
June 15, 2021, 02:27:03 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 14, 2021, 01:06:02 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 14, 2021, 12:44:31 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 14, 2021, 12:41:33 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 14, 2021, 12:11:13 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 11:52:11 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 11:38:44 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 10:26:51 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 09:57:56 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 09:29:08 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 08:53:25 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 07:22:05 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 07:02:28 PM
post Re: HFSSTC with fixed crystal-controlled frequency
[Solid State Tesla Coils (SSTC)]
Steve Ward
June 13, 2021, 06:25:20 PM
post First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 02:48:59 PM
post OpenTheremin v3 loosing calibration after minutes
[Electronic Circuits]
gianpaolo
June 13, 2021, 12:00:09 PM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Mads Barnkob
June 12, 2021, 07:28:03 PM
post Re: Rocket engine questions
[General Chat]
klugesmith
June 12, 2021, 07:23:12 PM
post Re: Rocket engine questions
[General Chat]
rikkitikkitavi
June 12, 2021, 12:24:06 PM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
Da_Stier
June 12, 2021, 10:06:18 AM
post Re: Rocket engine questions
[General Chat]
plasma
June 12, 2021, 10:01:29 AM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
Twospoons
June 12, 2021, 08:47:08 AM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Patrick
June 12, 2021, 07:03:10 AM
post Re: Complications in the design of the first DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
PEDRO HENRIQUE
June 12, 2021, 06:42:56 AM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
davekni
June 12, 2021, 04:20:53 AM
post Re: SKM100 Mini DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Willsmith001
June 11, 2021, 11:08:24 PM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 
SimplePortal 2.3.6 © 2008-2014, SimplePortal