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midwest tungsten orphin bin
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Aurigema, Andrew N. (KSC)[ASRC AEROSPACE]
¿ªÔÆÌåÓýHey Gang,
?
I bought 200 "preloaded" tungsten coils from Midwest
Tungsten' orphin bin and they seem to work fine.? They were something like
14 cent each and?had the aluminum in the center of a tri-braid of 0.025"
dia wires.??Total lengh of wire under amperage was 2" and they headed
up well and?coated out well.??
?
I have burned about 10 of them now and there is a
trick.? you have to ramp up slowly.??dull red first for a few
seconds then red then cherry red then real power.? That 10
seconds?dont count?towards the 10 seconds you need to exhaust the
aluminum from them.??
?
I have 36 of these emitters now in my chamber and will be
running a "re-use" test tonight.? I dont see why I cant hang?a little
120mg aluminum cane in the coil and bring up the power.? if that works,
then I got a way to use up the 3,000 aluminum canes I got by mistake.? They
are too much metal for a single wire but maybe just right for this much tungsten
coil.?
?
Just thought I would let you know that the orphin bin is an
amazing place to find stuff cheap.??
?
Andrew in soggy Florida.?
? From: VacuumX@... [mailto:VacuumX@...] On Behalf Of Ken Hunter Sent: Friday, August 08, 2008 10:36 AM To: VacuumX@... Subject: [VacuumX] Re: Aluminizing coating has a black tinge Hello Joe, --- In VacuumX@yahoogroups ...> wrote: > > Hi Guys, > > I am new to the group and have just started to play around with > aluminizing mirrors. I have a system which I managed to scrounge and > can achieve a vacuum of around 1x 10-4 torr. The first experiment > produced a really good aluminium coat. At this stage I thought this is > really easy. > Pride goeth before a fall, my second try produced a coating with a > very dark tinge to the coating. Anyone have any clues as to what might > be wrong. > Any help would be much appreciated. > > regards > Joe > |
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Ken Hunter
Andrew...
The XMS controller you're getting has the capability to ramp up the voltage/current to your specifications... EACH TIME YOU DO IT. Makes things very REPEATABLE. Ken --- In VacuumX@..., "Aurigema, Andrew N. (KSC)[ASRC AEROSPACE]" <andrew.n.aurigema@...> wrote: orphin bin and they seem to work fine. They were something like 14 centeach and had the aluminum in the center of a tri-braid of 0.025" diawires. Total lengh of wire under amperage was 2" and they headed up welland coated out well.to ramp up slowly. dull red first for a few seconds then red thencherry red then real power. That 10 seconds dont count towards the 10seconds you need to exhaust the aluminum from them.then I got a way to use up the 3,000 aluminum canes I got by mistake.They are too much metal for a single wire but maybe just right for this muchBehalf Of Ken Hunterside of the Groups main page.there's a lot more to read about this subject.third "Pre-Heat" option.originally thoughtthe problem was contamination, I now believe the problem wasa result of my rapidly heating the filaments up due to a lack ofhumor and the resulting impatience that followed.my "frustrated, full throttle, get it done" approach I had during my string ofcontamination is inevitable. A pre-heat session boils off the contaminents andgives the pumps a chance to remove the material from the chamberenviroment. Another possibility is the pre-heat and slow ramp up allows for ansurfaces inside the chamber.application of filament power produces a nice coating. A rapid "get it done"black coating :0need a bit deeper vacuum in the chamber to get consistent results...and this iscan achieve a vacuum of around 1x 10-4 torr. The first experiment mightreally easy. be wrong. |
I have 36 of these emitters now in my chamber and will be running athen I got a way to use up the 3,000 aluminum canes I got by mistake.They are too much metal for a single wire but maybe just right for this much As far as i understand with these so is the center aluminum thread only there to help the extra aluminum you put on to wet the tungsten thread better, faster and more even and then draw out the rest of the aluminum to the whole length of the tungsten. The amount of aluminum the center thread has is quite small and will only put a quite thin coat on the tungsten thread. Since you dont put more on it so could this very well be one cause that they wont work for a long time. I have a couple of these coils myself, but i havent used then yet, but since these are built with stranded wires so can they can hold quite much aluminum without starting to drop, much more then a single wire. Regards Henry |
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Aurigema, Andrew N. (KSC)[ASRC AEROSPACE]
¿ªÔÆÌåÓýHenry,
?
I agree that the center thread is just a teaser
amount.?
?
I ended up just burning that off in testing and putting the
120mg "candy canes" ?on the coils.? That worked out great.? The
coils get cherry red and the aluminum canes melt and wet out the coil very well
in about 10 seconds.? The coils "cool off" and get darker for 10 seconds
then all the aluminm is gone and the coils get bright red again.? It makes
for perfect emision of the aluminum.?
?
I position the?coils about 30 degrees off
of?vertical mode.? The molten aluminm can fall thur the coil if you
let it hang straight up and down.?
?
?
?
My setup has?4 coils arranged in?series.?
They are?powered off a single 120vac to?24 vac?transformer ( out
of an old 1875 watt drop out power supply ).? The transformer is pulling
about 12?amps at 120 vac so that is around 1440 watts total power.?
The voltage?thru the coils is around 3 vac?under load so the amps are
upwards of 400.? I use very serious 1/4" diameter fine stranded wire to
cary the power to the emitters.??
?
?
?
I have been thru 4 cycles now and the emitters are showing
no signs of decaying.? I can recomend this combo now that I have run it a
few times.??
?
Oh,? you have to heat that coil up slowly the first
time.? It will spit otherwise.? I heat the coils up slowly ( 10
seconds )? every time to not thermally shock them.? Same slow cool
down time.??
?
Andrew in soggy
Florida???
?
?? From: VacuumX@... [mailto:VacuumX@...] On Behalf Of henry_3507 Sent: Wednesday, August 13, 2008 1:51 PM To: VacuumX@... Subject: [VacuumX] Re: midwest tungsten orphin bin > I have 36 of these emitters now in my chamber and will be running
a |
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Aurigema, Andrew N. (KSC)[ASRC AEROSPACE]
¿ªÔÆÌåÓýKen,
?
Some how I missed a weeks worth of e-mails
??????? But now that I see this I am very much ready to automate my
process.? I am not sure how this will happen but I am go for trying.?
?
Right now I power my step down transformer?off
a?2.5 KVA variac ( rotary variable resister ).??This regulates my
120 vac line going into the transformer so i can bring up the coil slowly over
about 10 seconds.? Then I turn up the variac to about 80% capability (
output is like 90 vac ) and that brings my emitters up to cherry red for 10
seconds.? Then I slowly back off to nothing over 10
seconds.??
?
Can the new controler handel?15 amps @ 120 vac
????? Or is there some use of switching power darlingtons or solid
state relays that just pulse the 120 vac and simulate the same power
curve?????? I really dont care how this?works as long as it
does.??
?
It looks like I will be running about 1500 watts for
the?aluminum deposition process?and something like 2 or 3 times that
on the SiO process.?
?
Andrew in ( have not got a clue how any of this works
)? soggy Florida
?
ps......... I got the micro-dot cable.? Going to find
a crimper for that bad boy today.? I got?buds in the?tranducer
lab.? You should see the toys them boys play with.?
????? From: VacuumX@... [mailto:VacuumX@...] On Behalf Of Ken Hunter Sent: Sunday, August 10, 2008 1:15 AM To: VacuumX@... Subject: [VacuumX] Re: midwest tungsten orphin bin Andrew... --- In VacuumX@yahoogroups AEROSPACE]" ...> wrote: > > Hey Gang, > > I bought 200 "preloaded" tungsten coils from Midwest Tungsten' orphin > bin and they seem to work fine. They were something like 14 cent each > and had the aluminum in the center of a tri-braid of 0.025" dia wires. > Total lengh of wire under amperage was 2" and they headed up well and > coated out well. > > I have burned about 10 of them now and there is a trick. you have to > ramp up slowly. dull red first for a few seconds then red then cherry > red then real power. That 10 seconds dont count towards the 10 seconds > you need to exhaust the aluminum from them. > > I have 36 of these emitters now in my chamber and will be running a > "re-use" test tonight. I dont see why I cant hang a little 120mg > aluminum cane in the coil and bring up the power. if that works, then I > got a way to use up the 3,000 aluminum canes I got by mistake. They are > too much metal for a single wire but maybe just right for this much > tungsten coil. > > Just thought I would let you know that the orphin bin is an amazing > place to find stuff cheap. > > Andrew in soggy Florida. > > ____________ > > From: VacuumX@yahoogroups Behalf > Of Ken Hunter > Sent: Friday, August 08, 2008 10:36 AM > To: VacuumX@yahoogroups > Subject: [VacuumX] Re: Aluminizing coating has a black tinge > > > > Hello Joe, > > Welcome to VacuumX! > > Try looking through the past posts and the resources to the left side > of the Groups main page. > > There are a lot of hits if you search for "black coating" > Here's a snip from message 237. It may not be your problem but there's > a lot more to read about this subject. > > ** > > If you find yourself having "black" coatings, try implementing a third > "Pre-Heat" option. > > I recently ran into a string of failed coatings. While I had originally > thoughtthe problem was contamination, I now believe the problem was a > result of my rapidly heating the filaments up due to a lack of humor > and the resulting impatience that followed. > > The work around for the string of failed coatings has been a more > controlled ramping up of filament tempature instead of my "frustrated, > full throttle, get it done" approach I had during my string of > failures... :) > > My supposition is that while loading the filaments, some contamination > is inevitable. A pre-heat session boils off the contaminents and gives > the pumps a chance to remove the material from the chamber enviroment. > Another possibility is the pre-heat and slow ramp up allows for an > opportunity for the removal of residual H20 that clings to the surfaces > inside the chamber. > > In any event, while not an expert, I do know that gentle application of > filament power produces a nice coating. A rapid "get it done" > application of filament power results in a non-reflective flat black > coating :0 > > ** > > Also search for "discharge cleaning", Off hand, I'd think you'll need a > bit deeper vacuum in the chamber to get consistent results... > > Again, Welcome to VacuumX ! > > Ken Hunter > > --- In VacuumX@yahoogroups > "joeblack19502000" > > wrote: > > > > Hi Guys, > > > > I am new to the group and have just started to play around with > > aluminizing mirrors. I have a system which I managed to scrounge and > > can achieve a vacuum of around 1x 10-4 torr. The first experiment > > produced a really good aluminium coat. At this stage I thought this is > > really easy. > > Pride goeth before a fall, my second try produced a coating with a > > very dark tinge to the coating. Anyone have any clues as to what might > > be wrong. > > Any help would be much appreciated. > > > > regards > > Joe > > > |
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Andrew,
1800W for a 1500W variac is really to let it live on the edge and the windings would most likely fry if ran to long on this power. I think i have mentioned it here before but i have planned to use an secondary rewound transformer for higher amp out but doesnt control the power with a variac. The power is controlled by an triac instead and the triac i use can handle 40A at 600V so its more then enough for this. So if you need more power then the variac controlling principle i use to this might be something of interest, and its much cheaper to build then buying a bigger variac. I got it completely done a couple of days ago and it looks like this and it works like a charm: Output is 5.4V AC and 425A, but little more amp is possible but 425A out is 10A in on primary which is max what the household fuse can handle here. But thats 2300W out that will be sufficient for quit much i guess and boats as well. Regards Henry Can the new controler handel 15 amps @ 120 vac ??? Or is there some --- In VacuumX@..., "Aurigema, Andrew N. (KSC)[ASRC AEROSPACE]" <andrew.n.aurigema@...> wrote: see this I am very much ready to automate my process. I am not sure howrotary variable resister ). This regulates my 120 vac line going into the90 vac ) and that brings my emitters up to cherry red for 10 seconds.Then I slowly back off to nothing over 10 seconds.some use of switching power darlingtons or solid state relays that justpulse the 120 vac and simulate the same power curve ??? I really dontcare how this works as long as it does.Florida that bad boy today. I got buds in the tranducer lab. You should see theBehalf Of Ken Huntera much"re-use" test tonight. I dont see why I cant hang a little 120mgthen I amazingtungsten coil. 40yahoogroups.com> ] Onplace to find stuff cheap.[mailto:VacuumX@... <mailto:VacuumX% BehalfwasOf Ken Hunterside aanresult of my rapidly heating the filaments up due to a lack ofhumorand the resulting impatience that followed.my "frustrated, scroungeopportunity for the removal of residual H20 that clings to thesurfacesinside the chamber.application of andexperimentcan achieve a vacuum of around 1x 10-4 torr. The first with athis isproduced a really good aluminium coat. At this stage I thoughtreally easy. whatvery dark tinge to the coating. Anyone have any clues as to mightbe wrong. |
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Ken Hunter
--- In VacuumX@..., "henry_3507" <kmnhij@...> wrote:
I got it completely done a couple of days ago and it looks like425A out is 10A in on primary which is max what the household fuse can Nice construction Henry! Do you control the Triac from a variable resistor? Could it be controlled from a 0-10 volt source instead? The XMS-3 Deposition Controller and a lot of the other models outputs a 0-10 volt DC voltage to control the filament circuit. Any chance you would want to post the circuit diagram in the Group Files section? Ken Hunter |
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Thanks! The power is controlled with a variable resistor and the
black and brown cords up to the left is where i connect it to but i hadnt connect it when i took the picture. Sure, i can put the circuit diagram in the file section. I only had it on plain paper before but i have now rewritten it in my computer instead. Its in the file section under this name: Triac controller for highly inductive loads.jpg The design isnt mine but i have fixed some smaller and bigger errors that were in the original design. I have seen this in an application note some years ago from a big component manufacturer but i just cant remember who it was. To control this from a 0-10 volt source could be a smaller headache but its not impossible. The reason it would be difficult is first of all that the design isnt at all built for it and second so will the triac on and of timing has to be precisely controlled and this could be hard when controlling an inductive load, a resistive load would be a little easier. The circuit is driven with a high AC voltage and controlled with a variable resistor and we want to control it with 0 - 10 DC instead and that put problems into it since a sort of electronic conversion between these has to be built. It would not be impossible but it would take some time and work to do it just because it is not built to be used in that way. Regards Henry --- In VacuumX@..., "Ken Hunter" <atm_ken_hunter@...> wrote: outputs a 0-10 volt DC voltage to control the filament circuit. Any chancesection?
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Henry,
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I looked at the triac control for highly inductive loads that you posted. You do not show a mechanical switch in the mains circuit. You should be aware that the resistor-capacitor snubber circuit across the BTA-40 triac will pass a small amount of current into the transformer primary whenever the mains are energized. If the transformer is a setup-up transformer, then a serious shock hazard may exist at its secondary terminals even if the triac control circuit is turned "off". Might want to add a relay or switch to the lines side of the schematic. Dave Sure, i can put the circuit diagram in the file section. I only had it on plain paper before but i have now rewritten it in my computer instead. Its in the file section under this name: |
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There are many things that isnt in the circuit as well as a contact
also a bunch of components to reject interference from the triac switching and coils and so on. No one should built a circuit with mains connected if you dont have the knowledge about it and how to use it properly. As i said this is not my design its from a component manufacturer and i put it up as i got it and it is only a basic design without any other component then the circuit it self. But i calculate on the snubber circuit and i see that the snubber capacitor they have used are to big, there shouldnt be a bigger capacitor that 0.1 nF to be safe. Then the current that goes through the snubber isnt dangerous since its to low. But I will change this and i put a switch there as well even if this now isnt necessary whith the lower capacitance in the snubber. Regards Henry --- In VacuumX@..., David Speck <Dave@...> wrote: posted. across the BTA-40 triac will pass a small amount of current into themay exist at its secondary terminals even if the triac control circuitis turned "off".schematic. had computerit on plain paper before but i have now rewritten it in my instead. Its in the file section under this name: |
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