VFD or not to D....that is the question

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Jraef

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Ebay is on it too lol
where is the law listed?
can't find it under the state dept list

something similar happened in the early 80's
Toshiba sold the ussr (or china?) cc lathes that could be used to make sub props smooth and quiet
no gov docs or contractors that did business could use any of their equip
including copiers lol
had to certify such when submitting a bid
I had a link buried in my earlier post, here it is not buried

https://www.bis.doc.gov/index.php/f...13-nsg-plenary-rule-79-fr-46316-8-7-2014/file
 

Ingenieur

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The IEEE Spectrum had a very good technical piece on stuxnet
Kushner March 2014

wiki excerpt

Stuxnet requires specific slave variable-frequency drives (frequency converter drives) to be attached to the targeted Siemens S7-300 system and its associated modules. It only attacks those PLC systems with variable-frequency drives from two specific vendors: Vacon based in Finland and Fararo Paya based in Iran.[61] Furthermore, it monitors the frequency of the attached motors, and only attacks systems that spin between 807 Hzand 1210 Hz. The industrial applications of motors with these parameters are diverse, and may include pumps or gas centrifuges.
Stuxnet installs malware into memory block DB890 of the PLC that monitors the Profibusmessaging bus of the system.[52] When certain criteria are met, it periodically modifies the frequency to 1410 Hz and then to 2 Hz and then to 1064 Hz, and thus affects the operation of the connected motors by changing their rotational speed.[61] It also installs a rootkit – the first such documented case on this platform – that hides the malware on the system and masks the changes in rotational speed from monitoring systems.
 
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Jraef

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doesn't that restrict export to the listed countries?
...
not the import into the US
???
That's just the easiest reference I found, there are others, i.e. the NRC and the DoD that go into more detail about not even owning them. My company got notice from the DoD saying we had to hobble our firmware on a product we make that went to 650Hz, as well as forcing us to make it so that if anyone ever updated firmware on older versions, the updated firmware installed the hobble, plus we had to announce that units not updated with new firmware would be ineligible for service contracts. Pissed a lot of people off because as you might imagine, very very few people use speeds that high, but they were forced into doing firmware revs nonetheless, which equates to down time.
 

mike_kilroy

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Same limits applied to our servo drives. Can't give out old fw >600hz.

But I am fsirly certain we can still legally supply VFDs to 3000hz output. In this range too. Both a us source and a German source.

Where are you OP?

I believe key is that .2% regulation: So I believe v/Hz drives are still legal.

Sent from my SM-G900V using Tapatalk
 

mike_kilroy

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40 va
~ 0.05 HP or less
~ 0.004 lb-ft (60000 rpm) 0.05 lb-in lol

wth are you going to do with that?

Actually quite a lot! We have worked with high speed grinders over the years: 20,30,50,000rpm... Bryant grinder used to make ones with multiple heads. We would set drive parameters based on binary coded jumpers in the big MS connector that hooked it up. We have 32 motor option, so we can program in up to 32 different motor parameter sets, and that is/was used to pick the right set for the motor in the head being swapped in.

Today, for aluminum machining, high speed makes removing metal like using a knife on butter. It used to take around 48 hours to machine ONE airplane wing skin with typical old fashion 3-4000rpm spindles. Today, the 15-20,000rpm spindles slip thru that same metal in like 5 hours. Similar HPs.

Why do we have 30,000rpm dremel tools?

1.3kw @ 60krpm can remove a lot of material quickly when it makes the material almost like a liquid! Don't need so much torque for that.
 

mike_kilroy

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Not all that far from Fort Fumble errr Meade..

Your mentioned reference may have been from Fischer, the spindle mfgr, since we run so many of their hig performance spindle motors...

Your referenced part number PCS410 sounds a lot like our German product that we have acted as US Importer for since around 1990: Refu.com Today's model is PCS620... Commissioning a 45kw one next week at a big GE jet engine plant, although most commissioning and diagnostics nowadays is via internet hookup from my office.

So USA. If you want to PM me, I would be happy to send you a quote from our US mfgr who still sells standard VFDs that actually go up to 6000Hz (unless this too changed which I think not) on the output for speeds to 360,000rpm. Delivery probably is even from stock, pricing is generally not much more than generic VFDs. Realize that at those kinds of speeds, vector control is pretty useless; thus no issue with .2% speed regulation - if that is indeed the culprit. We follow the rules; getting in trouble once years ago for ITAR was enough for me!
 

Ingenieur

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Actually quite a lot! We have worked with high speed grinders over the years: 20,30,50,000rpm... Bryant grinder used to make ones with multiple heads. We would set drive parameters based on binary coded jumpers in the big MS connector that hooked it up. We have 32 motor option, so we can program in up to 32 different motor parameter sets, and that is/was used to pick the right set for the motor in the head being swapped in.

Today, for aluminum machining, high speed makes removing metal like using a knife on butter. It used to take around 48 hours to machine ONE airplane wing skin with typical old fashion 3-4000rpm spindles. Today, the 15-20,000rpm spindles slip thru that same metal in like 5 hours. Similar HPs.

Why do we have 30,000rpm dremel tools?

1.3kw @ 60krpm can remove a lot of material quickly when it makes the material almost like a liquid! Don't need so much torque for that.

I understand the need for high speed
but 1.3 kw >>> 40 va
30 times as much torque

but as was mentioned small stuff like dental drills are in the 40 va range
most have a vfd of sorts to get 20k rpm and gearing for the rest
 

GoldDigger

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I probably missed it but where did the 40VA come from?

I think Ingenieur listed it in post #24 based on reading the Federal restrictions. To be controlled the device needs to exceed that size as well as have high frequency and high accuracy.

mobile
 
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mbrooke

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2 pole motor = 3600RPM (synchronous) at 60Hz. 1000Hz/60hz = 16.67, x 3600RPM = 60,000RPM. No gear box.

I worked for Siemens at the time this all went down. The press got it wrong saying the intent was to destroy the centrifuges. The intent was to not have the enrichment work and have them flail around not knowing why and maybe give up after wasting all that money. That part almost succeeded, but what I heard that they didn't count on was the German engineers working for the Iranians not accepting that the process didn't work (possibly under threat of beheading). They apparently checked the actual speed against what the Siemens software TOLD them the speed was, then found the error and in investigating the cause of the error, found the virus in the software. Ironically the virus was introduced into the system by them. They hacked "free demo" Siemens software that they got in Germany and loaded onto thumb drives, because Iran was prohibited from buying it. Someone (likely the CIA or the Mossad) knew what they were up to and infected that free demo version of the software with Stuxnet.


Thank you for clearing this up- I did not know that until now. But it does not surprise me because I know the press usually gets just about everything skewed.

But, with all I read here, I had no idea the gov put limits on the output frequency :eek: Good to know too if I ever buy a VFD. Last thing I need is a fed check over a VFD I am going to take to bits (dismantle) anyway :lol:
 

mike_kilroy

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Thank you for clearing this up- I did not know that until now. But it does not surprise me because I know the press usually gets just about everything skewed.

But, with all I read here, I had no idea the gov put limits on the output frequency :eek: Good to know too if I ever buy a VFD. Last thing I need is a fed check over a VFD I am going to take to bits (dismantle) anyway :lol:

From owner of hi speed VFD supplier yesterday: "With drives made in US and sold to US to known entities for known applications, there are no frequency restrictions."
 
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