Understanding the LEMO - Making your cables last while protecting your camera

[Michael Ou]

Coming from live music and theater, I'm quite familiar with the various beefy cable connectors that are in use, such as Socaplex, stage pin, DMX (XLR of many varieties), Cam-lok and Posi-lok to name a few. All range from beefy to monstrous, but as I make the crossover to digital cinema I am introduced to a curious new plug that I am not familiar with: The LEMO. To those in the know, no need to read any further.
After reading of some possible catastrophic failure attributed to a very few unfortunate incidents of cable malfunction, I decided to familiarize myself with this little connector, and it's possible shortcomings (no pun intended).
Instead of breaking down the connector and naming all it's parts, I'll just post the important part and link to an animation found in the LEMO site wonderfully illustrating how it's ingenious little locking mechanism works. There are three little animations to click: "Connection system", "Absolute security" and "Disengagement".

http://www.lemo.com/PUSH/push.asp

After understanding how this connection system works, I can now see how problems can develop. Such as, if someone new to this plug tries to work with it. Also many of the owner/operators here rent their gear and I can just see a rental client or their cousin, yanking at what he/she believes to be part of the plug, but not quite grasping what's called the "outer release sleeve", the proper way to unlock the connector, causing the friction lock (collet) to dig in and breech the insulation resulting in the short that kills your camera. SHUDDER!!!!
With that said, and understanding how the mechanism works, the LEMO really is quite a clever bit of engineering, perfectly designed to resist accidental unplugging, but its NOT idiot-proof!

​Happy and SAFE shooting!

 

[Brian Iannone]

Thank you for this. I wasn't completely familiar with the locking mechanism, but I now understand how it works. No wonder I've been having such a difficult time disconnecting the power cable from my Scarlet!

 

[Nick Gardner]

Lemos biggest client is the medical industry. Anything with plugs in an MRI suite, or an OR, has Lemos on it. They are damn near idiot proof as long as you think before you force stuff. There is a reason they are used in highly demanding situations, they are the best.

Nick

 

[Michael Ou]

Glad I could help Brian!
Certainly makes sense Nick, the next time I'm in the hospital (hopefully no time soon) I'm going to look for them on the equipment, I don't think I can NOT look now! And I know the only question on my mind besides whether or not I'll live, is whether or not that cable on the Heart-Lung machine can also power my EPIC! lol Oh the silly things that amuse me!

 

[Mathieu Ghekiere]

Thanks for this link!

 

[Stuart English]

Coming from live music and theater, I'm quite familiar with the various beefy cable connectors that are in use, such as Socaplex, stage pin, DMX (XLR of many varieties), Cam-lok and Posi-lok to name a few. All range from beefy to monstrous, but as I make the crossover to digital cinema I am introduced to a curious new plug that I am not familiar with: The LEMO. To those in the know, no need to read any further.
After reading of some possible catastrophic failure attributed to a very few unfortunate incidents of cable malfunction, I decided to familiarize myself with this little connector, and it's possible shortcomings (no pun intended).
Instead of breaking down the connector and naming all it's parts, I'll just post the important part and link to an animation found in the LEMO site wonderfully illustrating how it's ingenious little locking mechanism works. There are three little animations to click: "Connection system", "Absolute security" and "Disengagement".

http://www.lemo.com/PUSH/push.asp

After understanding how this connection system works, I can now see how problems can develop. Such as, if someone new to this plug tries to work with it. Also many of the owner/operators here rent their gear and I can just see a rental client or their cousin, yanking at what he/she believes to be part of the plug, but not quite grasping what's called the "outer release sleeve", the proper way to unlock the connector, causing the friction lock (collet) to dig in and breech the insulation resulting in the short that kills your camera. SHUDDER!!!!
With that said, and understanding how the mechanism works, the LEMO really is quite a clever bit of engineering, perfectly designed to resist accidental unplugging, but its NOT idiot-proof!

​Happy and SAFE shooting!

What ? Where did you read about that "problem" ?

 

[Scott Crawley]

Yes Michael,

Are you simply referring to idiots who improperly grasp and pull on the cable or do you mean to suggest there is something more happening?

Stuart,

Since we have your attention here, and I have a question that is not completely off the topic:

I have read of differing experiences RE: hot swapping the Red LCD. Some have had problems, others seem to think it's OK. Is it a safe practice or not one that Red recommends or supports?

Thanks

 

[Ben Coleman]

Coming from live music and theater, I'm quite familiar with the various beefy cable connectors that are in use, such as Socaplex, stage pin, DMX (XLR of many varieties), Cam-lok and Posi-lok to name a few. All range from beefy to monstrous, but as I make the crossover to digital cinema I am introduced to a curious new plug that I am not familiar with: The LEMO. To those in the know, no need to read any further.
After reading of some possible catastrophic failure attributed to a very few unfortunate incidents of cable malfunction, I decided to familiarize myself with this little connector, and it's possible shortcomings (no pun intended).
Instead of breaking down the connector and naming all it's parts, I'll just post the important part and link to an animation found in the LEMO site wonderfully illustrating how it's ingenious little locking mechanism works. There are three little animations to click: "Connection system", "Absolute security" and "Disengagement".

http://www.lemo.com/PUSH/push.asp

After understanding how this connection system works, I can now see how problems can develop. Such as, if someone new to this plug tries to work with it. Also many of the owner/operators here rent their gear and I can just see a rental client or their cousin, yanking at what he/she believes to be part of the plug, but not quite grasping what's called the "outer release sleeve", the proper way to unlock the connector, causing the friction lock (collet) to dig in and breech the insulation resulting in the short that kills your camera. SHUDDER!!!!
With that said, and understanding how the mechanism works, the LEMO really is quite a clever bit of engineering, perfectly designed to resist accidental unplugging, but its NOT idiot-proof!

​Happy and SAFE shooting!

Good find. I'm just like you, coming from the live production industry as a lighting guy. I often have to deal with clueless stagehands and while I know how many connectors work this Lemo confounded me at first as well. That animation helps explain it a bit.

I don't think I would ever trust a stagehand to unplug one though

 

[William Albertini]

Thanks Michael for posting.

 

[Michael Ou]

Hi Stuart!

Great to see you here! There was a thread awhile back that, although fueled by an irate customer trying to sling mud on RED, did at least bring attention to the importance of proper cable care and the dangers of shorts. My take on the issue is that this is not a RED problem, but a problem for ALL electronics, and the first course of action is understanding how to avoid this. I'm posting the link against better judgement because it is ugly and accusatory and really should be viewed as a cautionary tale for proper cable care. But let me also state that nothing in this thread has been verified or substantiated. I just took what I could from it and sought to educate myself, so please, for others reading, take it with a grain or a whole shaker of salt:

http://www.reduser.net/forum/showth...now-they-won-t-fix-it!&highlight=cable+tester

It's really great that Red has created this forum and more importantly has an involved presence. THANKS!!!

 

[Michael Ou]

Yes Michael,

Are you simply referring to idiots who improperly grasp and pull on the cable or do you mean to suggest there is something more happening?

Yes Scott, sometimes those same "idiots" may have started their journey unloading and running hundreds of feet of soca off a truck and then come upon this little cable, lol. The little cable doesn't stand a chance! For those folks not in the know, it is quite an honest mistake to grasp the rear half of the plug assembly, thinking it's part of the plug (which it is) but not knowing about the internal locking mechanism, because it is not visible. Yesterday I WAS one of those idiots, today I'm not (at least when it comes to LEMOS, lol)

 

[Michael Ou]

I don't think I would ever trust a stagehand to unplug one though

Ha! Poor LEMO would suffer greatly under that bute, whatever her name is.

 

[Scott Crawley]

Yes Stuart, sometimes those same "idiots" may have started their journey unloading and running hundreds of feet of soca off a truck and then come upon this little cable, lol. The little cable doesn't stand a chance! For those folks not in the know, it is quite an honest mistake to grasp the rear half of the plug assembly, thinking it's part of the plug (which it is) but not knowing about the internal locking mechanism, because it is not visible. Yesterday I WAS one of those idiots, today I'm not (at least when it comes to LEMOS, lol)

LOL Don't you hate when that happens? Well at least you are smarter today!

 

[Michael Ou]

LOL Don't you hate when that happens? Well at least you are smarter today!

Or maybe not, I called you Stuart, but I promptly corrected my mistake. lol Sorry! and THANKS!

 

[conrad gaunt]

What ? Where did you read about that "problem" ?

I don't know exactly what problem, but if he means Red drive cables and Lemo in general are crap and break pretty easily.. he's right

 

[Michael Ou]

I don't know exactly what problem, but if he means Red drive cables and Lemo in general are crap and break pretty easily.. he's right

Ouch! I certainly did not say there was a problem, but rather how to avoid potential problems through research and sharing of information.

 

[Les C.]

Hey - thanks for posting. I would probably have ended up being one of the 'idiots' who grabbed the cable in the wrong way!

I wonder if there are more non-obvious ways to accidentally mis-handle the equipment?

Maybe there should be a RED-for-dummies FAQ. A list of the parts that are NOT hot-swappable, at the very least (as outlined in the manual).

I'd certainly read it in order not to do something too stupid that I'd immediately regret.

BTW - got part of the way through that EVF thread.

Sad how childlike people can become when on a computer and not face to face without the normal checks and balances of human interaction.

I'm pretty sure you helped prevent some other threads like that.

 

[Michael Ou]

Hey - thanks for posting. I would probably have ended up being one of the 'idiots' who grabbed the cable in the wrong way!

I wonder if there are more non-obvious ways to accidentally mis-handle the equipment?

Maybe there should be a RED-for-dummies FAQ. A list of the parts that are NOT hot-swappable, at the very least (as outlined in the manual).

I'd certainly read it in order not to do something too stupid that I'd immediately regret.

BTW - got part of the way through that EVF thread.

Sad how childlike people can become when on a computer and not face to face without the normal checks and balances of human interaction.

I'm pretty sure you helped prevent some other threads like that.

Thanks Les! You certainly read my mind! Hot swappabilty (is that even a word?), seems to be a biggie and definitely of interest. Right now, I just play it safe, rather than sorry.

Your RED-for-dummies FAQ idea is brilliant and should be mandatory reading considering all the new folks Scarlet has seduced! I guess in a way, that's what this forum serves as, but I know, a MUCH more condensed version would be useful.

Yes, I also only got partway though that thread before it just became utterly "non-constructive".

Thanks for the vote of confidence Les! I've been a longtime lurker, but after getting my Epics I've made it a point to be more active, to contribute and help rather than speculate and cause doubt. There are a lot of VERY knowledgeable people here, but I'm afraid sometimes they are also hopelessly outnumbered, lol.