Jump to content


Photo

HMI Bulb Orientation?


  • Please log in to reply
2 replies to this topic

#1 Matthew Macomber

Matthew Macomber

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 24 May 2018 - 05:25 PM

I have an Arri M18 and M8. Can someone tell me as a matter of fact whether the bulbs are supposed to be installed with the internal bar/rod up or down?

 

IMG_5479.JPG

 

Secondly, is it okay for the ceramic base to be cracked? I just noticed this upon close inspection.

 

IMG_5478.JPG

 

And thirdly, is it okay to spray a tiny bit of lithium grease on the rails inside the housing? I'm trying to kill the squeaking when adjusting the focus knob.


Edited by Matthew Macomber, 24 May 2018 - 05:27 PM.

  • 0

#2 Brian Doran

Brian Doran

    New

  • Basic Members
  • Pip
  • 5 posts
  • Industry Rep
  • New York

Posted 24 May 2018 - 06:27 PM

Osram, Phillips, and Ushio all list their operating positions as "any", though maybe they would tell you something different if you called. It seems to me that the orientation simply doesn't matter with single-ended lamps. The crack on the base of your lamp is certainly not good news, but I would expect the lamp to keep on running for now. Eventually, the vacuum seal of your outer envelope will fail, and so will the lamp. You might notice a white buildup on the glass as the lamp gets worse. 

 

As for greasing the worm-gear of your M18 focus drive, I would say go ahead, but be sure to use a high-temperature lubricant. It is possible that the squeaking is indicative of something other than corrosion of your focus drive. Perhaps the lamp-lock lever has been forced forward or backward by impact, maybe shipping. If that were to happen, the lamp carriage could become twisted slightly. When you move your lamp carriage into full flood position, does the lamp rotate slightly? 


Edited by Brian Doran, 24 May 2018 - 06:28 PM.

  • 0

#3 Matthew Macomber

Matthew Macomber

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 25 May 2018 - 10:03 PM

Thanks for your thoughts Brian. I won't worry about the bulb orientation until there's further evidence to then.

 

As for the worm-gear drive in the heads, I went ahead and sprayed a tiny bit of grease on em. They instantly quieted down. I tried to be very sparse on the grease - certainly don't want it catching fire or whatever.


  • 0


Glidecam

Media Blackout - Custom Cables and AKS

Broadcast Solutions Inc

Technodolly

FJS International, LLC

Tai Audio

Wooden Camera

CineLab

Rig Wheels Passport

Aerial Filmworks

Willys Widgets

Metropolis Post

The Slider

New Pro Video - New and Used Equipment

Ritter Battery

Visual Products

Paralinx LLC

Abel Cine

rebotnix Technologies

Gamma Ray Digital Inc

CineTape

Media Blackout - Custom Cables and AKS

CineTape

Broadcast Solutions Inc

Metropolis Post

Ritter Battery

Tai Audio

Glidecam

Wooden Camera

Willys Widgets

Aerial Filmworks

Rig Wheels Passport

Gamma Ray Digital Inc

rebotnix Technologies

Technodolly

Paralinx LLC

New Pro Video - New and Used Equipment

CineLab

FJS International, LLC

The Slider

Visual Products

Abel Cine