Film-Tech Forum ARCHIVE: Brenkert BX100 problem

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Posted by Bernie Anderson Jr (Member # 410) on 04-17-2000, 10:37 PM:

Hey,

are any of you guys familiar with BX100 and their problems. Here's one for you that I can't figure out.

I have 2 BX100's. I bought them from the theatre I was working in at the time. Brought them home, cleaned up the one very well and mounted it and got it working. When the were last used in the theatre they worked well. When I used them in my house for a little while they ran great, even a nice steady picutre that some of my machines at work don't have. I had let it sit for awhile (money ran out and I couldn't finish the screening room) When I went back to it a years and a half later, I oiled everything while hand turing the motor and then I turned it on. It's making a strange sound now.

It sounds like something is rattling loose in the gear box. The picture is still very steady and it runs fine but it's SO Much louder than it ever was. Like I said it sounds like something is loose and is rattling around in there.

It's hard to isolate the sound but it seems to be coming from the back of the projector and towards the top.

Everything that everyone suggests to me doesn't seem to be the problem. Everything seems to be tight and in good shape. Any suggestions on what it might be? Could it be the Star gear? If it was, would I still have a steady picture?

Bernie Anderson

Posted by Mark Gulbrandsen (Member # 72) on 04-18-2000, 11:04 AM:

Bernie,

First go through the entire machine top to bottom and tighten everything up again.Pay attention to end play of gears. Excess end play can cause a machine to make knocking sounds. Check the shutter blade hub lock screw. These were sometimes notorious for comming loose and if it does the shutter assembley can rattle. Also check these things..........
The framing compensator splines. They do wear out, and in most machies are usually sloppy. You would be amazed at what a new set will do for a machine. The next thing to look at is the fire shutter assembly and squirrel cage blower. They an make noise. The fire shutter can also make a chinkling sound when the machine is running if things are loose or vibrating a bit(and the machine shouldn't shouldn't be vibrating at all). And lastly be sure the intermittant is properly and fully seated and locked in place.
Hope something here helps...
Mark

Posted by Jeff Stricker (Member # 224) on 04-18-2000, 02:26 PM:

Mark's comment about the fire shutter reminded me that when I first got my Brenkert BX-40 running after years of disuse I got quite a bit of rattling out of the fire shutter actuator that runns off the govenor plunger that goes into the center squirrel cage blower. I lubed actuator and the bushing it runs through with light oil and it's been quiet since.

Posted by Bernie Anderson Jr (Member # 410) on 04-18-2000, 06:33 PM:

I'm assuming that the cage blower is the little spinning blower at the top? What does that do? I couldn't ever figure out what it's purpose was.

Where are the framing compensator splines located? You know, when I turn the framing knob it seems to relieve the sound a little bit, it's still quite loud but slightly goes away.

What did you mean by "be sure the intermittant is properly and fully seated and locked in place."? Could it be a bad intermittant? I was told by a good tech I know that as the machines running if you slightly push in on the intermittant sprocket from the side and you hear it get louder, it's a sign that they're going bad or are damaged. Is this true? Is there anyway to check? Actually, I've tried this at work on Century SA's and the ones that did create a chattering sound ended up going bad a couple of months later. (That particular theatre had no one really taking care of it)

Any suggestions you guys give me is great. Not too many people know these machines anymore and I love them, Every Brenkert I've worked with has one of the best looking pictures I've ever seen. The ones I have actually came from the Union Drive in New Jersey, so they have a certain sentimental value and instead of changing them out to something else, I would really like to get them working. But thanks again

Posted by Bernie Anderson Jr (Member # 410) on 04-18-2000, 08:07 PM:

I just thought of something, if you have the manual, if you give me the page numbers of the parts that I should look at that will help me alot. I just downloaded the manual for the BX100

Thanks again

Bernie

Posted by John Eickhof (Member # 323) on 04-18-2000, 11:02 PM:

Hi, Check the fan assy set screw (pg 45 part # X-1501) also the p-1026 on the governor assy. I have had these come lose and make noise, Also, check the fan housing around the blade for foreign articles..pieces of metal, dirt, a lost screw or something that may be rattleing. Also, check the X3603 'umbrella' gear on the shutter shaft drive assy (pg 44)
see if there are any teeth missing or flattened. When sitting idle for long periods, the inner & outer shutter shafts will bind together with residue from the oil,
causing excessive load on this gear, and tooth failure! The pitch will cahnge when framing. the other problem spot is the collars on this gear, make sure there is no end play on the shaft. Good luck! John

Posted by Gordon McLeod (Member # 33) on 04-19-2000, 09:27 AM:

On thing I find vey handy when trying to pinpoint a problem is a mechanics stethascope
It is basically a rod on the end of the stephscope that lets you hear a small pinpoint of sound from inside a bearing etc
handy device

Posted by John Pytlak (Member # 331) on 04-19-2000, 10:03 AM:

A stethescope is a good diagnostic tool. As Gordon notes, a mechanics' stethescope allows you to pinpoint noise or vibration in a mechanical component like a bearing. Even a low cost "blood pressure kit" stethescope can help isolate the source of any unusual noise, such as worn sprocket teeth plucking perforations.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Mark Gulbrandsen (Member # 72) on 04-19-2000, 10:25 PM:

Actually a regular or phillips screw driver works out just fine. Put the tip of the screw driver on the main casting near the suspect part and put the handle to your ear. BE SURE NOT TO PUT IT THE OTHER WAY AROUND! You'll hear all kinds of interesting sounds, especially in a ball bearing based machine. Since a Brenkert is all bushings and has no ball bearings things should be very quiet except near he area of the problem.
Mark

Posted by Gordon McLeod (Member # 33) on 04-20-2000, 10:23 AM:

The only problem with the screwdriver method is that you have to bend down close to the machine so other noise can be distracting also if it is a XL with the back off you don't really want to be standing in the oil rainstorm