This is topic PLEEZ, help me fix my changeover! in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Dave Bird (Member # 490) on 09-14-2000, 11:41 AM:
In transit, I must've damaged one of my Simplex changeovers, but the wirings old anyway, so I thought I'd try to fix it. Both coils are shielded from the core, but where to solder the wires? I think the Earth wire (common) attaches to both sides of the middle. This one seems to be soldered directly to the coil. The others (black and red) look to be attached to single strands of coil wire from each end AFTER the coil has been taped. Is this correct?
Other tidbits: Right (red) side coil is thinner. Where does the single ball-bearing go? Is the changeover lubricated (or is that just toxic goo)? If so, with what?
Thank you.
PS- I would've dismantled the other one to have a look, but am having trouble disconnecting the cable from the dowser.
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Dave Bird
Posted by Scott Norwood (Member # 30) on 09-14-2000, 12:53 PM:
Is this a standard "zipper" changeover? I'm familiar with the Century version, but I'm sure it's pretty similar. The ball bearing goes in the little hole in the top of the casting (after you put the sliding rod in but before you put the screw thingie in. It's supposed to keep the blade from dropping randomly during a show. I think that Brad has the wiring diagram in the manuals section here...I used to have one somewhere, but I'm sure that I couldn't find it easily. Don't oil the changeover; I did this once and it works OK for a while but eventually gets everything gummed up. Just keep everything clean (soaking everything in naptha seemed to work for me).
Oh, and don't open the hand douser on the lamphouse much more than a minute or so before each changeover...otherwise you'll melt the blade. I usually open the hand douser right after the motor cue goes by.
Posted by Scott Norwood (Member # 30) on 09-14-2000, 12:56 PM:
One more thing: you can order parts for the zippers from Wolk in Chicago. The coil itself is about $80 (is the coil different for Century and Simplex projectors?).
Has anyone tried the Kelmar changeovers? I know someone who's using them in his home theatre with X-L's and he apparently really likes them. I've only seen the zippers in actual theatre installations, though.
Posted by Travis Cape (Member # 466) on 09-14-2000, 01:18 PM:
The Kelmars are fine with automation. I think if they were used in a changeover booth, they would sound like a gun shot. They just seemed louder than necessary.
Posted by Gordon McLeod (Member # 33) on 09-14-2000, 02:52 PM:
The closing coil is smaller than the open because gravity helps the blade drop
Common which is connected to neutral is the centre between the two coils
Posted by Dave Bird (Member # 490) on 09-14-2000, 04:25 PM:
Thanks guys. I had a nifty picture drawn up (in full colour too), but couldn't figure out how to post it. Oh well. Yes, I have the wiring diagram, but it doesn't quite show where the solders are. Looks to be right to the coil. Gordon, even the common seems to be soldered to the inside of the opening coil (shielded from the actual core of the thing) and then linked by a shielded wire to the inside of the closing coil. But that's the part that's broken, so I just wanted to verify that. Wow, that's never happened to me, when I pulled the top pin - sproing - out comes the spring - and the ball bearing - which I spot bouncing across the concrete - and I'm thinking, oh shit, how many others were there! Cool, only one, I'll have to replace the one in the other machine (and the "ball-point-pen spring) which seems missing.
Thanks fellas!
Thank you
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Dave Bird
Posted by Dave Bird (Member # 490) on 09-14-2000, 04:27 PM:
Forgot, they're Essanay SA5's with the familiar "Simplex" plate cover.