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Simon White
Joined: 11 Aug 2004 Posts: 15 Location: Australia
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Posted: Thu Oct 28, 2004 2:34 pm Post subject: |
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Hey guys.
As I said in my other thread, I just received my Crown Graphic and have yet to put any film through it. I bought it from AlecJ on these boards and he was kind enough to throw in a solenoid for me.
Well tonight for the first time I batteried up the flash tube and hooked up to the shutter release. The shutter is firing, but when I have cocked the shutter it seems that the tripping power is weak and I have to press the red button about 2-3 times before the shutter will fire.
In detail, the shutter seems to only gradually move down with each press of the red button but when it has fired, uncocked, it fires very strongly as it seems it ought to when cocked ... but clearly does not at this point.
Is there anything I can do about this? Is it a common issue and an easy fix? Should I just live with it and rejoice?
It was the first time I put batteries in the focus spot on the top rangefinder tonight and I nearly wept with joy at how amazingly cool this device is. I was fairly excited about the battery tube tripping the shutter also! Is there something wrong with me?
Imagine what I'll be like once I've shot some film through it! I've already bought one grafmatic and have another one on the way. A 545i Pola back came with the purchase and I'm wondering if I should start out shooting type 55 just to get the hang of things.
Any thoughts, suggestions or words of encouragement welcome.
[ This Message was edited by: Simon White on 2004-10-28 07:36 ] |
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glennfromwy
Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming
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Posted: Thu Oct 28, 2004 5:10 pm Post subject: |
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The flash sync has it's own retard mechanism, similar to the slow speed mechanism for the shutter blades, and it sounds like it's gummed up and needs a cleaning. There are numerous threads on how to do it on this site. Everyone has their favorite way of doing it. A search will bring up lots of info.
_________________ Glenn
"Wyoming - Where everybody is somebody else's weirdo" |
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Top
Joined: 06 Apr 2002 Posts: 198 Location: Northern New England USA
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Simon White
Joined: 11 Aug 2004 Posts: 15 Location: Australia
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Posted: Thu Oct 28, 2004 7:02 pm Post subject: |
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G'day Top!
I tried the link but I am not a member and it wouldn't allow me to view it. Would you mind cutting and pasting if it's possible, or could you mail me the document if it has images?
psi_fan@yahoo.com
Apreciated. |
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glennfromwy
Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming
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Posted: Fri Oct 29, 2004 2:11 am Post subject: |
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Sorry, I misread your question. Must have been having another senior moment. To operate correctly, it is imperative that the solenoid be adjsted precisely. It requires enough slack for momentum to build up, then it will pull the lever down. Top is well acquainted with these and his help should get you going.
_________________ Glenn
"Wyoming - Where everybody is somebody else's weirdo" |
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Top
Joined: 06 Apr 2002 Posts: 198 Location: Northern New England USA
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Posted: Fri Oct 29, 2004 12:18 pm Post subject: |
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Simon;
I just posted you a couple of scans in PDF format; hope they help.
Top |
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Simon White
Joined: 11 Aug 2004 Posts: 15 Location: Australia
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Posted: Fri Oct 29, 2004 4:34 pm Post subject: |
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Hey Top,
Just got your e-mail, thankyou very much. I will check them out and get back to you if I get stuck. Greatly apreciated.
Ta!  |
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RKnoppow
Joined: 15 May 2002 Posts: 14 Location: Los Angeles
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Posted: Tue Nov 02, 2004 7:54 am Post subject: |
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What kind of shutter does this camera have? Kodak Supermatics are more difficult to trip than Graphex shutters and may need a stronger current to trip at 1/400th than a three D cell battery case supplies.
The solenoid must be adjusted for the right stroke for both tripping the shutter and for its delay time. The solenoid is meant for synchronizing medium delay flashbulbs that require 20 ms to come up to peak. Graphex/Rapax shutters were designed to have a lighter tripping pressure and to have the pressure constant with speed.
There were several makes of solenoids available for Speed Graphics, the most common are the Graflex and the Heiland. They are similar but have different linkages.
If this is a Graflex solenoid there are two adjustments. One is simply the position of the solenoid in the mounting clamp, the other is the position of the collar with the knurled ring. To start put this collar in about the center of its range. Then set the solenoid in its clamp so that the play in the link to the shutter is just removed. Check by tripping the shutter with it set at around 100th. Very slight adjustments of the clamp position will change whether the thing will trip the shutter or not.
If you want to adjust synchronization the easiest way is to use an oscilloscope if one is available. To do this set the scope for a trace time that puts 20ms near the center of the screen. Then, connect the battery case to the solenoid and also connect it to the external trigger of the scope. If the battery case has no other connections use clip leads to the contacts for the flash bulb. Set the scope trigger on single trace and adjust it so it goes off when you push the trip button on the battery case. Take the lens cells out of the shutter so that you can look directly through it. Set it at 1/200th (Wollensak Graphex/Rapax shutters can be set for 1/400th), Cock the shutter and look through it while tripping it with the solenoid. You will see the part of the trace that the shutter lets through. Adjust the knurled collar until the open time is centered on the 20ms position of the trace. You may have to juggle the clamp position to get the solenoid to trip the shutter and have the right delay.
In the bad old days extra-voltage batteries were available expecially for photo flash purposes because of the unreliability of the solenoid with normal batteries. This can also be cured by using a case extension that takes an extra battery or making an adaptor to fit a 9 volt battery or four AA cells in the case.
The higher voltage also helps with older type solenoids and also to reliably flash old bulbs.
If the solenoid is being used solely as a remote tripper it is, of course, unnecessary to go through the synchronizing procedure.
_________________ Richard Knoppow
Los Angeles, CA USA
dickburk@ix.netcom.com |
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