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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Tue Jun 01, 2004 7:41 pm Post subject: |
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Was out shoooting with my B&J yesterday when the top spring snapped near where the screw is that connects it to the frame that holds the hood & ground glass. Any ideas how to rebond the two pieces? A small weld may work, but I pretty much permantly attached the whole arm to the camera last summer when the screw hole that holds it to the body stripped out. I'm thinking maybe if I cut two small pieces of thin tin, and used them as reinforcement with some two ton epoxy that it could be strong enough. Any other ideas?
This breakdown isn't crippling to the camera. I can still stick grafmatics in and have them hold, just need to put a thumb on it, or press it against my body when I cycle sheets. |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Tue Jun 01, 2004 10:11 pm Post subject: |
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Check with a machine shop in your area that does coutom work and get a length of flat spring stock and make a new one. Let me know if yu do not find any. Use JB Weld not standard 2 ton epoxy to attach a tempary patch to the existing one.
Charles
_________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Rangemaster
Joined: 06 Jul 2001 Posts: 412 Location: Montana, Glacier National Park
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Posted: Tue Jun 01, 2004 10:29 pm Post subject: |
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I have some springs and for repair springs I have used the thin strip of metal that is in windsheild wiper blades, it has the right amount of tension an is stronger than all get out.
Dave |
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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Wed Jun 02, 2004 5:10 pm Post subject: |
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I made the JB Weld sandwich yesterday. Seemed really strong as I applyied force to it with my fingers. Reattached it to the camera and slid in a grafmatic. About 3/4th of the way in I hit heavy resistance. I give it a little push and the back piece of metal I used for reinforcment flys off and the weld breaks.
I imagine the added pressure has to to with the little bit of added ridigitiy not letting the spring flex just enough to squeeze that fat grafmatic in. I allready has the springs shimmed up about 1/16th of an inch to make instering the device easier. |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Wed Jun 02, 2004 5:39 pm Post subject: |
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The JB should have cured for 24 hours before use, standard epoxy would have given much sooner.
To gain extra give in springs so that things like a grafmatic fit reform the ends of the spring that fit over the focus plate pins into ovals that allow extra left/right movemnt.
Charles
_________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Wed Jun 02, 2004 8:08 pm Post subject: |
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The package just said 15 hours curing time, I think I gave it about 17 before trying it. Anyways, the two holes on the entry side are already ovals with no room left to make them bigger. The ones on the otherside or just circles though. Should I try beveling them out a little bit to give it more play?
I have the broken spring clamped up again in JB-weld, but this time I gave it a small gap to lengthen then arm a tiny amount. I'm hoping this will give it enough space so I can insert the graf without making too much pressure on the weak joint.
[ This Message was edited by: Sjixxxy on 2004-06-02 13:09 ] |
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Rangemaster
Joined: 06 Jul 2001 Posts: 412 Location: Montana, Glacier National Park
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Posted: Wed Jun 02, 2004 8:36 pm Post subject: |
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How long of a spring do you need, I have several that I purchased in a lot, and bought it for only two springs for a restoration I am doing....Send me a note, perhaps I have the right one to replace the one you have broke.
Dave |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Thu Jun 03, 2004 2:12 am Post subject: |
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A source for spring steel stock:
http://www.smallparts.com/
use quick search for Springs then click on the spring steel link.
When making new springs make the end loops oval and 1/8 inch longer than origional, cut lengths with a hacksaw and drill screw holes with a diamond bit in a dremmel; mount two small, 1/8 or 3/32, spring steel pins in a steel block to make a forming block for making the end ovals.
Charles
_________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Thu Jun 03, 2004 7:47 pm Post subject: |
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Well, pass #2 for the JB Weld failed horribly, so it looks like I'll be making some new ones.
http://www.smallparts.com/products/descriptions/fss.cfm I assume is what I'm looking for? 6" is long enough, 1/2" should be right to have enough room to bend the ovals from, but how thick should I go?
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Fri Jun 04, 2004 1:54 am Post subject: |
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Measure the length from pin to screw hole to pin following normal curvature of existing spring and then add 1/2 inch for the ovals, get the clostest longer length.
Next measure the width of the existing spring at its widest point. Too wide may interfere with gg holder/film holders.
If you don't have a caliper to measure the thickness then use a ruler marked in 32nds. or 64ths. and convert the measured thickness to a decimal equivalent and use a size close to it or just thicker.
For the striped mount screw, try retaping to the next larger size in metric, 3 or 4 mm should be slightly larger than the origional mount screw.
When I did a simular modification/repair on my Meridian I used close to the origional width and thickness spring stock, made the ends like a U on its side. This leaves the focus plate a little loose but it won't come out and film holders/grafmatics hold firm.
You can do minor adjustments on camera after basic forming has been done to tighten up the film holder/grafmatic to prevent light leaks.
I used 1/4 x .032 x 12 inch and cut it down to length around 6 3/4 to 7 inches per side on the Meridian, a 4x5.
Once you have the material, lay the camera face down on a flat surface.Lay the focus panel on the back in normal position. Mark a center mark on a piece of spring stock and place it over the mount screw or center of film plane if more than one screw is used per side. Mark the outer edges of the focus panel pins on the spring stock.
Now put a grafmatic on the back and lay the focus panel on top in normal usage position, and mark the outer edges of the focus panel pins again.
The inner mark is where the end of the oval should end plus 1/32 to 1/16 and the farest mark is where the inside of the begining of the oval should be.
Charles
_________________
While a picture may be worth a thousand words, a quality photograph is worth a million.
[ This Message was edited by: 45PSS on 2004-06-03 19:13 ] |
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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Fri Jun 04, 2004 5:55 am Post subject: |
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Well. I still think the 6"x.5" is what I'll need for the B&J. I just scetched up a little diagram of what the existing spring would look like with the tabs for the screw holes unbent to be cut from the flat stock.
5/8ths total width, but the 1/8th inch rise is just cosmetic, so I could do withough it and just use the strait edge from the stock material. Comes in packs of ten. Good, that gives me nine tries to mess up. I bet I can get the shape from the stock on a metal grinder.
It appears to be about 1/32nd thick on my ruler, but I wasn't sure is the black textured coating on it was accounting for most of that thickness making the actual stock really around 1/64th. I was thinking if it was really 1/64th stock coated, that 1/32th stock might be to ridgid or have to much tension making it more difficult to get the grafmatics in. I suppose extending the length of the ovals for the screw to slide around in would counter that though.
[ This Message was edited by: Sjixxxy on 2004-06-03 22:56 ] |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Sat Jun 05, 2004 1:54 am Post subject: |
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Oh!, its that style. I'd still go with the 1/32 (.032) stock as it will be more durable.
Making both pin sections match the right side in your drawing with the slots for the pin to be at an edge with the grafmatic installed will give the extra movement necessary to insert a grafmatic.
My springs were just a straight piece that paralled the focus plate and the pins extended at right angles to the focus plate.
With a ten pack you should have 7 left after making a working set and a template.
Chalres
_________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Fri Jun 11, 2004 12:48 am Post subject: |
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I got my spring steel today. Bench Grinder made short order of shaping the piece. That took about 15 minutes work.
Ran aground drilling the screwholes though. I used a typical hi-speed steel bit in a drill-press that was able to punch through the spring steel once, but after that I could only get a second hole about halfway through before the bit gave up. Must have wore out the cutting edge on the first hole. Maybe I'll go back tomorrow and take a closer look at the dremel bits available to me. Its just the basic starter set though. |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Fri Jun 11, 2004 1:16 am Post subject: |
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http://www.dremel.com/html/home_fr.html
under carving/engraving diamond bits 7134 or 7144 will be the best for the job at hand.
Chalres
_________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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Sjixxxy
Joined: 27 Apr 2004 Posts: 109 Location: Midwest US
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Posted: Fri Jun 11, 2004 10:15 pm Post subject: |
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Boy. More issues.
Found a dremel bit that made the screw holes easy enough, but trying to bend the tabs over into the 90 degree position resulted in two broken off tabs.
Any ideas how to make the bends? I tried putting it in a vice and bending it over with a pair of pliers, but couldn't get very far before the pliers themselves hit the vice making me unable to bend them any more. tried to finish it with light hammer taps, that ended up taking them right off. Think warming the metal with a torch a bit before trying to bend would help?
I don't think the .032 thickness is helping any either. Holding it next to the original spring it definitly is a bit thicker and has less give. If I can't get this stuff to bend, I have a feeling that I'd have better luck with thinner stock. |
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