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BarryS
25-May-2010, 19:38
The killer deal I got on a universal iris might not be so killer after all. :) I disassembled the iris and found that some of the iris blades had popped their pins. Does anyone have any idea on how to reinsert the pins so they're firmly secured? Any idea on how the pins were affixed in the first place? The pins have a slightly smaller diameter base that inserts into the hole on the iris blade. They may have been pressed into a slightly smaller hole for a friction fit, but the ones that popped out freely fit into the holes and fall right out. Some kind of brazing maybe? It seems like they should be fixable.

Vick Vickery
25-May-2010, 20:30
Without actually seeing them its hard to say, but my first inclination is to think about riviting them (spelling?) with a sharp pointed punch after they are back in place.

Steven Tribe
26-May-2010, 01:09
I think the fixing of the iris blades to their axel is something to do with making the original assembly easier. I don't think a few loose blades will influence the adjustment, locking and tightness of the grip. Looking into mine, without taking it apart, indicates there isn't much lateral play available which would effect the function. But it is necessary, I think, that all ends of both "rings" of fixing rings have wider heads.

I have been extremely disappointed with the "security" of my new addition. It seems to me that the whole system, width of the blades etc. makes it only really useful for the older, wide and deep thread types. It just doesn't seem to lock well on later finer threads. Two of the blades have a little distortion but I find it difficult to imagine that this would effect the efficiency so much.

Peter K
26-May-2010, 02:44
Degrease blade and pin and glue it with a little dropplet of epoxy resin. If the epoxy is cured clean the pins etc. with a sharp knife.

Keith Fleming
26-May-2010, 12:49
Steven,

My approach to the "security" issue has been to use gaffer's tape on the threads of the lens. I believe that in addition to being more secure it also provides better protection for the threads.

Keith

Stephane
26-May-2010, 13:09
Instead of the gaffer tape, I use vulktape on the threads. It is some king of self vulcanizing rubber that only glue to itself. It works for me.

BarryS
26-May-2010, 13:35
Thanks for the suggestions. I'll try some epoxy first and if that doesn't work, I'll try to rivet the pins or rather--have someone with metal shop competence rivet them. :) This is my second iris and I find them very useful, but in a limited number of circumstances--for testing lenses and checking coverage, and shooting with small to medium lenses in the studio.

eddie
27-May-2010, 12:53
i have tried the epoxy...it did not do it. i have tried everything on these and studio shutters....not a good outcome.

but as steven says a couple here and there will still allow it to function....more or less.

try the epoxy. keep us updated.

GPS
27-May-2010, 13:27
The pins were probably pressed to the iris leaves. If they fall out you could ask a metal shop to make new pins with a slightly bigger diameter and let them be pressed there again.
And indeed, the universal iris is a crude device that is not a solution for all lenses, let alone the questionable parallelisms of the assembly...

Steven Tribe
7-Jan-2012, 04:32
I have received an iris clamp for repair (5 pins have gone) I will post a repair and servicing "guide" the next few days. Suitable for kitchen table workshops!

E. von Hoegh
7-Jan-2012, 08:01
The pins should be rivetted into the blades. Turn the pins so they are a tight fit in the blades, then rivet the protruding end with a rivetting punch. Leave about 1/4 the diameter for rivetting, and chamfer the side of the blade that the rivet is formed on. Smooth off with a #5 or #6 file to prevent jamming. Good luck.

Steven Tribe
7-Jan-2012, 11:40
"The pins should be rivetted into the blades".
This is certainly a good idea IF the pins have not been lost!
I am in the situation with all the blades - but without 5 pins.

These have become a high value item and an overhaul and repair is well worth while. The solution I have is for we mortals without access to a lathe.

E. von Hoegh
7-Jan-2012, 11:50
Argh. Any chance you can find an obliging machinist?

Steven Tribe
8-Jan-2012, 06:30
The saga continues.
General Maintenance.

Taking apart the universal iris is quite straight forward. There are some very small screws so the usual desert plate storage (white!) is recommended.

The only screw I did not removed is the screw holding the adjustment lever (aluminium) to the turning pinion (iron alloy or perhaps, alumunium too). A sheared off thread here would be very time consuming. A single missing tooth on the pinion will not make the iris scrap, just more difficult to adjust.
My blades are pretty well perfect, but I know from other iris clamps that these can be very jagged at the edges. Bad bends and edges need to flattened - remember appearance is not important here. After this, check with fingers from both sides of each blade that the leading edges are complete smooth and wont catch on other blades. Check also that there are not other pins that are about to fall out.

The reason why the pins have fallen out seem to be twofold:

- when the hole left still has the original diameter, the riveted lip as just fallen off due to fatigue or a production mistake. I found one of these in my five "holes". This is very suitable for the lathe/rivet repair as already mentioned in this thread.

- when the hole is larger, and accompanied with paint loss, this is a sign that the rivet/pin has been forced of due to iris misuse or increased friction in the system.

I certainly found hardened grease, both in the pinion chamber, the rack teeth and on the surface of the turning disc and housing. The clearance between the disc and the inside of the housing can be very slight. The photo shows where this deposit is.

Basic maintenance is removal of all aged lubricant from all surfaces as well as renewal of this grease.

Steven Tribe
8-Jan-2012, 07:08
Pin repair.
The first thing I need to mention is that all 5 of my pins where on the same side of the blades. The pins that travel down and up and fit in the radial slots in the moving disc. I do not know whether this is the most common or just chance. I don't think that this repair method is unsuitable for the fixed hole side, although more care would have to be taken with precise lengths of the pin.

The basic method is shown as the first photo.
I found 5 screws that fit almost exactly into the slots. These standard M3 brass screws.
I wasn't prepared to drill slightly larger holes in the blades (material risk) so I used the taper handle end of a small chain saw file to enlarge the diameter until I could start a M3 thread tap and cut a thread.
The purpose of this thread is to be able a good puchase for the screw in connection with later soldering! I then mounted the brass screw (right side!) so it penetrated the plade by about 0.5mm. I then soldered (electrical type)on the flush side after removing a rim of black paint on the blade around the hole. I make no claim that the solder hangs on to the iron but that the filling up of the thread appears to lock the screw.

Then the screw is shortened to the appropriate length using a hacksaw. There is no need for precision here - just saw into the thread which looks about right. This hacksawing, and later filing, is a good test that the assembly is OK.

The flush side with solder is roughly filed flat and the threads of the screw on the other too, until there is friction free movement in the disc slots.

The last photo shows the completed assembly. Note the 5 new pins are placed in a row at the right. These are slightly longer than the original pins and easiest to position (using a thin screwdriver inserted in the iris gap) when they are next to each other. The disc "sloping descent" onto the pins has to started here.

Jody_S
16-Jan-2012, 21:07
Argh. Any chance you can find an obliging machinist?

I have recently set up a watchmaker's lathe in my workshop, and bought a couple feet of brass stock of suitable diameters, as I have several lenses in need of this sort of repair. But I haven't gotten around to trying it yet. The Boley lathe looks pretty cool sitting on the workbench though. The ziploc baggies with parts of lenses all over the damn place detract from the beauty of the machine, however.

c.d.ewen
16-Jan-2012, 22:26
The Boley lathe looks pretty cool sitting on the workbench though. The ziploc baggies with parts of lenses all over the damn place detract from the beauty of the machine, however.

You've got room on your workbench for lenses? :p

Charley

E. von Hoegh
17-Jan-2012, 08:01
I have recently set up a watchmaker's lathe in my workshop, and bought a couple feet of brass stock of suitable diameters, as I have several lenses in need of this sort of repair. But I haven't gotten around to trying it yet. The Boley lathe looks pretty cool sitting on the workbench though. The ziploc baggies with parts of lenses all over the damn place detract from the beauty of the machine, however.

If you want to make it more fun, disregard the compound rest and use the tool rest and a graver.;)

Jody_S
17-Jan-2012, 13:50
If you want to make it more fun, disregard the compound rest and use the tool rest and a graver.;)

What's a compound rest? ;)

All I have for the lathe is the flip-out file rest, there's a name for it but I don't remember. I'm shopping for the compound rest and milling attachment, as well as 3- and 4- jaw chucks. You can buy them new from China, but they're expensive; I'm hoping to find another scrap lathe locally.

E. von Hoegh
17-Jan-2012, 13:58
What's a compound rest? ;)

All I have for the lathe is the flip-out file rest, there's a name for it but I don't remember. I'm shopping for the compound rest and milling attachment, as well as 3- and 4- jaw chucks. You can buy them new from China, but they're expensive; I'm hoping to find another scrap lathe locally.

The thing you are calling a file rest is the tool rest for handheld tools. Boley lathes are very common, you shouldn't have to buy anything new. Be sure to keep the spindle bearings clean and well oiled. I've had nothing but headaches with the two Chinese lathes I've used, I can't imagine what Chinese stuff in this size would be like. Do you have a tailstock? you'll need the correct Boley item. Keep an eye out for a set of good 8mm collets.

BarryS
17-Jan-2012, 14:23
Steven-- Thanks for posting your pin repair solution. I'll have to dig out the bag with my extra iris and see if I can duplicate your repair.

Jody_S
17-Jan-2012, 18:53
The thing you are calling a file rest is the tool rest for handheld tools. Boley lathes are very common, you shouldn't have to buy anything new. Be sure to keep the spindle bearings clean and well oiled. I've had nothing but headaches with the two Chinese lathes I've used, I can't imagine what Chinese stuff in this size would be like. Do you have a tailstock? you'll need the correct Boley item. Keep an eye out for a set of good 8mm collets.

I have a few collets in so-so condition, and a tailstock. The retired watchmaker who sold me the lathe said the flip-out thing was the traditional tool rest from back when people ran these off a bow instead of an electric motor, like the boy scouts teach to start fires. Personally I would rather have a good turret tool-post with an assortment of cutting and drilling tools; I was spoiled those years with my 5,400 lb engine lathe. I actually have 2 Boleys now, I'm hoping to sell the 2nd 'bare-bones' machine in exchange for collets or tooling. I had a fairly complete set of Lorch 6mm collets that came with the one machine, but no adapter to use those on the 8mm Boley... so I've already sold those to someone who picked up a Lorch in the UK.

Here's a pic:
http://i8.photobucket.com/albums/a8/Kingsmeg/boley.jpg
In this forum, I shouldn't have to explain what that wooden thing on the left is. Nor the other assorted wooded objects in the background. In the top left, is my Hummer V vacuum electroplating machine ($50 from a storage locker, including solid Nickel and Chrome cathodes). If anyone has a formula for single-coat optical coatings (Fl-Al, Al-O?), please let me know. Every manufacturer has their own, and I gather they're all trade secrets because I haven't found a usable one yet.

E. von Hoegh
18-Jan-2012, 07:48
I have a few collets in so-so condition, and a tailstock. The retired watchmaker who sold me the lathe said the flip-out thing was the traditional tool rest from back when people ran these off a bow instead of an electric motor, like the boy scouts teach to start fires. Personally I would rather have a good turret tool-post with an assortment of cutting and drilling tools; I was spoiled those years with my 5,400 lb engine lathe. I actually have 2 Boleys now, I'm hoping to sell the 2nd 'bare-bones' machine in exchange for collets or tooling. I had a fairly complete set of Lorch 6mm collets that came with the one machine, but no adapter to use those on the 8mm Boley... so I've already sold those to someone who picked up a Lorch in the UK.

Here's a pic:
http://i8.photobucket.com/albums/a8/Kingsmeg/boley.jpg
In this forum, I shouldn't have to explain what that wooden thing on the left is. Nor the other assorted wooded objects in the background. In the top left, is my Hummer V vacuum electroplating machine ($50 from a storage locker, including solid Nickel and Chrome cathodes). If anyone has a formula for single-coat optical coatings (Fl-Al, Al-O?), please let me know. Every manufacturer has their own, and I gather they're all trade secrets because I haven't found a usable one yet.

These lathes were never run with a bow, the bow was used on a small dead center lathe called a turns. A bow was also - and still is - used on the Jacot tool for polishing pivots. You can adapt an old sewing machine treadle to run the lathe, this was the first power source, along with a hand wheel, for these lathes. The tool rest on your lathe is for turning conical pivots and other jobs where a hand tool is used.

I'll see if I can find a good source for accessories for yours.

The first single coatings were magnesium flouride, deposited by vacuum sputtering.

Jody_S
18-Jan-2012, 23:14
The first single coatings were magnesium flouride, deposited by vacuum sputtering.

On a whim, I just searched for magnesium fluoride on the 'bay, sure enough someone is selling a 500g bottle for $75.99 with free international shipping. I'll have to make sure Canadian customs won't stop this, but I have a feeling I'll be ordering some soon. I understood the multilayer coatings included aluminum oxide for abrasion resistance.

My 'Hummer' is generally used in scanning electron microscopy for depositing micron-thick layers of Au, Pt or Pd (yes, I have all of those cathodes also, plus a couple of oddballs), where it is commonly called a '(vacuum) sputter coater'. But it has several deposition methods. For all I know, this is exactly the type of machine that was commonly available in labs and was used to develop the earliest lens coatings.