Home
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in
Basic techniques to repair lenses (and cameras)
View previous topic :: View next topic  


PostPosted: Sat Oct 02, 2010 9:55 am    Post subject: Basic techniques to repair lenses (and cameras) Reply with quote

From time to time I see some colleague doing a repair try on a lens that always ends in disaster because he's not using the right tools and practices. So I've setup this post with my little experience, expecting it could be useful for some other begginer.

Repairing a lens shouldn't be too difficult if the disassembly sequence is known, the right tools are used and some minimal cautions are taken.

The most difficult part is to know the disassembly sequence. Older (unknown) lenses are like a puzzle, we have to figure out how to do that, but many newest ones are documented.

Some colleagues that have been able to discover the disassembly sequence, end in disaster because they do not take the proper cautions and don't use the right tools.

That's what I do, and I'm widely open to comment and suggestions to improve.

Basic tools:



Calibrated rubber tubes to unscrew the lenses. Many people use uncalibrated chair leg-ends that may damage the coating.



I'ts mandatory not to touch the lenses with the fingers. skin grease is a good base for fungus growth. I use clinical discardable gloves. Cheap and secure for the lenses.

Individual enses have to be treated with exquisite care. Never let them drop, so use always suction pads to pick them from inside the body (and never turn the body upside down to let them fall). Always use a wide microfiber fabric base to work on.





Important to mark the topside of each lens removed, to be able to place it back in the same position. I use small adhesive spots on the topside. Since them can let some adhesive remainings, I got a small ultrasonic cleaner (the one used by the opticians to clean glasses) so the last step prior to assembly any lens is to clean it up.





A spanner wrench is mandatory to unscrew those retaining rings. Never use scissors, a pair of compasses or an adapted plier: that's asking for disaster.

Always protect the exposed lenses with a small microfiber pad to avoid accidental scratches when manipulating.







Replaceable pins:



Never use plumbing metallic tools to unscrew filters, etc, from the outside. A simple rubber wrench will do the work without risks:...



In summary, repairing lenses is not so difficult, but to do it properly it's a not so easy.

Always work like being in a lab.

Hope this will be useful for anyone else...

Regards.

Jes.


PostPosted: Sat Oct 02, 2010 10:21 am    Post subject: Reply with quote

What a fantastic repair kit! Wow!


PostPosted: Sat Oct 02, 2010 10:43 am    Post subject: Reply with quote

Very nice (and not cheap!) set of tools. I would be interested in your comments on screwdrivers. Do you use a particular maker? I have great difficultly in finding a quality screwdriver which will work on stubborn screws without damaging the screw and without the screwdriver tip being destroyed.


PostPosted: Sat Oct 02, 2010 10:43 am    Post subject: Reply with quote

Many thanks Jes , for this fantastic guide for beginners.


PostPosted: Sat Oct 02, 2010 10:57 am    Post subject: Reply with quote

martyn_bannister wrote:
Very nice (and not cheap!) set of tools. I would be interested in your comments on screwdrivers. Do you use a particular maker? I have great difficultly in finding a quality screwdriver which will work on stubborn screws without damaging the screw and without the screwdriver tip being destroyed.


You're right!. I forgot to mention screwdrivers, and are a key piece in the repairing process...

Let me recap a little and take some shots on mine, but basically by now forget about the chinese boxes with small screwdrivers... Wink

Regards.
Jes.


PostPosted: Sun Oct 03, 2010 7:29 pm    Post subject: Tools: Screwdrivers Reply with quote

Along the time, I've been collecting many screwdrivers. Any that looks promising is being tested and remains in the toolbox or not depending on usefulness and quality.

I do prefer to buy specific ones that a mixed box, anyway I got the two kinds.

My favourite ones are the german made ones, brand "Wera". They are strong, well calibrated, have a magnetic tip and the extreme of the handle rotates. I buy them at the professional hardware stores, in Barcelona:



Next in my ranking are the Tooxem brand, (I think they are made in the US). I got a box of six of them, three flat tip of size 2, 2.5 and 3, and three cross (Philips) tip, sizes 000, 00 and 0:

They dont have magnetic tips, but are sturdy and have good ergonomics as well:



I also have some of the ones used by the watches repairmen:



I also keep a box of assorted "strange" tips, bought at Bauhaus:



My recommendation is not to buy "collections" of screwdrivers, but the single ones that are needed for a specific repair project.

Always use the proper screwdriver that fits firmly in the screw head and has the same width. This will prevent damage to the screws. Nothing worse that a broken screw head and a broken screw inside the thread...

Regards.
Jes.


PostPosted: Sun Oct 03, 2010 8:25 pm    Post subject: Reply with quote

Thanks for the advice - I think it is better to learn and begin fixing lenses by your own as I experienced a lot of unprofessional slaughtering by amateurs they called themselves "lens doctors".
Very Happy


PostPosted: Sun Oct 03, 2010 9:42 pm    Post subject: Reply with quote

MF-addicted wrote:
Thanks for the advice - I think it is better to learn and begin fixing lenses by your own as I experienced a lot of unprofessional slaughtering by amateurs they called themselves "lens doctors".
Very Happy


Sure!... Buying the tools is always less expensive than repairing a single lens. Wink

Regards.

Jes.


PostPosted: Sun Oct 03, 2010 9:51 pm    Post subject: Reply with quote

Just another issue: What to do when one doesn't find the proper tool???

The asnwer is easy: build it by yourself.

As an example:

I'm repairing an old toy from Fisher Price, a music box that looks like a vinyl disc player. It has four screws in the backside, each inside a long tube. Looking at the screw one can see it's a hexagonal head. None of my hexa tools fitted into the tube, so no way of trying the head size.




What I did was to use an exhausted ballpen body.
Melting the top with a lighter and pressing the melted plastic against the head gave me the tool I needed:





Regards.
Jes.


PostPosted: Sun Oct 03, 2010 11:40 pm    Post subject: Reply with quote

Excellent collection of small tools, Jes.


PostPosted: Sun Oct 03, 2010 11:44 pm    Post subject: Reply with quote

Brilliant solution!


PostPosted: Mon Oct 04, 2010 4:24 am    Post subject: Reply with quote

Very useful information Jesito- Thanks for posting this with images. Its a pity that the MFlenses spanner wrench isn't available anymore,looks like best one out there.


PostPosted: Mon Oct 04, 2010 7:22 am    Post subject: Reply with quote

Thanks for sharing Jes.
That's a wonderful set of tools you have.


Still the tools are more expensive than a service here Very Happy
Cleaning is between 10-15 eur - done professionally.


PostPosted: Mon Oct 04, 2010 7:40 am    Post subject: Reply with quote

std wrote:
Thanks for sharing Jes.
That's a wonderful set of tools you have.


Still the tools are more expensive than a service here Very Happy
Cleaning is between 10-15 eur - done professionally.


Mmm... it's a pity that the shipping costs would be higher than the work ones... If not I'd be thinking in sending some Wink

Regards.
Jes.


PostPosted: Mon Oct 04, 2010 8:21 am    Post subject: Reply with quote

@Orio, Dave, std, Khatmandu, many thanks for your comments.

Jes.


PostPosted: Mon Oct 04, 2010 6:16 pm    Post subject: Reply with quote

Very nice kit, Jesito.

I took a camera repair class taught by a grizzled old repair guy about 20 years ago, and learned a few things from him. One has to do with screwdrivers. He pointed out that the screws found in cameras that look like Philips actually aren't -- they're "cross point." According to him, the angle of the tip is different. Cross points have a shallower angle than Philips. It was not easy to find cross-point screwdrivers, though. I think of my three or four sets of "jeweler's screwdrivers," only one is cross points. Used to be, back then, you could buy repair tools from Vivitar, and I bought several cross point and slotted screwdrivers from them. Still have 'em.

A couple of items I'd add to Jesito's list are: Naphtha -- a great all-around solvent for getting gummed up things ungummed up. Useful for shutters and other precision areas. And PlioBond -- or contact cement, if you can't find Pliobond. They're essentially the same thing. This is a flexible cement that works great for reattaching rubber focusing grips to lens barrels that may have come loose, or for reattaching leatherettes to camera bodies. Sometimes you don't need it with the leatherettes. You can use acetone to "reactivate" the dried out adhesive on the leatherette and it will re-adhere itself to the camera body.

I will also use denatured alcohol and cotton swabs (Q-tips) for some cleaning chores. Like, for example, a Canon FTb I bought last year. The mirror cushion had rotted and a previous owner smeared the rotted rubber across the focusing screen. It was a mess. I didn't feel like having to dismantle the top end of the camera to remove the focusing screen and give it a proper cleaning, so I thought I'd try a cotton swab soaked in denatured alcohol. Wiped it across the focusing screen, and to my surprise, it removed all traces of the gunky sticky rubber residue. I had a spotlessly clean focusing screen. This combination also works well just for general detail cleaning of a camera or lens's exterior.

Also, I've passed along this recommendation here before from time to time, and I will again. If you get stuck and you have questions that folks here can't answer -- like say you're taking apart a fairly complicated zoom lens or hoping to fix a camera's meter -- then I recommend you drop in at the camera repair forum over at KY Photo:

Go here and click on "Maintenance and Repair."

http://www.kyphoto.com/cgi-bin/forum/discus.cgi

There are some very knowledgeable folks who hang out there, including Rick Oleson, a well-known repair guy. I've gotten help several times from forum members when I was stuck.


PostPosted: Tue Oct 05, 2010 8:27 am    Post subject: Reply with quote

Thanks for your comments, cooltouch.

Regarding solvents, I do prefer to use Isopropylic alcohol, either pure or dilluted to a 70% (depending on the application), although I keep a can of lighter fluid for the case it's needed.

Regards.

Jes.


PostPosted: Thu Oct 07, 2010 8:20 pm    Post subject: Reply with quote

Isopropyl alcohol certainly works well, and I too keep a bottle handy. I prefer denatured, however, because the regular iso that you buy off the shelf at your local drug store is about half water, and after the alcohol evaporates, water remains. This can be a problem in some situations. With denatured alcohol, I don't have this problem.

It's worth noting that "lighter fluid" and naphtha are the same thing. Cool


PostPosted: Thu Oct 07, 2010 8:51 pm    Post subject: Reply with quote

cooltouch wrote:
Isopropyl alcohol certainly works well, and I too keep a bottle handy. I prefer denatured, however, because the regular iso that you buy off the shelf at your local drug store is about half water, and after the alcohol evaporates, water remains. This can be a problem in some situations. With denatured alcohol, I don't have this problem.

It's worth noting that "lighter fluid" and naphtha are the same thing. Cool


Well, the one I use is 100% water free, I buy it at a chemicals store for labs.
You're right, most commercial alcohols (ethilic, methilic...) come with some water dillution. Denaturated have the problem of the add-ons (colour, smell) that are added to make them ucomfortable for the human use... and they also remain after evaporation...


Regards.

Jes.


PostPosted: Thu Oct 07, 2010 8:52 pm    Post subject: Reply with quote

cooltouch wrote:
Isopropyl alcohol certainly works well, and I too keep a bottle handy. I prefer denatured, however, because the regular iso that you buy off the shelf at your local drug store is about half water, and after the alcohol evaporates, water remains. This can be a problem in some situations. With denatured alcohol, I don't have this problem.

It's worth noting that "lighter fluid" and naphtha are the same thing. Cool


Well, the one I use is 100% water free, I buy it at a chemicals store for labs.
You're right, most commercial alcohols (ethilic, methilic...) come with some water dillution. Denaturated have the problem of the add-ons (colour, smell) that are added to make them ucomfortable for the human use... and they also remain after evaporation...


Regards.

Jes.


PostPosted: Thu Oct 07, 2010 9:13 pm    Post subject: Reply with quote

The denatured alcohol I buy has less than 10% of the denaturing additives, which I don't really consider to be a problem. Some folks develop a sensitivity to these additives, however, so I should probably add a cautionary note about its use -- use protective gloves, don't inhale fumes, etc.


PostPosted: Thu Oct 14, 2010 8:17 am    Post subject: Reply with quote

I worked with a spanner wrench at work and was dissapointed.
My modified big old caliper was much better - here are some pictures of it:
http://www.4photos.de/camera-diy/kamera-reparatur-werkzeug.html
It is big enoug for all the lenses I open Very Happy

For some tasks I use a part of a bicycle tube. The rubber is good to open some filter rings. But I still need something like those rubbers you mentioned.

For flash capacitor draining I build a adjustable resistor with high voltag cables - but I think there are better commercial devices to buy - for less money.

I use Wiha PicoFinish Phillips screwdrivers.


PostPosted: Thu Oct 14, 2010 12:53 pm    Post subject: Reply with quote

ZoneV wrote:
I worked with a spanner wrench at work and was dissapointed.
My modified big old caliper was much better - here are some pictures of it:
http://www.4photos.de/camera-diy/kamera-reparatur-werkzeug.html
It is big enoug for all the lenses I open Very Happy

For some tasks I use a part of a bicycle tube. The rubber is good to open some filter rings. But I still need something like those rubbers you mentioned.

For flash capacitor draining I build a adjustable resistor with high voltag cables - but I think there are better commercial devices to buy - for less money.

I use Wiha PicoFinish Phillips screwdrivers.


Thanks for the info!. The caliper mod is a sound idea... I think I have a spare one to try Wink The benefit is the big handle that will provide a good push.

To discharge capacitors, I built this unit that is very effective:



The diodes provide a fixed voltage to the LEDs that light whilst there is energy stored in the capacitor. The resistor R1 has to be able of disipating 5 Watt or more...

Regards.
Jes.


PostPosted: Tue Nov 02, 2010 11:06 pm    Post subject: Reply with quote

Thats a great thread here! Thanks Jesito!

Could you please advice some supplier of these tools? Where to get them, what prices are appropriate, what to seek for?

Thanks!

b


PostPosted: Tue Nov 02, 2010 11:29 pm    Post subject: Reply with quote

berraneck wrote:
Thats a great thread here! Thanks Jesito!

Could you please advice some supplier of these tools? Where to get them, what prices are appropriate, what to seek for?

Thanks!

b


A little difficult. Our official provider, Alex (HK300) is not visiting the forum since July. I've found some alternative providers for some of the tools.
Please, tell wich of the tool are you interested in and I'll try to give you a rough idea of how much it can cost and where to find a similar one.

Regards.

Jes.