Richard Haw's Classic Nikon Repair and Review

In the previous article we’ve outlined most of the essential tools for repair and maintenance of classic Nikons and Nikkors. Now, we’ll be discussing the best application for these tools so that you’ll less likely to destroy your gear by stripping or snapping a screw.

Just like everything else in life, you may mess up in your first few projects and that is OK. In my case, I messed up three projects because there is just not a lot of online materials for this and any useful information out there are scattered or can be irrelevant at times. The lack of proper tools when I first started was also a big contributor to my failed projects since I thought that it would be just as simple as fixing your average kitchen appliance. The good thing is I have managed to fix the failed projects now and I’ll show you how to prevent messing up your project from my experiences.

This guide isn’t going to be organized in any order, I’ll be updating this from time-to-time as I find new ways or remember anything that I have done in a previous project. A good deal has been discussed on the previous article so please refer to that as well and I will try not to repeat anything that can be found there.

Screws and Drivers:

The rule is to use the right type of driver for the right head type. If the tip of the driver does not fit the screw’s head properly and there is play then you are using the wrong driver. Forcing your way will just strip the head so stop and find the right size or modify one to fit. This is simple for slotted drivers, crosspoint drivers are a little tricky and you should only buy ones that will fit the heads perfectly. Of equal importance is the direction in which you’re turning your driver. clockwise for tightening, counter-clockwise to loosen, always remember this – “lefty-loosey, righty-tighty“. This isn’t a rule because you’ll find left-handed threads where the reverse is true. This mostly occur with cameras than lenses, those screws are usually found near the advance mechanism of a camera. It’s rare to find one and it’s difficult to determine which one should go which way.

For the plus (+) drivers, if you stick to the JIS standard you will be just fine most of the time because the slots for JIS screws seem to be the same across-the-board, hence the JIS standard. I have never heard of anybody having a need to modify the JIS drivers at all.

Things can be tricky for minus (-) drivers, the slots seem to come in varying widths and lengths. If the tip does not fit the slot perfectly then the tip is too loose and to make it fit properly you’ll need to grind the tip a bit until it fits. Just make sure that you grind it carefully so that you won’t grind-away too much metal from the tip and end up with a tip that’s too big to fit. Be sure to make the walls of the tips parallel, a wedge-shaped tip will damage the slot as you turn it. The walls of the slots are parallel so your drivers should be as well. You’ll need a micro-meter for this or just buy the expensive ones.

The shorter drivers are used for precision & comfort so that you will have more control and your wrist will have less strain since you are using your fingers to turn them.

The longer drivers are used for larger screws that have seized due to seals, dirt or corrosion. They’ll provide more torque because you are using your wrists to turn them instead of your fingers. Their larger handles also help a lot in generating more torque.

Always press on the screw with the proper amount of pressure. If there isn’t enough pressure there’s a chance that you will strip the head of your screw. Putting too much pressure will lead to slippage since you will lose control of the driver and that will leave a scar on any surface the tip will scratch.

The older Nikkors have the tendency of having excessive amounts of Loctite used on the bayonet screws (and elsewhere) and you should be very careful when working with these. There will be times when you would need to put a drop of acetone on the screw to soften whatever they have used and just apply the correct pressure and torque to loosen them.  I sometimes heat the screw with a butane torch to burn whatever sealant they used on the screw but since I started using the longer shafted VESSEL drivers, I don’t find this necessary anymore. This screw burning practice is a very common hack for auto mechanics (specially on rusted screws). There will be times when the only way to loosen a screw is to heat it but keep that to a minimum.

Be aware that screws come in different sizes in accordance to its use as was discussed in the previous blog post. Below are illustrations of these screws and where they are usually found.

Above is a picture of M1.7 screws used for extra-strength, usually found in these parts, the helicoid keys are a common place for these. Longer/bigger lenses usually have these instead of the more-common M1.4 ones. These are commonly found in parts of the cameras where stability is important, these can always be found in the body casting or the advance mechanisms.

The M2 screws are usually found in the bayonet but they can also be found in other places. Larger/longer lenses will have more of these in key parts of the barrel where there is a need for more stability. Cameras have plenty of these in the advance mechanism’s gear-train.

M1.4 screws are generally used for the rest of the lens. This is the standard size for most smaller Nikkors. These can be found in more delicate parts of a camera such as the rangefinder assembly or the timing mechanisms.

Do not mind my speech and humor, hay fever and Jägermeister don’t go well together. Note that I burnt the paint in the aperture ring while I was heating it. I was in an awkward position, I cannot see very well without my glasses. This is the sort of thing that can easily happen when you are not careful so I hope that this will serve as a warning to you. Botching up a job is easy, all in the name of science. Please read and watch this article on how to work with Nikon bayonet screws (really important).

If a screw is difficult to remove, use a soldering bolt, heat the screw until it is too-hot for you to touch. Doing this will soften the compound and this will enable you to unscrew it without damaging the head.

Below is an illustration from Conex, it shows the different types of heads.

Generally, internal screws should be of a flat-head type so it’s flush with the surface to avoid fouling anything. The oval ones are for the outer cosmetic parts such as the aluminum grip. Pan-head ones can be found occasionally. The rest of the types shown are rarely used if ever.

The metal used for the screws come in different types, too. Nikon used good quality stainless steel or brass screws back in the day and later used softer, inferior screws in their later lenses and cameras.

You should also be careful about the pitch of the threads. Pitch is the space between ridges in the threads. Usually, M1.4 screws will be 0.3, M1.7 screws will be 0.35 and M2 screws will be M4. Using the wrong-pitched screw will result in a ruined thread.

If your screw’s head is badly-corroded or you stripped one accidentally, you should only use a screw or bolt extractor to remove it. Always remember to buy the right type irregardless of brand. The best one I’ve used is this on the picture below.

To use it, simply drill a hole on the screw that is 1mm-1.5mm (and into the shaft). Also make sure that you lubricate the spot with WD40 so the drill bit will not overheat or else it will dull the tip of the drill or snap it. Drilling too deep into the screw will result in flaring of the screw and its hole when you use the extractor so be careful. Next, put the extractor on a hex handle and twist it the opposite way. The screw extractor will bite-into the drilled hole and use friction and torque to force the screw out. If used properly, you can even remove a head-less screw. This is the best way to remove stuck screws. Avoid using gimmicky tools like Moody Tools’. They are just a waste of time and money (I bought a set) and it does not come with any documentation at all. It may work for some people but for what we want, it’s useless and over-priced.

The extractor that we just discussed can be bought in Rakuten. You can use similar ones but just be sure that it is the 1mm type and is similar to what I have here.

To extract screws with exposed heads that are taller than 1mm, use a set of nejisaurus screw-extraction pliers. It does a quick, clean job. Just make sure that you purchase the smallest one. They are special pliers with a notch in the front part of the jaw to grab screw heads. I even managed to remove a headless screw with this once. So long as there is something that is exposed and is tall enough to grab, the nejisaurus will get it.

For screws that are too-corroded that twisting them will result in the heads snapping-off and leaving the rest of the screw’s shaft inside the hole, start by drilling a hole with a bit that is slightly smaller than the hole or screw. As an example, use a 1mm bit for a 1.4mm hole, it will bore-through the shaft. Next, use a hand-tap that’s equal to the size of the hole to clean-up any stuck material or left-over screw parts and to finally repair the damaged threads.

An alternative to the technique just described above, you can also drill the hole with the correct diameter and tapping it with a slightly larger tap. For example, for a 1.4mm screw hole, use a 1.4mm drill bit and tap it with the next bigger-sized screw (1.7mm). Doing this will turn the hole into a 1.7mm hole so the screw size will also change. You can also do this for the threads that are so badly-worn that the right-sized screw turns up being too-loose it won’t even engage the threads, resulting in a free-turning screw. If you have to use the original screw, you can insert new material into the hole and use a tap that’s similar in size to the original screw and make a new hole. This is an advance technique and is difficult to master.

Just remember that these techniques are best done on parts and surfaces of your gear that won’t be seen since they will obviously look improvised and should be used as a last resort.

There are times when the correct screws can’t be obtained and you are only left with modifying a screw to-fit. The easiest way is to mill your new screw from an existing one but there are cases when I had to make new ones with a die. This is more hardcore than it sounds and you’ll need special tools for this task.

That’s all for this article. Screws and drivers sound so elementary but you’re in for a surprise because you can write a whole book about them. These are the fundamentals of any camera and lens repair skillset, you should master these in order to proceed to more advanced skills.

To be continued…

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