Mil-Shock DIY Modification
From G-Shock Wiki | casio watch resources
by Andy (kontai69)
The DW-5600 G-Shock is a longtime favorite of mine (I've had one for many years). However, due to my skinny wrists, the resin strap never fitted me well. I then learned about the Mil-Shock model. The Mil-Shock is a custom model where the 16mm lugs are widened to fit a 20mm nylon zulu strap. As others have also done, I decided to make a (semi-original) version of my own from a newly acquired DW-5600. This guide lays out all the steps needed to achieve this modification, along with photos of the process.
Step 1: Remove the bezel and strap.
Use a micro Phillips screwdriver to remove the bezel screws on the side of the watch. Pry off bezel. Use a springbar tool to remove the straps.
Step 2: Widen lugs.
I used a 20mm Maratac Mil-series strap (same as the original Mil-Shock) from http://www.broadarrow.net/maratac.htm. I used a Sharpie to markup the lug area I needed to remove. I placed tape around the case to prevent inadvertent scratching of the crystal and case. I used a Dremel tool to grind away most of the plastic and used a small file and 400 grit sandpaper to carefully remove the last amount of plastic until Sharpie ink was all gone.
The "20mm" strap actually measured 19.5mm, so I widened the lugs to little over 19mm. I suggest measuring your strap in case of similar production variations.
I used a cylindrical high speed cutter bit with my Dremel tool: http://www.dremel.com/en-us/attachments-and-accessories/attachment-accessory-detail.htm?H=188537&G=66237&I=66276
Cover the area of the case between the lugs with thick tape to prevent gouging from inadvertent contact with the cutter bit. For the sanding, I tightly hand-wrapped the sandpaper over something flat and solid with a square edge. This produces a flat inner lug surface. The square edge produces a crisp corner between inner side of the lug and the case. I used the metal handle of a case opener.
Step 3: Drill new lug holes.
I used regular spring bars instead of the solid pins as with the original. I used a micro drill bit and pin vice to make new spring bar holes (original ones gets grounded away from lug widening). I used calipers to match the diameter of the drill bit to the diameter of the spring bar ends (0.7mm). I drilled completely through each lug from the outside in.
In lieu of a bench vice, I mounted the case onto a small plastic box using double-sided foam tape. Unfortunately, you can not just pull the watch off due to the extremely tight bond. To detach the watch, I use fishing line to cut the tape off the surface (use a motion like flossing your teeth). I used a pin vice (small hand drill) with micro bit set to make my holes (got it on eBay). Make sure to carefully position the holes! Too close to the edge and the holes will be weak. Too close to the case and the strap will not pass through. Keep the drill bit as aligned as possible as you are turning the pin vice. Even with my careful measurements and very steady hands, the lug holes were slightly out of alignment with the other. For best results, use a drill press where you can drill all the way through both lugs with one drill stroke. The holes will be much better aligned.
Step 4: Install spring bars and strap.
You can compress and install the springbar by hand since there is no strap in the way. Then thread the strap through the lugs.
Adjust the position of case along strap for best fit on wrist with the bezel off! You will not be able to do so with the bezel on because of the tight fit.
In the photos above, you can see the effect of the holes being slightly out of alignment with each other; the springbar does not run exactly parallel to the case. Fortunately, this is barely noticeable once the strap is attached and should have a negligible effect on the integrity of the springbar attachment. The advantage of using springbars is that the compressible ends normally have a little "wobble," making them forgiving to slight hole misalignments. If using a solid pin, the holes will have to be in perfect alignment in order to pass the pin though both lug holes.
Photos of the end result:
The watch now better fits my 6.5" wrists. It feels and wears much more compactly than the stock band.
The strap neatly slips underneath and is secured by the bezel edges.
The nylon strap is soft and comfy. Any excess strap can be neatly folded underneath the keeper.
Anyways, I finally now have the perfect G-Shock for me. I highly recommend this mod. I'm sure it can also be applied to other models as well.