BlackHawk Serpa Cocealment Holster for the Springfield XD Subcompact

Review of the BlackHawk Serpa Cocealment Holster for the Springfield ‘XD Subcompact

Model: 410531BK-R

Short form model number: 31

BlackHawk model 41053BK-R

Two things to understand about BlackHawk holsters: they are well designed but do not make good “concealment” holsters.  The holster is 4” long in total length or 6 ¼” with the holstered weapon, and 2” from the breach cutout to the end.  The depth is right at 2 ¼”, so concealing this under a shirt will produce a noticeable bulge.  The best discrete holsters are flexible cloth holsters that can be comfortably sandwiched in the waistband (IWB).  I used a BlackHawk Serpa holster for my Berretta 92F while on deployment with the US Army and had no trouble with at all.  My positive experience with the BlackHawk holster on deployment was what led me to look for another.

Benefits of the Serpa holster include:

• The best retention and release system I’ve used.
• Smooth draw that allows your trigger finger to be aligned outside of the trigger well in one fluid motion.
• Durable
• Looks good –in my opinion- the design of the holster compliments modern firearm design.
• Holds the ‘XD subcompact snuggly without play.  I read a review that said otherwise, but I have not experienced any rattling or movement.

Don’t mind the bulge; it’s my smartphone!

The 410531BK-R came with a paddle that acts as alternate means of securing the holster to pants.  I personally do not care for the paddle as it is more of a hassle to remove and makes no difference in concealment.  The benefit of the paddle is that it can be worn without a belt and offers a more stable platform than a belt.

The bottom line is that this holster is in my opinion one of the best duty holsters on the market.  I’ve used a button holster, Velcro, push-draw (level II), and believe that BlackHawk offers the best holsters to date.

DIY Microfuge

Completed microfuge.

Manufactured microfuges can be too costly for a non-professional considering the infrequent use.  For the purpose of saving money and satisfying the desire to create something, a low speed DIY centrifuge can be built from a fan.  Initially, I explored using a low cost 25,000 RPM router, but it proved too dangerous, too powerful, and reached high temperatures within only a few minutes of operation.  After considering different options, I purchased a 900-1,100 RPM fan, removed the blades, and fastened it to a stainless steel cooking pot to protect against the possibility of tubes turned projectile.  To create the rotor I used a lightweight stainless steel mixing bowl and heat treated the bottom to tighten and even it up.  For the purpose of maintaining high speeds I kept the capacity to only two 2.5 ml micro tubes.  The tubes have a 12.7mm diameter lip and a 10.72mm diameter body before the taper.

Fan motor and speed control for microfuge.

Relative centrifugal force (RCF) = 0.00001118 x r x N^2 where r equals the radius from center to the tube bottom in cm, and N equals revolutions per minute (RPM).  Given that on high the fan is rated up to 1,100 RPM and the radius is 10.8 cm, we can estimate that the RCF is close to 146 g on the high setting and 98 g on the low setting (assuming that the rotor and tubes equal the fan blade weight).  Ideal RCF for pelleting whole cells or performing a UA is between 200-400 g, so with this particular setup it would require longer than normal centrifuge time to achieve a good separation.  The benefit is that the risk of cell rupture or cast fragmentation is low.

The project as a whole was a success; however, two related problems manifested after testing:

• The unit vibrated slightly due to imbalance.
• The motor began to heat beyond normal operating temperatures.

Balancing of microfuge motor.

Removing vibration is a challenge as it requires near perfect mounting of the rotor assembly and a level motor.  Under normal operating conditions as a fan, the motor would be cooled by air pulled by the blades through the motor housing, but with the blades removed and the presence of vibration, the motor will become hot to the touch during operation.

The most effective and lowest cost DIY centrifuge needing little modification would be a 900 RPM 24” box fan with 10.72mm holes drilled at the fan blade ends.  The fans can be purchased for around $10 out of season, and can produce a RCF of close to 200 g.

Charging a Dead 12v Car Battery with an Inverter Arc Welder

The inverter output read 50v which can accelerate gassing and corrosion correlating to the battery’s charge level

Using a DC/ inverter arc welder to partially charge a completely dead battery is possible. I decided to take this approach after my wife left the dome light on all night with the keys in the ignition. In this case the battery was so low that it could not even operate the door locks. Before attempting this there are some very important things to understand: 1, never attempt this on a battery that is near or above a 70% charge (12.32 volts on a digital multimeter); 2, never leave it unattended; 3, it can potentially damage the battery and it is most certainly hard on the battery [see update at end of page]; 4, it can potentially harm you, so always disconnect cables at the welder and not at the battery, and wear protective gear; 5, it can potentially harm your auto’s electrical system, so disconnect the battery from the car; 6, stop the process if the battery becomes hot to the touch.

I connected jumper cables from the battery to the respective positive and negative welding leads, and then turned on the unit at the lowest setting of 10 amps for the charging period. The inverter’s duty cycle  is continuous under 50 amps. The amps were fine, but the inverter was putting out 50 volts (under load also). I knew that the excess voltage would cause hydrogen gas to form faster than usual, and corrosion or even warping of the positive battery plates. Since the battery was almost completely drained I was not as concerned about the effects of the excess voltage. Charging this way can become more hazardous as the battery level increases; there are stories of people who’ve blown up batteries from leaving them on the welder well into the topping charge, and from disconnecting at the battery terminal which resulted in sparks.

The objective was to put enough power back into the battery to start the engine and let the alternator take over. Continually monitoring the battery temperature is critical; if it became hot to the touch then I was ready to stop the process and let the cells equalize. The process worked after 1 hour and 30 minutes the car started up like a charm after shutting down the inverter.

Update as of July 2015—-

My battery failed due to a bad cell at 5 years from the date of purchase.  I suspect that charging it with the d/c inverter 4 years before contributed to that.

Fujinon Mariner Series WP-XL 7×50 Binoculars Review

Review of the Fujinon Mariner series 7×50 WP-XL (without compass) and WPC-XL (with compass)

Fujinon WP-XL 7x50 binoculars have proven their worth in the field

Both binocular models are the same unit. These were the least expensive Fujinon binoculars at $180, before the Offroad Series, but they are far from entry level for performance. I’ve owned these for about a year prior to this review, and have used these at Broadway shows, in the mountains of North Idaho and Alaska, at sea (on a cruise), birding, stargazing, and in the rain. The binoculars perform extraordinarily well, and are in my opinion one of the better 7×50 binoculars you can buy under $200. Following are some facts and observations that are typically not included about the binoculars on seller’s sites:

The body color is closer to grey(as seen) than the blue displayed in pictures, and it’s a hard composite. The only rubber parts are those that are colored black. The binoculars’ prism was affected in one of the tubes per a boating supply retailer after performing a drop test. To that I say it must have been some drop, because the binoculars feel sturdy. The composite body makes the unit light which means longer viewing in an unsupported position, and they float in water. The prisms are supported in a metal bracket internally, and you can safely assume that they are bak-4 at the given price and brand.

The optics can become ever so slightly distorted at the extreme edges –as do all binoculars without an additional field-flattening lens –usually found in the high end models. Looking at an object with intense sunlight coming from the same direction sometimes causes a hazing effect with the sun just out of field of view. The lower internal surface has a tendency to catch light at the right angle and create a partial halo that is only seen when using eye glasses with longer eye relief. The partial halo disappears if the eyes are fully seated in the cups.

The optics are fully-coated. Fujinon verified this after I read from four major retailers that the optics are multi-coated, and five others that they are fully-coated. The coating looks to be a slight purplish color which means that Fujinon opted to increase the brightness of the green/yellow wavelength for ocean goers. In multi-coated lenses there are usually a few more coatings that reduce the reflection of the other major visible wavelengths –each additional coating decreasing the reflection of its compliment. Plain uncoated glass reflects about 4% of the light at every surface, and even the yellow/green compliment will have some positive effect on reducing reflection in the other wavelengths. In theory, and assuming that like most binoculars this one uses six lenses with one coating on each side, light transmission will be under 86% (a single coating reduces light loss down to 1.3% per surface, so (.987)^12=.8546).

The focus is individual, so instead of adjusting for every distance, I adjust to 30 meters for bird watching which gives a nice crisp image from 30 meters and into infinity. The eye relief is good enough to where I can keep my glasses on without folding the cups over. For viewing objects closer than the focused distance, the binoculars can be moved slightly away from the eyes.The bottom line is that these are great binoculars that present a bright, crisp image, don’t fog up, are waterproof, and float. For the complete fully multi-coated binoculars with a field-flattening lens, expect to pay over $600 for a reputable brand.

Changing the Front Hub Assembly on a 2003 Ford Explorer

2003 Ford Explorer Hub Assembly

Replacing the front wheel bearings on your 2002-2005 Ford Explorer yourself will save you around $200 per side in labor costs. Start by renting a hub puller assembly, a 30mm socket and ½” breaker-bar, and a 5 lb. slide hammer that threads into the hub puller for later use. You’ll have to purchase the entire front hub assembly for this truck; the design does not allow replacement of the bearings only. Before starting it is important to understand that the three bolts holding the hub assembly in place are very difficult to remove because of their location, torque, and thread-lock coating. If that does not deter you then continue on.

Brake assembly and rotor

Raise the truck and place jack stands under the vehicle, and then remove the tire. Once the tire is off, remove the entire brake caliper assembly by removing the two large inward facing bolts that hold it to the steering knuckle (the big metal piece that has everything attached to it). There is no need to remove anything else on the brake assembly. Take the breaker-bar with the 30mm socket and remove the axle nut (large central nut –you can’t miss it). There will be some play between the socket and axle nut, but it does the job. With the axle nut removed, the rotor should be free to come off along with the brake assembly.

Carefully place the brake assembly on an upside-down bucket without putting too much stress on the brake lines, and certainly don’t let the assembly hang freely from the brake line. The speed sensor line will be attached to the break line with clips. You can follow the line up into the engine compartment and detach it from the locking point just on top of the wheel well. The new hub assembly will come with a speed sensor cable and clips built in. I clipped my sensor cable to allow the caliper assembly to move farther away from the hub. Be sure and make note of how the cable is positioned in relationship to everything else.

Hub puller/ axle pusher on hub assembly

Attach the hub puller to the wheel studs and use the lug nuts to hold it in place. There should be a threaded spike that presses into a dimple on the quarter axle. As you screw down on it, it slowly pushes the quarter axle out of the hub assembly. DO NOT overextend the axle out of the hub because it can damage the boot between the quarter axles, and damage the gearing inside the boot. The object is to simply move the axle back far enough to access the three “hell bolts” facing the engine that hold the hub to the steering knuckle.

This is the hard part, unless you opt to remove the entire steering knuckle. Use a 15mm  exaggerated offset box end wrench or breaker bar to loosen the bolts. Some people have actually ground down their sockets to fit in the limited space. Ford installs these bolts with a lock tight substance that can make removal nearly impossible. I broke a wrench trying to remove these bolts. The process may be very slow. I tried using break loose and a blow torch to tease the bolts loose. I was able to completely remove three of the six bolts on both front bearings. The nice thing is that the steering knuckle has no threads, so I was able to cut the bolts with a 4.5” angle grinder cut-off disc. It could barely finish the cut, but once done the bolts will just slide out of the steering knuckle. New bolts should be provided for the hub assembly, and sometimes the brake assembly and axle nut.

Steering knuckle and quarter axle with hub assembly removed

To remove the hub, replace the threaded spike with a slide hammer and work it like it owes you money. The hub will come out away from the truck. Avoid using a crow bar (like the one in the picture) because it can damage the aluminum steering knuckle and it doesn’t provide the even force that is needed to draw out the hub. Don’t worry about the black silicon substance; it does not make removal any more difficult. Reassembly is simply a reversal of the process without using the puller or hammer.

Create a Land Navigation Map from Google Maps

Orienteering map made from a Google Maps image

Start by selecting “Terrain” to get a topographical display in Google Maps, and print the picture. A closer zoom generates more isoline detail with the respective elevations. Printing the map in the desired dimensions can be a challenge because of the way the Google Maps interface functions.

The second part is to add azmuthal projections (arbitrary grid lines) to the map for accurate use with a protractor. Google Maps is oriented to true North, so the top of the image is perfectly aligned to the geographic North Pole, unlike grid North which is aligned to the Prime Meridian. I like to shoot an azimuth with the compass, and use the same degrees on the map without the hassle of converting magnetic North to true North and back. To achieve this, the deviation between the Norths can be found on USGS maps in the margin, or by using this diagram:

If you live around the Great Salt Lake, then you would add 15 degrees going from the map to the compass, or subtract 15 degrees going from the compass to the map. If you live in New York then you would do the opposite; subtract 15 degrees going from the map to compass, and add 15 going from compass to map.

Lay a protractor on the printed terrain map so it is square with the map (0 deg. perpendicular to the right and left margins), and make a mark in the center and at the appropriate map-to-compass degree. Take a straight edge and draw parallel grid lines through the map. Now, when using the map you can orient your protractor’s 0 degree line to the drawn in grid lines, and transfer your compass reading strait to the map without adding or subtracting.

Finding Your Location on the Map

A method called resection is useful where you can see two known points on the horizon and on your map. To find your location, simply shoot an azimuth (aim your compass) at the first point and take the reading, then center your protractor on the map’s known point and orient it to the grid lines. Find the same degree on the protractor and make a mark. Take a straight edge and draw a line through the known point to the degree mark, and repeat for the second known point. Where the two lines intersect is your location. You may continue doing this throughout the trek to chart your movements.

Using resection to find your location on a map

The map above shows resection using the three highest peaks as known points. As the map size is increased, the grid lines will deviate from the curvature of magnetic North, and the more difficult it will become to find exact locations. On this map, the distance between major isolines is 400 meters, and the distance between the minor isolines is 80 meters. This image is in the panhandle of Idaho, hence the 20 degree addition (rounded).

Amscope B490B Compound Binocular Microscope Review

Amscope compound binocular (b490b)

I was willing to assume a little risk in buying a compound microscope made by a company without major brand recognition, and it has paid off. To start, my major and background is in accounting (managerial/ cost accounting to be specific), so while I’m not a microbiologist, I do have an intimate understanding of manufacturing, pricing, and the related perception of quality.

My wife, who majored in nursing, was impressed by the Amscope B490B. She said that it looked like one of the university’s lab microscopes. My first reaction to the microscope was reverence –I was really expecting suboptimal equipment for under $250. All of the parts were packaged with care, and the unit is metal with smooth movement and good tolerances. One thing that immediately discloses that the unit is less expensive to manufacture is the use of large hand-retaining screws used to keep the head and condenser in place, as opposed to something more discrete. Every piece of glass in the unit looks like it was given due care during the design phase and manufacturing. I have yet to use the 100x oil objective since the oil that came with the unit is cedar oil. I’m going to get some quality oil that will not gum up or leave a residue over time. The objectives present a great picture with the 10x eyepieces. Notwithstanding the very small exit pupil and related dim display, the 20x eyepieces work well also up to 800x (20×40) magnification. I was also surprised to find that the unit is par focal.

There are a few complaints that I have, one being that the weight of the stage causes it to lower out of focus sometimes. There is an adjustment locking ring to keep the course adjustment from moving, but it only works if you turn the ring with more effort than should be necessary for such an instrument, and there is no indication of which way to turn it. Furthermore, the fine adjustment can and often does spin freely under the weight of the stage even with coarse adjustment locked out. The design of the microscope does not allow for the condenser to be brought closer to the light source which is sometimes necessary to create good contrast at higher magnifications. The reality is that these shortfalls are minor inconveniences.

It’s hard to believe that such a nice instrument is under $250. My best guess is that Amscope has contracted with the Changsha Faith Machinery & Electronic Equipment Co. to use their excess capacity after filling assembly orders for the other brands. On the other hand, it could simply be low conversion costs. Whatever the case, I highly recommend this product to students and hobbyists as a best value buy up to $400.

Note: The Chinese manufacturer’s model number is the XSG-309L with the exception that the Amscope model does not have plan eyepieces or objectives.

Air Rifle Projects

After purchasing a .22 precharged pneumatic air rifle, I decided to pick up a 100 cf steel SCUBA tank for quick refills. I found one on Craigslist for $170, which failed a visual inspection later. I received a second opinion that the steel tank was not safe at the cost of $40, so I went ahead and purchased a new 100 cf Catalina aluminum tank for $270. The total endeavor was $515 with a DIN valve.

The aluminum tank is both larger and heavier than the steel tank, weighing in at 50 lbs. To make transportation to the range easier I fashioned a  hand truck out of .5″ square tubing. The total cost was only slightly less than a bottom line retail hand truck. An 80 amp inverter was used to weld the pieces together. The tube walls are only 1/8″ thick, so the stick would sometimes burn through if left in the pool for more than three seconds. I picked up some 50 lbs rated wheels at Lowes which really gave the truck a smooth ride.

With the hand truck finished there was the question of what to do with the failed steel tank. It had no salvage value other than scrap, so I decided to turn it into a simple pellet trap. Most pellet traps in the store are not designed to catch projectiles with speeds at 950+ fps, but the steel tank with its 3/8″ walls could stop a .22 lr. Fins had to be welded around the opening to prevent the pellets from tracking around the circumference and flying back towards the firing line (and they sure did). Two targets hang inside the trap: a small one for 30 meters, and a larger one for 60 meters. My particular brand of rifle is supposed to land a group within an inch at 46 meters (50 yards). The targets are hanging on a threaded bar, and when struck they spin several times.