Tuesday, December 15, 2015

Darts Sighting Aid

It's been a while since I have posted.  I've been making lots of stuff but unfortunately much of it is being patented so I can't give any details yet.  Finally got some time to work on my stuff.  Well last father's day my lovely wife got me a professional Winmau dart board.  I've been slightly obsessed, playing any chance I get.  Desperate to improve my game, I came across this sighting aid.  It helps you ensure that your eyes are perfectly aligned with the center of the board.  It looked like something that was easy enough to make.  A little searching on the web yielded these plans.  I grabbed some scrap wood and started cutting.

The 3 pieces: 500 x 250 x 12 mm, 500 x 100 x 12 mm and 500 x 30 x 30 mm

glued and clamped the pieces together

spray painted white line down the center

Next I sanded the edges and masked a 6 mm line down the center of the boards with painters tape.  Then I spray painted everything flat black.  When I removed the tape, I was left with a nice straight white line down the center.  I used a plumb bob to find the center of the dart board on the floor and made a mark.  Then I centered the line of the sighting aid on the mark.

When you are standing to one side of the board or the other, the line appears broken.  When you are perfectly aligned with the bullseye, the line will look like one long line.  Centering yourself with the board should improve consistency.

off-center view

centered view

Well the sighting aid works.  Let's hope it helps my game.

Tuesday, November 17, 2015

Glock 17 Magazine Block

The Glock 17 usually comes with a 17 round magazine.  Well, in New Jersey you are limited to a maximum of 15 rounds.  Since NJ is the only state with that odd number as a limit, 15 round magazines are difficult to find for any firearm.  As a result, the Glock 17 ships with 10 round magazines in NJ.  Now I can live with giving up 2 rounds, but not 7!  Nobody makes a 15 round magazine for the Glock 17 (and no, the 15 round Glock 19 magazine does not fit the Glock 17).  So, I designed this magazine block to limit the standard 17 round magazine to a maximum of 15 rounds .

Magazine Block

The block fits between the floor plate and the magazine insert; keeping the internal design of the magazine unchanged.  Magazine function and reliability are completely unaffected.

Here is how to legally convert a 17 round Glock 17 magazine to hold 15 rounds.  All of this must take place in a state where 17 round magazines are legal.

1.  Go to Shapeways and order the magazine block.

2.  Get yourself some epoxy.  I use JB Weld.  Crazy Glue won't cut it; it is too easy to pull the pieces apart.

3.  Drive to a free state and purchase a 17 round Glock 17 magazine.  Bring the block and epoxy with you.

4.  While still in a free state, disassemble the magazine.  Check to make sure the block fits in your magazine. It should be a tight fit.

5.  Swab the inside of the magazine, insert, base plate, and block with alcohol to remove any oil and/or dirt.

6.  Apply epoxy to the bottom of the magazine insert and set it on the magazine block.

7.  Apply epoxy to the sides of the magazine block and slide it in place.  Make sure not to insert it too far.

8.  Apply epoxy to the bottom of the magazine block and slide the base plate back on.  (It may be necessary to load 15 rounds to fully seat the magazine block down against the base plate.)

9.  Wipe off excess epoxy.  Keep the magazine vertical so that any excess epoxy runs down towards the base plate, not into the magazine.  Stay in the free state until the epoxy sets!

10.  Return home and enjoy 50% more ammo in your Glock 17.

Now the magazine is permanently converted to 15 rounds.  I am not an attorney, but according to attorney and firearms law expert Evan Nappen a blocked large capacity magazine is legal "as long as it is permanently blocked".  By epoxying all of the parts together you cannot take the magazine apart and convert it back to 17 rounds without destroying it.  DO NOT INSERT THE BLOCK WITHOUT EPOXYING IT IN!!!  That is not permanent.  You will be in possession of a banned magazine; committing a fourth degree crime punishable by up to 18 months in jail and a fine of $10,000.

Click here to order.

Sunday, November 16, 2014

Crosman 1400 Repair

Sears branded version of the Crosman 1400

A few months back I purchased three vintage airguns for a great price. They were a Sears branded Crosman 600 with the original box and manual, a Daisy 1894 BB gun (the original version, not the re-issue), and this Sears branded Crosman 1400. The 1400 was the only one that worked. I took it out for the first time a few weeks ago and had a blast plinking in my back yard. That is until one of the seals failed and I heard a hiss come from the rifle after I pumped it up. Look like it's time to reseal it. I ordered a reseal kit from Bryan and Associates.

nice walnut stock
someone must have dropped it, the trigger is broken and the guard is bent
much nicer all steel front sight than the 140

I want to give credit to Nick Carter of Another Airgun Blog for the helpful instructions on the tear down. I think this is an early version from the early 1970's as evidenced by the sliding breech cover. The 1400 has a blow off valve meaning that the valve is held closed by the trigger. You cannot over pump this rifle like you can with a hammer-struck valve. It is an upgraded version of the Crosman 140 and the Sears branded version were usually of even higher quality. I thought about a complete restoration but the rifle is in pretty good condition and it is going to be a shooter, not a wall hanger. I'm just going to get it working, clean it up, and go shooting!

stock screw and safety removed
First I removed the stock screw. The entire screw came out instead of just the nut. Then I drifted the the safety out with a punch. Then the action can then be removed from the stock. With the action removed, I wiped the stock down with Formby's Lemon Oil to bring some life back to the dry walnut. That stuff works miracles on old wood.

trigger group removed
looks like heavy corrosion in the trigger group

With the action out, the trigger group is removed. Keep track of the screws, they are not the same. The small one goes in the rear. An offset screwdriver helps here.

pump cup looks good

Next the front roll pin is drifted out with a punch. The end plug and the pump arm are removed from the pump tube. The pump cup looks good and had suction when I removed it. It is a pain to replace so I'm going to leave it unless I have problems.

breech cover removed
rear screw (with spacer) and bolt removed

The sliding breech cover is removed by taking out the one screw. Then the rear screw is removed. It goes though a plastic spacer which must be removed before the rear plug can be removed. One the rear plug is removed, the bolt can be pulled out the back.

breech screw removed

Next the breech screw is removed and the barrel can be removed from the pump tube. At this point the plastic spacer and transfer port can also be separated.

threaded bushing
end plug and hammer pieces

A threaded bushing has to be removed to take the end plug out of the pump tube. I drifted it out from the top with a punch. Note the orientation of the bushing. Then the hammer pieces are removed from the rear. The end plug had a little bit of rust.

orientation of valve parts
valve disassembled

The valve can then be pushed out of the front of the pump tube. The valve is unscrewed to get to the seals and spring. That's it for the disassembly. I cleaned each part with Break Free CLP, wiped them off, then coated them with Crosman Pelgun Oil. I scrubbed any rust with CLP and 0000 steel wool. The white spacer had some rust stains. Simple Green did nothing but CLP and a little elbow grease did the trick. I cleaned the barrel with CLP on a patch and jag. Maybe I'm crazy but it feels as if the barrel might be choked as the patch felt harder to push out of the end.

new seals

Match the new seals with the old. Start by replacing the valve seals. The valve then inserts from the front. Make sure the threaded hole in the valve lines up with the bottom hole in pump tube. The hole in the black part of the valve lines up with the transfer port in the top of the pump tube.

The hammer pieces then install from the rear. The orientation of the rear valve piece is wrong in the picture. The hole should line up with the top hole in the pump tube.

transfer port cutting tool
new transfer port (L) and old (R)
The new transfer port seal in the reseal kit was too short for the 1400. It looks like it was for the 140. The white spacer requires a longer transfer port seal. No worries, I made a new one from 1/4" nylon tubing. I used my transfer port cutting jig to cut the new piece. The tubing is inserted through the 1/4" hole and then a drill bit is inserted inside the tubing. Then a sharp razor blade is used to cut the tubing. The cutting jig ensures the the cuts are square and allows you to cut very small slices from the tubing for an exact fit. I measured the old transfer port seal at 5.26 mm. I cut the new one to 5.30 mm allowing some extra material for compression.

bent trigger housing
1400 trigger group

Now for the trigger group. I had a nice adjustable 160 trigger group that I thought I could swap for the broken trigger. Unfortunately the sears are not the same. Guess I need to fix this one.

removing the dent

I used a piece of aluminum rod and a plastic mallet to tap out the bent trigger guard in my vise. It turned out pretty nice.

lots of corrosion
not bad!

With the bend removed I attacked the corrosion with some CLP and a brass brush. It cleaned right up. I put the trigger group back together, adding some grease on any contact areas.

ready to rock
Lastly, I replaced the pump assembly tapping the roll pin back in. I oiled the pivot pins and greased the high wear areas. Put the action back in the stock and bolted it back together. Time to shoot.

Crosman Premiers at 10 m with 5 pumps

I headed outside on a balmy 48° day and set up my chronograph. Here are the average velocities.

Pumps     Velocity (fps)
  2                 339
  3                 412
  4                 474
  5                 520
  6                 556
  7                 586
  8                 605
  9                 628
  10               639

Ten pumps was tough and only gave a few more fps. I tested the accuracy at 5 and 6 pumps at 10 m with Crosman Premiers and JSB Exact Diablos. The Premiers edged out the Exacts. The best group of 5 was 15/16" with the Premiers at 5 pumps. Given the mediocre sights and my mediocre eyes, I'm pretty pleased. But targets be damned, this gun was made for plinking. I was able to destroy 2" Daisy Shatteblast targets without any problem at over 90 feet once I had a the elevation dialed in. The windage was spot on; pellets smacking the narrow stakes every shot. I think this may become one of my favorite airguns. Real steel, real wood, timeless style. Now to get the rest of those vintage airguns working.

Friday, November 14, 2014


I finally got a 3D printer. Well technically it's not mine, it belongs to my lab. But I have access to it! We decided to purchase one to make custom parts for our hexacopter. We could order a whole bunch of 3D printed parts online for what the printer cost us, but having one in-house allows us to prototype much faster and correct any problems with the designs quickly. Plus it's just fun!

results of Make magazine review

I spent a lot of time selecting which 3D printer to purchase. I finally settled on the Ultimaker 2. It got excellent reviews, print quality appeared excellent, and the machines seemed to have a reputation for working well out of the box without too much fiddling around.

After unboxing I went through the setup process which basically just involves cutting some zip ties, snapping on a few pieces, loading the filament, and leveling the build plate. Most of the setup was pretty easy but leveling the build plate took a few tries. The process is straightforward: raise the plate to about 1 mm from nozzle, put a piece of paper between plate and nozzle, and adjust the leveling screws until you feel a little friction in the paper. The problem was my machine came with the build plate screws almost maxed out to their highest position so that I did not have enough adjustment to raise the plate to the nozzle. Once I realized what was wrong, I cranked the screws to bring the build plate down several millimeters and then repeated the process.

leveling screw

As soon as the build plate was leveled I tried a test print.  The Ultimaker 2 prints directly from an SD card. The card comes preloaded with several models. After telling the printer I was printing in PLA, I selected the UltimakerRobot file and hit print.  About 45 minutes later the print was finished.

first print!

The first print came out pretty nice. The base printed with a major hole which I think is due to a gap in between the old test filament in the machine and the new filament I loaded. No big deal, I should have removed the old filament first. Some of the overhangs are a little messy.  And there are tiny gaps in the layers which may be from slight under extrusion (not enough plastic coming out of nozzle). I'll adjust some settings and try again, but it looks like I'm not too far off from getting some excellent prints.

hole is my fault, not printer error

So far I'm pretty impressed with this machine. I can't wait to get this thing dialed in and start printing some useful stuff. I want to document all of the prints that come out of this machine so I can keep track of the settings and help other people get their UM2's dialed in. I don't want to bog down this blog with boring printer settings so I have started a new blog just for that purpose at Ultimaker2Prints.blogspot.com. Check it out.