Tuesday, March 31, 2015

Interstellar TARS Model Project Interim Report - 1

Interstellar TARS Model Project
Interim Report - I

Object: To design, draw, and produce the robot from the movie, 'Interstellar' into an model figure.

I. Introduction
I heard about the movie Interstellar since quite a long times ago. It was such a big hit not only in the United States but also in South Korea. Everyone was talking about the movie and especially the robot in the film. However, I could not see the movie until last a few weeks ago since I had too much works to finish. Finally, I watched the movie at the local town's small movie theater--since big theaters such as Regal Cinema no longer had Interstellar. I was just very fascinated by the robot in the film. I really wished to have the robot like that. With my skills of making plastic models--although it was not so professional--I have a good confident to make this model into real.

II. Plan of Making
I will not be able to make the full size robot with an actually functioning robot like the one in the movie; I thought I could make one by myself in small scale. I collected some data and information of the robot, and then started to design the robot through Autodesk. Later, I waited until the DVD version available so that I can watch only the robot parts over and over again to collect more detailed information (accuracy is always good!)

My model is about 3 inches x 6 inches. I first produced the prototype version of the robot with 3D printer with dimension of 3/4 inches x 6 inches for now. This will be changed however! I figured that the length of square of the base times eight is the height of the robot.

Fig. 1. Autodesk Blueprint of Part 1
First, I made only the first part of the robot (It is the far left side part of the robot when facing the front). This part is not going to be used for the actual final part. Rather, this part is for getting a good basic sense of how the model will be look like and to ensure there is no design defections.

Since printing just a big one chunk of plastic bar is not so cost effective and takes a lot of time, considering economic factors, I decided to make two parts and put them together. Just like a plastic model.

Fig. 2. Showing the inside of the two separate parts.
Painting had been applied before the picture was taken.
Fig. 3. Side view of the figures.
Fig. 4. Bottom view of the figures 
After I retrieved the figures, I sandpapered each part and assembled them to spray the metallic silver paint. Later, this became a problem though. The figures matched perfectly although I had to give a little sandpapering.

Fig. 5. After sprayed silver paint
As you may can figure that the surface of the figure is not quite so smooth like a Porsche. This is one thing I cannot figure out yet. I can probably sandpaper a bit more, but if I do, it will decreased the size of the figure. I was thinking about using a primer before applying the paint. I have never used a primer though--honestly, I do not even know what that does! Third solution is to use a putty to fill up all little holes and make the surface very flat. However, I truly do not think I can make the figure's surfaces' so flat. It is most like to accept the second solution--using a primer.
Fig. 6. Size configuration with a ruler (inches)
Since 3D printer cannot print so accurately as 0.01 inches, I am going to use a laser cutter to slightly give a line shape on the figure. It will not cut through all the way but give a little intaglio. I have not decided if I want to use the laser cutter after the painting or before the painting. Will the pain catch a fire?

I bought a very fine Sharpie black marker to fill in the lines once they get engraved. However, I doubt the lines are wide enough to be filled up with a black marker.

The following picture is a practice figures to give a good sense of visual measurement of the thickness of the 3D printer model and the laser cutter's power.

Fig. 6. 3D printed models and laser cut acrylic plate
III. Recommendation
When I sandpapered first and assembled the parts together, I figured that there is quite a wide gap between the parts. Since this is not so ideal for the quality of the final figure, I should glue the parts together and then sandpaper the figure. I also considered to use a putty; however, due to financial matter, such proposal has been denied.
The holes for the magnets are too big. Since I already purchased magnets for this model, I will have to make some kind of a thin wall to keep the magnet inside but keeping the hole small enough to look similar to the real one.

IV. Conclusion
I have a long way to go. It is only a prototype so far. However, seems everything is going well for now. I am going to use a laser cutter to give a slight line by engraving the surface of the prototype to test if this way of giving line is suitable.

All images used in this post are created and taken by Hosung Won. All rights reserved.

Next Report will be updated on April.

Friday, March 20, 2015

British Cromwell Tanks Used by North Korea During Korean War

At the beginning of the Korean War, The Korean People's Army (KPA) invaded South Korea on 25 June 1950 with superior fire fires including T-34/85 tanks and multiple rocket launchers. At that time, the only armored vehicle power South Korea had was M8 Greyhound light armored car. With the surprising attack by KPA, South Korea retreated to south-east but later recaptured the capital Seoul with helps from UN forces.

North Korean troops came to Seoul with 150 T-34 tanks
In sometimes near 2011, three pictures were uploaded in Korean community sites and heated up people pretty good. Two pictures of them are British Cromwell tanks operated by KPA, and one of them is South Korean Marine Corps using the Cromwell tank.

There are a lot of talks about how North Korea obtained British Mk VIII, Cromwell light tank during the Korean War. While there were a lot of discussions and arguments over how KPA obtained the tanks that are not made in Soviet Union but made in Britain, several researches have done. This post is going to discuss the source and routine how KPA used British tanks.

During Korean War, though it has not yet confirmed, there is a story which British Centurion tank destroyed British Cromwell tank operated by the Communist Chinese Army (CCA) in early 1951 near the south of Seoul. No one could confirm the story since there is no recorded data or documents.

Weighted down with sundry items ranging from guns and trench shovels to a radio set, Sgt. Derrick Deamer, left, and Pvt. Clem Williams wear full battle gear as they chat on the British sector of Korea's Naktong River front in South Korea on Sept. 14, 1950. Both are with British forces fighting with United Nations' troops against the Chinese Communist troops. (AP Photo/GH)
This story is a bit confusing since there were absolutely no connections between CCA and Britain, and early CCA only brought light firearms such as machine guns and mortars. CCA later brought Japanese tanks and few T-34 tanks to the Korea but not in 1951. There was no possibility for CCA to bring such heavy weaponry in early 1951.

Centurion tanks of the 8th King's Royal Irish Hussars wait with troops
of the 1st Commonwealth Division to cross a pontoon bridge over the Imjin River.
Imperial War Museum
During the Korea War, British considered sending one entire tank battalion to Korea. They were considering not to send any tanks other than Centurion heavy tanks since sending other light and medium tanks such as Cromwell tanks and Churchill tanks could make maintenance and supply difficult.

However, before the deployment of the tank battalion, the U.S. advised Britain that the road conditions in South Korea are challenging, and maneuverable road is so narrow, that light and medium tanks are also necessary for South Korea.

Britain took this suggestion and deployed Churchill and Cromwell tanks along with Centurion heavy tanks to South Korea.

While the Centurions were the primary gun tank used by the Brits in Korea, a platoon of Cromwells belonged to the 8th RI Hussars and some small number of the OP section of 45 Field Regt, RA. Further, C Co, 7thRoyal Tank Regt was equipped with Mk.VII Churchills, equipped with flame throwers, although they were never used as such. Neither type saw use after spring, 1951.

A British Churchill tank raises dust cloud as it shells the South Korean capital from its position across the Han River in Yondungpo, South Korea on Feb. 11, 1951. (AP Photo/Jim Pringle )
Now we know that British tanks entered South Korea and Cromwell tanks were of them. But, isn't it possible that Soviet Union gave Cromwell tanks to China?

Generally people believed that the Cromwell tanks are from Soviet Union. During World War II, Western Allied forces supported Soviet Union with military resources including tanks. It is possible that British also sent a few Cromwell tanks to Soviet Union as a lend-lease aid. After on, Soviet Union possible reinforced KPA or CCA with the Cromwell tanks.

However, this assumption of Soviet Union was wrong. The Cromwell tanks used by KPA was the ones that British tank battalion brought with. In the story of the Cromwell tanks, there is an unknown battle "Happy Valley Battle." This battle was the key to the mystery.

When researched these Cromwell tanks if Korean War with books written in the U.S., there were no mentions about the "Happy Valley Battle" or only a short descriptions were briefly mentioned in the book. The "Happy Valley Battle" is therefore known as a forgotten battle of forgotten war among British Korean War veterans. While the importance of this battle was significant, not too many materials nor archives are remaining.

The following is a link about Happy Valley Battle:

At Happy Valley or 'Go-yang'
Before The Third Battle of Seoul, UN forces retreated from Seoul in the threat of CCA forces using human sea wave tactics. To earn some times to safely fall back, the U.N. urgently dispatched British's Ulster infantry battalion to near 'Go-yang' and 'Nam-yang' provinces, north of Seoul. Ulster infantry battalion included British Royal Hussar Tank Battalion's 14 of Mk VIII Cromwell tanks.

For four days, British troops of Ulster battalion successfully resisted and earned time for the U.N. troops and Seoul civilians to retreat from Seoul. The day before January 14, 1951, Ulster battalion was ordered to retreat from the defense line to South and regroup with UN troops. However, CCA noticed the withdrawing plan and ambushed Ulster's battalion. 157 British soldiers were killed and 20 soldiers were captured. Moreover, all 14 Cromwell tanks were also captured by CCA.

After recaptured Seoul, British solders are checking the Cromwell tank
left in Happy Valley Battle.
The reason Centurion heavy tanks were not dispatched instead of Cromwell light tanks was because of the road condition. Routes near the front line at Happy Valley was too narrow that only cargo carts could barely manage to pass. This kind of road was impossible for Centurion tanks to cross, but Cromwell tanks could barely pass.

CCA using human sea wave tactic.
However, this became a significant disadvantage for the Cromwell tanks. With limited maneuvering capabilities in narrow and small roads, Cromwell tank crews could not operate the tanks effectively and resist well against a great number of CCA troops rushing toward Cromwell tanks like leeches. CCAs threw hand grenades in between tank's wheels and easily detracked the tanks to climb on the tanks. One Cromwell tank was destroyed in a tunnel which is now used as a subway tunnel.

Chinese captured 12 Cromwells from recce troop of 8th RI Hussars during battle in narrow valley near Ujiongbu in late November 1950. Column of this tanks was ambushed by Chinese Infantry and few members of their crews managed to escape.

An eyewitness of destroying Cromwell tanks later complained to researchers and historians that he could not do farming for three years because the destroyed tank's engine oil contaminated rice paddies. His story confirmed that one of the tanks was destroyed by a grenade thrown into the engine room of the tank by CCAs. Other witnesses said, after the U.N. forces recaptured Seoul and marched toward north again, all destroyed tanks were quickly collected by U.N. forces.

A destroyed Cromwell tank at the Happy Valley Battle
While a history of Korean War written by the U.S. did not have detailed information about this Happy Valley Battle, Korean War book written by Britain had somewhat detailed information about the battle of Cromwell tanks. Especially a part explaining British tanks discharging against Cromwell tank after recapture of Seoul is well written. The book explained this so called "The Battle of Cromwell Tank."
February 11, 1951, two British Centurion heavy tanks commanded by Captain Strachan and First Lieutenant Redford found an unidentified tank hiding under the right side of Han-river railroad bridge while supporting the U.S. reconnaissance company. The commanders order to engage and destroy the unknown tank. The AP shots shot through the side armor and destroyed it. Interestingly, when commanders checked the destroyed tank, they realized it was a British Cromwell tank. It was Centurion tanks "Cuaghoo" from 3rd squadron that destroyed the tank.
Today's view of under the Han-river railroad bridge.
It is road full of traffic right now, but it used to be a sandy beach
Probably CCA or KPA drove Cromwell tank down to Seoul and hid under the railroad bridge in case of airstrikes or U.S. tanks crossing the Han-river. However, unexpectedly, British Centurion tanks found the Cromwell and destroyed them.

A Centurion heavy tank firing
Then, a question arises here: was it CCA or KPA drove and used this Cromwell tanks? The answer to this question is later solved when South Korean Marines landed in Incheon (a city next to Seoul) and captured one of the Cromwell tanks.

1A Cromwell tank which North Koreans abandoned in Incheon beach.
A British soldier with beret is checking the tank.
Above picture is one of the three pictures that heated up Korean internet sites. During Korean war, Incheon beach was defended by KPAs, not the CCAs. If KPA defended the beach and the Cromwell tank was used to defend the beach, then KPA must used the Cromwell tank. However, the contradiction is that the Cromwell tanks were captured by CCAs.

2A Cromwell tank operated by North Korea soldiers with Soviet tank crew's helmets
Above picture is another of those pictures. It is very clearly seen that the tank operators are KPAs wearing Soviet's tank crew helmet. The uniforms soldiers are wearing in the picture also prove that they are KPAs. During the war, CCAs did not have uniforms with insignia. However, the uniforms in the picture have insignia, showing that they are KPAs.

On September 1949, Mao is inspecting Japanese Type 97 CHI-HA tanks.
CCA had tank forces but not so much during Korean War. Although CCA had quite a few Japanese Type 97 CHI-HA tanks, they did not have enough skills to use them for the war, and the tanks were inferior to most of tanks at the time. Later on, CCA imported very limited numbers of T-34 Soviet tanks to use though. However, it was in 1952 and 1953 when CCA sent tanks to Korean War.

CCA not only did not have firm tank battalions but also had lack of knowledge and skills on operating armored vehicles and tanks. The reason I am mentioning about CCA tank forces is because this relates to KPA using Cromwell tanks.

USMC passing by a destroyed North Korean T-34 tanks
Lieutenant General Robert P. Keller, USMC (Ret.)
Before the Korean War, KPA had several tank crews trained by expert Soviet tank instructors. A full brigade equipped with about 120 North Korean T-34/85s spearheaded the invasion of South Korea in June 1950. The North Korean tanks had overwhelming early successes against South Korean infantry.

However, majority of T-34 tanks were destroyed due to lack of experiences compared to those tank crews of the UN forces, and superior fire powers of U.N. forces such as the U.S. M26 heavy tanks and ground-attack aircraft, and the U.S. infantry anti-tank weapons. The M4 Sherman (M4A3E8 model) and British tanks such as the Centurion, Churchill, and Cromwell destroyed numbers of T-34/85 tanks too.

But still, during the early stage of the Korean War, several KPA tank crews remained in the war. Those KPA tank crews had basic knowledge on how to operate T-34 tanks but probably could also operate the British Cromwell tanks in similar ways. Thus, it is possible that since CCA troops did not understand and know how to use tanks, they handed the tanks to KPA to use against the U.N. troops.

The two pictures of Cromwell tank strongly support this theoretical assumption quite well. Thus, it is highly reasonable that the Cromwell tank destroyed by Centurion tank was operated by North Korean tank crews.

3A Cromwell tank with Korean saying "Marine Corps" at the bottom front of the tank
Above picture is the last picture that heated up the internet. Now, the tank is operated by the South Korean Marine Corps. In the picture, British officer on the right is talking to a soldier. The story with the Cromwell tanks get very confused at this point now.

South Korean Marines launching attack at Incheon beach 
The inference is that the South Korean Marines landed in Incheon and captured the tank from North Korean defense forces. This maybe the very first tank that is operated by South Korea by that time, since the very first South Korean tank company was founded on December of 1951 with helps from the U.S. Marine Corps.

Korean tank crews are learning about the U.S. tanks during Korean war.
To conclude, there were British tanks used by North Koreans during the war. Those tanks were captured by Communist Chinese Army at the Battle of Happy Valley. However, trained North Koreans operated these tanks instead of Chinese since Chinese did not know how to operate tanks. Although it is very interesting how North Koreans used the Cromwell tanks against UN forces, but we should not also forget the forgotten battle of brave British troops during the Korean War. In addition to this novel story of Cromwell tanks, I hope more people to remember the Happy Valley Battle, which British troops fought against Communist Chinese Army to earn times for UN forces to retreat.


Wednesday, March 18, 2015

I Passed my General Class HAM Test

I must say that I was extremely nervous about this test.

For Technician test, I spent a good month long time to study the materials. Also, the study materials were somewhat basic and not so challenging. However, General class was more difficult. There were more technical and theoretical materials to study. Very few limited items were repeated from Technician class. Thus, I had to give more special care on this General class test.

Yes, I wanted to take some more time for preparation of the test, but I could not. The only time available for me was the Spring break, and I spent the entire break solely just to study this General class. If I had one more week, then I may could end up the test with a better score.

Anyway, I passed the test. I have my General class license now, and that is GOOD! Yet, I have no any real antenna nor transceiver to make a proper radio communications. Although I have a handheld transceiver but do not want to count that as a 'radio.' I have no plan to get any better radio yet. I will have some experience with radio at university's HAM club.

When VE told me saying "Do you want to try again?", I thought I failed the test and soon became very upset. But, when other VE asked him, "What do you mean try again? He passed!", I knew that I passed the exam, and the VE was just giving me a hard time. He recommended to give a shot on Extra class test; I declined since I knew I am not going to make that one.

I have no any upcoming plan to take Extra class test at all. HAM member suggested me to have some experience with radios first before take the test. After all, Extra class is more demanding than Technician or General class.


Tuesday, March 17, 2015

I Strongly Support Deployment of THAAD Missiles To South Korea

Since last few years ago, there have been a lot of voices concerning about the deployment of Terminal High Altitude Area Defense (THAAD). Not only South Korea but also neighboring nations including Japan and China are showing their perspectives on this missile too. Especially, Koreans are wondering and questioning what the THAAD is and if they need it.

First of all, in briefly, what is THAAD?

THAAD is a missile intercepting nuclear warheads falling from the sky. This is very important because a lot of people get confused what THAAD actually does. It intercepts nuclear warheads that are detached from a main missile and free falling from a high altitude toward targets. Which means, THAAD must be stationed at where the target of enemy's nuclear missiles are going to be, and it is a defense weapon, not attacking weapon.

If THAAD is stationed in the U.S., that is to protect the U.S. from any outer threats. If THAAD is stationed in South Korea, that is to protect South Korea from any outer threats too. Theoretically and technically, THAAD is not developed to intercept a missile being launched into sky with warheads in, but to intercept warheads detached from the missile and falling from the sky (I am repeating this because it is very important.)

Above is a video made by Lockheed Martin explaining why THAAD is essential for the defense of South Korea against the nuclear missile and other missile threats from North Korea. South Korea needs THAAD to protect land, citizens, and so more.

Above picture explains what types of intercepting missiles are used for each different stages of ballistic missiles. As shown, THAAD is to intercept warheads falling from the sky. At the moment when the ballistic missile being launched up into the sky has the highest possibilities to intercept, using ABL, KEI, and SM-3. However, if those fail to intercept, GBI is launched to intercept the warheads again. At last, if GBI failed to intercept, THAAD is the last defense system.

Problems with North Korea and within South Korea

Believe or not, there are quite a few people hate the U.S., and often show in favor of North Korea or their communistic or socialistic theories. The terrorist who slashed the U.S. ambassador, Mark Lippert is these kind of people. Hating the U.S., liking socialism, North Korea, and more.

They think that accepting this THAAD missile is same as submitting ourselves to the U.S. and giving them tremendous money for the weapons. They also claim that the hostilities with North Korea must be avoided by not accepting this THAAD missile. North Korea already has shown their frustrations and threats to South Korea for accepting deployment of THAAD. North Korea often threatened South Korea saying that they will launch and attack South Korea with their nuclear warheads.

It is very controversial and hard to understand those people living in South Korea, enjoying the output of democracy and capitalism claim their voices on standing on the same side with North Korea.

Problems with China

A lot of times, China showed their concerns with the installation of THAAD missiles in South Korea. If China is going to attack the U.S, the ICBM will NOT go through Pacific. But rather it will head to the U.S. through north pole (look at the globe).

China said that THAAD is to protect the U.S. from the attack of China. However, as I previously mentioned from the introduction, THAAD is not capable of doing so.

There are two possible explanations here:

1. AN/TPY-2 Raytheon Portable Radar

This radar is a long range and highly accurate missile radar that can spot everything in sky. Detectable radius of this radar ranges from 600 km to 2,000 km, which includes basically entire half part of China if stationed in South Korea. Of course, China will not like this situation since the U.S. will be able to identify and track down all movements in sky. However, the U.S. and South Korean governments released that the particular radar will be deployed in South Korea is only capable of 600 km detection radius range. This distance includes almost entire North Korea but not including China at all. Thus, China's concerns over this radar is unreasonable.

2. North East Asia Expedition Obstacle.

China has developed and produced nuclear warheads. If possible target is the U.S, the U.S. forces stationed in South Korea and Japan are major obstacles. Thus, attacking these two nations in the event of war against the U.S. is important.

However, if South Korea installs THAAD with AN/TPY-2, even if the missile and radar ranges are only within North Korea, majority of Chinese naval and air forces are detectable and defensible. This means, the deployment of THAAD completely will forcibly alter what China is planning against North East Asia powers.

Because of these two reasons, China has been showing deep concerns and almost threatens South Korea not to install any THAAD. However, officials of South Korea and the U.S. do not understand and blame them for attempt to exert their influences.

"(Neighboring nations) can have their positions.
However, they must not attempt to exercise their influences over our
national defense and security policies"
Daniel R. Russell (Assistant Secretary of State for East Asian and Pacific Affairs):
"South Korea has not installed this THAAD system yet. But, it is strange
for a third nation to mention about this theoretical matter."
I indeed strongly feel that THAAD is essential for the defense of South Korea. This is not a attacking weapon but a defense weapon to protect ourselves from the threats of North Korea. Any other influences and oppositions are unacceptable while it is a matter of saving thousands of thousands lives of South Koreans.

South Korea needs THAAD. And I believe we will have one.

Tuesday, March 10, 2015

Finally, I Received My First Transceiver!

Well, finally!

Today, I received my transceiver, which was very unexpected. Because, this week is a University Spring break. That being said, all universities must be closed; however, residents mail pick up station was open. So that is good! I was overly excited to receive an email saying that I received a package! (my university has a system that whatever packages shipped to the on-campus residents will head to the mail pick up station. Then, the station will send an email to let residents know.)

It took nearly a month to get this one though. It is smaller than I expected, but should be very useful with my radio communication skill.

But........ everything started after I opened the box and checked the radio.

What the...? Do you see that horrendous scratches, scrapes, and marks?! But I ordered the new one! I was very upset and angry to receive such item after that long a month of waiting. I was going to contact the eBay seller and request an exchange.

However, well... I did not. I just closed the case. Because it is just too much for me to send the item back and receive another new one. After all, I awaited just too long. Simply just too long. I found that just satisfied with this item is fine. The radio itself is not an expensive one anyway.

I am just glad to receive my first radio... I cannot wait to try and contact other HAMs!

Wednesday, March 4, 2015

I Pray for Complete Recovery of Mark Lippert

Today, Mark Lippert, the U.S. ambassador to South Korea, was attacked by a terrorist.

A person who attacked Mr. Lippert is Kim who has a previous career of pro-North Korea activities and other hostile activities such as throwing a cement block to Japanese Ambassador. Kim used a 25 cm (about 10 inches) long knife to assassinate Mark.

I blame this person very strongly. He must face the justice and be executed to death. Such hostility to an ambassador is a major crime. He later told police that he tried to spear through Mr. Lippert's neck and killing him. However, Mark resisted and avoided any life threatening wounds.

This person, Kim does not represent the entire South Korean people. It is very complicate to explain what it is since it involved politics and ideologies. However, Kim for sure is a pro-North Korea communist who claimed that the U.S. troops should leave South Korea. Kim and other people normally doing such things, such as criticizing the U.S. and shouting for the peace talk or negotiation with North Korea are widely known as 'COMMIES' (literally!).' Yes, while South Korea is facing North Korea's threats, there are such commies with wrongful thoughts. These people are very complicatedly related to a lot of societal and political factors--this is why it is hard to explain.

I personally feel that Kim must be transported to the U.S. and face the court justice of the U.S. Because court justice of South Korea is very week and delicate that Kim may not receive any death sentence or anything similar. Also, human rights are overly 'abused' even for serious rapers or homicides. If he gets court justice under the ruling of the U.S., he will get at least more powerful sentence.

My other South Korean patriots and I, who truly appreciate the U.S. and support the U.S., blame Kim. We all hope Mr. Lippert to get recovered soon.

Sunday, March 1, 2015

My First Transceiver Just Won't Get Here.

Well, even before I acquired my first Technician License, I just knew that I am going to pass the test. I was that confident about the study I did. And of course, I passed the test which was piece of cake.

As you can see from the picture, I ordered this a nice handheld transceiver at Feb 09. Today is 1st of March. I still did not get this radio!

I asked the seller about this, and the seller sent the item again. I was really hoping to receive the item either on last Friday or Saturday. However, it did not arrive yet. Thus, I am going to wait till tomorrow again. If it does not arrive, I am going to contact the seller again.

I was begin patient very well, but now it is getting ridiculous.
I understand that there were awful weather conditions. But, taking this long is same as buying the exact same radio from China with less price. I bought this radio only because the item is located in the U.S. (I don't trust items shipped from China nor Chinese sellers)

I will wait one more day and will see...