Monthly Archives: February 2015

Lesson learnt: Two wheels good, three wheels bad …

(and why physics/mechanics knowledge is still very relevant in the digital age!)

After the first two days of the lunar new year, where lots and lots of relatives from my parents-in-law side came to visit, I decided that it was time to do something AGAIN about the sliding door to the toilet … (somehow, when many different visitors use it, the “flaws” of my first repair attempt, described below, showed up quite a bit).

Now, those of you who have sliding doors or windows at home might know that when the sliding mechanism does not work well, it means that either 1) too much dirt and yuck have accumulated onto the tracks and/or 2) the roller wheel needs replacement. So, after trying to see if it was 1) (by cleaning the track and laying a coat of candle wax on it), I figured it was the roller wheel that was causing the problem. Upon removing the door, I saw that one of the wheels had cracked.

The nice lady at the hardware shop sold me two of the wheels for $1.50 each, and suggested that I should buy two wheels so that I could place THREE (3) wheels on the door to spread the load (i.e. weight of the door) on three wheels instead of two. Yup, sounds like a good idea, I thought (assumption here is that it was the weight of the door that caused the wheel to crack), and duly went about removing the old wheel and housing and fitting in the two new wheels bought (to join the other older wheel that was still OK). One new wheel was fixed to the end of the door and the other was secured in the middle.

the roller wheel with housing for $1.50 each

the roller wheel with housing for $1.50 each

This job can cost a little bit if you get the hardware shop to do it, especially if the one that needs replacing has been riveted into position (which mine was) instead of having a screw to secure it (see below):

see the screw sticking out of the housing ... better to use this method to secure the roller wheel housing, than rivet as it will be easy to replace the next time ..

see the screw sticking out of the housing … better to use this method to secure the roller wheel housing, than rivet as it will be easy to replace the next time ..

(to remove the cracked wheel that was riveted down – use a drill to remove the rivet head by drilling it away; the rest of the rivet should be accessible and can be pulled out using round-nose pliers).

By the weekend before Chinese New Year, the sliding door  (the one half of it that had been fixed) had three wheels attached, was sliding better than before the wheel replacement, BUT still not very smoothly!!

Applying some mechanics principles to trouble shoot, (and noting the “stress test” of the first two days of relatives using the door), I decided to remove the third wheel (the one in the middle), leaving behind the two wheels at both ends of the door.

(the interested reader may wish to see if he/she can figure out why this solution works; note that all three wheels are running smoothly. Answer in italics at the end).

VOILA!! it really works much better now … 🙂

Lessons learnt: TWO WHEELS GOOD, THREE WHEELS BAD!! … and

1) the advice given by the hardware store people may not actually work

2) you never know when Physics/Mechanics principles learnt decades ago can be very relevant to daily life 🙂

Why two wheels work better than three (most of the time):

imagine that the three wheels are not perfectly aligned on the guiding track, which is very likely the case. Then, the door is actually supported by only two of the wheels. If the two wheels are the ones in the middle and at one end, then there is actually a turning effect when the door is pushed, which makes the door NOT slide smoothly. This turning effect will not be present when there are just two wheels, secured at the two ends of the door.

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“Flower & Bird” (花鸟) and Opportunity

Opportunity is a bird that never perches. ~Claude McDonald

So, whenever I see a potential bird or flower shot, I take it …

“…one opportunity leads directly to another, just as risk leads to more risk, life to more life, and death to more death.”
― Markus ZusakThe Book Thief

Hornbill, as seen from window in the girls' room

Hornbill, as seen from window in the girls’ room (taken with Canon Powershot)

Exotic bird, seen on riverbank, at the end of bamboo boat ride in Wuyishan (Nikon 5100)

Exotic bird, seen on riverbank, at the end of bamboo boat ride in Wuyishan (Nikon 5100)

A sunbird that is a regular visitor to the garden ...

A sunbird that is a regular visitor to the garden …

Green parrot, sighted in Bishan Park, near the bridge to Bishan Park Condo, during morning run (taken with ASUS Zenfone)

Green parrot, sighted in Bishan Park, near the bridge to Bishan Park Condo, during morning run (taken with ASUS Zenfone)

Lotus flower and Bee, Bishan Park lotus pond, while cycling with SY this morning ... usually the flowers are not so near to the path but this one was perfect as it was just beside it (Zenfone)

Lotus flower and Bee, Bishan Park lotus pond, while cycling with SY this morning … usually the flowers are not so near to the path but this one was perfect as it was just beside it (Zenfone)

Dragonfly and lotus leaf, Bishan Park Lotus pond (taken with Zenfone)

Dragonfly and lotus leaf, Bishan Park Lotus pond (taken with Zenfone)

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Good Timing with Japanese Cranes …

Must say Mr Ang’s lesson on painting Japanese cranes was once again perfectly timed, just like last year’s session on peaches (see previous post on longevity peaches).

This is the piece done in class ...

This is the piece done in class …

I had wanted to change the “longevity peach” paintings in the living room since they have been there for one year already but had not identified what to replace them with. Then, we had our lesson on cranes (5 Feb), celebrated father-in-law’s 81th birthday (7 Feb), and as I researched and practised drawing more Japanese cranes (and pine) over the next few days, suddenly realised they also symbolised “longevity” and were perfect substitutes for the peach paintings. So, on the next lesson, I got Nana (classmate, who used to be a Chinese Language teacher) to see what words I could add to the paintings, and then asked Mr Ang to help me write the characters:

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And some of my classmates think I am such a wonderful son-in-law in spite of my explanations that it was all just “coincidental” and that I wanted “to change the living room decoration” only 🙂

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What the fish! Part 3

This is how my “fish paintings” was finally used as CNY decoration for SM’s class …

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and haha, they are actually placed showing the “wrong” side  🙂
(the side that I painted on is shown below). And one of her teachers whom I had met recently asked her whether her dad was an artist!! (think he was puzzled because I did introduce myself as a (ex) JC math teacher during the meeting!!)

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Walking barefoot and other random stuff …

It is good to feel the ground (grass, road, …) … every step brings a different sensation!!

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walked this path back and forth this week,

walked this path back and forth this week, and then did a short run to entrance of reservoir and back

and Upper Pierce Reservoir is a great place to do so with these flowers in bloom  (and managed to identify three of them from my book of “1001 Garden Plants in Singapore” 🙂 )

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crossandra infundibuliformis? (须药花)

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??

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catharanthus cultivar? (periwinkle 长春花)

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??

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lanthanum camera (五色梅)

And in between the barefoot walk and run, practised with my new G Key bangdi (shorter type of dizi used in Northern style playing) when these waves suddenly crashed onto the reservoir shore …

suddenly, these waves appeared and crashed against the reservoir shoreline while I was practising dizi ...

suddenly, these waves appeared and crashed against the reservoir shoreline while I was practising dizi …

And Friday after early morning lesson for dizi, met this fella at Punggol Promenade after doing a run to Sengkang CC … (the pond has quite a number of them out suntanning at around 12 noon)

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and started this random week with a talk on Monday at NTU listening to Jane Goodall in person!!! and bumping into 3 random people – ex colleague, ex student, and parent of a current tuition student!! These sentences from Wikipaedia “nicely” captures the importance of her work:

Goodall’s research at Gombe Stream is best known to the scientific community for challenging two long-standing beliefs of the day: that only humans could construct and use tools, and that chimpanzees were vegetarians. … In response to Goodall’s revolutionary findings, Louis Leakey wrote, “We must now redefine man, redefine tool, or accept chimpanzees as human!”.

Jane Goodall, NTU LT19A, 5 Feb 2015, talking about her effect ...

Jane Goodall, NTU LT19A, 5 Feb 2015, talking about her effect …

and always find it inspiring to be around people like her!!

(END – of this post about random stuff 🙂  )

 

 

 

 

 

 

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