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Wednesday, 25 July 2012

The Final Hurdle


Well, it's been a while since I last posted properly.

It's good news - I am now a Marine Engineering Officer of the Watch.  I went to the MCA's offices in Southampton on 9th July and had a rather gruelling hour of examination - which seemed to be riddled with material normally reserved for Class 2 Engineers, not Class 3 (can't go back for a Class 2 exam until at least 18months more sea time + another exam).  An hour normally means things are going badly - however although it felt like that because of the questions posed, I was told no problems at all at the end and he was happy to sign me off with my certificate of competency.  The other two of my friends that went in that day both passed, and they had a similar experience to me in terms of length and the types of questions.  Apparently we were just unlucky to get that type of oral.  But, it doesn't matter as we all passed anyway.

It took a while to hit home, mostly due to how hard the exam felt.  However, the good thing is that you find out at the end of the exam whether you passed or not - there's no waiting.

It was also more good news yesterday, as Chris B and Chris T both passed their orals too.

The next step is the ETO (electro technical officer) top up in September, which will give me more electronics, radar and GMDSS fault finding skills.

It's now fully hit home and since the exam I have changed tasks, to sort with Emily the many small jobs that need completing before the wedding.  However, this morning my licence arrived by courier at 8:15am.  



It's like the new passports - has similar parts inside, except says I hold the relevant ticket etc.  I haven't shown the inside details on here for security reasons!

Also, a certificate came along with it.

Completed Workshop Pieces

Below are the final workshop photos of my work pieces in various stages of completion.  This is all from a few weeks ago.


The Ratchet (Final Workpiece)

Marking Out



Tapping the first thread



Drilling and reaming the hole for the ratchet wheel

The three copper rivets I made on the lathe

Brass bush with sprung ball bearing inside - made on lathe (fits into the ratchet wheel and used to hold socket on)



Rivets now hammered down

Rivets filed down smooth

Final shape marked out - ready for the milling machine

Milling the ratchet handle


Video showing milling cut on ratchet handle (conventional milling)


After milling

Ends ground down to rounded shape

Rathet wheel turned after first stage on the lathe

Drilling holes into ratchet wheel

After flats have been added so it's 12.7mm AF (across flats)

Turning down the outside diameter to get the ratchet wheel teeth made

Teeth finished

Well within tolerance (measures 38.01mm)

Ratchet pawl marked out



Setting up to centre drill the hole that the bush goes into

Hole drilled

Wheel finished - just needs heat treating and then the bush inserted


Heat treating the ratchet - holding it at cherry red

While cherry red, it's dropped into oil - gains the black colour

Cleaned back off and ready for tempering


Heated to 'blue' colour, then dipped in oil.  Goes black once again.  Then  I pressed the brass bush into the wheel.  All finished.

Brass bush and sprung ball bearing up close.  I then tested it for hardness and it was around 48 rockwell.  This is not quite as hard as standard hex keys etc, but not bad considering the hardening process was done by hand with a blow torch.  As it's a bit too soft it means on the second heating I took it a bit too hot above normal 'blue'.  

Finished - takes about four to five working days to complete!





It's not a Heyco ratchet, but it's pretty good!



Thread and Brass Nut Assembly 

Thread cutting




The thread itself finished - inspection time



Inspecting the thread at 10x magnification

50 x magnification.  Now the pitch of the thread is checked, the angle of cut on the thread, and the  quality of the cut

Brass nut in raw form

Drilling the hole for the internal thread


Turned down to length with inside hole reamed.  Ready for thread cutting

Internal thread cut - continual checks are done while cutting until male fits female well
  





Cutting the flats onto the nut





Finished!


The Milled Cube (best paper weight ever)

Turning down the cube to length


Cube after milling - complete




Scraping Plate (serious & tedious pain)

Plate having been filed flat and then hand scraped until smooth - this takes serious patience.  Takes about four hours of scraping to get it done.  Some people have taken up to a whole day to get this bit done!  Hand scraping is used to get surfaces properly flat - you may have heard of hand scraping bearings before?


Top of plate has milled parts.  This part is first

Milling other channels in it

All finished - scraped side is the bottom.  Bottom notch has been hand chiseled out.



Offset Plug (Consists of one male part, one female - offset centre by 10mm) 






Setting up the offset on the lathe with the four jaw chuck and the DTI (dial test indicator)



Video showing dial test indicator.  Each revolution of the pointer = 1mm.  Needs to be ten exact turns when setup on each male and female part so that they marry up perfectly


Turning down to length
  
Finished parts

Finished parts together.  Drilled hole with a bolt holds parts together





The Trinity