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Skipjack 19 foot open launch By Michael Mott 1/8th scale Small


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hi Micheal i,ve just started today to read your log and i,m very impressed so far and i,ve only got to page 7 so far, i,ve down loaded your pdf and gone side way,s on your external link,s thank you for them i,m learning a lot i will be following your update,s i don't suppose there will a download for the full plan and just think your log will be a most invaluable building instruction,s and when i find the Watch button i will be pressing IT.

 

 

gary

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I have spent the last 3 days at the wooden boat festival in Hobart and was amazed to see just how common the reversing mechanism in this build is. There are heaps of examples here in beautiful old boats and thanks to Michael I know exactly how they work

Steve I am glad that I have been of help regarding these mechanisms.

 

Gary, thank you for your kind words. I have been very fortunate in my working career inasmuch that I have always been able to work doing the things I enjoy doing the most. The interesting thing is that while I worked building models commercially I did not have much interest in building models for myself.

 

I have a tendency to work in spurts and am very focused during these times, I think it has a lot to do with solving ways to accomplish the next part. currently I am procrastinating about what part to tackle next. A little bit of "model-makers block"

 

Michael

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 I think it has a lot to do with solving ways to accomplish the next part. currently I am procrastinating about what part to tackle next. A little bit of "model-makers block"

 

Michael

 

Haven't you got a cylinder head to make Michael?   ;)

 

I love watching you solve your problems and like others greatly admire your talents. But take your time, we'll still be watching.   :)

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A little bit of "model-makers block".  Writers block, designers block, artists block, yes we all go through it from time to time.  There’s usually something in the back of our mind nagging us.  The car that needs to be fixed, the furniture that needs to be moved, the book we want to read, go do that nagging thing and come back refreshed.  We will still be here.

 

Bob

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I have a tendency to work in spurts and am very focused during these times, I think it has a lot to do with solving ways to accomplish the next part. currently I am procrastinating about what part to tackle next. A little bit of "model-makers block"

 

I get this same thing but I find the best way to cope with it is to work on another project (or mini-project) for a few days after which I can usually find inspiration on my model again.

 

 

 

 

 

 

Lextin.

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No snow today ... It's just freezing your n.ts off ... The snowdeck is probably thick enough not to have some more downpoor

 

I cannot imagine how you will make the spark plug ... Will it have any porcelain insultaion ?

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  • 2 weeks later...

I was able to get a little break from driving today and was able to stay home. I had a couple of hours in the shop and worked on the spark plugs a little more.

 

A few more bodies were turned up out of brass. the small diameter stub represents the plug body and will be filed to a hex section the larger diameter of the rest will represent the circular plate that is on top of the head covering the oval plate as in this picture

 

1790.jpg

 

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Next I cut a strip 1/8th by 1/8th off the side of a scrap of Corian that I used as a cutting board in the kitchen using the tablesaw.

 

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Some time ago I made a special 4 jaw collet from a bolt in order to make square headed bolts out of 1/8th square stock

This came in handy for turning down the Corian to .078" diameter after drilling a .028" hole about 3/8" deep

 

post-202-0-80487400-1425259312_thumb.jpg

 

I turned short sections 1/16 long down to the finish diameter and progressed toward the chuck, this helped to support the work. once the full length was turned I slipped the steel core rod into the Corian and then pressed the brass over the Corian, using the tailstock chuck to ensure a good alignment.

 

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and a shot with the finger for scale

 

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The electrode was tested with a piezoelectric crystal to see how the spark would work and it worked fine I will need to add a steel in for the ground so that the spark jumps from steel to steel and not steel to brass.

 

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I will do some more experiments on the fabrication next week if I get time.

 

It was a good stress reliever today to focus on the model and take my mind of other things.

 

Michael

 

 

 

 

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Thanks for all the likes, Thanks Jack, Judy sounded great on the phone this evening, I am looking forward to seeing her tomorrow.

 

Here is the short clip of the spark test I suppose I could have waited till dark then the spark would have been more visible, when it is set up with the electronic timing the spark will be triggered by the magnet in the flywheel.

 

Michael

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Terrific, Michael. Working spark plugs! Who else would have thought of it? Sorry to read of your wife's health issues. I hope things will continue to improve for her. I'm sure it's a stressful time for you. Best wishes.

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Here, I was thinking the motor would be using glow plugs and model aircraft fuel... but, my jaw is dropping... working spark plugs.   I hope it runs on regular and not premium gas.  ;)  From the camming, (I went back and re-looked again) it looks like a 4-cycle then?

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Michael,

 

Incredibale, I couldn't believe my eyes at the size of those sparkplugs. Don't know whether Judy will be glad when she sees that cut Corian board ...

 

Take care driving, and best wishes to Judy

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"I would never have believed someone could hand build a spark plug that small,"

 

Mark I have seen a smaller one on one of the model engine sites.

 

Druxey, thanks for the well wishes.

 

"From the camming, (I went back and re-looked again) it looks like a 4-cycle then?"

 

Mark yes it will be 4 cycle I still need to separate the cams from each other in order to set them properly on the cam shaft.

 

"Don't know whether Judy will be glad when she sees that cut Corian board ..."

 

When I have finished re trimming the edge no-one will be able to tell it being an odd sized piece of scrap to begin with :)

 

Jack, thanks for the support.

 

And thank you to all who posted the like option, it means a great deal to me to be able to connect and share our hobby.

 

Michael

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Bob, Row, Denis thanks for your great comments, and for all the likes recently.

 

 

.how much clearance at TDC?

 

I had to go back an measure it, it is set to be .047" I might need to change that, I don't know at this point. but the design will enable me to make a change if I need to.

 

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spark plug.pdf

 

I will be making a small short sleeve at the bottom end of the plug that will thread in this will be then notched to creat a short stub to act as the ground for the plug so that the spark jumps from steel to steel.

 

Michael

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  • 2 weeks later...

Thanks to all for the likes and comments

I have not been able to spend much time in the shipyard this last few weeks, but things have improved a great deal this week, Judy is home now.

 

I did manage to get some time today to make some changes to the spark plugs. I was not happy about the way the plug were integrated into the head structure so after a couple of experiments I now have proper spark plugs they are made from some Allen key, that I annealed.

 

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The thread is a 6x40 I had to make them long reach which meant it was a bit tricky drilling a .028" hole almost 1/2 inch long through the Corian core which is only .078" diameter.

 

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The hand shot for scale

 

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The brass now functions as it was intended to hold down the oval cap to enclose the water cavity, and the spark plug threads into it.

 

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All I have to do now is add a brass  0 x 80 or a 00x90 threaded section to the top of the electrode in order the be able to make a good positive connection with the ignition cables. i will need to see how easy it is with the 00x90 which is a better scale size.

 

Michael

 

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