Author Topic: Bernay Build - MZT  (Read 26729 times)

Offline mzt

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Re: Bernay Build - MZT
« Reply #75 on: September 04, 2012, 03:48:02 PM »
Exactly!
Luckily the chuck got released at the same moment.

Marcello
This is a fitting job,
not a production job that can be measured in.

Offline mzt

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Re: Bernay Build - MZT
« Reply #76 on: September 06, 2012, 10:01:15 AM »
YET ANOTHER RUNNER!   :DrinkPint: :DrinkPint:

<a href="http://www.youtube.com/watch?v=iW5eE7jC4Ro" target="_blank">http://www.youtube.com/watch?v=iW5eE7jC4Ro</a>

In spite of the poorer materials, runs even better than the bronze model: I suppose the main reason of that laying into having
used teflon tape packings on the pistons and rods, where I had put natural fiber in the other.

Wonder what would happen on the if I might find some thin soft leather, like that used to line Gucci's bags insides, I could cut into
long, narrow, stripes and fit them as packing material.

Marcello


PS.
I see I've forgotten tightening the valve brackets screws before taking the video: they're stabler now.

This is a fitting job,
not a production job that can be measured in.

Offline steamer

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Re: Bernay Build - MZT
« Reply #77 on: September 06, 2012, 10:07:32 AM »
Well Done Marcello!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Bogstandard

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Re: Bernay Build - MZT
« Reply #78 on: September 06, 2012, 10:19:50 AM »
Sorry I haven't commented on your build before Marcello, I'm a little bit busy at home.

Lovely engine you have got finished there, and a good runner as well. :NotWorthy: :NotWorthy:  :whoohoo: :whoohoo:

Have you thought of some way to fit a slip eccentric, so that it can be reversed? Then it would make a very nice marine engine.


John

Offline ozzie46

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Re: Bernay Build - MZT
« Reply #79 on: September 06, 2012, 11:40:13 AM »


 Well done Marcello. That is pleasing to watch with all that motion. I followed the build and it was inspiring. I didn't comment  much but enjoyed it immensely.


 Ron

Offline vcutajar

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Re: Bernay Build - MZT
« Reply #80 on: September 06, 2012, 12:57:18 PM »
Well done Marcello.

 :whoohoo: :whoohoo: :whoohoo:

Vince

Offline zeeprogrammer

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Re: Bernay Build - MZT
« Reply #81 on: September 06, 2012, 12:59:27 PM »
Beautiful job Marcello.
A very interesting engine.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline mzt

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Re: Bernay Build - MZT
« Reply #82 on: September 06, 2012, 01:30:19 PM »
Have you thought of some way to fit a slip eccentric, so that it can be reversed? Then it would make a very nice marine engine.

John

John,

I have given quite a few thoughts about reversing the engine rotation during the builds (the left valve brackets have an hole I drilled for the eccentric rod , 'just in case' I decided to go that way): in the end I decided to stay with the plans and make both of them identical.

As for the slip eccentrics, though I have never built an engine making use of them (hence, not yet very clear ideas about their works) I suppose (SUPPOSE) they could be fitted, but their use would require (SUPPOSE, again) either moving the 'eccentric rod' to the other side of the cranckshaft or being replaced by a longer/shorter one anytime the rotation is reversed. I had even given thoughts to a telescopic eccentric rod, with a pin to lock it at the correct lenght, or a screw adjustable one but, as I said before, decided to make nothing of that.

Just for clarity, I've attached a picture showing what I called 'eccentric rod': there may be a more proper term but none is coming to mind.

Marcello
This is a fitting job,
not a production job that can be measured in.

Offline Don1966

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Re: Bernay Build - MZT
« Reply #83 on: September 06, 2012, 10:39:41 PM »
Beautiful job Marcello, but I doing like the brass one better. Great video as well.

Don

Offline mzt

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Re: Bernay Build - MZT
« Reply #84 on: September 10, 2012, 10:35:23 AM »

Pipe works

The flanges I had scrapped not being large enough to accept studs and nuts could be rescued for screw mounting.
Instead of threading both sides of the pipes, on these two I went for the much simpler flaring, holding the pipe in
the vice between two pieces of wood I had previously drilled to the pipe diameter.





In hindsight, I should have gone for flanged connections on the other end of the pipes, too. How neater (and easier) it would have been!

Some unexpected problems

At some point, while running the engine, it quit autostarting when stopped at some positions of the crank. Further experiments
lead to having the engine refuse to start at some more positions of the crank. "Interesting, worth investigating?"

When slowly turned by hand, it seized and locked into position: it?s now a problem I definitely have to solve if I want to make a video of it.

Two causes: not enough clearance into the valve arms bearings (?they?re a little tight, but will wear with use??) and
?thoroughly cleaning the engine then running it forgetting to add a dab of oil into each joint. Never a good idea.

The yellow marks on the valve rods, in the picture below, show where the bearings brass embedded itself into the steel,
then probably galled and finally welded itself in place. Had to bruise my knuckles for over an hour to get them free again.




Now, with added clearance (and plenty of oil) it?s working again.





Marcello









 
This is a fitting job,
not a production job that can be measured in.