Author Topic: Middletons Inverted V twin  (Read 2813 times)

Offline Jasonb

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Re: Middletons Inverted V twin
« Reply #15 on: November 10, 2020, 07:37:09 AM »
Small nuts (and hex screws/bolts) assuming you are using American threads

https://godshallscustommachining.com/products/model-hex-nuts

I did not see your question about the crank throw before. It should be 5/8". This is the original hand drawn Middleton for that crank, there is also an alternative one which also shows 5/8.
« Last Edit: November 10, 2020, 07:44:42 AM by Jasonb »

Offline crueby

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Re: Middletons Inverted V twin
« Reply #16 on: November 10, 2020, 12:23:26 PM »

One further thought - cutting studs from threaded rod and using scale nuts (smaller hex a/f size than normal machine screw nuts for a given thread) is usually far lower cost than buying hex head screws. Also more typical of what was used for fastenings on the real machines from 1865-1940 ish time period.

I'm interested.  Where do I find these?  thanks
Available in some sizes from a number of suppliers, search for Small Pattern Nuts.

Offline cnr6400

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Re: Middletons Inverted V twin
« Reply #17 on: November 10, 2020, 04:07:42 PM »
As Chris mentioned, look for "small pattern" nuts. In the Micro Fasteners site, the link below (for stainless nuts) gives a choice between small pattern and regular machine screw nuts.

https://www.microfasteners.com/home.php?cat=629

Good luck on the shopping. Don't be shy about buying 100 nuts rather than trying to find just a few - you will be surprised how much hardware is used on models of old machinery. Chris Rueby will attest to that! Personally I think 6 or 8 studs and nuts on say a steam engine's steam chest cover looks MUCH better than just 4 studs and nuts, or philips head machine screws. (even though 4 fasteners will probably be strong enough and function OK. )

Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #18 on: November 11, 2020, 02:18:01 AM »
As Chris mentioned, look for "small pattern" nuts. In the Micro Fasteners site, the link below (for stainless nuts) gives a choice between small pattern and regular machine screw nuts.

https://www.microfasteners.com/home.php?cat=629

Good luck on the shopping. Don't be shy about buying 100 nuts rather than trying to find just a few - you will be surprised how much hardware is used on models of old machinery. Chris Rueby will attest to that! Personally I think 6 or 8 studs and nuts on say a steam engine's steam chest cover looks MUCH better than just 4 studs and nuts, or philips head machine screws. (even though 4 fasteners will probably be strong enough and function OK. )

that's what I need!  Thanks
I ordered one package of each.  Comes in packs of 100
They are actually a great price.

Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #19 on: November 13, 2020, 11:37:41 PM »
Not much left.  I need to make piston and piston rod.
Dad says he is making a flywheel.  I'll have to true it up when I get it, he don't think that is important  :Argue: :Argue:

I'm starting to like the cap screws.  They are growing on me, reminds me of a stamping die I used to work on.   Its not like this engine is a scale replica of the original design.  I'll see what the small nuts look like when I get them, then I can decide.

Any of you guys that made the  "Coventry by Roy Ozouf"  can you recognize my valve link?  I think this looks a lot better than what was on the prints.

Thanks for looking!
Dennis



Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #20 on: December 15, 2020, 12:26:23 AM »
Hi all!
Archery was in the way again.  Much practicing with my daughter and myself.  Its finally over for a bit and I got back to business.
put it together yesterday to see if it would run.  It wouldn't run very good. 
It runs better at really low air pressure, and soon as I increase the pressure, it runs like crap. 
Can someone tell me what is wrong?  :happyreader: :happyreader:



Offline crueby

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Re: Middletons Inverted V twin
« Reply #21 on: December 15, 2020, 12:33:06 AM »
sounds like either a sticky spot in the revolution (if you turn it by hand can you feel the resistance change somewhere? ) or the timing of the valves is just a bit off, giving it a bit of a gallop as the piston on the near side in the video hits bottom. I like to connect just one cylinder at a time to air pressure and test, it can isolate where the issue is. Possible that one direction on one of the pistons is not getting pressure into it, or the exhaust is not opening soon enough.

Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #22 on: December 15, 2020, 12:36:12 AM »
I quit working on it last night and went to bed.   It finally hit me what could be making it run somewhat good at low pressure and bad at high pressure. :hammerbash: :hammerbash:
If you guys don't mind, I'm thinking a few of you guys will tell me right away what it is.   :popcorn: :popcorn:
Here is a video of it running much better. 
I still need to add the large brass ring on the flywheel, (laying on the left side of the engine) but it seems to run really good. 
Check out my new valve linkage!
I bought the brass fittings from PM research with 1/4" brass pipe from McMaster Carr.  I really like these fittings.
Found some low temp silver solder at Brownells, and wow, it sure does work good.  It says the melting point is around 550 degrees F
Now for the crappy part of painting and making it look nice.


Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #23 on: December 15, 2020, 12:58:22 AM »
sounds like either a sticky spot in the revolution (if you turn it by hand can you feel the resistance change somewhere? ) or the timing of the valves is just a bit off, giving it a bit of a gallop as the piston on the near side in the video hits bottom. I like to connect just one cylinder at a time to air pressure and test, it can isolate where the issue is. Possible that one direction on one of the pistons is not getting pressure into it, or the exhaust is not opening soon enough.

That was fast Chris   ;D ;D  I was posting my next one before any of you would read the first one.  hahah
It DOES have something to do with the exhaust.  Everything was timed perfect, and nothing was sticking though.

How about a bottle of whiskey for the first person to guess it!   :cheers:

Offline crueby

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Re: Middletons Inverted V twin
« Reply #24 on: December 15, 2020, 01:00:11 AM »
Sounds like your shop elves stuffed a potoato in the exhaust pipe then!  :o I had an engine where I had it all assembled, would not run right, then on taking it apart found that one gasket had no hole in the center!

Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #25 on: December 15, 2020, 01:26:01 AM »
Maybe not appropriate on an engine build forum, but its my thread so I can brag a little.  :whoohoo:
Here are some pictures of this last weekend at NFAA Indoor Nationals.  They cancelled the shoot in March because of COVID.  The NFAA decided to do a virtual tournament and let everyone shoot.  As of right now my daugther and  I are in first place!!
She broke the national record in her class (Young Adult Bowhunter) by one X....600 91X, and this old man....first year shooting as an old man (Senior Freestyle) class, tied the national record!   600 118X
There will be other locations around the states to host the tournament the next two weekends, but we are sitting pretty good. 

The last two pictures is my daughter back in September at the National NFAA outdoor field tournament. She got first place.
 
« Last Edit: December 15, 2020, 03:48:09 AM by flopearedmule »

Offline crueby

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Re: Middletons Inverted V twin
« Reply #26 on: December 15, 2020, 01:35:01 AM »
Thats some awesome shooting! I've never gotten that serious about archery, but have done enough to know how good those scores are.  :ThumbsUp:

Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #27 on: December 16, 2020, 12:01:10 AM »
Sounds like your shop elves stuffed a potoato in the exhaust pipe then!  :o I had an engine where I had it all assembled, would not run right, then on taking it apart found that one gasket had no hole in the center!

I guess that's close enough. lol

my end caps on the cylinders were sticking in to far and covering up the ports.  I needed to go deeper with the cylinder ports. 
It was like a flow control on an air cylinder that was closed too far and the air couldn't get out.

Offline gary.a.ayres

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Re: Middletons Inverted V twin
« Reply #28 on: December 16, 2020, 02:08:53 PM »
Congratulations! All my life I fondly imagined that I'd be quite good at archery. Eventually I joined a club only to discover I was rubbish at it.

So I left the club and bought my first lathe...   :)

The Middleton V-Twin looks great. I have a copy of Model Engineer with a picture of a finished example of it on the cover. Very handsome...

Notifications on for your thread!

Offline flopearedmule

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Re: Middletons Inverted V twin
« Reply #29 on: December 20, 2020, 02:16:00 PM »
Thanks Gary
It has been years of practice.  This score was the best I have ever done in a tournament.  Pretty happy it was the Indoor Nationals where my performance peeked.

Engine runs awesome!  Just have to finish the flywheel and paint it now.  It was a pretty straight forward build.
There were some errors on the prints from the article, but thanks to ACad, I got them all fixed.
take care