Author Topic: The McOnie Oscillating Engine  (Read 27253 times)

Offline Dunstaneloi

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Re: The McOnie Oscillating Engine
« Reply #45 on: July 24, 2018, 08:48:13 AM »
Thanks Jason. I usually use hand reamers but they are no use for bottoming blind holes, hence the query about suppliers. My 'trigging' is almost non-exitent despite an expensive education, but my wife came down from Oxford with a Mathematics first so perhaps we can sort it out.

Mike

Offline Ramon Wilson

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Re: The McOnie Oscillating Engine
« Reply #46 on: July 24, 2018, 09:12:22 AM »
Mike - Forgive me for being blunt but - if you ask for someone's help and they take the time to reply the least you can do is acknowledge it  :(

Tug
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(a very apt phrase - thanks to a well meaning MEM friend)

Offline Dunstaneloi

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Re: The McOnie Oscillating Engine
« Reply #47 on: July 24, 2018, 05:54:45 PM »
Hi Ramon.
Blunt is fine by me. I was following up JasonB's comments before getting back to you to see if his suggestion was possible. We found it a problem from the drawings. So we scanned them, enlarged them, projected the relevant lines with pencil and ruler, then used a school protractor and came up with 3 degrees of angle. Thanks for the pointer to ARC.  I have been giving a lot of thought to your method for the crankshaft and am going to abandon the flame-cut blank supplied with the castings and follow your way. It will make a much more beautiful job, and as soon as the temp in my workshop drops below 30C I shal be off.  Apologies for the delay in replying.

Regards, Mike.

Offline Ramon Wilson

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Re: The McOnie Oscillating Engine
« Reply #48 on: July 24, 2018, 10:44:24 PM »
A couple of pointers Mike -

As drawn it appears to show either tapered chamfers each side of the web or, as I'm convinced were meant, to show the curves created by turning the webs at the angle.  Personally I didn't think this would be realistic so kept to plain milling to finish shape plus those little feet to aid the pressing. You pays your money I guess.

I checked my drawing and had not annotated an angle (none shown as you say) but concur with your 3 degrees - that's what mine measures any way. There are some notes made to the effect that the make up across the webs and the two eccentrics are .5mm wider than the distance between the two frames/bearing blocks which throws the centre line of the shaft relative to the cylinder out. I solved that by losing the .5mm off the water pump eccentric. Worth checking your drawings as I believe there were two issues (though I think mine are in fact the later ones)

That there are several mistakes on these drawings is well known however I'm pleased to say Anthony got all the parameters dead right and the design itself appears sound - when I finally assembled the valve gear on mine I stuffed an airline into the inlet port using a bit of silicone tube as a jury rigged seal and the engine just turned over and ran instantly without any assistance from me.

Just check the dimensions involved in any make up before you cut - you won't go far wrong.

Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Online Jasonb

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Re: The McOnie Oscillating Engine
« Reply #49 on: July 25, 2018, 07:13:58 AM »
I made an assumption that the taper started 1.5mm in from th eedge of the web and came up with 2.95 degrees using trig so sounds like we are all in the same ball park.

Another built up one here

http://www.eckartkercher.de/McOniebau01.htm

Offline Dunstaneloi

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Re: The McOnie Oscillating Engine
« Reply #50 on: July 25, 2018, 08:05:21 AM »
Thanks for the pointers Ramon, especially the 0.5mm difference between the bearing blocks.
 
As for the chamfers on the crank webs, they are not on the engine on the cover of ME 25 April 2008, (the start of the series) which is presumably Anthony's model, nor on the Cotswold Heitage YouTube clip, so I suppose it's what the individual wants their engine to look like.

As for checking dimensions, I stick to the old adage, 'measure twice, cut once !' I'm off for a steam test on my 5"g. LB&SCR 'Gladstone' this morning. Fingers crossed as it failed last time due to a blocked gauge glass bottom fitting.

Mike

Offline Ramon Wilson

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Re: The McOnie Oscillating Engine
« Reply #51 on: September 14, 2018, 11:19:41 PM »
Hi Guys, just thought you might like to hear that finally I have this engine finished  ;D

I've spent the last few weeks beavering away at the remaining work so that at last it will be going to Forncett ME Day in a couple of weeks not only finished but being able to run too  :) :) - Yep I'm well happy.

As said before it runs well and very smoothly. I do need to tweak the governor a tad as it is not as smooth as it could be but it's not going to take much. I think it either needs a spring to work against or maybe a collar to limit lift. Though I bought some red paint I couldn't 'see it' in that so opted for the beige treatment - anyway here are some pics.





























I did take some video but will need to upload it - it's too late tonight I'll see what I can do tomorrow.

It's been a long journey getting here in several well spaced steps but someones so pleased with it |I'm allowed to display it on the sideboard  ;)

Regards to all who have taken an interest in this lovely design

Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Online crueby

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Re: The McOnie Oscillating Engine
« Reply #52 on: September 14, 2018, 11:30:19 PM »
That is stunning! Beautiful job, excellent finish on everything.


 :ThumbsUp:

Offline Ye-Ole Steam Dude

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Re: The McOnie Oscillating Engine
« Reply #53 on: September 14, 2018, 11:31:13 PM »
Hello Ramon,

Absolutely beautiful and the perfect color scheme.

Have a great day,
Thomas
Thomas

Offline pgp001

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Re: The McOnie Oscillating Engine
« Reply #54 on: September 14, 2018, 11:40:16 PM »
Lovely job, the colour suits it well.

Just curious why some of the crank bearing pedestal nuts are loose, are you needing some adjustment for running clearances ?

Phil

Offline zeeprogrammer

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Re: The McOnie Oscillating Engine
« Reply #55 on: September 14, 2018, 11:41:18 PM »
I can't add much  more. Beautiful!  :ThumbsUp: :ThumbsUp:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Zee-Another Thread Trasher.

Offline b.lindsey

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Re: The McOnie Oscillating Engine
« Reply #56 on: September 15, 2018, 12:00:54 AM »
Gorgeous Ramon. Like others, I love the color too.

Bill

Offline steam guy willy

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Re: The McOnie Oscillating Engine
« Reply #57 on: September 15, 2018, 01:26:35 AM »
Wow ,really good will love to see it running and looking forward to forncett !! Very brave painting it that colour as any slight defects will show up ! so very accurate and precise work done , Beautiful

Willy

Online Dave Otto

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Re: The McOnie Oscillating Engine
« Reply #58 on: September 15, 2018, 01:30:04 AM »
Beautiful engine Ramon!

Dave

Offline 10KPete

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Re: The McOnie Oscillating Engine
« Reply #59 on: September 15, 2018, 04:26:52 AM »
Now you've done it. Raised the bar another notch! Absolutely beautiful. :praise2:

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

 

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