Model Engine Maker

Engines => From Plans => Topic started by: chucketn on July 06, 2018, 12:36:41 PM

Title: Harry Wedge Oscillator
Post by: chucketn on July 06, 2018, 12:36:41 PM
The book “Model Stationary and Marine Engines”, by K.N. Harris has a drawing of a Single Cylinder Marine engine designed by Harry Wedge, on pg 7. Does anyone have that book that would be willing to make me a copy of that drawing? I have a .pdf of the book, but the diagrams are poor quality and the dimensions are hard to read. Or, possibly tell me where to find more info on that particular engine? My intention is to re-draw this engine in Fusion 360 and 3d print casting patterns.
Title: Re: Harry Wedge Oscillator
Post by: Bluechip on July 06, 2018, 12:58:48 PM
Chuck

It's on P9 on my copy  :ThumbsUp:

The diagram on the book itself, together with many others, is not too good. Printer  / publisher none too competent.  :headscratch:

My scanner is not connected at the moment.  I'll have a go later on today and e-mail the pics. if no-one else offers.

Dave
Title: Re: Harry Wedge Oscillator
Post by: chucketn on July 06, 2018, 01:31:37 PM
Thank you Bluechip.
Title: Re: Harry Wedge Oscillator
Post by: Bluechip on July 06, 2018, 02:21:07 PM
Scanned ...

PM sent ...  :ThumbsUp:
Title: Re: Harry Wedge Oscillator
Post by: chucketn on July 06, 2018, 04:16:07 PM
Thanks, Dave.
When I get them drawn up, I'll share the drawings here.
Title: Re: Harry Wedge Oscillator
Post by: Bluechip on July 06, 2018, 04:32:10 PM
e-mail & piccy sent  :)

D.
Title: Re: Harry Wedge Oscillator
Post by: chucketn on July 06, 2018, 05:11:44 PM
I can see the dimensions clearly in your scan, but my computer is groaning under the strain... LOL, I have to crop sections of the scan in Paint and then print that bit. But, I can see the dimensions and that was the important bit... Thanks again.
I'm surprised no one has re-drawn this neat little engine before, or at least I couldn't find it if they did... It'll be a good test of my Fusion 360 skills.
Title: Re: Harry Wedge Oscillator
Post by: Bluechip on July 06, 2018, 05:56:17 PM
Hi Chuck

You need a new PC ...  :D

Some of the trouble is this HP scanner ...  :headscratch:  I did a scan @200DPI and the fractions were unreadable  :Mad:

But here's the problem. It won't scan & 400, 600, 800 DPI, it invariably gives an error but it starts to work again @1200 DPI ....

Don't know whether the driver is crook or what.  If I set for colour instead of Grayscale it works fine  :insane:

Anyway, if it does the job we've cracked it.   :DrinkPint:

Dave
Title: Re: Harry Wedge Oscillator
Post by: chucketn on July 06, 2018, 06:29:58 PM
Yes sir, we've cracked it. I have had to open the drawing in Paint and crop out the pieces  as my old puter nearly had a coronary trying to print the whole drawing from Paint.

2 questions  for those that have this book:
    1. There seem to be some dimensions missing, should I  fill them in best guess?
    2. On the drawing there are several  sideways f's. What do they indicate. I was a manual draftsman some 50 years ago, but don't recall anything like that...


Title: Re: Harry Wedge Oscillator
Post by: Zephyrin on July 06, 2018, 06:42:03 PM
Cute little engine ! in page 9 & 10;
just reading the book, note the refinements in the design of the steam ports, with straight side to improve a faster and complete opening and the corresponding larger port in the steam block...
alas poorly visible drawings, dotted confused, far too small !

some outside dimensions are missing, as it was common with blue prints for machining castings.
Title: Re: Harry Wedge Oscillator
Post by: b.lindsey on July 06, 2018, 09:20:17 PM
Not looking at the drawings but the "f" can indicate a finished surface.

Bill
Title: Re: Harry Wedge Oscillator
Post by: chucketn on July 07, 2018, 01:23:19 PM
Thanks all for your responses. I am learning a lot from this project. Finished surface, I should have known that, Bill. Thanks for refreshing my memory...
Title: Re: Harry Wedge Oscillator
Post by: Jasonb on July 07, 2018, 02:59:04 PM
Key to Elmers symbles below, F = Flat as in lapped which may be what it reffers too, depends on what the actual surface is doing.

Edit, just looked at the drawing it is just a finished face on the casting.
Title: Re: Harry Wedge Oscillator
Post by: 10KPete on July 07, 2018, 03:11:10 PM
The 'sideways' script f was placed on the dimension extension line to indicate the surface was to be finished, as opposed to being left as cast. Not seen too  much these days but quite common back when....

Drew many little efffs back before 'puters ruined the art of drafting...

Pete
Title: Re: Harry Wedge Oscillator
Post by: chucketn on July 07, 2018, 05:49:44 PM
Jason, I actually have that page from the addendum to Elmers plans. I admit I didn't think of it when I wrote the question, as the plan I'm redrawing isn't one of Elmer's designs.
Thanks too, Pete.
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