Author Topic: Building a bigger Easton & Anderson Grasshopper  (Read 107381 times)

Online Jasonb

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Building a bigger Easton & Anderson Grasshopper
« on: September 16, 2012, 08:02:10 PM »
Some of you may have seen in the past me mention my intension to build this engine in a bigger size, well I?ve started.

It will be based on the 1/12th scale model by Anthony Mount that was serialised in EIM and also reproduced in his second book. Plans are also available from Bruce Engineering as well as castings.

I intend to double the size to 1/6th scale and having recently obtained some photos of the original engine will try to make mine truer to that. This will result in an engine with the following spec.

Length 15 ??
Width 10 ??
Height 14?
Flywheel dia 10 ??
Bore & stroke 1 7/8x 2?

The prototype was quite a small beam engine, most people think of the large waterworks pumping engines when a beam engine is mentioned but this one was smaller and would likely have been used in a mill or factory to drive overhead line shafting. That?s why it can be built at a relatively large 1/6th scale and still fit the flywheel on my lathe (just).

I probably won?t do a bit by bit build but just show some of the more interesting parts which will mostly be the fabrication of the items that are supplied as castings in the Bruce model and anything else that I think others may be interested in.





J

Online Jasonb

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #1 on: September 16, 2012, 08:03:19 PM »
I?ll make a start with the two crankshaft pedestalls, these are basically the same except the outboard one is longer to compensate for not sitting on the engines base casting.

I started by machining some cast iron block to 2? x 11/16? section then mounted it on its side in the mill vice and using the ARC function on the DRO cut a ?? radius quadrant with querk on one edge.




And then the opposite edge




The same process was carried out on the other edges until I had two embryo pedestals, the bases were cut to 4? long from 1x3/8 flat steel and drilled for mounting bolts and small discs added for a raised ?cast? area around the hole.


 


The CI blocks were then drilled and tapped so they could be screwed and loctited to the bases, Yes there is a place for socket head screws on period engines and that place is out of sight




Once the loctite had set I could locate the bearing heights from the base of the fabrication and using the boring head these were cut to 7/8? dia, note the plug gauge in the second photo used to ensure the hole matched the already machined bearings.






This work was done before I got the photos of the original from which I can see that the bearings should have had flat tops but I?ll stick with a bit of artistic licence. The tops were radiused using the ARC function again.




Then a ?? endmill was used to cut flats for the nuts to seat on and a 3/8? hole bored for a boss to take the oil cups. Holes were drilled for the studs, clearance down to the ctr line and tapped below.




A slitting saw was the fitted and used to split the blocks in two.




A bit of hand work was then required to round off all the external corners to help get that cast look.




Followed by an application of JB Weld and plastic metal to fillet all the internal corners.




While that lot set I machined up some 1BA studs, washers, nuts and locknuts. Finally the filler was smoothed off and a coat of primer sprayed on to see if the filler looked OK, I think it did.







J

Offline sbwhart

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #2 on: September 16, 2012, 08:26:36 PM »
Well if the rest of the engine are up to the standard of those bearings Jason it will be an absolute cracker.

 :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp:

I've never used the rad function on the DRO thats certainly sown me what it capable of.

I'll be quetly watching the rest of the build with great interest.

Stew
A little bit of clearance never got in the way

Online Jo

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #3 on: September 16, 2012, 09:21:57 PM »
Jason, I am looking forward to this :ThumbsUp:.

I had not seen those photos of the original engine before. I now realise how much Anthony simplified the original model. I must try not to go back and "fix" things now that I have a better idea what they should look like. The good news is that the engine in the photo is not sporting a governor belt and neither is mine :ROFL:.

Jo
Enjoyment is more important than achievement.

Online Jasonb

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #4 on: September 16, 2012, 09:37:17 PM »
Thanks Stew & Jo

Stew, its the first time I have used that function with the Z axis and it took a while to figure out the book :shrug: trial and error won in the end. The X-Y combination is a lot easier to figure out.

Jo, the source for the photos has suggested that the engine drove line shafting with a 2:1 step up and that the governor took its drive from the shafting, the arrangement that it has now with the iffy support was likely a lash up when it was moved to preservation.

I'm not sure if having the photos was good or not, I've had to revise how I was going to do the base casting and also looks like I will need to add the baring holes to the flywheel :facepalm:

Online Jo

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #5 on: September 16, 2012, 10:01:22 PM »
the arrangement that it has now with the iffy support

That support :facepalm: no where did Anthony show how it was supposed to mount at the bottom. It lined up with one of the bearing blocks so I had no choice but to do what I felt was a bodge :shrug:. When I finally tracked down his engine and for that matter your photo's, I had actually mounted it in the correct place  ;D.

Those baring holes do look nice :insane:.

Jo
Enjoyment is more important than achievement.

Offline tvoght

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #6 on: September 16, 2012, 10:36:33 PM »
First rate fabrication. I know you don't want to over-document, but I hope you won't be stingy. I know a good educational opportunity when I see one.

I'm laughing at myself. I have cut a number of stepped arcs on my current project by printing out lists of coordinates and cranking to the numbers,  checking off each point with a pencil. When I read this about the ARC function, I went out and checked my DRO manual (a really pretty nice product of the UK). Sure enough, my Newall DRO supports ARC. I know I've read it there before, but somehow never connected the dots.

Thanks for that!

--Tim

Offline Don1966

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #7 on: September 16, 2012, 11:10:46 PM »
Jason I to would like to see more of your built log. All of you engines and documents are first rate.
I do hope you share it with us, I am in this for the education myself.

Don

Offline Captain Jerry

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #8 on: September 16, 2012, 11:32:11 PM »
That is great work, and great photography.  This will be a very enjoyable thread as you usually provide. 

What is the double eccentric set up for?  Line shaft engines are not usually reversed and I don't see any linkage.  Is it some sort of adjustable cutoff? 

Jerry
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There are things that you can do and some things you can't do. Don't worry about it. try it anyway.

Offline steamer

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #9 on: September 17, 2012, 02:17:11 AM »
Beautiful work Jason!

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

Offline sbwhart

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #10 on: September 17, 2012, 07:16:38 AM »
Just a little off topic but I thought some of you guys would like to see this video of a Grasshooper in steam, its at the Manchester Museum of Science And Industry, this particular engine was used to haul trucks hence it fitted with a slip eccentric so that it can be reversed.

<a href="https://www.youtube.com/watch?v=SV7o4b0Mvfo" target="_blank">http://www.youtube.com/watch?v=SV7o4b0Mvfo</a>

Stew
A little bit of clearance never got in the way

Online Jasonb

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #11 on: September 17, 2012, 07:53:14 AM »
I'll see what I can do about extending the build log.

The two eccentrics drove Meyer Expansion valve gear which cuts the steam off early to make for more economic running. On the model  one is a dummy the other driving a standard slide valve.

J

Online Jo

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #12 on: September 17, 2012, 08:20:42 AM »
The two eccentrics drove Meyer Expansion valve gear which cuts the steam off early to make for more economic running. On the model  one is a dummy the other driving a standard slide valve.

J

Which reminds me: Be carefull when you drill the steam inlet as it can break through into that dummy outside (second) gland packing "gap" :facepalm:.

Jo
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Offline b.lindsey

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #13 on: September 17, 2012, 11:26:32 AM »
Amazing start Jaon. Looking at the original pictures and you usual attention to detail, this will make for a very elegant model. Looking forward to following along!

Bill

Offline swilliams

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Re: Building a bigger Easton & Anderson Grasshopper
« Reply #14 on: September 17, 2012, 12:06:32 PM »
This looks mighty cool Jason. I'm climbing aboard

Steve

 

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