Author Topic: Potty Grasshopper Engine  (Read 20139 times)

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #25 on: October 01, 2015, 02:27:34 PM »
Doesn't time fly when your having fun:- time I did a update.

Next bit the eccentric this is exactly the same as for my mill and vertical engine except that it needs to rotate or slip (slip eccentric) around the crank shaft to change the direction of the engine. To do this you need to have a pin to act as a stop on the crank shaft and to section part of the eccentric. As I'm designing this engine for those with limited kit, the easiest way for them to machine these features is to first make a bush with a 3mm hole in it from the same material that the crank shaft is made from, then all you have to do it use this bush to drill the crank shaft for the stop that way it will be perfectly on centre.



And to section the crankshaft use this bush to make a little gauge so that you can section the eccentric accurately.





Next bit the bracket that will support the valve levers, this is made form 1" box section mild steel.





Square the bit up and mill the base nice and flat



Then drill the hole for to take the pivot bearing.



Drill the fixing holes.



And silver solder the pivot bush in place.



Mill away the unwanted bit of the bracket leave the bush intact until the end as this will give added support for the machining.



Thin down the back



Thin down the front



When done cut away the part of the bush not wanted,



 and this is where it fits on the valve chest.



Levers:- made from some 5/16" square bar, first drill the holes for the two levers.



Cut them from the bar and make up a mandrel and with them on the mandrel nibble them down to thickness.



Clean them up to shape with a file and this is where they fit.



Next bit the entablature, the base made from 1/4 mild steel plate cut to size nice and square and mark the centre point out



Using a wobble bar centre up on a four jaw and drill the and bore the centre hole a nice fit on the cylinder cover.





Use the cylinder covers to spot through to drill 3mm



Drill and tap the side M2



Keeping with the circular theme for the side plates, square the plates up and mark one out.



Drill a couple of holes in both plates and use these to clamp them together.



Drill the rest of the holes.



Hacksaw roughly to shape.



And file to shape.



And this is how it looks on the cylinder.



Cheers

Stew

A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline awemawson

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Re: Potty Grasshopper Engine
« Reply #26 on: October 01, 2015, 02:50:32 PM »
Very nice Stew. A fair few hours there I'll be bound.
Andrew Mawson
East Sussex

Offline tom osselton

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Re: Potty Grasshopper Engine
« Reply #27 on: October 01, 2015, 03:07:30 PM »
Very nice progress!

Offline jcs0001

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Re: Potty Grasshopper Engine
« Reply #28 on: October 01, 2015, 04:26:40 PM »
Great work and an education to see you you are doing it.

John.

Offline krv3000

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Re: Potty Grasshopper Engine
« Reply #29 on: October 01, 2015, 04:55:30 PM »
hi that's coming a long nice

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #30 on: October 26, 2015, 07:00:15 AM »
Cheers Lads

Bin a bit distracted from this over the last couple of weeks:- short holiday domestic duties etc.

But I cobbled it together:- lot of the nuts and bolts left off so things are not sealed and I didn't fit the flywheel, but I still tested it on air and it ran




Next job strip it down fit give it a paint job and a base and a few other button and bells.

Cheers
Stew
« Last Edit: November 25, 2015, 05:34:37 PM by Stilldrillin »
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline awemawson

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Re: Potty Grasshopper Engine
« Reply #31 on: October 26, 2015, 07:40:55 AM »
Very nice Stewart  :thumbup:

I'm guessing that that's reving rather faster than the full scale one would  :scratch:
Andrew Mawson
East Sussex

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #32 on: October 26, 2015, 09:40:34 AM »
Very nice Stewart  :thumbup:

I'm guessing that that's reving rather faster than the full scale one would  :scratch:

Yes its going a lot faster I had to turn the pressure up to compensate for all the leaks and lack of fly wheel, hopefully I can run it slower when I get it assembled correctly. In the mean time her's a vid of the real thing running.





Cheers

Stew
« Last Edit: November 26, 2015, 05:21:24 PM by Stilldrillin »
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #33 on: October 28, 2015, 11:19:06 AM »
Here is another vid, with the fly wheel fitted with the second main bearing and all the nuts and bolts in place.



Stew
« Last Edit: November 26, 2015, 05:23:24 PM by Stilldrillin »
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #34 on: November 20, 2015, 06:56:49 AM »
Here's the completed engine.








Cheers

Stew
« Last Edit: November 26, 2015, 05:25:05 PM by Stilldrillin »
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline modeldozer

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Re: Potty Grasshopper Engine
« Reply #35 on: November 20, 2015, 09:50:05 AM »
Just beautifull.  :bow: :bow: :bow: :bow:

Cheers  :beer:
Abraham

Offline tom osselton

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Re: Potty Grasshopper Engine
« Reply #36 on: November 20, 2015, 07:59:22 PM »
Looks fantastic! I've enjoyed watching the build progress.

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #37 on: November 21, 2015, 07:27:25 AM »
Thanks for your interest Guys

Here's a family picture of all three engines bullt with the same basic cylinder design.



Cheers

Stew
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline Stilldrillin

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Re: Potty Grasshopper Engine
« Reply #38 on: November 22, 2015, 06:25:06 AM »
That's a wonderful build Stew!  :clap: :clap:

It would look very good, in a workshop/ engine house diorama.  :thumbup:

That "modular" cylinder design has worked very well. Three very successful engines!

David D
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline krv3000

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Re: Potty Grasshopper Engine
« Reply #39 on: November 22, 2015, 06:33:03 PM »
brill just brill

Offline mechman48

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Re: Potty Grasshopper Engine
« Reply #40 on: November 30, 2015, 08:20:30 AM »
Superb Stew, just superb... :headbang:  :clap:

Might get round to making one in the not too distant future; from the drawings you kindly sent.

George.
George.


Always look on the bright side of life, & remember.. KISS..' Keep It Simple Stupid'

Offline millwright

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Re: Potty Grasshopper Engine
« Reply #41 on: November 30, 2015, 02:52:30 PM »
Another excellent job Stew they look good together. Will there be a number 4 or more on the same cylinder i wonder?

John

Offline sbwhart

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Re: Potty Grasshopper Engine
« Reply #42 on: December 01, 2015, 01:52:08 AM »
Another excellent job Stew they look good together. Will there be a number 4 or more on the same cylinder i wonder?

John

I wasn't really planning on building a fourth John, I have a Loco that I won't to build, but things are developing that may call for a fourth engine, I have my eye on a nice table engine, so as they say watch this space.  :proj:


 :beer:

Stew
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline Stilldrillin

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Re: Potty Grasshopper Engine
« Reply #43 on: December 01, 2015, 07:56:12 AM »
I have my eye on a nice table engine, so as they say watch this space.  :proj: :beer:
Stew

Go on, Stew!  :poke:

You know it makes sense.......   :thumbup: :clap:

David.
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!