Author Topic: Potty Grasshopper Engine (Read 25614 times)

sbwhart · « **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

awemawson · « **Reply #26 on:** October 01, 2015, 02:50:32 PM »

Very nice Stew. A fair few hours there I'll be bound.

tom osselton · « **Reply #27 on:** October 01, 2015, 03:07:30 PM »

Very nice progress!

jcs0001 · « **Reply #28 on:** October 01, 2015, 04:26:40 PM »

Great work and an education to see you you are doing it.

John.

krv3000 · « **Reply #29 on:** October 01, 2015, 04:55:30 PM »

hi that's coming a long nice

sbwhart · « **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

awemawson · « **Reply #31 on:** October 26, 2015, 07:40:55 AM »

Very nice Stewart

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

sbwhart · « **Reply #32 on:** October 26, 2015, 09:40:34 AM »

Quote from: awemawson on October 26, 2015, 07:40:55 AM

Very nice Stewart

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

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

sbwhart · « **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

sbwhart · « **Reply #34 on:** November 20, 2015, 06:56:49 AM »

Here's the completed engine.

Cheers

Stew

modeldozer · « **Reply #35 on:** November 20, 2015, 09:50:05 AM »

Just beautifull.

Cheers

Abraham

tom osselton · « **Reply #36 on:** November 20, 2015, 07:59:22 PM »

Looks fantastic! I've enjoyed watching the build progress.

sbwhart · « **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

Stilldrillin · « **Reply #38 on:** November 22, 2015, 06:25:06 AM »

That's a wonderful build Stew!

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

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

David D

krv3000 · « **Reply #39 on:** November 22, 2015, 06:33:03 PM »

brill just brill

mechman48 · « **Reply #40 on:** November 30, 2015, 08:20:30 AM »

Superb Stew, just superb...

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

George.

millwright · « **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

sbwhart · « **Reply #42 on:** December 01, 2015, 01:52:08 AM »

Quote from: millwright 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

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.

Stew

Stilldrillin · « **Reply #43 on:** December 01, 2015, 07:56:12 AM »

Quote from: sbwhart on December 01, 2015, 01:52:08 AM

I have my eye on a nice table engine, so as they say watch this space.
Stew

Go on, Stew!

You know it makes sense.......

David.

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Author Topic: Potty Grasshopper Engine (Read 25614 times)