Potty Grasshopper Engine

[sbwhart]

The inspiration for this engine comes from a haulage engine on display at the Manchester Museum of Science and Industry, the engine was built in the 1840 and was used to haul wagons up an incline at an alkaline works, being an haulage engine it would run in both direction via a simple slip eccentric.



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

The model will be far from a scale model of this engine as I intend the design to be as simple as possible suitable for beginners, so I have taken huge liberties in the design, it will use the same cylinder and piston valve as my Horizontal Mill Engine and Vertical Cross Engine.

This is the assembly drawing



I had planned on using a cast fly wheel but had problems sourcing a suitable casting they were all too big and chunky, fly wheels of this period were far lighter affairs, in the end a had a blank laser cut that I've machined up and painted I've posted this else ware on the forum, but for those who missed it this is the finished fly wheel.



I've nearly got all the cylinder parts finished but as I've used the cylinder for other engines that I've ran threads for I won't bore you with its construction.

As this is very much a work in progress I won't make the drawing available until the engine is finished and I've caught up with all the changes there inevitably will be.

Cheers
Stew

[Johnb]

Interesting Stew. Looking forward to seeing progress.

[sshire]

Stew
I'll be watching this. As I said in a recent post, watching your builds is a learning experience.
Always wondered, why no one (that I've found) makes thin flywheel castings. The look of yours is so elegant and many engines of the period used these thin flywheels.

[tvoght]

Looking forward to the build Stew. I'm already up to speed on the flywheel from the other thread.

--Tim

[b.lindsey]

Another great one to follow Stew...I am looking forward to it.

Stan...there is this one from the PMR guys:  http://www.pmmodelengines.com/shop/gas-accessories/flywheel-castings/
Not sure if the scale is exactly right for Stew's engine but its one of the few thinner ones I am aware of...6 1/2" diameter by 3/8" rim width.

Stew, your fabricated one is still a beauty though and far more detailed.

Bill

[sshire]

Bill
I hadn't seen that one.
I'm intrigued by Stew's laser cut flywheel. Located a laser cutting firm nearby. I'll report in my build thread.
Apologies for the hijack.

[sbwhart]

Hi Chaps

This is the firm I had my fly wheel cut at LaserMaster Linda <sales@lasermaster.co.uk>; in the UK they are based in Cornwall UK I had a first class service from them the wheel was delivered 1 week after placing the order, and the quality was first class. It was cut nice and clean with a square cut the beam tends to cone out so to compensate for this a good machine can be canted, to square the cut up.

Its best to email them a dxf file that way they can load the drawing direct to the machine I've attached the my dfx drawing you are welcome to use it.

Stew

[sbwhart]

Whoops forgot the attach the drawing

[Jasonb]

Stan and anyone else on the other side of the pond, just remember to tell your laser cutters that Stew's drawing is dimensioned in millimeters or you could end up with a 160" flywheel

Most firms like to have one dimension so they can check the size of the part incase it has been scaled on the drawing.

Another thumbs up to LaserMasters who also did a good job for me recently.

J

PS Stew you might want to delete your details from that drawing to save spam.

[sshire]

Thanks Jason.
I'll be drawing my flywheel and exporting the .dxf file as I want curved spokes for the Coventry engine.

[cfellows]

Stew, really outstanding job on that flywheel!  I had to go find the original article to refresh my memory on how you did that. 

Chuck

[Tennessee Whiskey]

Stew, I'll be following along.  Your mill engine build was going on when I first started in the hobby and was a great source of inspiration.  Let the chips begin 

Cletus

[sbwhart]

PS Stew you might want to delete your details from that drawing to save spam.

Thanks Jason

I forgot that I'd added my details for the cutting firm, I thought it would simplify things if they needed to contact me.

And thank you Chaps for your interest and kind comments.

A model with a 13'4" fly wheel now that is something I'd like to see 

Stew

[sbwhart]

Another great one to follow Stew...I am looking forward to it.

Stan...there is this one from the PMR guys:  http://www.pmmodelengines.com/shop/gas-accessories/flywheel-castings/
Not sure if the scale is exactly right for Stew's engine but its one of the few thinner ones I am aware of...6 1/2" diameter by 3/8" rim width.

Stew, your fabricated one is still a beauty though and far more detailed.

Bill

Bill The PMR fly wheel is one I rejected I just didn't like the look of it the spokes were all wrong, I think the casters have a problem casting a light fly wheel something to do with the shrinkage rates,  I suppose there are high tech injection/vacuum moulding techniques out there but they would be far to expensive for model engineering, my laser cut blank cost a little less than a chunky cast one, and the amount of machining is similar.

Stew

[NickG]

Looking forward to watching this Stew. Nice looking grasshopper and the laser cut flywheel was a good idea!