Alyn Foundry Nattie

[Admiral_dk]

So it actually works like a Scotch Yoke - simple, elegant and most likely very reliable 

Per           

[Alyn Foundry]

Possible inspiration ?? 

You’re definitely going to need those flywheels now Ray.


<a href="https://www.youtube.com/watch?v=beIW4E4Emmk" target="_blank">http://www.youtube.com/watch?v=beIW4E4Emmk</a>

   Graham.

[RayW]

Still a few more bits to do yet Graham. Have just ordered some 2 thou shim for the exhaust valve.  Also need to sort out lubrication for the big end as I have used a split brss bearing. Then of course, there are a couple of non-standard extras to be made!

[RayW]

Some time ago, Graham suggested that it would be fun to add a mechanical oiler to Nattie to replicate the ones fitted to the full scale National engines. As a complete novice user of Fusion 360, I thought it would be an interesting project to try and design and build one. The photos show the (almost) finished end result, just lacking the full outlet pipe, which will drip oil into the cylinder, and a drive belt to provide drive from the side shaft.
For those not familiar with this type of oiler, the drive pulley is connected to a small crank on the end of which is a short length of chain. The bottom of the reservoir is filled with oil, through which the chain is dragged as the crank revolves. The oil trapped on the chain is scraped off on a slanting length of rod, below which is a cup into which the oil drips and runs out through the outlet pipe.
The beauty of this type of oiler is that the supply of oil to the cylinder is directly proportional to the speed of the engine. The faster the side shaft revolves, the faster the oiler is driven.

It was necessary to build up the cast flange on top of the cylinder as it sloped markedly towards the centre of the cylinder and there was insufficient depth of material to drill and tap for studs. A thick piece of steel was shaped and attached with JB Weld, When set, the top was milled level and tapped and drilled for two 6BA studs,

[RayW]

Nattie number 105 comes alive! After one frustrating morning of trial and error with the timing settings, today I managed to hit on exactly the right spot and away it went. The speed is very controllable just by varying the position of the flame, both in distance away and height.
At present there is no lubrication to the cylinder as the mechanical oiler has been removed for modification, but, as Graham has discovered with the prototype, once an initial oiling has been given, very little more is required.
This is the first Nattie apart from Grahams prototype to run, so, as you can imagine, I am feeling pretty pleased with myself.
This is the YouTube link <a href="https://www.youtube.com/watch?v=0vBdj2NHh98" target="_blank">http://www.youtube.com/watch?v=0vBdj2NHh98</a>

[Jasonb]

Well done ray, goes like a good un

[RayW]

Over to you now Jason!

[Jasonb]

As I was saying to Graham the other day the latest small Stuart replica is almost finished then I need to get back to Nattie and Little Otto, even more so now as a pile of rusty specially coated iron for another Alyn engine arrived on Monday.

[Kim]

Great first run, Ray! 

Kim

[Alyn Foundry]

Good morning Ray.

Congratulations on a fine running vacuum engine.   

Yes, there were two built initially and neither of them showed any signs of life some 20+ years ago. Sadly my friend Mike passed away before he could see a runner. His engine, although the second carries the number 112 ( home address number ) and now resides Stateside with his son.

   Graham.

[Admiral_dk]

Congratulations with a very fine runner       

Per

[RayW]

Nattie looks very smart in her new clothes. Just a few more jobs to do now, ie. smoke hood/chimney, wooden base, burner, and mechanical oiler.
How about a nice brass Nattie nameplate Graham?

[Alyn Foundry]

Hmmm, now there’s a thought…..

Here’s an example of an early National gas engine makers plate.

A paint job makes all the difference Ray, well done. 

   Graham.

[Alyn Foundry]

Geoff, the curator of the Anson engine museum sent me a photo of the Brass makers that would have been fitted to engines of that era.

As you can see, it is very nicely detailed. The only problem with a casting is that as the size is reduced so the detail becomes difficult to reproduce. ( see attached cast Brass Robinson plate )

I’m toying with maybe a Laser etched plate that just burns off a Black painted background? The prices of lost wax and the like are really prohibitive. It would put nearly 30 % on in kit cost.

Can Any members here suggest an alternative solution?

   Graham.

[Jasonb]

Etching?

Should go deeper and OK with small size fonts