Lamp Post Engine

Guilty as charged Simon, I do indeed subscribe to MEW. Interesting use as a work light. An improvement perhaps on the current candle power !! I am unsure of the demarcation between the two magazines ? The Lamp Post engine would certainly have some interesting machine setups and manufacturing problems to solve which I though would lean to MEW. Besides that, it would make for an interesting article in said magazine. Just my thoughts.

Nigel can you give me a little more information on the motor. DC? Brushed or brushless? Approx size as I don't want to spend a long time waiting for a delivery and getting the wrong one as the only two small motors I have barely give out 0.5 volts.

David

Hi Nigel. Not sure how you go about producing an article. You need one of the moderators to come along and inform you. As an alternative, you could post some drawings in your photos page and we could get started on it as I am sure a few on here would give it a go. Cheers.

Info on preparation of articles for publication is *** HERE *** this is for MEW but presumably similar for ME.

John

There is a pack that Neil Wyatt could email to you with all the information you need, including forms to provide the detail they need to pay you. Yes, they do pay for articles, you would probably not want to live only on the proceeds of writing for ME or MEW, but it does make a nice little incentive.

You could write this up in several different ways, for example a short article with a few photos of the finished article, or a longer series with drawings. For the latter you would want some photos of the various machining setups, which can be awkward if you didn't take them at the time.

Sometimes people are a bit shy about writing, which is a pity as I think we miss out on some interesting stuff because of this. You don't have to be Shakespeare to write for these magazines, so don't be afraid to give it a go. It is a nice model.

regards

John

Nigel,

I sent you a couple of MPs

Sam

Good for you Sam, far too many at Westminster...... I'll get me coat

Cheers, Martin

Hi Nigel.

The development drawing looks ok to me and clearly worked for you. Did you use a sheet metal folder for the fold lines when producing the shape ? Cheers, Jim.

Nigel, it may have been easier to have used an adjustable set square using an edge of the sheet as your datum line, but full marks for the method you used.

I've shown this thread to my partner, the reaction was "thats pretty, it would make a lovely Christmas table decoration"!

As we all know, when ones partner makes a comment like that its a request to make one. A look in the box of things that might be useful has found a small slide valve cylinder, a possibly usable flywheel and a small motor that may be suitable as a generator.

I'm looking forward to building my take on the "lamp post engine", a make it up as I go along project. Anyone else having a go?

John

John,

As an alternative (temporary) power supply, especially if you intend it to be a table display you could, instead, drive the steam engine, running the electric motor (and LEDs) from a battery. That way a compressed air supply would be unnecessary.

Okay! Not so cool?

I'll wash my mouth out

Sam

Using the electric motor to drive the model is an interesting idea.

What I am going to try is using compressed air from a small pressure vessel, (~2" dia x 4" long) concealed in a base to drive the engine for short periods. My intention is to charge the vessel with a bicycle shock pump so could have up to 300psi available!

John.

and there was I ... Fondly imagining a repurposed Sugar Bowl, filled with Coal

”one lump or two, my dear ?“

MichaelG.

John you could also include a small spirit (idea for Xmas) fired boiler then you would have a self contained unit

Edited By JasonB on 14/07/2020 10:10:06

It's easy to estimate from the piston stroke & cylinder size how much air the engine will eat. Never trust my maths, but I reckon a 2" dia x 4" pressure vessel holds about 25 cubic inches of air at normal pressure, or about 500 cubic inches compressed at 300psi (formula from Engineering Toolbox)

So an engine using 0.5 cubic inches of air per stroke would do about 1000 revolutions before running out of air - not long.

The other challenge is the need to reduce the pressure from 300psi to whatever the engine runs best at, probably in the range 3 to 15psi. The regulator on a commercial air compressor does this by bleeding air from the high pressure side through a valve worked by a diaphragm controlled by a spring, which the user can tighten or loosen to adjust the output pressure. I don't recall seeing a home-made design, or a commercial unit that could be hidden in the base of a model engine. I've not looked hard.

I wonder if paint ball accessories might help? Disposable liquid Carbon Dioxide (about 900psi) in 12g, 88g, 12oz and 20oz cylinders. Also, air cylinders in various sizes and pressures up to 4500psi. But I think they have to be filled professionally, and it all looks a bit pricey.

Fair bit of fuss using compressed air to show off engines in the home, a secret electric motor quietly turning the engine is much easier to arrange. (I test my engines with a small Stanley compressor, it has a 1.1kW motor and a 6 litre reservoir. Far too big and noisy, it dominates the scene.)

What's needed for showing off engines is a small quiet compressor producing a lot of air at moderate pressures. Easy to get high-pressure low volume and low pressure high volume compressors, but not quiet mid-pressure, mid volume pumps. Airbrush compressors are often recommended.

Dave

Fullsize air compressor in the workshop with pressure reducer/regulator and then 30 foot of 1/4" clear plastic tube run along the skirting boards to the display?

I'm wondering about actually running the engine on the dining room table now, oil being flicked about won't enhance the flavour of the meal!

S.O.D., I broadly agree with your numbers. The cylinder I plan to use should consume about a quarter of the air you have used in your sums, assuming my sums are correct. Might need to find a bigger vessel to get a few minutes running. There is a vessel sold for the initial inflation of tubeless bicycle tyres, can't remember what its called, might be worth a try.

I might consider disposable Co2 cylinders if my original ideas are unsuccessful.

Like the idea of some form of boiler, thing is, this is supposed to be a quick project, it could easily develop in to much more!

John

Sorry, no details of the glass boilers, some of the German suppliers do simple kits with them in but a small metal boiler would work, the plastic tube acts as the safety valve popping off if pressure gets too high

The other option is just to supply a length of tube and pass it around the table to see who has the strongest lungs, couple of "steam" engines I have built recently can be run by blowing, even my 10V will do it but not for long as I go blue in the face!

What about a small electric boiler, are they available as kits/plans..?

I saw a video of one running a small engine and thought it looked rather good, dont know if it was diy or a kit/plan. The boiler was horizontal and looked to be around 10 inches long by 3 inch diameter, thought it good been able to run these small engines on steam and not having to consider fuel types for the boiler.

Ron

Anyone know if the lampost engines is going to be written up or do I have to start from scratch?