lubricating engines that run on air?

[kev]

lubricating engines that run on air?

A lot of people run steam engines on air or design engines just for air, is there a way to provide a steady continuous lubrication at the engine ie not relying on some form of atomiser at the compressor end?

[Dan Rowe]

The simple way is to buy an air line lubricator. These often come with a filter and a regulator made for air operated tools in the shop.

Dan

[kev]

yes Im aware of those but I was thinking about something small to go with the engine along the lines of a displacement lubricator fitted to a steam engine

[b.lindsey]

Kev, what I usually do is put a few drops of light oil directly in the air line before connecting it to the engine and applying pressure. Then once the line is connected and pressure applied the oil will be pushed into the valve/cylinder, etc. and lubricate things for as long as a typical run takes. Continuous running would best be done with an inline lubricator as suggested however.

Bill

[kev]

Yes I also normall pop a drop into the inline before running but what im after is a reasonable easy way to machine some form of inline oiler as in one per engine or cyinder. A mechanical lubricator is a good solution but expensive. I would think it needs to atomise the oil into the air stream, any idea how the inline oilers for tools work

[Dan Rowe]

Kev, Here is the link to a miniature one that shows the principals of operation.
http://www.spiraxsarco.com/Documents/ML3M_Monnier_Miniature_Compressed_Air_Lubricators-Technical_Information.pdf

Dan

[kev]

Thanks Dan, thats a very interesting but complicated design. Im currently thinking a little wild and thinking about bubbling up air through oil, so imagining a cylinder of oil, inlet at the bottom (maybe with a non return valve) and the outlet at the top. Air bubbles up through the oil and becomes "oily" on its way to the engine. maybe not efficient but very easy to make.

[kev]

how about this

[b.lindsey]

Simple yes kev, but with even minimal pressure I think the oil will be churned up enough that a lot will exit to the engine. You can give it a try, maybe with a much lower oil level you might have a chance.

Bill

[10KPete]

I can see that working, but I'm with b.lindsey on keeping the oil in the pot. Baffles???

Pete

[sshire]

I like the baffle idea. Maybe a stack of "washers" with spacers between each.
An aside, and I'm being serious here. Love the Crap-o-cad. Bogs used to put them up regularly.  Rough ideas don't need Solidworks or Inventor.
I have a feeling that this is going to turn out to be a useful thread.

[10KPete]

An aside, and I'm being serious here. Love the Crap-o-cad. Bogs used to put them up regularly.  Rough ideas don't need Solidworks or Inventor.

I'm with you on pencil sketches. I've used AutoCAD for decades (before Windows!!) but I don't use it much anymore.
90% of the 'hobby machinist' stuff like engines and parts don't, for me at least, require CAD. I find pencil sketching much
more free. When I design, I don't worry so much about what size the part is, which with CAD you have to know to even
create the part! Too constraining. Quad paper and a pencil; that's the ticket for me.

Oops, sorry about the hijack!

Back to the original idea. I think something sorta tall with baffles just might work. Certainly wouldn't take much to bodge
one together for trial.

Pete

[derekwarner]

Those sketches from Mr Moore [bogs] were actually transcribed   onto the inside surfaces of empty [ ] fag packets .......... Derek

[kev]

sorry I have no fag packets and here is an even simpler crap-o-cad

re baffles maybe something simple machined on the end of the outlet?

[kev]

and this I guess needs a look at

http://www.screwfix.com/p/air-tool-mini-in-line-oiler-/4389H?kpid=4389H&cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&cm_mmc=Google-_-Shopping%20-%20Power%20Tools-_-Shopping%20-%20Power%20Tools&gclid=CPu-muv72cgCFSgFwwod1PYIRQ#product_additional_details_container

[mklotz]

My concern is that the vapor pressure of oil is fairly low so simply bubbling air through it may not pick up very much oil.  Some mechanism by which the oil is atomized before coming in contact with the air seems intuitively better.

But, hey, what do I know?  Clearly some experimentation is in order.  Comparing different implementations by having the exit air impinge on filter paper for a fixed amount of time and then weighing the papers might work.  Of course, none of this may matter much for the limited time that most model engines are operated.  Bill's (and my) approach of squirting a drop or two into the air line before attaching may be all that's needed.

[kev]

dont disagree with you I tend to put drop oilers on my cylinders as I like to lub up before and after

As to weighing paper that all sounds a bit technical, probably be happy its working if I get an oily splatter, will try and find an hour to play during the week. 

[Stuart]

Kev
at  that price its not worth making one


Stuart

[kev]

absolutly unless you want a nice bit of brass bling

[sbwhart]

I'm with the squirt of oil in the air line brigade, I've run engines for a couple of hours after just one squirt with no ill effects, still plenty of lubrication in the cylinder and good for a couple more hours, air doesn't have the same degrading effect as hot steam on the lubrication.

Stew 

[SwarfnStuff]

My two cents worth, you could try stuffing some steel wool or scotch brite into the oiler cylinder to act a baffles. A few drops or mililitre of your favourite oil should wet the 'wool' enough for the air to gather some? Worth a shot and easy to do.

John B

[joncarruthers]

sounds similar to the old 'oily sponge' air filter on mowers? Might try that on my engine.

+1 for the sketches, I use a slate and chalk on the wall over the lathe, old school.

[kev]

Like the steel wool baffle idea, one to try.

Chalk and slate Im close my workshop walls are gloss white and there are board markers all over the place for making notes and sketchs.

[Bearcar1]

I have never used a bubbler type of lubricator so I can not honestly speak to its successes or failures. I have used the methods already explained however and found them to be quite satisfactory in performance. My initial thoughts to your original post was why not apply the same principles as a "mist" coolant device some use on their milling cutters. Essentially an atomizer effect much the same as the air tool units but less sophisticated in nature. Think "the venturi effect" wherein liquid is drawn into a stream of air that is passing over a tube that projects down into a fluid. The fluid is drawn into the airflow due to the low pressure created as it passes over the fluid intake. A metering screw could be incorporated to control the fluid's introduction at the intake opening. I am of course merely spit balling here but believe that simply bubbling air through oil will not deliver the adequate results you seek.


BC1
Jim

[Admiral_dk]

Sorry but I do not like the steel-wool idea - you might end up with a bunch of very small "steel dust" in the engine .... rusting away ....

Steel-wool can destroy many thing if not cleaned away with extreme care - I've seen alu-wheels and all kind of aluminium parts ruined with steel-wool on motorcycles and the same goes for wood and steel-wool.

[SwarfnStuff]

Fair point Admiral. Steel wool could well do just as you say, I was merely throwing it in there.
    Scotch Brite perhaps safer? Then thinking some more,    what about an aquarium bubbler stone shaped to fit? Guess that would depend on the amount of air throughput. The amount of oil needed would surely be minimal so I see a lot of head scratching, tooth sucking going on as these ideas get kicked about. 

[steamboatmodel]

When running steam equipment on air I treat it the same as any other air tool and run it with a proper air tool lubricator and proper air tool oil. After all when running on steam you use proper lubricators and steam oil, not stopping and dropping a couple of drops in when running.
 Regards,
Gerald.