Flame Eater (Flicker Engine) Mechanical Engineering Project

[jjssj]

I to make a flame eater engine for my engineering project.

I have come across J. williams design.
http://www.projectsinmetal.com/?dl_id=21.

The project task is to either create a new design or to implement a design and improve it.
I have chosen to create a mini engine i.e. flame eater.
However i require as many different designs as possible, how precisely how a flicker engine works, and design/change the specification of the engine plans already created. What could i do to improve the engines effeciency.

I need to create a PDS (product design specification)

Any infomation will be helpful i.e books, sites, plans, personal experience etc...

Thank you

 

[black85vette]

Hello and welcome to the forum. Sorry I don't have the information you need. But there are many here who can help. At least this will bump your post back up to the top of the list and see if someone might help.

 

[Jadecy]

The flame licker is a fairly simple design but requires precision machining, correct materials selection, and proper flywheel size to provide the correct amount of inertia. If the flywheel is too heavy or too lite the engine will stall and fail to run. The piston to cylinder fit must be as close to a perfect slip fit as possible which is .0005 per .5 inch of diameter. This is a vacuum engine and is very particular about friction and proper piston fit. Anything you can do to reduce friction will help. I don't remember the name of the book but their is a book out there outlining general design. Materials is another consideration. Stainlees steel works well as a cylinder. I would suggest a cast iron piston. Keep the piston as lite as possible. Do not use oil anywhere near the cylinder. It will keep the engine from running. Powderd graphite is a good dry lubricant and will also help seal the piston to the cylinder.

These are just some items I am aware of. Therre are others that may have additional tips or information.

Hope this helps!

 

[NickG]

I don't want to put you off, but I wouldn't do a flame licker as your project.

I am currently making the design you quoted and it's very tricky indeed. It is an unorthodox design too. I have about 15 years experience of making models and I'm finding it my toughest challenge yet.

here is the build log: http://www.homemodelenginemachinist.com/index.php?topic=6803.0

Nick

 

[jjssj]

Any suggestions on what model engine would be easier to build?
Thanks for all the help so far.

 

[NickG]

A compressed air engine is much simpler.

Probably more scope to improve a design too. You could start off with an oscillating engine for example which is simple enough and what most people start out with. Then add another set of ports and cylinder cover / gland to make it double acting.

Or maybe these rocking engines that you will have seen people doing. There must be scope for improvement with those. Maybe a twin cylinder version?I haven't seen that done before. Very few moving parts so they are quite easy.

Nick

 

[cfellows]

I would have to agree with the others. I've built 3 or 4 different flame licker engines and have only had moderate success in getting one of them to run. They are great engines when built perfectly, but are very difficult to get them to run.

Compressed air engines are the simplest to build and the most forgiving of imperfect machining. Unfortunately, you need an air compressor to run them. But virtually any steam engine design will also run on compressed air.

Chuck

 

[MikeR C]

If you want to do a flame licker, I did, you might consider a "Poppin" looks like several have been built by members on this board and they don't seem to be that hard to get to run. You could scale it up, larger parts are easier to deal with, up to a point .The warning about precision from Jadecy still holds. The poppin was a feature in, I believe, Live Steam Magazine.
You might consider looking here as well:

http://www.jerry-howell.com/Menu-1.html

Jerry calls his flame lickers "Vacuum (atmospheric) Engine". Don't overlook a stirling engine or, and I'm interested in these, a Ringbom stirling.
There would be many things to try on a flame licker, Graphite piston vs cast iron vs whatever and the same choices on cylinder both with liners and without. Cooling is another area that could be explored, most engines are air cooled and they eventually over heat and stop.
You might consider going here, there is a complete explanation of how a flame licker operates:

http://heetgasmodelbouw.ridders.nu/Webpaginas/pagina_happer_principe/happerprincipe_frameset.htm


Flame lickers are a popular engine type and if you did your build on this forum, along with the results of your experiments, I'm sure you would generate a lot of interest and have a large knowledge base to help you. Please don't be discouraged regarding the warnings that have been posted on your engine. We just want you to understand what you are getting into, we don't want you to go into this blind, rather we want you to be successful and in turn be able to advise us.

Hope this helps...
MikeR C

Added picture of a commercial flame licker, as I remember the flywheel was 6" or 7" in diameter.

 

[jjssj]

"you might consider a "Poppin" looks like several have been built by members on this board and they don't seem to be that hard to get to run"

Whats the difference between poppin engines and the flame eater, just watched this video [ame]http://www.youtube.com/watch?v=HLjZfT-2Apw[/ame], and the only difference i see is there are two flywheels(does this increase stability) and the valve is external, correct me if im wrong.

Thanks again for all the help, mikeRC especially as you have given me the confidence to continue with the inital flame eater engine, or I may go with the poppin engine. Need to do more reseach.

 

[MikeR C]

Flame eater, flame sucker, flame licker, flammenfresser, vacuum engine, vlamhapper, atmospheric engine, are all the same thing and they run on the principal illustrated here:

http://heetgasmodelbouw.ridders.nu/Webpaginas/pagina_happer_principe/happerprincipe_frameset.htm

Poppin is a flame licker, the engine drawings you posted are a flame licker, and if you search on Google Photos with the above key words you will see many other kinds. They have different number of fly wheels and different valve mechanisms, some are horizontal and some are vertical, and there are ones with more than one cylinder. Some run with a dry piston and some run with oil. They all have a couple things in common if they are to run, this is outlined in Jan's webpage, they have to be very free running no binding and most use ball bearings. They must have a good fit between the piston and cylinder, free moving but no extra clearance. And the valve, however it is made, needs to seal correctly.
They are not THAT hard to put together, I built a Poppin using a 6" Atlas wornout lathe and bearings out of old hard drives and it runs.
I hope this clears things up, have fun!

MikeR C

 

[NickG]

Well said Mike, I don't want to put anybody off, just give them all the information we can.

Still having trouble with mine incidentally. I think the best I've had is a few extra revolutions when spinning the flywheel - but I'm not even sure about that to be honest! Am at a bit of a loss with it. Going to finish it off with a proper burner then try setting it up.

If I'm still banging my head against a brick wall with it by January I think I'm going to try making a poppin myself. At least then I'll know whether it's my shoddy machining or the design that's a bit more marginal than the others.

Nick

 

[jjssj]

What do the fins on the Cylinder do? Is it just for cooling. Can they be seperate and made out of another material.
If more fins were added what does that mean/do. The idea come up because i could add more fins and create them with another material which is a conductor of heat.
What factors make the engine run at a higher rpm? run effecient more effecient.

 

[NickG]

Yeah, they are for cooling. But the puzzling thing is that if it's cooled too much , it 'quenches the gas too quickly, before the valve can close thus creating a shorter or no power stroke. So the cylinder needs to run at a certain temperature but needs enough cooling to maintain that temperature. Otherwise the heat gets too high and the temperature differential probably becomes too small.

The cooling probably isn't as critical as on a stirling type engine where you are heating and cooling the air inside the engine, here we are sucking in very hot gases and then cooling down.

It's a bit of a can of worms, especially this design.

So I would like to say that extra cooling would make it more efficient, but I'm not sure it's as simple as that. Also, the more you can shroud the flame etc the better, you don't want to draw in any cold gas or air.

Nick

 

[jimmyocharlie]

i'm going to tackle a flame gulper as my next project. having read a lot of threads on the topic, i'd say to build one EXACTLY to the plans. once this works, you'd have you base for any modifications.

if you've not got any experience, i would suggest making the EZ engine, its a good introduction and the feeling of getting it running will keep you going

 

[NickG]

Jimmy,

Yeah I've made lots of air / steam engines in the past and I'd agree, they are ideal to start with as you can get some real pressure behind them so even if badly made the chances are they'll run.

A stirling engine made to my own design is what I class as my best achievement so far. That required some trouble shooting but I got there in the end. I have made my flame licker to a higher standard than the stirling but no joy! I'm not about to give up any minute, but I may try the poppin version and build to print if I end up going around in circles with this one!

The thing with the plans is people design them to suit the materials they have or can easily get. I don't think Jan Ridders will have fine tuned or done any calculations in that design, I think he's just done it with experience of what feels and looks right and to suit what he had to hand. I think it's probably his machining ability / experience that tells. He suggests for example that the clearance between bore and piston needs to be no more than 0.03mm but at the same time, it needs to have negligible friction - not easy for the beginner to achieve, or me - as I'm proving!

Nick