Philip Duclos Fire Eater

[fcheslop]

Hi Bob, Iv found on a few flame gulpers they need a bit pre heat but on the Duclos unless its a bit humid they dont suffer and will start straight from cold as was the case for that wee video I showed
It maybe a case of the alloy cylinder expanding so you loose vacuum Iv not built an engine with an alloy cylinder /graphite piston but do know graphite is more stable hence on the Ridders engine the materials have been chosen to try and keep the expansion prob to a min.When I built my Duclos engines I simply used what the designer recommended and not had this sort of prob
The CRS piston may cure the prob.
Good luck its nearly there

 

[CFLBob]

Well, the new piston didn't make the difference. Still won't run properly. Actually, it won't run at all at the moment. There was some sticking at the very end of TDC, and I moved things to try to fix it. Now nothing works, not even the piston that worked two days ago.

I'm about out of ideas here. Maybe I need to take some time off and not think about it.

 

[minh-thanh]

Hi CFLBob
I've seen the way you try with the cylinder-piston, flywheel ... it's ok with the way I do (It's hard to say exactly when i only see videos ) , have you checked the dimension and location of the hole air intake is correct ? (It also determines the valve opening and closing time )

 

[CFLBob]

Hi CFLBob
I've seen the way you try with the cylinder-piston, flywheel ... it's ok with the way I do (It's hard to say exactly when i only see videos ) , have you checked the dimension and location of the hole air intake is correct ? (It also determines the valve opening and closing time )

Yes, it's centered where it's supposed to be and the right width. The exact position of the valve is very adjustable.

 

[minh-thanh]

If everything is correct to plan, you should check the cylinder - piston, you should check them with the light, with each position of the piston in the cylinder you do not see the light passing through- But they have to move smoothly, that is how I checked.

 

[CFLBob]

Post mortem. I can measure the pistons with a digital micrometer. I can only measure the cylinder with calipers as far in as they stick, which doesn't mean much. My cylinder measured between 1.001 and 1.002.

The CRS piston is too small. 0.9989" That's the diameter of the 1" bar I made it from. All I did other than cut to length and bore the inside to size was de-bur it.

My "too small graphite pistons" are 1.0000 and .9996". Pretty obvious the problem is the pistons, and I recall thinking about that steel bar being too small when I decided to go with graphite.

Clearly I can't bore it out smaller so I see two possibilities. The one I've heard of would be to sleeve the cylinder. I've heard of doing that but have no idea what to use or how to do it. The second possibility is a friend said I could electroplate some copper onto the graphite. I have no idea how.

The thing that drives me nuts is that it literally seems like the piston goes from too tight to too loose within about .0002" diameter - it's really, really critical. That just doesn't seem reasonable. The steel piston would jam at the end of its travel at TDC. I loosened the two SHCS holding the flywheel to the base and moved the holder to the right so that the piston doesn't go as far into the cylinder as it did. Wait. Why should it jam? The cylinder could be tapered; smaller at the end. Could the cylinder wall have a bur? Didn't feel anything by finger. The graphite didn't jam either because it's softer material or because the top rim is more rounded than the steel from me holding sandpaper against it. The rounded edge didn't get affected by the narrower spot. All this is guesswork.

If there's something wrong with the cylinder, it seems unfixable, except for putting in a sleeve.

Suggestions appreciated!

 

[fcheslop]

Hi Bob, if the cylinder is wrong just bore it out slightly over size the engine wont know the difference. I dont know with any degree of accuracy what my engines is.It just dont matter
You cannot measure a bore accurately with calipers as you are measuring a chord and not the dia
CRS with not be truly round.
Has the graphite piston worn tapered
Do a simple test on the lathe Grip a bit of bar the length of the cylinder with no tailstock support and give it a couple of light cuts then measure it at each end or nearest to the chuck and the other end if its got a taper youre engines bore probably has as well..
If the taper is slight you could make a simple lap to make it true
These engines do need good fits and are infuriating at times although you are getting near
Just some thoughts

 

[CFLBob]

This is about as good as it gets. I find that if I let it get to room temperature it starts pretty reliably and continues to run. Room temp is about 80 in the air conditioned shop, with a ceiling fan blowing nearby. As it warms, the position it wants the flame to be in seems to change, but that might be the vibration from the engine running is moving the lamp, and if I held the flame in one spot, it would keep running!



This is with the third graphite piston, the biggest.

I'm trying to convince myself whether it's "done" or not. Do I turn another graphite piston, maybe .001 bigger than this?

 

[Brian Rupnow]

You're done. You've built an engine--it runs. Give yourself a break. Go on to other things. You may want to come back and revisit this one sometime in the future, but I'd say to consider yourself finished.---Brian

 

[fcheslop]

Congratulations on a runner
Glad you persevered with it
Whats nest
cheers

 

[werowance]

congratulations on a runner.

on mine, flame likes to be just forward of the intake hole not centered on it and with the wick actually touching the cylinder. seems to keep it from sucking cold air in or something. but I definitely think you can call it a success.

 

[rlukens]

https://www.amazon.com/dp/B00R5E5PI6/?tag=skimlinks_replacement-20
20 bucks and you're covered.
Btw, I built my first steam engine on my dads's little Atlas, at 13. I didn't know how to read mics so I made the cylinder first.

 

[CFLBob]

https://www.amazon.com/dp/B00R5E5PI6/?tag=skimlinks_replacement-20
20 bucks and you're covered.
Btw, I built my first steam engine on my dads's little Atlas, at 13. I didn't know how to read mics so I made the cylinder first.

Well, there's a story there, but thanks for the link. I need a set like that.

I made my cylinder first, too, so that I could fit the piston to it. My concern about the cylinder having a taper was because of the boring bar moving my QCTP while I was boring the cylinder to size. I was pretty sure that I fixed that and it came out straight but when you spend weeks trying to get it to run, every little concern comes back. Making the piston to fit the cylinder still requires you to know what a good fitting piston feels like. I didn't know. I'm not 100% sure I know how it's supposed to feel now.

As for what's next, I was going to ask for recommendations. I'd like to build some sort of internal combustion engine, but I have no idea of what's a good project for a relative beginner. I'd assume something with castings instead of bar stock, but I'm ignorant. It's probably too early in my engine building "career" to try a 1/4 scale automotive engine.

This is only my second engine, and the first one I made from bar stock and drawings, with nothing else to go by. My first engine was the Little Machine Shop wobbling steam engine. The kit came with DVD showing how to build every part, which was a good thing for a rank beginner.

I have some improvements to my shop I want to do, so some of those are probably the immediately next thing.

 

[minh-thanh]

Congratulations !
Good news of the day
Good luck with new projects !

 

[CFLBob]

Congratulations !
Good news of the day
Good luck with new projects !

Thanks for all your help!

 

[CFLBob]

Congratulations on a runner
Glad you persevered with it
Whats nest
cheers

Thanks for all your help, Fraser.

I haven't picked out the next project.

 

[Cogsy]

Congrats on getting it to run - lots of frustration but you got there in the end! I agree with Brian, you can always revisit it down the road a bit if you like, but I'd call it done and start something else for now.

For a first I.C. engine, the Webster is what a lot of people start with. It runs great and is relatively easy to build, while you learn all the skills to build a more complex engine. Castings are more difficult to work with than bar-stock so you want to work your way up to them.

 

[Tim1974]

I’m so happy mate that’s a runner

 

[CFLBob]

Congrats on getting it to run - lots of frustration but you got there in the end! I agree with Brian, you can always revisit it down the road a bit if you like, but I'd call it done and start something else for now.

For a first I.C. engine, the Webster is what a lot of people start with. It runs great and is relatively easy to build, while you learn all the skills to build a more complex engine. Castings are more difficult to work with than bar-stock so you want to work your way up to them.

I looked up the Webster engine on YouTube to get an idea what they look like. It looks very much like this engine, with the important differences and (famous last words) doesn't look that bad to do.

I like the idea of something that could produce some power. I imagine it's producing a fraction of a HP, but more than the flame eaters.

Last night I was telling my wife I thought it would be cool to build something along the lines of a one cylinder lawn mower engine. Maybe a whole 1 HP. Four stroke would be cooler than two stroke with oil mixed in.

On the topic of the Duclos fire eater, I've been thinking that since it runs better cool, maybe I could add cooling to it. I noticed the engine minh-thanh was showing had a little fan pointed at the cylinder fins. Coming from the electronics world, I thought about the CPU coolers you can get to actively drop the temperature of your PC's processor. It gave me a lot of thoughts along this line.

 

[Brian Rupnow]

Build a Webster. They are the perfect beginners i.c. engine. It was my first engine and I have videos of it running various things. ----Brian Rupnow
https://www.homemodelenginemachinist.com/threads/anybody-want-to-guess.7687/