Has anybody built the flame eater “Nick”?

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ian S C on 16/06/2016 12:08:07:

… and a strip of wet and dry (start with a good bit courser than the 2000 grit, say 400 to 600, 1200 is as fine as you need [ didn't know you could get 2000]) …

Ian S C

Hi Ian,

I just bought a mixed pack of 3000, 5000 and 7000 wet and dry. I spotted them on Amazon while looking for 2500 (which works well) and bought them as an experiment.

They're marked "Matador Wasserfest, Starcke, SiliciumCarbid, Waterproof, Made in Germany".

7000 grit feels slightly more abrasive than an ordinary sheet of paper. No idea yet if they are worth the money.

Cheers,

Dave

[Brian JohnParticipant @brianjohn93961]

I see your point. My first Stirling engine did not have its work cylinder polished ; I just used it as is after machining it with the boring bar. Now that I know a bit more about polishing the inside of cylinders using the dowel and 1500 grit I might have more success without oil.

I will give that flame eater piston another touch with the 1500 grit tomorrow so that it is drop through. My first efforts with this engine will be without oil but if nothing happens….. !

[Ian S CParticipant @iansc]

Dave, by the sound of those figures for wet and dry paper, there must be a different way of grading the grit, here 1200 is virtually smooth, mine is probably imperial, per square inch, while yours is some metric measure. Ian S C

[Brian JohnParticipant @brianjohn93961]

I am still waiting for the replacement slide valves to arrive (accident with silver soldering) and the flywheels are being painted now (one more coat of Killrust red). All other parts are now ready for assembly. The diagram on the instructions shows the block on which the engine is mounted to be right at the end of the wooden base but this is not correct as then it would be too far from the burner. I have moved it in a bit but I still have to bring the burner in to meet it. To do this I have had to mount the burner on 4mm barrel washers otherwise the height adjustment wheel would not have sufficient clearance. The original design calls for it to hang over the edge of the wooden base.

I do like the idea of some sort of horizontal adjustment for the meths burner. I am open to suggestions as to how I can do that. I am thinking of two brass U shape rails and the burner can be slid along on this ?

I also do not like the cylinder bracket arrangement which relies on soft solder to support everything. It was pointed out to me earlier that the fillets are not doing much to support the bracket. The brass is not very thick so I am not confident of the strength of this part. I am thinking of making something else out of brass angle which you can see already cut sitting on the wooden base. I have also ordered replacements parts for this so I will experiment a bit when they arrive.

NOTE : shim washers, barrels washers…what is the correct term ? I tried to buy some here in Cairns and nobody even knew what I was talking about so I ended up making them myself.

Edited By Brian John on 03/07/2016 07:48:30

Edited By Brian John on 03/07/2016 07:54:59

[Ian S CParticipant @iansc]

"I ended up making them myself", that's what a lathe is for. Sometimes I run out of screws, or bolts, and as town is 40K away, and I have to rely on others for transport, I just have to DIY, other times I'm in town and buy cap screws for a job that would be perfectly ok with home made. A lot of bits and pieces just can't be bought. Ian S C

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ian S C on 18/06/2016 12:42:20:

Dave, by the sound of those figures for wet and dry paper, there must be a different way of grading the grit, here 1200 is virtually smooth, mine is probably imperial, per square inch, while yours is some metric measure. Ian S C

 

Hi Ian,

Sorry about the delay replying, I missed your post.

Well it's hard to tell who's got the finest paper when our sheets are a world apart!

I think I've got the real McCoy though, what I've bought turned out to be ultra-fine grades. Here's a link to the Starke Brochure, unfortunately it's in German, but it includes this graphic:

True these are ISO sizes and your system might well be different. Our P1200 has 15 micrometre grains. Do you know what your 1200 grain size is?

The US has a different system and you might well have that. CAMI 1000 is the same as ISO P2000: they both have a 10.3 micrometre grit, which makes a very fine paper.

Part of the fun of model engineering is deciphering the various metric, imperial, gauge and other systems!

Cheers,

Dave

Edited By SillyOldDuffer on 04/07/2016 21:42:09

[roy entwistleParticipant @royentwistle24699]

I once bought it as Crocus paper

Roy

[Michael GilliganParticipant @michaelgilligan61133]

This range may be of interest:

**LINK**

They also stock variations on the theme.

MichaelG.

Edited By Michael Gilligan on 04/07/2016 22:40:31

[Brian JohnParticipant @brianjohn93961]

This guy has put horizontal adjustment on his flame eater burner and I think it is a much better idea. I am hoping to copy that somehow.

**LINK**

[Ian S CParticipant @iansc]

I have some Crocus cloth somewhere, it has a cloth backing like carborundum/emery cloth. The sheetsare the same size as wet and dry paper. An American product I think.

The burner on my flame licker is held in place with a magnet.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I got tired of waiting for those replacement parts from Germany. I am not sure what has happened there as they are usually very quick but I have decided to assemble the engine without the slide valves just to see how it all fits together at this point. There is still a slight tight spot between the piston and cylinder but I am hoping this will work itself out ; the two large flywheels provide a lot of inertia and the engine rolls over quite readily.

If anybody is building this engine now then be warned that the diameter of the spigot on the main cylinder (part 20) is given as 20mm but this is too big for the hole in the cylinder bracket (part 19). I had to reduce it down to 19.4mm to get it to fit. Even at this reduced diameter the spigot was still too big for the supplied gasket which had to be trimmed with a scalpel blade in order to fit it between the cylinder and the cylinder bracket.

It does make me wonder why there is a gasket here at all ? Is it to reduce the heat transferring to the cylinder bracket ? I only soft soldered the cylinder bracket ; I think I should have hard soldered it. I will do that when the new parts arrive. The instructions do not say anything about it even though for all other parts they are very specific regarding soft or hard solder being required..

I have not fixed the burner in place yet. I am still thinking how I can install some sort of horizontal adjustment.

Edited By Brian John on 07/07/2016 13:51:54

[paul rushmerParticipant @paulrushmer83015]

I have the kit for "Big Nick" and this comes with a 2 axis adjustable burner, it looks like yours but a little higher sliding on two 3mm rods operated by another hand wheel and M3 studding. Hope this helps.

Paul

Could scan the drawings if you would like.

[Brian JohnParticipant @brianjohn93961]

That would be a big help. I have a fairly good idea what I need to do but drawings would help clarify the matter. I am not sure why they have not supplied such a burner with this kit as it really does need to be adjusted in 2 axis.

[Brian JohnParticipant @brianjohn93961]

After much fiddling about and trying many things, I have realised that this burner as built cannot be fitted with horizontal adjustment. Any horizontal adjustment would mean raising it higher and even 4mm higher places it too high. I think the vertical adjustment on this is totally superfluous : at its lowest setting is where it is supposed to be so why raise it higher ?

Having ascertained that the burner must be fitted flat to the wooden base, then that means the adjustment wheel must hang over the edge and that means bringing the engine base in closer. The diagrams show the engine base to be right on the edge at the other end but that would mean it would be about 20mm from the burner flame…not very useful ! The engine base must be 18mm from the edge of the larger wooden base and this should put it in the correct place (hopefully). I have had to take the whole thing apart to redrill two more holes so I can shift the engine base.

NOTE 1 : the instructions do not give any measurements for placement of the burner or engine on the wooden base.

NOTE 2 : perhaps reducing the length of the wick nozzle would allow for some vertical adjustment. I might try that if I build another of these engines.

Edited By Brian John on 09/07/2016 09:28:53

Edited By Brian John on 09/07/2016 09:29:52

Edited By Brian John on 09/07/2016 09:33:16

[Brian JohnParticipant @brianjohn93961]

The spare parts arrived from Bengs so I have had another go at some of the parts which previously gave me problems. I have started machining the flywheels but this time I did not ream then out to 6mm; I just drilled them out to 6mm and I now have a perfect fit with the supplied crank and there is no wheel wobble. Same thing with the crank plates : they were drilled out to 6mm and not reamed for a perfect fit.

I did try to silver solder the cylinder bracket (part 19) but that was not successful as my soldering tile which was mounted on a wooden saw horse exploded due to the high heat. It really went off with a bang.

Lesson learnt : home made soldering station is only for soft soldering !

The instruction do not say which solder to use for part 19 but I have since received advice from Bengs that it is to be soft soldered.

I was going to silver solder the second crank shaft to the crank plates to see if it would distort as warned in the instructions but I think I will just stick with soft soldering it together as I did with the first set. I have had enough excitement for now.

Edited By Brian John on 12/07/2016 09:36:13

[Ian S CParticipant @iansc]

For a brazing hearth you,v got to be careful with the materials used, I find the best to use is the soft Hebel bricks, they reflect the heat into the work, and don't absorb it. I'v only got bits of these bricks, and my hearth is a angle iron frame with old fire bricks from an old fire place, these are not the best as they absorb the heat.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I tried to get this engine assembled and running today but I came across some unexpected problems. Because I made the slide control with a bush which is held on the shaft by two grub screws I forgot think about how I could adjust this once the engine was assembled. I had to drill some extra holes in the cylinder bracket (photo 9) so I can get the tool through there. The other grub screw can be accessed through the meths burner.

So I had to keep taking the engine apart until I got everything where I wanted it. The slide valve bearing which rubs against the eccentric gave me problems too and I ended up using bearing lock to hold it inside the brass sleeve.

But the biggest problem is the last : the slider plate will not stay on the slide control and falls out of the cylinder head (photo 10). I measured everything to see if I might have made the cylinder too long but that is all correct. At this point I am not sure how to fix this and I will have a think before doing anything. I might shave 0.5mm from each end of the cylinder. I could also leave out the gasket which fits between the cylinder and the cylinder bracket. All that should give me another 1.5mm which might be enough to keep the slider plate on the slide control.

 I have looked at photos of other builds and I notice that some people bend the end of the slider plate so this must be a common problem. I did try bending it but it still comes off. The end of the slide control rod is a bit too small to drill for a pin.

 

Edited By Brian John on 14/07/2016 09:55:05

Edited By Brian John on 14/07/2016 09:56:54

Edited By Brian John on 14/07/2016 09:58:11

Edited By Brian John on 14/07/2016 09:59:04

[Brian JohnParticipant @brianjohn93961]

I just realised that if I make the cylinder length shorter than I will have to move the meths burner in closer. That is why I tried to give the burner some horizontal adjustment : I knew I would need it eventually. As you can see from the photo, the vertical adjustment is pointless. I am really not sure why they designed it like that. Maybe it is a burner initially designed for another engine ?

At this point the simplest solution is to make that small piece on the end of the slide rod longer so it is less likely to slip out of the slider plate but I am not quite sure how I can do that. Perhaps I can solder a small piece of brass onto the end of it…maybe !

Edited By Brian John on 14/07/2016 12:30:54

[Brian JohnParticipant @brianjohn93961]

I did manage to drill a 1.1mm hole in the end of the slide rod. I then fitted a U-shaped piece of brass wire through the hole to keep the slide plate in place. That seems to have solved that problem but the engine will not run. I experimented all afternoon with various valve settings but no luck.

1. The instructions say that the slide plate should be closed just before bottom dead centre : is this correct ?

2. I am also puzzled about the ball valve : how high should I set this using the M3 screw in the exhaust ?

3. I do not like the look of the meths burner. The picture shows it on its lowest possible setting but is this still too high in relation to the cylinder opening ?

[JasonBModerator @jasonb]

1. sounds about right

2. try 1mm of ball lift

3. don't have so much wick sticling out then the flame will be lower

 

Edited By JasonB on 15/07/2016 10:27:57

[Brian JohnParticipant @brianjohn93961]

2. Only 1mm….do you mean the ball should not rise any higher than 1mm ? I had it much higher than that. Would that have stopped it from running ?

Edited By Brian John on 15/07/2016 10:34:48

[Brian JohnParticipant @brianjohn93961]

I trimmed the wick so that it was very short but the engine blew the flame out. I then removed the burner from the wooden base and trimmed about 3mm off the brass nozzle with the dremel tool. The flame seems to be at the correct height now. I will leave the burner unscrewed for now so I can experiment with the flame distance

The slider plate continued to give problems by getting stuck in the raised position so I removed the main cylinder and shaved 1mm off the cylinder head end. Upon reassembly the slider plate is now sitting correctly on the slide control valve so that problem seems to be solved. I should have done this in the first place.

I am now getting a very encouraging ''pop pop pop'' sound when I turn over the engine. It will only run for about 15 seconds before stopping. I tried lubricating the piston and cylinder with machine oil as I did with my Stirling engines but this made things worse and the engine seized up. I think the flame being in contact with the cylinder burnt the oil and resulted in heavy carbon deposits on both the cylinder and piston.

I cleaned the cylinder and piston with 2000 grit and I now have an excellent fit between piston and cylinder. It is even better than before. This time I lubricated by rubbing the piston with a lead pencil. Tomorrow I must buy some powdered graphite.

I have found the best setting the for the slide control valves. It is just as given in the instructions : the slider plate is closed just before BDC. Other than experimenting with the ball valve I am not sure what I can try next. It is very close but still no cigar ! Unlike a Stirling engine where you have to adjust both work and D pistons/cylinders, this engine has only one piston and cylinder. It should be relatively simple to get it going from here but I am fast running out of options.

Edited By Brian John on 16/07/2016 08:58:26

Edited By Brian John on 16/07/2016 08:59:22

[roy entwistleParticipant @royentwistle24699]

I have found the best setting the for the slide control valves. It is just as given in the instructions

Now there's a surprise

Edited By roy entwistle on 16/07/2016 11:32:40

[Brian JohnParticipant @brianjohn93961]

Yes, it is a surprise. These instructions are translated from German into English and things are not always as they seem.

The main problem now seems to be that what is a good piston/cylinder fit when cold is not a good fit when everything is hot…and things get hot very quickly. I might have to try for an undersize cold piston to get a good fit when hot. Piston rings would solve the problem too but nobody else seems to need piston rings when building a flame eater. Anyway, I have no idea how to make piston rings so I will try to keep it simple for now.

Edited By Brian John on 16/07/2016 11:40:55

Edited By Brian John on 16/07/2016 11:41:19

[Ian S CParticipant @iansc]

Brian you do not want piston rings of any sort, friction, or the lack of it is more important in these motors that in a Stirling Engine. Just remind me what is the cylinder and piston made of?

Ian S C

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