Scott Flamelicker (Vacuum Engine)

[Dean W]

All looking very well, John.  Thank you for the detailed write up.  I know that is quite a bit of work in itself. 

[Bogstandard]

Dean,

The work I am showing at this time was done last year, since then lots of things have happened to me, so soon after I finish showing where I got up to, I should be almost in a position to carry on with the build.

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I have actually been making custom screws and other little bling bits, and if anyone has ever done them before, they are very time consuming. One little screw can take well over an hour or so.

I got to use the ER32 collet adaptor that I made a while ago today, and it was great.

I was doing multiple very small parts, and it held them perfectly concentric and they all turned out exactly the same.




This is what I have been making, screws, tubular rivets and decorative studs, all to a common theme, a six pointed star surrounding a central circle. Very easy to do but also effective. They are also very easy to tighten up with a pair of round nosed pliers.
I also made the piston to con rod joint, that once assembled inside the engine will never be seen.




This shows the context that they will be used in, one holding a bearing in place, another holding con rod to crank disk, bifurcated rivets for the curly bits on the end of the arms and decorative buttons at the centre of each flame valve operating arm and cam follower.

You have most probably noticed, I have tried the paint out on the crank disk, and I am not really sure about it. It is a satin finish metallic, which I have never used before and it looks sort of strange compared to my normal hi gloss efforts. I think I will give it a go and see what it looks like when a larger area is done.




I actually had the engine rough assembled tonight, just to check for fits and friction. With no oil anywhere, when the flywheel was spun gently, it gave a least a dozen nice smooth revolutions, so I don't think friction is going to be a problem.

There are still a few bits to make, mainly the main spindle, flame valve assembly, a leaf spring for the camshaft follower and power take off pulley. Plus of course the burner, the gas parts have arrived but I have yet to go out and get the plumbing fittings for it.

I am hoping to get the basic engine running very soon, then stripped down for painting and polishing.


Tonight's little exercise turned out to be a bit of a dirty job.


One of the most important parts on the engine, the flame valve.

This is what it is made out of, a lump of graphite that has been rough sawn on all six sides, with not one side flat, straight or square.




When working with graphite, the dust can get everywhere. You can spray with fine mist of water, but the dust is even worse to clean up.
Not really recommended, I taped paper towel down to the vice and table to attempt to stop it going everywhere, and I kept the air blower well away from the machine. NEVER use anything other than easily torn paper like this, cloths and rags are a definite no-no.

I had to go thru the whole routine of getting the part all flat and square, and I used a razor sharp flycutter to do it. The dust just stayed in the local area, and was wiped away very gently from the parallel's surfaces at the change of face.

I used the flycutter because it gives a highly smooth and flat surface (as long as the machine is in tram), and will save me having to lap it flat later.




Once it was to size, by gently pecking away with the drill running a lot faster than normal, 1500 rpm, I got the drill thru the part very accurately.




Using a 90 degree countersink, the three bevel edges were added.
Everything while handling this material is done very softly, finger pressure to set down onto parallels, just using the weight of the vice handle to tighten the vice up, and of course slow steady cuts. You can easily shatter edges or even break it in half by being even a little heavy handed with it.



Spot on size and not a chip in sight, and the valve face was as flat as though I had surface ground it.




This is the face it will operate against, opening and closing the port so that flame gets sucked in at the right time.




This is the state of my hands just by handling the stuff, and I haven't even touched the dust hardly, so you can imagine what state the front of my t-shirt is in. That is one I will have to sneak into the washing basket.



I am still a little undecided about the springs supplied for holding this valve onto the face, they look decidedly heavy, so I will try them, but if they are too much, a redesign will be called for.


As this little engine is progressing steadily towards getting to a running state, I thought I had better do something about the gas burner I will be using.

These are some of the parts that actually make up the gas burner.
I purchased online a new pipe and jet holder plus the right sized jet. For the price they cost, they are not worth making yourself, just a load of machining hassle. Also needed were a couple of end feed plumbing bits, which I managed to pick up while I was out yesterday. Not exactly the correct ones shown on the plan, but they will do just as well.

The plans call for a brass mixing chamber pipe to be made, I don't know why, as it can't be for cosmetic reasons, because it is hidden under the engine, a bit of 15mm copper plumbing pipe will do just as well.

If you look at the plumbing bends, on each flange they have a stamped in safety code. They will look awful on the finished burner, so they have to go.




Mounted up onto an expanding mandrel, some good quality cutting lube (standard cutting fluid for copper is tallow, or as a substitute, full cream cows milk) and a change to a new tip soon had them turned off using shallow cuts.




There is a little of the lettering left, as it was rather deep, but that will come out in final polish. Looking better already.




Next came the four air supply holes for the gas jet and mixing chamber, they were soon drilled in their correct positions.




Now ready for first stage silver soldering.




I set it up this way to keep the top part in the correct position to the other two pieces. It needs to be totally central in position, not tilted over one way or another. The joints were set up with Tenacity 5 flux and 1/16" easyflo silver solder. Thicker solder than normal was used because the joint cavities will take a bit of filling.
The top joint was completed first, then once set, the job was laid down and the second joint completed.




A quick dose, first of steel, then brass wire brushes on the buffing machine soon had it cleaned up enough to go onto the second part of the build sequence.




This is roughly where the burner will sit on the finished engine, with the refillable gas tank at the far end, just past the flywheel.
The engine is up on bolts at this time, as I won't be making the wooden bearers until I get well into the finishing off bling sessions.



There needs to be some parts made and fitted to finish off this burner, they will be shown in the next installment.



John

[steamer]

All looking very well, John.  Thank you for the detailed write up.  I know that is quite a bit of work in itself. 

Isn't it though!?   Great job John!  Lots of good set ups there!

Dave

[Bogstandard]

Here is a little more for you to get your teeth into.

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There were three things that needed to be made, on the right, the jet holder clamp, which if made to the plans was all threading and allsorts, this one will just be stuck in the end of the tube with a clamp screw to allow the jet to be adjusted backwards/forwards. In the centre is the mixer venturi, made by drilling thru with a centre drill that has a 1/8" drill point on it. It penetrates half way thru with the 60 degree angled bit, the rest being the 1/8" tip. This not only speeds up the gas flow but mixes the gas and air together. Lastly on the left is the burner rose itself, it has been hollowed out on the back so that the face that the holes are drilled into is only 1/8" thick. This also isn't to plan, I did it to stop the thin 1/16" drill wandering off course if it had to drill the whole depth of the rose.




Using the Divisionmaster and ER collet chuck on the RT, I first went around the rose and spot drilled all the hole positions, then followed the same route with the 1/16" drill




The rose was a tight push fit into the burner tube, plus the tube was very slightly swaged over on the end to make sure it won't pop out when it heats up
The jet holder clamp and the venturi will be loctited into their correct position when I get back to it.




The venturi, sitting in the background, needs to go down the tube from the jet end by a specific amount, so by using the thin depth reader on my digivern, that is what I did.




It was a nice 'grippy' fit down the tube, so it was tapped down with a hammer and soft drift until it got to the correct position. I got it to within 0.005" from where the drawing said, and because I have made the jet easily adjustable in/out, the perfect position for mixing can very easily be reached, a few seconds at most. It was loctited in position, as suggested in the build instructions.




The jet tube holder was then tapped into the end and again, loctited in. You can see in this shot, the venturi down in the tube, just past the air holes.




This is my cosmetically challenged refillable, commercial gas tank, it will be cleaned up and painted.
In the centre of the top you can see the 'Ronson' filler valve, which allows you, with an adapter screwed onto a disposable plumbers torch canister, to fill the tank with gas (in fact not full, but only about 2/3rds, there is a stack tube below the valve inside that prevents overfilling). These are tested to much higher pressures than boilers, 360 psi.
The control valve isn't a normal steam one either, it has to be a special gas control valve. When I used to make these tanks, from thick walled brass seamless tube and flanged end plates, with an internal stay, the Ronson filler and control valve were always purchased, not made by myself.




A thread was put into the side of the jet tube holder and a brass screw fitted. This allowed easy adjustment of the jet backwards/forwards in relation to the venturi.




I tried the burner out not only with the brass rose that I had made, but also with a piece of ceramic burner material, made from an old boiler burner.

The brass one gave a much better jet pattern.




I hope this little vid shows what you need to know.

<a href="https://www.youtube.com/watch?v=pVVXJz_2_E8" target="_blank">http://www.youtube.com/watch?v=pVVXJz_2_E8</a>


Just for a little bit of interest, here are a few pics of this engine, built in the 1990's. It looks like that the build was done exactly to plans, almost. The crankdisk has a different shape.

Just so that you can visualise the general layout.
Looking at it, I think I might knock myself up a shorter gas tank, as the one I have is too long. But I do have a couple more copper based ones somewhere, one of those might fit the bill a little better.
The plans contain all the information if you need to make one yourself.




The linkage to the flame control valve.



A close up of where the burner sits and how the graphite block seems to sit in the burner flame almost permanently. I think I will have to knock up a few spares as I expect they will get burnt away.




It also looks like they have reduced the top to bottom height of the block, I will have to look if that is required when I get mine to a running stage.

Just by looking at other peoples builds can give clues to little problems that might need fixing before it will run correctly.



A little more slow progress. I have been trying to sort out a decent spring hanger method, rather than the crappy ones shown on the plan and what you can see in the few piccies I showed last time.


This is how I got on.

The ones at the back, I incorporated into the valve arm hub, and by measuring that up between the arms, I managed to get a length for the graphite block to lifting arm spacer, so a couple of those were knocked up out of brass.
Once that was done, a quick measure up between the back spring tails and I could start to make up the top hangers.




This shows where the springs have to stretch to, plus it shows how the cam follower and lifting arms work,




After an hour or so's work, the top hangers were made. The bottom left hand one has slipped on the shaft slightly as the grub screws have yet to be tightened, but you can now see that the springs are now well secured and running parallel with the operating arms, rather than the haphazard way they are suggested to be mounted.



How they sit with the cylinder and water jacket fitted. I started to set up for a very basic try out, with the grub screws all tightened up and the timing somewhere near. I am going to have the engine with the flywheel running clockwise when viewed from this side of the engine, rather than from the other side. That means the flywheel retaining pulley screw is tightening up during running rather than trying to unscrew itself.



Unfortunately, I failed miserably.

I was attempting to run the engine with the cam follower arm retained by a grub screw onto it's shaft rather than a pin right thru it. I did that for ease of disassembly during trials. It kept slipping, so it looks like I will have to pin it now rather than later. Also, I need to shorten the studs slightly that hold the cylinder head on, the graphite block spacers are just touching them. Before going ahead and shortening them, I will make and fit the cylinder head gasket first, that just might give me the clearance I need.




Getting there slowly.


John

[vcutajar]

Hi John

Glad I could catch up on your build here.

Vince

[Bogstandard]

Glad you could catch up as well Vince, if you were following on HMEM, you wouldn't have seen the last one, or this.

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I need to carry out a few little mods to get this engine up and running, so this post concentrates on two of them, mainly how to make gaskets, which I will be showing in full, so that maybe a few people can pick up a tip or two.

I am making this head gasket for three reasons, the first is to seal the cylinder from the outside world, second is to attempt to stop a lot of heat transfer to the cylinder and water jacket and thirdly, to make the studs shorter so that they don't interfere with the valve operation.

I swear by different thicknesses of PTFE for making gaskets, it seems to have no bad faults at all, only good, when used in this context.

So getting a piece of 0.015" thick of about the correct size, the OD of the head was marked on it and the centre found.

Take note of the real el cheapo compass cutter that was bought for a couple of squid a few years ago off a market stall, for cutting these circular gaskets, I just couldn't live without it.



I used to really struggle, trying to cut circles with this cutter until I found this method.
I stick both the centre pin and blade thru the material and into the wood underneath (not too deep) and holding onto the top of the compass to keep it steady, I rotate the gasket material against the cutter blade, rather than trying to use the compass like you would normally use it.




If you get your blade to pin measurement to size, and cut it how I have shown, you should end up with a perfectly fitting gasket.




The next trick is using another indispensable bit of kit for use in the workshop, transfer punches. I have duplicate sets of these in Imperial, metric, number and letter sizes. I use them not only in their guise as transfer punches, but also used instead of drill blanks, which are very expensive indeed. In fact, all my sets of my transfer punches added together only came to the price of one set of good quality drill blanks. How accurate do you really need to be in the home shop, these are well within 0.001" of drill blanks, if not even closer.

The gasket material is slightly transparent, so it was easy to align the top and bottom holes up, then it was just a matter of pushing the correct size pointed transfer punch down the hole until it marked the gasket.





I didn't push hard at all, but all holes are well marked up, and in an accurate position.




The holes were easily punched out with a tube punch, and the finished punched holes fitted perfectly onto the water jacket studs.




Using a couple of general screws and nuts, the gasket was trapped between the cylinder and it's head. The material around the outside was carefully cut away, very close to the metal.




Resulting in a perfect and long lasting gasket.



Once all assembled up, you can now see that the threads don't protrude as much thru the nuts, so that is one problem cured.
It looked like a long process, but in fact took well less than half an hour.




This fix is nowhere near as complicated.
The plans call for either a taper or roll pin to lock the brass part onto the rod. I hate using roll pins, purely because they can sometimes be very difficult to get out once in position, this would be just the case here.

All I did was to accurately drill right through the brass bush and steel rod, then tapped it out 2mm. A recess was put in to take the cap head. Now I can take it apart very easily whenever I want, but still have very secure fixing. The original grub screw hole (hiding around the corner) will be filled with a bit of brass threaded rod, and by the time I have finished blinging, will never be seen again.



Continuing on, getting things sorted in the hope that I can get some power out of it.

A few revelations after I got things done, I will explain a little later.

The grub screw holding for the valve lift arms needed beefing up a bit and to get them gripping properly, flats were required on the cross shaft.

With the cam set to give maximum lift and a machinists jack holding the graphite block in the correct position, by using a transfer punch down the grub screw hole, the shaft was marked up where the flat needed to be.




By mounting the shaft in the milling vice with the pop mark at the very top, a flat was cut on either end.




Next came the grub screws themselves. I had been using stainless ones, but unfortunately they are always rather soft and you can soon round out the Allen key hole if you give them a bit of white knuckle treatment.

So for this job I went back to my normal high tensile steel ones after I had ground the ends flat so that they will sit correctly on the flat on the shaft.




By the time I had finished twiddling about it was time to try to get some life out of the engine, so by jury rigging the burner in position I gave it a try.
By playing about with the timing for ten minutes, I knew that I had it spot on, plus I had to do some serious bending of the cam follower rod to get things something like.

A few minutes later, I had it turning over a couple of times by itself, and I can now tell you, it is another 'duck quack' sounding engine.

But no matter how much I tried, I couldn't get it to run continuously. Then I noticed something quite alarming, as the cam is, it does not allow the inlet port to be fully uncovered, so the graphite block is in fact stopping the flame reaching the port correctly, hence the lack of continuous running.




I am now going back to the drawings and check out all the geometry of the cam and lifting arms. I built everything to plan, and all that has been double checked at least twice, so it isn't my making at fault, but the basic design which hasn't been modified to show what is required to actually get the movements required to have the engine running.

I can now see why, on the engine I showed earlier, they had actually made the block a lot narrower, and as I suspect, they had the same problems as those I am finding now. I don't fancy making a higher lift cam as that will raise a few clearance issues, so, because I have a load of graphite I can play with, I am going to see if reshaping the graphite block will improve things in the running department. That might also mean I will have to make a new cross shaft with the holes in a different position, but I can get around that for the time being by bending a few brass arms.

As I said, I needed to check out the geometry of the plans. I just used basic Pythagoras for working it out, not wanting to bring operating arcs into the equation, but the information that it gave me showed that I have more than enough movement for the block to work correctly.

I also reshaped the block to what I thought it needed, but I will have to show you that next time, as I haven't taken any pics of it yet.



This is the reason for no piccies. I wanted to try it out first, just to see if I had my calculations right.

<a href="https://www.youtube.com/watch?v=Mi_T60n52jg" target="_blank">http://www.youtube.com/watch?v=Mi_T60n52jg</a>

I seem to be gasping for air. In fact I am just recovering from a chest infection and a cold, hence I haven't been in the shop for a while. But within 10 minutes of getting in there this morning, the engine was basically up and running, not too well, but plenty good enough for me to see that it has potential. The sound has changed from a 'quack' to an i/c engine exhaust sound, and unlike the other flame licker I built, this one has usable POWER, so maybe a little generator might find it's way onto the scene.


John

[Bogstandard]

I would just like to say, all the prep work I had done beforehand really helped, things like getting the cylinder, piston and bore spot on square and lapped in.

Once I had the block reshaped, there was absolutely no mucking about at all, I put the flame to the hole, and away it went, not one drop of lube required anywhere.

But anyway, just a few pics to show what I had to do to the block to get the flame to the hole. The flame sits at an angle of 45 degs, so I reshaped it so the flame had a nice long runup.


Just as a reminder, this is what the block looked like when made from the plans, the top angle wasn't long enough to get the flame to the hole, it was blocking it's access.




About 0.050" (1.25mm) was removed from the bottom of the block to allow it to drop a little lower, as it was nearly touching the two lower nuts when at full drop. The top 45 deg edge was machined to be a lot longer.




Just another view.



Having got most of the flywheel tidied up, just requiring a few more hours to finish it off, I decided I need to make the combined power takeoff pulley and flywheel/crankshaft clamp. For models such as this, which don't have too much power, I prefer not to drill or make special fittings for the flywheel, that way, they always run nice and true. The crankdisk is first locked on, then using spacers and other components right the way along to the other end of the crankshaft, the whole lot can be tightened up together, as long as the flywheel turns in the correct direction for tightening up the screw/nut.

For many years now, I have been picking up very old sash weights from the scrap yard for pennies each (on average 30 pence, about 50 cents US). These give me a great source of very fine grained cast iron up to 1 3/8" diameter.
I stuck the weight onto my power hacksaw and soon had a 2" long lump for my use.




Unfortunately, with these cheap materials, you have to put a bit of work into it to get the good stuff out. In this case, the hard casting skin, which if attacked with a normal pointed carbide tip or HSS they would be flattened or broken in seconds.
I use the wide angle part of the tips in a special facing/roughing tool holder.




The same goes for the main outer skin, another type of roughing cutter removes it very easily.




Very quickly, I was the proud owner of a piece of over 100 year old, super fine grained cast iron bar.

So a C-o-C was drawn up to give me a working drawing of what I wanted.




You may have noticed that I am working with my lathe in 'Myford' mode, I will be swapping this chuck over onto the mill RT once the pulley has been roughed out.

The outer face was relieved a little for when I get it onto the mill in the final stages for cutting the half round drive belt slot.
Both sides now needed a 7mm deep recess cutting into them. So a quickie grind up on the offhand had a rough trepanning tool that will do the job. It left a few chatter marks on the bottom face, but I was not worried about those, they can easily be cleaned up later.




This is where it will be mounted when finished, compressing everything up nice and tight into one long unit.
Notice how nice the finish comes out on this material, no polishing was done at all, just basic deburring.




Basic lathe work done, time to get onto the RT to have a bit more machined off it.




After some very rough calculations, and by use of the Divisionmaster, I had all the holes in the right places.




Then it was just a matter of joining up the holes using the X & Y axis of the mill and the RT in manual mode.

I also put a few more slots in as well, as shown on the next pic.




This is an awful pic, it looks like the spokes are all twisted and the wrong shape, but in fact, I hadn't deburred it before taking the shot, and what you are seeing are mainly shadows from the heavy burrs being thrown up by the flash on the camera.

Once deburred and cleaned up with a bit of filework, it will look spot on.




This will now be put to one side, until the flywheel has been finished off, and when I have the RT set up to vertical for another job I am doing, then the half round slot can be finished off.

I just thought I had better prove that this bit would come up rather well before everyone forgot what it originally looked like.

I spent a couple of easy hours this evening, just cleaning up and putting the curved face on top of the pulley. I have still yet to put the half round groove in, plus the threaded stud.


This is the main bit you will see.




Plus the bit you won't.




It is such a shame to cover up most of the finger work with a coat of paint, but hey! that is what it is all about.

Eight spokes, just like the big one, but in a different configuration.

It hasn't come out too bad seeing it started off as a lump of unwanted scrap iron. All you need to do is look at that old bit of metal, and visualise the beauty within.

It is up to you then to get that piece out of it. Material cost, about 5 pence.


I just had to get this bit out of the way, so instead of waiting to stand my RT upright, I did it with the spindexer.


Having set up the spindexer in the vice, I first positioned the cutter half way across the face, where I had cut a relief into it. Then with the cutter tip a few thou lower than centre, I just fed the cutter in from the side and gently hand turned the spindexer in an anticlockwise direction, so that the tip of the cutter was doing all the work.




I just kept feeding the cutter in a bit, then doing a revolution, then feed a bit more, until I got to the depth I wanted.




After tapping out the centre spindle and fitting in a bit of stainless studding, I could use the pulley to fix the whole flywheel shaft together. Everything ran nice and sweet and true.

This shot shows how the spring belt will work, hopefully the other end will be going to a small generator, or maybe a pump.




Just a bit more work on the flywheel and these two bits will be ready for paint.

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I found a little bit of info that might come in handy for those who want to try the gas route.

In the UK we have standard jet sizes, and the one I used in the burner on this engine was a #5.


Number 3 which has a 0.15mm (0.006") dia jet bore

Number 5 which has a 0.2mm (0.008") dia jet bore

Number 8 which has a 0.25mm (0.010") dia jet bore

Number 12 which has a 0.3mm (0.012") dia jet bore

Number 16 which has a 0.35mm (0.014") dia jet bore

All have 1BA thread on the end of them.

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So this is the last post to bring this engine build up to date.

I will have to see if my health will allow me to finish it off sometime in the near future.


John

[Dean W]

Though I remember many of the bits and pieces you made, going through much of it again just shows how much
a guy can forget.  Some of the pictures looked new to me.
It all looks very good up to where you have it now, John.  I like the way it sounds, too.  A satisfying pop! 

[gbritnell]

Great build John. I built a flame licker many years ago with a stainless shim stock valve, really picky. I like the idea of the carbon valve.
gbritnell

[ScroungerLee]

 Great work and a very nice write up.  I really appreciate the time you give for explanations of techniques and why you chose to do things the way you did.

Lee

[Hrmech]

I have built this engine but I can not get it to run. I am struggling with the timing, the piston and cam position. Could you please advise.

[Bogstandard]

Hi H,

Welcome to the site.

The way the cam is made, this engine can work in both directions, I have mine running clockwise when viewed from the side away from the flywheel (see last video).

First things first, you must ensure that the cam follower bearing is in contact with the cam at all times, make sure the spring underneath the operating arm holds the bearing in contact all the time.

The basic setting is to set the loose cam so that the carbon block is lifted fully upwards just as the follower leaves the hi spot on the cam, not half way along the upper face, covering the inlet hole completely, then holding the cam solid, turn the crankshaft until the piston is at TDC. If you now tighten up the cam grub screw, your settings should be good enough to run.

Notice how I had to cut away the carbon block to allow easier access for the flame. The flame position can be rather critical in these flame lickers and is the cause of most of them not running.

When I get back onto my build, I will be changing the block movement from dropping downwards to open the port, to be being lifted upwards to allow the flame to enter the port directly from underneath without having to wait for the block to get out of the way.

I hope this helps.


John