Scott flame licker build

[J Harp]

Well egg on my face. It's easy to see now that I know what I'm seeing. Strange how a wrong first impression can be so persistant.

Jim

[Bogstandard]

No problems Jim, it gets to us all at sometime or another

Better to ask than not understand.


John

[Bernd]

Jim,

Didn't you know John is a master illusionist?   

Bernd

[J Harp]

Yep, it sure got me, I looked at it several times and saw the same thing each time. I first saw an ad for Fram filters in the Progressive Farmer magazine when I was a teenager. For years I thought it was Farm filters until I heard someone ask for a Fram filter at a parts counter. Good thing I never needed to ask for one or I would have embarrassed myself.

Jim

[Bogstandard]

It looks like I have abandoned this post, but far from it.

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, bifurcated 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.


Bogs

[Bernd]

John,

That is a very neat idea.

It sure will give your engine a unique look with those screws. I like it very much.

Your ER32 tool setup has given me an idea. I wonder if a setup like that could be done with a C5 collet? (sorry  I know)

Bernd

[madjackghengis]

I think Bernd understated it just a tad bit, those bits are stunning and really show off the levers.  I echo Bernd's question and idea about a five C version of such an attachment.  I hope your journey for the plumbing parts goes well, I'm itching to see this engine run. cheers, Jack

[Jasonb]

Comming along well John, though you could have saved yourself an hour or two



Though They are not easy to come by in small sizes and quantities.

I take it the rivits are only drilled a little way in so that the shank does not expand within the rod holes and lock everything up? Just enough to retain the pin.

J

[lordedmond]

John (bogs)

How are you using the bifurcated rivets in a model application my take on that type of rivet is that they are used to hold leather or such . correct me if i am wrong but I remember them as rivet split up the shaft leaving two legs , that you can open out and fold over


from OSX dictionary

bifurcate verb |ˈbīfərˌkāt |
divide into two branches or forks:
adjective |bīˈfərkāt, ˈbīfərkit |
forked; branched:


Stuart

[Bogstandard]

I have tried those before Jason, and they don't quite look right, just like any other mass produced fittings. Plus these are shouldered bolts and plain shanks, not usually available, so I make them myself.

I used the reshaped heads a fair amount when I took Elmer's basic mine engine up a level or two.



Both square and star headed were used to cover up bearings that weren't on the original build.



Yep, the bifurcated rivets are drilled to exact depth for just gripping onto the backing washer and not the other two plate parts. They have to swivel against each other as the angle of operation changes.


Bernd & Jack,

In all honesty, I think a 5C fitting would just be too high to be plonked on top of an RT, especially as you would have to have some sort of closer for them.

I have a large collection of 5C collets, but I think whatever chucks and fittings I have now for the RT and dividing head is perfectly adequate for what I want to do.

But I do suppose you could use something like this.

http://www.chronos.ltd.uk/acatalog/5C_Collet_Fixture_for_Milling_Machine_Bridgeport_etc.html


Stuart,

You are quite correct in your assumption of it being a two legged rivet, maybe I should have called it a semi tube rivet.

I was just using a term we used in the forces when working on aircraft, where the two legged versions would never be allowed, except maybe by some of the fabric trades, but even then, I would have expected them to use the same as I used purely for safety's sake.

They make disassembly very easy, just drill down to the bottom of the hole with a larger drill and the whole lot comes apart.

C-o-C at the bottom to explain use.


John

[lordedmond]

Thanks John for the explanation  and CoC


More like a manual pop rivet with a tapered pin to expand the part outside the joint

[Bogstandard]

That's OK Stuart, sorry for the confusion, just me using my old terminologies again rather than the correct ones.

John

[arnoldb]

Once again, good progress John.

And thank you for the explanation on the rivets; I was also wondering about those.

Would it be correct to say that one can adjust the amount of play between the pivoting parts of the riveted joint by just punching it a bit more ?
I've not seen rivets used a lot in model builds of late, and I'm wondering why, as it seems a good method to use for many things...

Kind regards, Arnold

[Bogstandard]

Normally Arnold, you use a rounding over type of punch to make it look slightly like a dome head rivet, but a taper punch is plenty good enough for what I am doing, in fact I will be using a 90 degree centre punch end so the swelling is more towards the surface, so leaving the parts turnable loose rather than clinching them together.

The depth of hole plays an important role, too deep and it swells inside the rotating parts and locks them up, and yes, the easy way is to gently punch until you get the correct side float (not sloppy) and still have nice fairly free rotation.

If you want to get very technical and work it out with a calculator, there are charts about to give you starting points. But really it isn't necessary, I just drill down to depth until the drill tip reaches a point the same thickness as the parts being joined, and put a supporting washer on the opposite side of the head. I leave about 1/16" protruding from the washer.

http://www.doidge.com/english/semitub.html


John

[Bogstandard]

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.


Bogs

[Bernd]

John,

Would a vacuum cleaner nozzel placed near the cut to suck away the dust have worked?

I wouldn't through that shirt in with the other laundry. Might get that stuff all over the other laundry or were just telling porkies? 

Bernd

[Dean W]

Nice job on the valve, John.  I liked the way the fasteners came out, too.  They look like they were crafted, rather
than just cookie cutter punch outs.  I think they will look good in place.

Dean

[Bogstandard]

Bernd, would you like a vacuum droning away in your ear for about hour and a half while you are trying to concentrate on something. No thanks, and besides, once I wrapped up the paper towelling, it was basically all gone.

No joking about the t-shirt, but over here we have things like washing machines and powder to get things clean, we gave up pounding laundry on rocks at the side of the stream a few centuries ago.


John

[NickG]

All looks brilliant John. Don't think there's any need for great tension in the springs either. Just enough to keep it flat against the port face.

[Bogstandard]

You are quite correct Nick, the springs are only there to keep the block in position, the vacuum produced by the engine will keep the block sealed against the face.

This is the quandry, too much spring pressure and there will be too much friction produced and the block will wear away in no time. The springs are a rather heavyweight about 3" long, maybe a bit more, and 1/4" diameter, but I do have an elegant looking redesign if these are just too strong in the beginning.

This engine will of course run with all these supplied bits in place, without any mods being done, but how long would it last?.

I always look for improvements, not for the sake of it, but to produce a more efficient design by well known methods. Most engines will run quite merrily without all the mods, ballraces et al, but when you do fit them, they make a very significant improvement not only in running quality, but to engine longevity.


John

[Bernd]

No joking about the t-shirt, but over here we have things like washing machines and powder to get things clean, we gave up pounding laundry on rocks at the side of the stream a few centuries ago.


John

Over hear we just throw them away. Why waste money on a washing machine and detergent. 

Bernd

[NickG]

I agree, I think it will be unnecessary friction wearing the block a lot faster, they sound quite strong.

Your mods will no doubt make significant improvements. I guess the valve is quite a good design feature as the little bits of graphite from the block will be sucked into the cylinder and lubricate it and should keep the port face nice and clean. You can see a slight build up on poppin now, don't know how long it would take for that to build up and prevent a good seal. I've handed it over to my Dad now who seemed impressed, put a little note in saying "this one works" but have yet to show him.

Another thing I noticed on poppin that alters the characteristics is the spring that keeps the cam follower against the cam. How is that done on yours John? Because it's just a strand of spring wire on poppin it's easy ish to change the tension.

I've never really played with the cam timing because it seemed to run well from where I first set it but I think the thing you can play with is how much before bottom dead centre it closes. Because of the light weight valve it opens when it wants to, when the pressures equalise - I think yours will do the same if your springs are light enough.

Nick

[Bogstandard]

Hi Nick,

Despite my reservations, I had the original springs set up this morning for a try out, and they don't need to be stretched as far as I thought, so I am going ahead and making some custom spring hangers for them. If they do work out too strong, I have another idea that can still use the hangers I made this morning.

My cam spring is a fairly substantial leaf spring about 1/4" wide by about 1/32" thick, and with all the weight of the operating linkage, it still keeps the ball raced arm in very good contact with the cam.

I do have a fair amount to play with regards to timing, about 10 degrees, also because it will be running on gas, it can easily be throttled, just turn the gas up/down. I have also modded it so that the cylinder can be slid backwards/forwards, giving me control of how close the piston head can be near the cylinder head. I have it set at this time with about 0.002" clearance, so that should be able to completely evacuate the cylinder before the next cycle starts. Just another thing to try out.


John

[Bogstandard]

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 instalment.


Bogs

[madjackghengis]

Hi John, that burner assembly is looking very nice, it looks like it should put out a fair sized flame, and the solder work came out very well, I'm hoping to emulate it with my oddball flamesucker, so it can be speed controlled, as you indicate will be easy for your engine when it is finished.   Can't wait to hear it run.  :beer:cheers, Jack