3D printed plastic burner experiments (photo heavy)

[Irondragon Forge ClayWorks]

More Power arrr arrr arrr.

[G-son]

Very interesting progress in this thread, and nice to see that research almost a century old still can give good inspiration. These waisted burners look alot like a basic vacuum ejector - just with a smaller angle on the exit, but that makes perfect sense as long as we don't want to turn that area into the flame retention nozzle. 
Lots of interesting information, and I really want a metal lathe to be able to make things like these. 

[D.Rotblatt]

LOL, Loved that show! Life is cool, we get to play with fire and hit hot stuff with hammers! 

Well, here's the latest iterations. Those below plus rev3.1 with AFB's Fancy Intake.  If you can't read the plans below; from left to right rev 3.1, 3.2, 3.3. second row: original 2 degree wasp, rev3.4 (it is mis-marked 3.3).  I made one change from the original 2degree wasp injector and that was to change the intake funnel from a spline made funnel to a simple arc with diameter of 1.25".  This did work better then the original, it pulled more air.

On most of these I would have liked to go with a slightly larger mig tip.  The next size up I had was .052, and that gave a rich green flame.  I think just a thousandth or two larger would do the trick.

 

Here's pics of all the burns.  Same .046 mig tip @5lbs.  I tuned them by choking them til the flame turned slightly green, then pulling back til the green was gone - aiming at a neutral.  I used a tripod so the camera was the same distance from each flame.  I also set exposure to the flame as it seemed more accurate to what I was seeing.  Conclusions on bottom, but most of these worked easily.

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Rev3.1:

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Rev3.1 with spiral:

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Rev3.2

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rev3.3

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rev3.4

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Rev3.1 vs rev3.1s (with spiral intake).  I really noticed little difference.  There didn't seem to be much swirl.  3.1s seemed a little more stable, but when I pulled the choke back to allow for more air it didn't go as lean as rev3.1.

Rev3.1 was pretty awesome, I need to try it with a slightly larger mig tip.

Rev3.2 and 3.3 have progressively shorter tubes after the intake hole, and larger intakes.  I didn't notice much difference, but I'll have to play around with some mig tips slightly bigger to see if they tune in.  I need to buy some # drills.

Rev3.4 was a surprise.  I just experimented and ignored the 2 degree slope.  Instead I made a spline curve.  The intake hole is bigger then 3.1 but smaller then the other two.  It had a flame that was very good looking, no inner cone at all. It is small and would be easy to cast.  The flame was smaller then the other injectors but went from lean to rich easily.  It bears more work.

DanR

 

 

[Frosty]

7 hours ago, G-son said:

These waisted burners look alot like a basic vacuum ejector -

They have common aspects with what I know of as Jet Ejectors, Vacuum pumps. We're talking the same machine just different terms. 

AFB and Dan are making linear inducers in such a way so as to get high performance. Burners like my T burner on the other hand are "jet ejectors" that have been de-tuned WAY below capacity to make burners. Jet ejectors are so much stronger induction devices I was able to get pretty high performance with a very basic bit of: plumbing, minimum tools and shop skills. Something almost anybody who can read a scale and drill a straight hole can make and put together a forge.

I have the publication you posted here saved on my comp. It's about what I had to work with sort of. 

Good stuff, thank you G-son.

Frosty The Lucky.

[Another FrankenBurner]

Did some test pours today.  

 

We have a furnace heated with a v46 half inch burner which was used to cast some iron today.

Also tinkered with a couple of new experiments.  I am happy with their performance.  Here is one of the flames:

[D.Rotblatt]

4 hours ago, Another FrankenBurner said:

used to cast some iron today

Cast iron!!!!  Now that's cool!  I've done large bronze pours, but not iron.  I'm inspired!  What kind of iron, and what kind of crucible? 

DanR

[Mikey98118]

Nice flame, too.

[Another FrankenBurner]

Dan:The top ingot grey cast and using a graphite clay crucible.  

You've mentioned bronze here and there, is this your preferred casting alloy?  If so, any particular reason for that?

Thanks Mike.  I am very pleased with the new experiments.  

[Frosty]

When you say "some" iron about how much? 

I'm pretty excited. 

Frosty The Lucky.

[Another FrankenBurner]

Both ingots were tests.  The iron ingot landed at 1.5 lbs.  We went into it with some doubts and fears so we cautiously started nice and small.  No more doubts or fears.  We were happy the little burner did the job and we are excited.  We have more experiements to do.  We have some plans.  I am playing with more then one new idea.  It is exciting.

[Frosty]

1.5 lbs is a respectable test, no sense getting crazy just to find out if it develops enough heat. 

This is so very cool. 

Frosty The Lucky.

[D.Rotblatt]

1 hour ago, Another FrankenBurner said:

You've mentioned bronze here and there, is this your preferred casting alloy?  If so, any particular reason for that?

A number of them.  I started using it for pommels and quillions on knives - which were brass.  Kind a pain to cast.  Then I found silicon bronze was a wonder to cast, no flux necessary, casts easy, beautiful look, etc. The first I got was from scrap form a boiler, but I use either Herculoy or Everdur alloys now.  Then I started doing metal sculpture, and bronze is the classic way to go. I think it's what I'm used to.  I've also done aluminum and silver.

But now I have to try iron!  Fantastic that your little 1/2" burner was able to heat up the furnace to at least 2300F.  Just looked it up and was surprised that the melting point of gray iron is 2100-2200F, which is about the pouring temp of silicon bronze.  It says the pouring temp is from 2450 to 2700 (thick to thin walled castings).  Not too bad.  Its on my list!  Which grows and grows and ..... sigh 

DanR

[Mikey98118]

3 hours ago, Another FrankenBurner said:

If so, any particular reason for that?

Well, there are some major advantages to choosing silicon bronze as a casting alloy; one of which is that it can be repeatedly cast, without major changes in its chemistry; it is also not inclined to produce toxic fumes...

[Another FrankenBurner]

Thank you for the information.  Casting is another fun way to work with metal.  Plus we still get to play with fire.

[Mikey98118]

On the other hand, cast iron is super tricky. The problem isn't reaching melting temperatures; hobby casters have been doing that with Mikey burners, and fan-blown burners for twenty years (even longer with oil burners). The problem comes from how very inclined it is to turn super hard during casting. Lots of frustrated hobbyists over that issue

[G-son]

Cast iron that cools down too quick becomes white cast iron, where the carbon remains dissolved in the iron in the form of iron carbide. Softer than the tungsten carbide some drills and other cutting tools use for cutting edges, but still a very hard substance. 
When it cools down slowly the carbon separates into small graphite flakes throughout the metal, making it darker grey, which gives it the name grey cast iron. 

Not only an issue when casting, but very much so when you weld cast iron too. There are several quick and easy methods to weld cast iron, nickel electrodes in a stick welder for example, where you weld a short distance and then hammer the weld as it cools to compensate for shrinking so the tension doesn't crack it, but the area just around the weld turns to white cast. Heating the area/entire piece red hot and welding it with oxygen/acetylene and filler made of cast iron, followed by packing in insulation for a very slow cooldown is still one of the best methods to weld cast iron - unfortunately it's very slow, requires disassembly and many precision machined parts would need re-machining after the heat cycle, so it's not a popular method any more.
Just imagine ripping an engine apart, building a firebrick oven around the cracked block, filling it with coal to heat it, cover with sheet metal until hot enough, open the cover enough to get in there and weld, then cover up again, stop the air supply and wait for a day until cool... and then spend lots of time machining whatever was distorted before you can use it again. Today you'd just get another block, as long as you can.

[Buzzkill]

When I was a kid I remember my dad building an oven from a 55 gallon drum split the long way and powered by charcoal and a vacuum cleaner reversed.  He heated up a cracked engine block and welded using nickel rod.  After all the tedious welding he closed the lid, shutdown the the air, and left it alone to cool slowly.  In the morning when he opened the lid he found that thin portions of the block had melted and run down the sides.   I think that was the last time he welded cast iron. Because of that memory I only braze cast iron for repairs and I rarely do that.

[Mikey98118]

Probably, the easiest method is to take into account that most iron castings well end up as white cast iron, and not plan on including threading in the cast part, etc.

Of course, one can always look up the formula for the special cast iron that is bendable; something about a special form of graphite used in it...

[G-son]

Ductile cast iron? I think that was the name, and if I recall that is made by a special heat treatment, not special ingredients. But there is something special about the graphite if I remember this right, it gets a spherical shape rather than the usual flakes, and since the rough flakes are where cracks usually start in regular grey cast iron you get rid of the problem with it cracking easily.

[Mikey98118]

I think you're pretty much on the right path with your comments. For some reason, none of the guys complaining that their castings were way too hard to build equipment from were ever willing to try making ductile cast iron.

[G-son]

I believe the process was complicated, or seemed complicated when I read it anyway - something about holding it at a high temperature for many hours or so. But as you can turn regular grey cast into white cast just by heating it cherry red and letting it cool down "fast" (that basically means not packing it in insulation), I'd guess you can go from white to grey by heating it cherry red and making sure it cools down as slow as possible.
If I keep guessing, I'd say that the problem on DIY casts at least in part originates from them being small. Not enough metal to hold the heat when poured into a cool casting mold, temperature drops too fast. 

 

[Another FrankenBurner]

Thank you for the information guys.  Sounds like another area for research and tinkering.

[D.Rotblatt]

We love google....Here's a little article on heat treating of iron: https://www.industrialheating.com/articles/94644-heat-treatment-of-cast-irons

Basically in a nutshell, to anneal, heat to 1450-1650 for 1 hour/inch, cools at about 100 degree/hour, so overnight should work.  Different alloys have different times/temps.  Needs a electric furnace to properly anneal.

DanR

[SLAG]

Mr. D.Rotblatt,

Thank you very much for the reference.

I skimmed the article tonight and will read it in more depth tomorrow.

I have also 'bookmarked' it too.

SLAG.

[jlpservicesinc]

Great read on cast iron.