Another FrankenBurner

3D printed plastic burner experiments (photo heavy)

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1 minute ago, Another FrankenBurner said:

I don't have any pictures of the sprues and the porosity problems currently, but I will get some.

As a general rule, if possible you want all parts with a similar thickness. Barring that, you sprue into the thickest (if possible) and put the thinnest furthest away.  Metal crystalizes as it solidifies, and the crystals are denser than the liquid (it shrinks), so needs to draw liquid metal from somewhere else.  Thinner sections cool quicker than thicker sections.  If an area doesn't have a place to draw metal from, you get porosity which is space between the crystals (though it can also come from dirt, trapped gas, or pieces of investment that have broken off).  Ideally, you want to control the cooling of the metal to start furthest away from the button and to end closest to the button.  The last place you want the metal molten is the button (or cup) where you pour the metal in, so it should be of large cross section.  Sometimes you have to sprue into two places to get this to happen, or put a feeder next to a thick section of your casting.  Remember, with aluminum you can remelt the sprue and button, so make the sprue short (though long enough to cut off easily) and the button large.

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Based on what you said, I know we did it wrong.  We are changing the feed system.  I suspect you are exactly correct about what I am seeing.  Sprued from one end and the ribs freezing before the lower portion would explain where I am seeing the porosity problems.

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Oh my :D

Look how small the mixing tubes are compared with the size of the forge they're running yellow  hot.

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We were excited to finally put something to a forge to see the end results of all the work.  We built that forge large to test the 1/2"  burners.  I don't remember but I am wanting to say it is in the 450 in3 ball park.  We are happy with the performance.  The 1/2" burners are nice in that they are so small and their output is high enough for what we are doing with them.  

My daily driver is a refrigerant jug forge(150 in3) with a top mounted 3/4" modified sidearm burner.  The sidearm burner is huge and sticks out like a large arm which sometimes becomes a moment arm.  It runs rich enough to show green and has to be turned up enough to cause dragons breath to get to forging temps.  I will be putting one of the 1/2" guys into it to see the changes.  I am hoping for and expecting fuel savings.  These new burners are happy to burn clean in a variety of configurations with some tuning.  They can also be turned down very low which will be nice for the idle circuit.  With the sidearm, the idle setting had to be set high to prevent the burner from huffing.  

I have been playing with nozzle design lately.  I am up to v4 on the nozzles.  I want to understand the dynamics of stepped, tapered, and stepped tapered.  This includes playing with the harshness of the step, the angle of the taper, and the length of the nozzle.  I also want to understand what happens when the nozzle outlet size is much larger then usual, what the pros/cons are, how large is too large, and why.  We are happy with the kastolite nozzles.  They can be shaped however desired, they don't oxidize, and they don't transfer as much heat to the mix tube.

Here is a half inch burner with a 1.5 inch stainless experiment nozzle:

121058564_nozzlehot.thumb.jpg.13e1766da61c6651d369038fc89c4400.jpg

It will heat.  I reduced the exposure so the flame could be seen and look at that beautiful blue:

1457299437_nozzlehot2.thumb.jpg.5e7ace55fee11e128bc2963d0bc31378.jpg

At the other end of the nozzle size spectrum, we held the 3/4 burner to the cast nozzles of the big forge.  The nozzles were smaller sized(1.25 outlet) for the 1/2" burners.  Here is that flame with a cold forge:

forgefire.thumb.jpg.3b07843e9a922996cbb2761889a76f71.jpg

We didn't have the mix tube aligned with the nozzle very well.  The nozzles point more towards the ceiling then that flame is.  The kastolite is fresh and that is what is causing the contrasting orange. 

 

 

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Oh MY! That's beautiful.

Frosty The Lucky.

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What I am seeing in the three photos all agree in my mind as to what is going on here. The top photos shows a flame retention flare almost into the completely yellow incandescence that a Mikey burner can get only from propylene gas (it runs about one-third hotter in air than propane). The second photo shows picture perfect flame from a burner that if I remember correctly has a jet orifice that would be reducing in one one of my burners. The third photo higlights the orange clound of oxidized nozzle particles that your burners are producing because of their extra flame temperatures, if my conclusions are correct, and if the photos show the same pictures that a human eye would.

Tentative conclusions are:

(1) You now are likely to be running the hottest air/fuel burners in the world--by far.

(2) Start working on refractory flame retention nozzles right away; those flames are way too hot form stainless steel.

(3) Mikey burners are now yesterday's news. Congratulations, champ :D

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That or cast hard refractory, SS won't last long at all. 

I want at least one, maybe two.

Frosty The Lucky.

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On the hotter better burner guys for sure. Though I think Theo had us hooked on 3D printing with his knife furniture for a while now.  I long for the days when I could use cad (STUPID TREE!) and the money to buy a printer. :(

Frosty The Lucky.

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I think he should include his latest two flame retention nozzles turning orange and yellow, along with the others on Burners 101, so folks can see just how hot flames can get.

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I'm just waiting to see how they make a multiple outlet burner work. If I could get my next forge idea to work with a single inducer I'd be grinning big time for the fiddly bit details removed.

Frosty The Lucky.

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Thanks guys.  They are hot indeed.  We now have a few kast o lite nozzles working.  We 3D printed forms for the big forge so the nozzles are kast o lite and cast directly in the wall of the forge.  We have not had any problems but they have not been in service long.

I am now playing with reusable printed forms for the nozzle design experiments. 

1996710757_nozzlecad.thumb.jpg.92843ec1b63bc29cf565fb61eb1de349.jpg

What I am more excited about, I am starting to play with NARB design.   

My father had an idea for a feed system which he cad, printed, assembled, and it is now in investment for a pour tomorrow.  We are attempting 6 in one pour.  Fingers crossed.

IMG-0600.jpg.3ad5755fb32b84f8a37e53949e7a6795.jpg

 

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3 hours ago, Another FrankenBurner said:

We are attempting 6 in one pour.  Fingers crossed.

I'm interested to see how those cast!  Looks good.  The inducers on bottom and is that a feeder tube on top of each?  I've got to say, casting straight off the 3d printer looks like a blast!  I'm getting inspired!

3 hours ago, Another FrankenBurner said:

I am starting to play with NARB design

Take a look at my experiments with 1/8" holes on the ribbon burner (it's in the NARB thread).  It's been really successful.  Welded a billet with it the other day at 2350F, and got the temperature down to 1450 F for normalizing and heat treating.  Besides it's bizarre singing for the first 2 minutes until it's hot, it's working up to my highest expectations.  It will not backfire at any pressure.  The inducer on that is just a Reil burner.

Although on writing this, I'm wondering if the NARB defeats the purpose of this type of inducer.  All the cyclic action is wasted once it goes into the ribbon burner.  In my observations of my NARB, it's just about air and gas in the right ratios being pushed into the plenum.  I'm noticing little difference between using a Reil burner, Mickey burner or my hybrid style burner with my NARB head.  Just a little difference in the richness. Frosty or Mikey, correct me if my thinking is wrong...it's based only on a few of my own observations.

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Yes, there are feeders into the tops from the main sprue.  I had mentioned what you said about the ribs freezing first and my father added those feeders.  Also, oversized sprue and risers for the large liquid mass to pull from.  We are feeding to the bottom of the lower reducer so we may need to add blind risers if we still see porosity at the top of the reducer.  

I follow the NARB thread, I have kept up on your 1/8 inch NARB.  It looks great.  I want to play with NARBs just because I am the tinkering type and have some ideas which will drive me crazy until I have tested them.  

As to the inducers usefulness in the NARB, I think it could be a good carburetor.  As a tube burner, it induces more air and mixes better then any of the other styles I have played with.  When playing with different nozzle shapes and sizes, it can usually be tuned to burn clean.  Hopefully that holds true when it is faced with a NARB.  

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7 hours ago, Another FrankenBurner said:

As to the inducers usefulness in the NARB, I think it could be a good carburetor.

I'm sure it would be a great carb.  Just don't know if it would be a better carb than anything else.  And I emphasize I don't know. Just a question to ponder or experiment with.

Curious, did you design these to allow for a damper or baffle of some sort to change the flame to a more reducing flame?  I find that very useful for welding (as I no longer use flux), and for heat treating.  In HT I bring the pressure down as low as the burner will support and then change to really rich flame to bring the temp down to around 1500F.  I find myself playing with the damper all the time.

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I have nothing intelligent to add to this thread.  It is amazing.  I’d just like to add that I’m glad to have been along for the ride as you few inventors and tinkerers have reframed the industry in terms of burner design.  If Frosty, Mikey, and you guys got together and wrote a book detailing your collaborations and improvements I would buy it.  In fact, you guys should find a way to monetize your creations.  You deserve it.

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This evenings pour was a complete failure and disappointment.  For the first 30 seconds, it was beautiful.  Then the mold blew out due to vacuum again and filled the safety reservoir and molten aluminum headed down the vacuum tube towards the pump.  It filled fittings.  Luckily, it was stopped by a screen.  We will be using a larger safety reservoir and have an inline filter from now on.  We learned a lot and have several ideas to play with for the next pours.  

3 hours ago, D.Rotblatt said:

Just a question to ponder or experiment with.

It sure is.  I will be experimenting.  I have a few NARB and other ideas to play with.  It sounds like Frosty will be trying one with his NARBs as well.  

3 hours ago, D.Rotblatt said:

Curious, did you design these to allow for a damper or baffle of some sort to change the flame to a more reducing flame?

Yes.  There are two true round sections so that it can use a sliding choke like on your hybrid style burner.  If you look back into the first pages, there are some images of prototypes with chokes.  Once we have the casting process figured out a little better, I am going to change the model so the OD matches the ID of some readily available pipe or tubing.

Also, I have run the latest versions with my pressure gauge resting on the minimum peg without huffing or going rich.  

47 minutes ago, Lou L said:

I have nothing intelligent to add to this thread.  It is amazing.

Thank you sir.  Science and fire, how could it not be fun to tinker with?  As far as a book, most of those details are in this thread, on this awesome forum.  As to monetization, that was never the original intent.  I just wanted to tinker with burners and hopefully end up with some hot ones for my forges.  Others have stated they want some too, so now we are going to try to supply them.  

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1 hour ago, Another FrankenBurner said:

This evenings pour was a complete failure and disappointment.

Bummer.  Maybe one problem here is the mass of metal.  Another solution to solve the porosity problem is to thin the cross sections rather then to feed more metal. Hollow out the top section and add ribs, and sprue into the bottom thicker section.  Kind of like this image but with a solid bottom:

image.png.83bb887e14d5f4e243e23162aa5ad36c.png

That way only one side will be thicker then the fins. 

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8 hours ago, Lou L said:

Mikey, and you guys got together and wrote a book detailing your collaborations and improvements I would buy it.

Too late. There's Another Frankenburner in town; his burner blew our old jalopies off the road; he gots to write the book now :D

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Thank you for the kind words Mikey.  They are encouraging.  

We attempted another cast today.  This was a gravity only experiment.  The surface texture is rougher.  Some of the investment showed full detail which was not in the cast.  The porosity is much less and the cast is more complete.

Here it is hot out of the flask:

cast.thumb.jpg.a1622cb1d74b6ee3b0683134b6a6a05d.jpg

We like what the vacuum does for us and will continue to experiment.  We are still experimenting with investment as well. 

I am also building an Arduino based ramp/soak temperature controller.  I have some code work to do.  We currently manually control the cycles which is tedious and we are not ramping the temperature properly.  The casting process will be much easier on us so experiments will be more often.  The flasks will not be thermally shocked which will hopefully increase the success rate.  

I had ordered some generic tweco 14T-30 mig tips.  The flame shows much more green/rich then some Miller standard 030 tips.  It makes me wonder if the jet is larger and delivering more fuel or if it is a change in mixing due to a different fuel stream shape.  I am going to put a flow meter inline to compare.  Not all mig tips are created equal.  

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