Another FrankenBurner

3D printed plastic burner experiments (photo heavy)

Recommended Posts

I too looked at any other mold method.  The third rib makes that difficult.  At one point, I had printed the inducer in thirds thinking a silicone injection mold for wax.  I also played with inducers with only two ribs so that I could make split forms for sand but the inducers don't mix as well as the three rib version.  

For the open back reducer of jwmelvin's, this post has a picture of his flames.

Share this post


Link to post
Share on other sites

Yes there are plenty of pictures of it running a jet nozzle. It seems to work fine but I have no comparison really. I’ve been thinking to build a different style inducer for comparison. 

Share this post


Link to post
Share on other sites
13 hours ago, Another FrankenBurner said:

The third rib makes that difficult

Yup.  I was thinking of making the ribs as separate pieces with a top and bottom, but finish work, and getting it aligned exactly would be too painful.  I could do something like that on my CNC mill, but even then, I don't think it's worth it.  I think something more like jwmelvin's would be an easier sand cast.  Playing with the CAD right now.  My other option is to do some lost wax, but I'm not set up right now.  Used to do a lot of ceramic shell casting, but I have a good sized burnout kiln if I want to do regular burnouts.  Rather do sand, it's so much quicker!

43 minutes ago, jwmelvin said:

plenty of pictures of it running a jet nozzle. It seems to work fine but I have no comparison really

the pic that Frankenburner linked shows a really nice flame.  I think it's worth pursuing. 

Dan R

Share this post


Link to post
Share on other sites

Here is a recent v46 cast:

cast.thumb.jpg.c891ce0146620ec40cf898163ea2a11e.jpg

There are still some voids.  You can see print lines in the good sections.  We are playing with the degas process.  We are also wondering about left over ash.  We are going to burn out an investment and break it open to see what it looks like inside. 

We are also going to purchase a commercial investment to play with.  I have looked into R&R Plasticast and Certus Prestige Optima.  Prices vary widely.  Does anyone have a recommended supplier?  

Here is the same cast next to the new 3/4 v54:

burners.jpg.b492705f51f571c6bafa1e36ebc99cac.jpg

Share this post


Link to post
Share on other sites
2 hours ago, Another FrankenBurner said:

Here is the same cast next to the new 3/4 v54:

MAN those look sexy!

Here's a thought for you casters. Rather than sand casting how about making an inflatable masters to make your waxes?

Remember silk bicycle inner tubes? The inflated like a rock but were limp as steam off a tea cup when deflated. If the master patterns were made from a similar material they could be: assembled, inflated, injected with wax and when cooled deflated and removed for reuse. 

Some wax rods to make a gang mold, invest, burn out and cast by the batch?

Hmmmm?

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Since hard soldering aluminum is a simple trick, why not cast them in two pieces, and solder those pieces together afterward?

Share this post


Link to post
Share on other sites

Thanks Jerry.  They were already hot, now they are sexy too.  The 3D printing makes it easy so why not.  

Inflatable masters... silks... waxes... are we talking about burners?  Interesting idea.  I tried to think about the process but then I started to smell smoke.  How would an inflatable mold of a complicated piece be made?

Casting in two pieces and soldering them together also sounds complicated.  It would most likely require splitting one of the ribs.  It would also require post cast work.  Though I doubt it would affect much, it would have a seam.  I would probably have to thread after the cast.

If we can successfully investment cast it, it will not require any post work except removal of the sprues and buffing.   The threads have come out clean in a few of the pours.

I still haven't given up on a silicone mold for injecting wax.  Not having to print a sacrifice for each inducer would be great.  Worst case scenario, we have to print for each inducer and use commercial investment.  Even then, it would still be worth doing.  

Thank you for the recommendation John in Oly.  

Share this post


Link to post
Share on other sites
On 6/3/2019 at 8:29 PM, Another FrankenBurner said:

I still haven't given up on a silicone mold for injecting wax. 

That was my suggestion, inflatable silk or equivalent master molds for injecting wax rather than silicone. NOT casting . . . aluminum.:rolleyes: Have you ever smelled burning silk?:wacko: 

Frosty The Lucky.

 

Share this post


Link to post
Share on other sites
On 6/3/2019 at 9:29 PM, Another FrankenBurner said:

I still haven't given up on a silicone mold for injecting wax.

My 2 cents: 3d print it in two halves with keys.  Make silicon mold of the two halves.  Pull waxes from the molds, then assemble the waxes.  A cheap soldering iron can be used on the outside to weld the waxes together.  A filler wax like "patch-eze" can be used to fill the inside seam and any pinholes.  Maybe 10-15 minutes each to assemble depending on final finish you want.  Probably the easiest way to make wax multiples of these with silicon molds that I can think of.

Looking really nice.  Been playing with some 3D prints of my own, I'll post results after some more testing.  Results are taking me in other directions that may work also...we'll see.

Dan R

Share this post


Link to post
Share on other sites

Does the layering affect the flow? Have you tried any smoothing techniques to get rid of the layer lines? Acetone vapor is used to smooth ABS, but it doesn't do squat to PLA. I've heard tetrahydrofuran works. Solvent smoothing is of course a breathing hazard. 

Using sprayable PU glue could possibly work as a filler.

Share this post


Link to post
Share on other sites

Say what you want, previous iterations don't hold a candle to that last attempt.

Share this post


Link to post
Share on other sites

I'm thinking this burner is down to production procedures, design development is just fine tuning / tinkering. 

Dan: Any thoughts on inflatable master molds for wax injection? It's just a WAG, I can see details I haven't worked out, mostly because I don't really know enough to know what the details are. My ideas are unpolluted by knowledge.

In other endeavors I've "welded" wax together by flash heating the joints over a soft torch flame. No forms for investments, mostly making Christmas candles and similar colored wax. . . thingies.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

J.P.Hall, that one made me laugh.

Meadowgrove, I am not sure how the layering affects flow.  I will try to smooth one out to see the impact.  The ridges are small enough that I suspect the impact will be minimal but you never know.  Maybe the layering is providing a golf ball effect and is actually a good thing.  Maybe not and it is reducing flow.  Good question.  

Frosty, I think you are right about being down to production procedures.  I have printed several since v46 whenever I got new ideas.  Most of which I could not see any improvements.  I have one version which induces more air but it throws off the fuel vs air induction curves.  I would rather not have to mess with a choke when adjusting fuel pressure.  

We will keep tinkering with how to make these things reliably.  

Share this post


Link to post
Share on other sites
12 hours ago, Frosty said:

Dan: Any thoughts on inflatable master molds for wax injection?

Actually first I've heard of them.  Probably too expensive for the stuff I do...I taught a class in foundry for sculptors so we didn't get into production techniques.  I'll have to google it to check it out, sounds interesting.

6 hours ago, Another FrankenBurner said:

I would rather not have to mess with a choke when adjusting fuel pressure.

My 2 cents again...I really like to be able to change the atmosphere in the forge with a choke.  I use a reducing atmosphere to do welding (I don't use flux), so a choke is necessary for that.  Something to think about, but if it's for your own use, then it really doesn't matter :)

DanR

On 6/3/2019 at 9:29 PM, Another FrankenBurner said:

I still haven't given up on a silicone mold for injecting wax. 

Oh...just realized a second method to make the core.  You could make a separate mold to cast a solid investment core that would be placed in a second mold that you then inject the wax burner into.  Does that make sense?

Share this post


Link to post
Share on other sites

Have you considered printing directly in metal as a viable mass-production method?

There are plenty of commercial companies where you can upload your 3d model to their website, and they will give you a quote based on size, complexity, infill, etc of the model.

From a quick search, I have found companies who can print in Aluminium, Stainless, Steel, Titanium, Brass, Bronze.

 

If cost effective vs printing in wax, casting (and accounting for trial and error, failure rate),  it might be the way forward?

Share this post


Link to post
Share on other sites

I will not be omitting the possibility of a choke on any burner.  My personal burners all have a choke.  

The burner I have which induces more air runs richer at low fuel pressure and leaner as the pressure is increased.  To maintain neutral, the choke has to be adjusted as the fuel pressure is changed.  Whereas v46 has a fuel volume curve and an air volume curve which more closely match with fuel pressure changes so the choke does not have to be fiddled with.  The only time choke needs adjustment is to change forge atmosphere or at shutdown when top mounted.

The problem with the print to metal services is expense.  To use one of these services for the inducers would cost several hundred dollars per unit.  I want the end cost to be lower.  Maybe in the future when the cost drops it will be worth looking into again.  

Share this post


Link to post
Share on other sites
16 hours ago, D.Rotblatt said:

Actually first I've heard of them.  Probably too expensive for the stuff I do...I taught a class in foundry for sculptors so we didn't get into production techniques.  I'll have to google it to check it out, sounds interesting.

An inflatable master for injecting waxes is just an idea I had. I have ideas all the time, often reality isn't a factor, I can't help it you know.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

OK...here's my experiments on 3d burners.  First I was thinking of something like the Frankenburners, but able to be sand cast, so I thought I would try putting some spiral ribs inside the funnel move the air into a vortex. This burner produced a really nice flame for the first try, but I wanted to see if the spirals in the funnel in fact caused the gas to spiral, so I exchanged the iron pipe with a clear plastic 3/4" pipe on and ran the injector with air and some incense for smoke.  What I found (and I'm sure this is what Mikey and Frosty know well) was that the air is drawn around the MIG tip by the jet of gas,  but the air only moves quickly close to the stream which is in the center of the funnel.  Near the sides of the plastic vortex the air is moving very slowly, so the spiral ridges didn't effect the motion of the air downstream.  

Conclusion: though this shape seems to produce a much better flame than a pipe reducer would, but it does not induce a spiral motion to the gas mix.  Looking at the flame, it might not be necessary.

On to experiment 2....

 

IMG_7630.JPG

IMG_7631.JPG

 

IMG_7626 copy.jpg

Share this post


Link to post
Share on other sites

Experiment 2.  

I was looking at Amal burners which people say work well.  There is a jet that shoots the gas into an intake.  After the intake is a venturi tube that looks to be about a 1:12 taper that extends an inch or so into the 3/4" pipe.  So I thought I'd try to make one that used some of these features to see what it would do...also that could be sandcast.  The inside tapers to about .6" then widens at about 4 degrees to the ID of the 3/4" pipe.  The idea is that this will accelerate the gas pulling in more air.  The jet can be moved forward or back to choke the burner to get a richer flame (I like control over the mix).  With the jet pulled back it seems to be a fairly neutral flame.  This is the exact same jet used in the burner above, at the same pressure.  In both I am using a 6" piece of 3/4" pipe.

I also tried an injector with a spiral inside the choked part of the venturi, and found that though it imparted a spiral vortex to the gas flow, but the flame seemed to be off center.  It may have required a longer pipe (a full 8-9").

Conclusion: Nice looking flame. Doesn't seem as good as the Black burner, but shows promise, good mixing, more stable then the black injector.

 

 

IMG_7718.JPG

IMG_7719.JPG

IMG_7721.JPG

AMAL.jpg.4928a0e68b41ad80174d3f7f8d5f4311.jpg

 

IMG_7711.JPG

Share this post


Link to post
Share on other sites
On 6/6/2019 at 4:39 PM, Frosty said:

often reality isn't a factor, I can't help it you know.

Reality?  Reality?...I don't need no stinkin' reality!

Share this post


Link to post
Share on other sites
12 hours ago, D.Rotblatt said:

Reality?  Reality?...I don't need no stinkin' reality!

So long as you got the goods reality is over rated. Eh?

Yeah, I did clear pipe smoke tests and saw pretty much what you describe, I don't know if it did me any good though.

I'm wondering if fluting the OD of the jet holder in your second series of pics might improve or inhibit vortex.  

I now return control of your reality to wherever you keep it out of sight.

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Nice experiments.  The orange one looks good.  I tried some similar experiments I called version 3.2.

Do the flames look the same to the eye as they do in the pictures?  

21 hours ago, D.Rotblatt said:

Conclusion: though this shape seems to produce a much better flame than a pipe reducer would, but it does not induce a spiral motion to the gas mix.  Looking at the flame, it might not be necessary.

Are you meaning the spiral ridges in the reducer or the shape of the reducer itself?  

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.