twigg Posted February 5, 2021 Share Posted February 5, 2021 Note to mods: I will be making a separate post about the forge seen in these pictures on another thread, and there will be a lot of overlap between the two posts. I decided to make this its own thread because there seems to be interest in small burners, and it's easier to search like this. Tonight I made my first crack at a 3/8" Frosty tee for my ~45 cu. in. two-brick forge. I think there's more gains to be had, but it performed really well off the bat. All pictures taken at 2 psi, with the orifice positioned as shown in the 2nd picture, almost poking into the mixing tube. Parts: 3/8 x 3/8 black iron tee 1/8 NPT x 1/4 flare fitting adapter 0.8mm 3D printer tip (surprisingly large!) 3/8" x 3" black iron pipe nipple I'm not including the stainless coupling on this list because it ended up being useless even once I tapered the ID. The methods used are identical to Frosty's T burner instructions, except the tap is an M6x1mm for the 3d printer nozzles and I tapped the hole for the printer nozzle in the flare side of the adapter, because I use NPT 1/8" for all my burner connections. I suspect this is a very non-optimized burner because a 0.8mm 3d printer nozzle is just as big as a 0.025" mig tip (same as you'd use on a 1/2" burner). I struggled right off the bat with this little troublemaker inducing too much air. That's why the orifice is jammed so far forward in the pictures. What I can say is it's screaming hot as is. At 2 psi it brought the hottest part of the forge to a mid yellow and seemed ok to forge with (mid orange). I didn't have time to see how hot it would've gotten at 5psi, but it was definitely toasty. As you can see in the 4th picture, I had to put the end of the flame nozzle about flush with the lining of the forge to get the flame to be stable. Once the forge got hot, I was able to back out the nozzle. Other thing I would say was that my fabrication tolerances were a mess tonight, but the burner was still pretty hot. On the first picture, you can see the flame is lobsided by the tempering colors on the nozzle. On the video, you can see it doesn't have a stable envelope. Still more work to be done! Edit: I live at 5500ft. That means air here is on average 80% of the density you'd get at sea level. I do all my testing in a heated workshop at 70degF, so there's no air density fluctuation with temperature. Link to comment Share on other sites More sharing options...
FlatLiner Posted February 6, 2021 Share Posted February 6, 2021 Nicely done. Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 6, 2021 Share Posted February 6, 2021 To begin with, if I think you did it wrong, but "if it ends up right; then you wasn't wrong." Next, #D printer nozzles are going to rearrange small burner rules A LOT !!! Finally. what you may want to mess with is intenal sleeves (with internal bevels on the end that ends up within the fitting). Why? Because you can make your burner even hotter that way. And as Frosty keeps pointing out; make one change at a time. Link to comment Share on other sites More sharing options...
twigg Posted February 7, 2021 Author Share Posted February 7, 2021 Would center drilling a bevel in the inlet of the 3d printer nozzle do the same job as an internal sleeve? Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 7, 2021 Share Posted February 7, 2021 Apples and oranges. The internal sleeve, with the bevel, is just a way to bring the burner inline with Frosty's instructions, since the middle opening in the ""fitting isn't the next size down from the two air entrances. I realize that you have to deal with the fittings you can get. Link to comment Share on other sites More sharing options...
twigg Posted February 7, 2021 Author Share Posted February 7, 2021 Ah sorry, by "fitting" I thought you meant the brass adapter. Now I understand you meant the tee itself. I'm still a little confused though. Does the sleeve go inside the mixing tube and extend just into the tee? Is it supposed to reduce the ID of the mixing tube? Thanks for bearing with me. I did start off with a 1/2 tee and a reducing hex bushing (because I didn't have a reducing 1/2" tee), but I went down to the 3/8 tee once I saw that it was inducing too much air. Link to comment Share on other sites More sharing options...
Mikey98118 Posted February 8, 2021 Share Posted February 8, 2021 It does go inside the mixing tube, and can extend just into the tee, or stop short of it; either way, so long as it is beveled. The point isn't reducing the ID of the mixing tube; that is just a fortunate side benefit in your case. The point is that the "T" fitting that Frosty designed his burner to be used with has a smaller center opening, and that difference creates a Funnel shape to be incorporated in that area of the casting. that funnel combines and interacts with the two air openings to create considerable swirl in the incoming air flow; this combines the air and propane together far more efficiently than would happen without it. How so is it convenient in your case? I truly believe your forge needs a 1/4" size burner to be happy, and this is a very easy way to turn your 3/8" burner into one; thats why! Of course its going to make Mikey even happier than you, to see a working 1/4" "T" Link to comment Share on other sites More sharing options...
twigg Posted February 10, 2021 Author Share Posted February 10, 2021 Came to the understanding that buying a reducing 3/8 x 1/4 tee online for a few extra bucks makes more sense than fabricating a tapered sleeve. Waiting on that to ship. Link to comment Share on other sites More sharing options...
twigg Posted February 11, 2021 Author Share Posted February 11, 2021 I made a nozzle and played around with some open-air testing, as well as testing different orifice sizes on the 3/8 burner. (I also made a kitchen-sink 1/4" burner, but I'm putting that in a separate thread for the sake of search-ability). Short version: yep, it's really friggin hot, even outside the forge with a crude step nozzle, and the turn down range goes below 0.5psi (measured at the tank, not at the accelerator!) So I found by happy convenience that I could take the stainless steel coupling I internally beveled and slide a length of 3/4" stainless pipe over it to make a very crude but effective step nozzle. The 3/4" pipe section was 1-1/2", and I put it 5/8" down the length of the stainless steel coupling (which was 1" long and had the same OD as a 1/2" pipe nipple). Took some tuning, but I was able to get the nozzle itself red hot. The placement of the 3/4" section relative to the fitting is critical. The other thing I noticed with this burner is that the turn down range extends crazy low. Below 0.5psi measured at the tank. The flame is most stable above 2psi, but it's still there. I have a feeling this is just a feature of 3D printer nozzles not having a long orifice like mig tips do (less length, lower friction, more flow per psi). https://youtu.be/nmbW6GNCQZQ Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 13, 2021 Share Posted March 13, 2021 twigg, My apologies for missing this section until now. The flame in the video is too reducing, BUT the flame in the photo looks very promising Hope you keep at it. Your work is important. There are loads of people who want a forge this size, and yours is already the hottest I've seen. Being able to run your burner at 2.5 PSI is also very important, as it makes 1 lb. fuel canisters practical; all long steps in the right direction for jewelers and hobbyists. Link to comment Share on other sites More sharing options...
twigg Posted March 13, 2021 Author Share Posted March 13, 2021 Thanks Mikey! I appreciate the words of encouragement. I hadn't thought about canisters, I'll have to add that to my to-do list. I feel like freezing might be an issue. I definitely plan on keeping at it. I haven't had anything to post for a while because my landlord's been working on high end furniture in the shop so I've been steering clear. My mini lathe should arrive Monday if the tracking page is to be believed, and that'll let me mess around with fancier nozzles and let me drill dead-center holes in the tees. All my free time has been going into studying lathe stuff in preparation. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 14, 2021 Share Posted March 14, 2021 Oh goody; a mini-lathe! I always wanted such a sparkly of my very own (s[slobber, drool ,droll :-) Ah, tool greed; guess I'm not completely fossilized after all. Link to comment Share on other sites More sharing options...
twigg Posted March 14, 2021 Author Share Posted March 14, 2021 Hehe, I hear you. I'll be sure to post about it when I get the chance. I have no idea how I'm gonna get to sleep Sunday night. It's worse than being a kid on christmas eve! For right now, my goal is to keep playing with my 1/4" T burner from my other thread and find out why the wire temperature is lower than this 3/8" burner. I'm hoping that a dead-center hole will fix that issue. After that, experimenting with the mixing tube length and nozzle shapes to reduce the tertiary flame on both burners. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 14, 2021 Share Posted March 14, 2021 Well, it is a short well mannered tertiary flame in the photo Link to comment Share on other sites More sharing options...
Frosty Posted March 14, 2021 Share Posted March 14, 2021 A lathe is THE tool of excellentness for making burners. Congrats, have some fun without trying to make anything yet to get the feel of it. The first rule of running a lathe is. Don't run the tool into the chuck!!! Frosty The Lucky. Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 15, 2021 Share Posted March 15, 2021 I thought the first rule was "Don't wear loose clothing of long hair near a running lathe"? Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 15, 2021 Share Posted March 15, 2021 I thought the first rule was "Don't wear loose clothing or long hair near a running lathe"? Link to comment Share on other sites More sharing options...
Andrew LB Posted March 2, 2022 Share Posted March 2, 2022 On 3/14/2021 at 12:26 PM, Frosty said: A lathe is THE tool of excellentness for making burners. Congrats, have some fun without trying to make anything yet to get the feel of it. The first rule of running a lathe is. Don't run the tool into the chuck!!! ouch! You know... it's highly recommended to wear pants around heavy machinery. lol. On a serious note, i did manage to annihilate a nice boring bar not paying attention yesterday. It actually buggered the screw hole and the cutter is now slightly loose. So have there been any developments on the 1/4" and 3/8" burners? i'm ordering parts to build one for a fire extinguisher mini forge and am trying to decide between the two. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 2, 2022 Share Posted March 2, 2022 You can always turn the burner down to save fuel, but not visa versa. Also, starting at 3/8" size, turn-down ranges start to shrink, but the performance requirements multiply. I have built 1/4" burners, but don't think they are a wonderful choice; just my two cents worth. Link to comment Share on other sites More sharing options...
Frosty Posted March 2, 2022 Share Posted March 2, 2022 I've never even built a 1/2" T though I know more than one who have. Another thought, rather than the need for serious precision to get a 3/8" burner to work make a ribbon burner for a 1/2" T. I discovered NARB made a 3/4" T ridiculously stable from stop to stop on the regulator. It'd be easy to turn a 1/2" powered NARB way down and it'd provide really even heat in the forge. Frosty The Lucky. Link to comment Share on other sites More sharing options...
Andrew LB Posted March 4, 2022 Share Posted March 4, 2022 Mini forge is done, just waiting on the parts for the burner which come sometime today (friday). I figured since i was placing the order, i'd get some extra Tee's in case i screw it up, and a couple of the 3/8" flare to 1/8" mip fittings that ill tap one of them with M6 for testing out some of the 3d Printer nozzles i have (0.6, 0.4, 0.2) and the other with for my .030 and .035 MIG tips. I also got a 3/8 tee and 3" nipple ijn case i get too frustrated trying to make the little one work. I was also thinking about chucking a Tee in my lathe and removing the threads on the two air intake ports and smooth everything out for better airflow. kinda reminds me of porting and polishing an intake manifold. The one thing i'm a little confused about is the burner nozzle. Is the flared nozzle only used for open-air testing of the burner, and not when installed into the forge? It looks like many people fit the end of the burner into a flange. I have a black pipe merchant coupling and possibly a stainless steel one that ill use between the shell and the burner opening on the forge. /edit Here are some photos of the mini forge, the 3d printer nozzle threaded into the gas fitting, and how i used my wood lathe to flatten and find center on the T-fitting. Since i lack a metal lathe, i used a very sharp gouge i didn't care much about ruining and when moved very slowly, it managed to cut the pipe. I don't recommend this because if it were to catch, the results could be catastrophic Link to comment Share on other sites More sharing options...
Frosty Posted March 5, 2022 Share Posted March 5, 2022 Did you drill the T for the jet mount or just use it to find center? If you drilled it in the lathe use a center drill bit rather than facing it off. Next time, rather than facing it just take a flat stone to it while it's turning or a piece of chalk whatever you use it will mark center like watching the night sky in stop action. Either with scratches or charcoal or whatever will make circular patterns everywhere but the center where it'll be a spot. Below pic are center drill bits, they come in all sizes an are also known as "counter sink bits," a shop can't have too many. Frosty The Lucky. Link to comment Share on other sites More sharing options...
Andrew LB Posted March 5, 2022 Share Posted March 5, 2022 Oh those are nice. My only countersinks are the wood variety except for one metal one with the diagonal hole through it. It wouldn't have worked for this application. When i faced off the top of the T, i did so with it threaded into the nipple as well as a merchant coupling since the chuck held it far better in the coupling due to nice parallel sides. Most of these chinesium fittings are not made to the most stringent of tolerances. I wanted to face it off enough so the brass fitting would sit flush which unfortunately left that wall quite thin. I did get two of these T's so in case i screwed up. If i need to thread the backup T, ill put it in the lathe chuck and while turning, just hit the center area with my dremel with a carbide burr in it. I used one of those Burrs to de-thread the reducing coupling nozzle, and both air inlets on the T, as well as the inside of the interior of the nipple to reduce the "step" so it reduces turbulence. I didn't get a chance to fire it up this evening because the ball valve that i thought was 3/8 was actually 1/2" and i figured it would be good to be able to turn it off immediately instead of waiting for the gas in a 12 foot hose to clear out. Just for kicks i hooked it up to a the sink faucet using an barb adapter and some tubing and the little jet of water is almost perfectly dead center. So in the morning ill see if it works with propane. I give it about a 40% chance of success since I have this habit of straying from the tried and true instructions due to this condition i contracted as a kid where nothing is allowed to be left stock. lol. Link to comment Share on other sites More sharing options...
Frosty Posted March 5, 2022 Share Posted March 5, 2022 I drill and tap the T on the same nipple that's going to make fire for me, that way everything stays centered. You want to use a "CENTER DRILL" the type counter sink you describe isn't intended to start holes. A center drill is also a counter sink and they do NOT wobble with the littlest center punch or a flat spot. I removed the threads from a T and a thread protector to enhance performance and discovered it didn't help at all. Maybe made it a worse performer but I didn't experiment beyond the one. Without threads the intake ports are much larger, that alone should've improved induction significantly but it didn't so I didn't do it again. My thought is that the threads actually reduce friction through the Bernoulli effect. Each thread forms a ridge and air flowing across it behaves as if it's a curved surface creating a boundary layer of near vacuum and the flow accelerates. Just like an airplane wing. . . Maybe. Enjoy redesigning as you go, most of us do. I know I've never looked a device or thing without redesigning things. I've learned not to do it in reality until I've messed with the "original" unless I see something obviously wrong. Frosty The Lucky. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 5, 2022 Share Posted March 5, 2022 Removing the threads increases the diameter of the two entrances; this should act to strengthen burner performance in a similar manner that choosing a T fitting with a smaller center hole does. But you state that it does not increase performance. If I trust what you state--and I do--then it is only reasonable that some such principle as you suppose must be in operation, to account for this. I'm just so glad that it's your rabbit hole and not one of mine in view there Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now