Burners 101

[Mikey98118]

On 3/28/2022 at 12:04 PM, Trevor84 said:

Excellent combustion, woohoo! I think I know what you're saying about a neutral burner wanting fine adjustments, a lean/oxidizing is a lot isier to detune to get neutral. The burners I've built that start out neutral always seemed to ride a fine line with the A/F

Yes; although some burners have more adjustment in the neutral range than others, even of the same design, the range is short, and usually stablest on the edge of oxidizing.

[Frosty]

Thomas: I've used old locker shelves that would screw together in a 90* angle. A version of Trevor's solution worked pretty well but I used a Christmas popcorn sized tin with the top open. 

I haven't been particularly happy with any I've tried but the above two "work."

How sensitive the T burners are to breezes is one of the things that amazed me so much about NARB, it doesn't flicker unless it's a genuine wind around 15mph. and then I can just angle the forge differently and it's okay.

Frosty The Lucky.

[Mikey98118]

Wind baffles are kind of like a bandage. If the problem is wind gusts, rather than breezes, only a positive pressure system is really going to get the job done. How many people want to work out in that kind of weather?

[ThomasPowers]

As windy conditions are typical in our part of New Mexico I'd  say most folks want to work out in that kind of weather.  In general the hot dry winds are more of a problem than the cold dry winds.

Sort of like how many people go out in rainy weather where you are at?

[Frosty]

If I want to do demos I have to block the burner intakes against breezes and worse. Until NARBs changed that for me.

Frosty The Lucky. 

[Mikey98118]

Well, being, a ship fitter, I spent a lot of years working out in the rain. However, since retirement I've NEVER worked out in the rain. I just wait for dry days

I figure that most of the guys on here are playing at a hobby, or trying to start the business of their dreams. You know--happy dreams; not nightmares.

Since there are always people who end up with the short end of the deal, there is going to be some use for ways of doing things the hard way, which brings us right back to forced air burner systems.

[Mikey98118]

Not that forced-air or fan-blown burners constitutes doing thing the hard way, but working outside under adverse conditions definitely does.

[Mikey98118]

Mounting a homemade side handle

Rotary tools and die grinders can be braced for straight travel (similar to cutting with angle grinders), rather than the typical swinging arm motion (tendency to curve, binding the disc, resulting in kickback), by mounting a side handle near to the tool’s spindle; this provides greatly improved control for surface cutting. Twenty years ago, 2” angle grinders like Proxxon’s Long Neck Angle Grinder, or the Merlin 2 from King Arthur Tools, were the only power tools that could easily make straight line cuts in small burner parts; they were designed for inline motion, and had steel safety guards. A rotary tool with a safety handle mounted can now do a better job, more safely, for a small fraction of their prices.

    What has changed, to make this possible? See-through safety guards couldn’t be purchased back then; they can be now. When cutting along an ink or scribe line, it is tempting to bend over the tool, to provide an adequate view; a very bad habit, unless the tool has a safety guard; it’s also frustrating to try to see the cut with steel guards. But you can place your disc just short of the cut line, and work in safety and comfort, when you see the line by looking through the guard.

    Some rotary tools already have a removable plastic handle, but they are set up at about seventy-degrees for increased comfort during buffing, grinding, and drilling; not at right angles, for better control during a surface cut.

    Most hand-held rotary tools have a threaded plastic collar that is protected by a plastic cap (AKA front cap; nose cap; housing cap) around the base of the spindle. These rotary tools have a neck diameter of 0.750” (3/4”) at the short lip betwen its threads and the plastic housing’s shoulder; this is the area that a sheet metal side handle sets in, trapped between the shield and and tool housing’s plastic shoulders. Dremel popularized those same threads to securely mount attachments, such as their flexible drive shaft, and other manufacturers copied Dremel. The threads on safety shields are are 17mm (0.670”) with a maximum diameter of 0.633”. It is easy to buy a 3/4” flat washer. A flattened tube end can be welded, or brazed to the washer, creating a similar kind of handle as the ones that provide ergonomic stability to angle grinders.

    Or, you can layout a washer and handle shape on a piece of sheet metal, and employ your rotary tool to fashion a side handle; this allows the use of aluminum, stainless-steel, or brass sheet metal, which will never rust or need painting. The plastic shield, securely traps it in place, when needed; or it can be quickly removed, when it would be in the way.

    Why bother? Because wrist movement can’t be braced anywhere near as effectively as inline movement (which only becomes practical with the aid of a side handle). Where the handle is positioned has nothing to do with whether you are right or left-handed, and everything to do with moving the cut-off disc opposite to the direction that the disc is trying to force the tool to travel along part surfaces. You need the handle to help tow—not push—a cutoff disc forward along the cut line, once it starts to break through the kerf.

    A side handle helps the disc to grind a straight line through the material from the formation of a groove through to the end of the cut, greatly reducing kickbacks; especially when dealing with the last fraction of an inch at the end of a line.

    Best procedure is to run the disc back and forth on the part’s surface, while a groove forms and gradually deepens, cutting through the part only at the very end of the process; this means that increased control of your arm movement, becomes more essential—not less.

   

Caution: Whether or not a handle improves the safety of your rotary tool, depends on power switch location and type; that can’t be listed for every model, since there is such a variety of on/off switch designs and locations. Mounting a handle will increase stability as you cut. But, stopping the tool before lifting a cutting disc from the kerf is considered “best practice.” It is good if the switch type and location allows this, with side handle added. if switch type or location makes that impractical already, then no safety is lost by adding a handle. If the switch can be safely used to stop the tool during surface cutting at present, but adding the handle would change that situation, leave it off; this is quite unlikely, but possible.

Warning:  

The main point of a side handle is to help in surface cutting, but cutting with an electric die grinder must be done far more carefully than with a rotary tool:

        (1)  Any safety at all requires a power switch with the right location and type. The switch must be easy to shut off, without           jiggling the tool, in the slightest degree. Movement while turning the tool on doesn’t matter, since that is always to be done   before touching the work.

(2)   A high-power die grinder must be run at half speed during surface cuts. A medium-power die grinder can be run at full speed.

(3)  The cutoff disc should not be larger than 1-1/2” diameter; smaller is safer. Take your time working up to the fastest speed, and largest disk, that you personally can safely use.

(4)  The disc must be breakable; a resin-based friction disc; and thinner is safer than thicker; it isn’t less likely to break of course, but will be less likely to fling the grinder about while doing so. Do not employ a grit coated steel disc, or a toothed circular saw blade, even in a medium-power electric die grinder. When kickback occurs, it is necessary that the accessory be destroyed, rather than the grinder being flung about near your body. Don’t kid yourself that you’ll always avoid kickback; that’s not in the cards.

(5)  The grinder should not be used for surface cutting in confined spaces, or with your body unable to be properly braced, with or without a handle installed. If you must cut in a confined space, use a 15/16” friction disc; better safe than sorry.

 

Safety, is seldom an absolute, except in the negative sense. “Just don’t do that” is clear and simple advice. To suggest that someone “do that safely,” is absurd. Whenever you attempt to do anything, some risk is involved. Using an electric die grinder, can never be perfectly safe; cutting with one involves substantial risk; especially if safety procedures are not observed.

    Why not use one of the new mini-saws, instead; isn’t that what they’re for? If you’re cutting on flat surfaces, yes. If you’re cutting off the ends of angles or pipes, the saw still maintains an advantage, so long as you pay close attention. When cutting air openings into pipe or tubing, no. If you’re cutting into curved surfaces on cylinder ends, to create equipment shells, no. And of course, they can’t be used to make internal cuts for air openings.

[Mikey98118]

 

 

Freeing up jammed rotary accessories

Collet nuts on rotary tools may need to be sharply rapped once or twice with the tool’s tiny wrench, to free up jammed accessories. Unscrew the nut a partial turn, so that the accessory can slide free; sometimes, they will revolve, but cannot be slid forward and removed. What has happened is that the collet, which the accessory’s shank slides into has jammed in place, locking the accessory’s shank together with the collet. Tap sharply, on the end of the nut with nothing larger than the tiny wrench that comes with your rotary tool; this will transmit just enough of a shock wave through the parts, to break the collet’s grip.

    Should a new tool come from the factory with the collet stuck in place, unscrew the nut a couple of turns, and poke the shank of an accessory against the top of the collet (at an angle), to break it loose.

    If you change accessories frequently, you may find relief from this irritation with a brass collet; brass collet kits, which include 1/8” collets, sell for around $5.00 on eBay and Amazon.com. Just as some collets release better than others, some collet nuts are better too. Most collet nuts fit other spindles, so switching a better collet nut from a less used rotary tool to your favorite, should be an obvious move.

    Some people simply replace the collet nut (and its sticking collet) with a Dremel keyless chuck. Make sure to buy this attachment from Dremel; a cheap look alike won’t work very long, if it even works at all. How clever is this move? Enough that some rotary tools are now being sold with this kind of chuck, instead of a collet and nut. Nothing succeeds like success.

    That said, even the Dremel chucks aren’t problem free. Keyless chucks cannot be tightened anywhere near as effectively as keyed chucks, or even collet chucks, and these tiny keyless chucks increase that problem; obviously, your whole hand can tighten a keyless chuck on a drill motor far better, than a finger and thumb can tighten one of these. Some people have ended up using pliers. A drop of oil or lithium grease in one of the jaw ways (the groove they ride in) will smooth performance.

[Trevor84]

Sorry Mikey, jumping in again quickly to let you guys know I just wrote up a post on a new micro burner. If you want more pics there's a bunch there but heres the gyst of it I guess. 

 

 

[Mikey98118]

Congratulations Trevor. That is an excellent flame; especially in such a small burner

You may want to go into some detail on its construction. Lots of people will probably want to build one.

What an excellent jewelers torch that would make.

[Trevor84]

 

Thanks I'm hoping this can be one of those easier options. It's not nearly as hard a Mikey burner especially with the square file or a 16" bastard file on edge because the dimensions work out simple..... 

This is definitely inspired by the Mikey and Oliver upwind burner and uses Frosty's 1/8"mnpt taped inner for the mig and outer to mount it. 

 

I'll be making a few more over the next couple weeks and updating. I will be making a couple with some kinda handle or bunson burner type stand. I don't have real oxy-pro torches and the plumbers torch sucks for heating anything other than solder so I'm hoping this to be a reasonable in between for bending and twisting but never thought of it for jewelry. 

 

 

[Mikey98118]

I have made 3/8" and 1/4" burners mounted on 16 oz. propane canisters, by starting out with cheap propane torch-heads.

[Mikey98118]

To avoid surface cutting problems

(1)  When starting a cut, be sure the accessory is already turning; do not start, or restart a cut, with the tool still.

(2)  Gently lower the disc unto the part surface, with the tool held firmly, and lightly run the disc back and forth on the part surface, next to the cut line, to establish a groove. Deepen the groove by continuing to run the disc lightly back and forth, until it starts to break through the material’s far side; at this point, the groove is called a kerf. Don’t press the disc against the part. Just let the disc do the work.

(3)  Always delay actually cutting into the kerf until you have no other choice.

(4)  Start and stop the cut short of the end of the marked line, and finish the cut later, with a small diameter disc, for greater control, as these two areas are likely spots to create kickback problems.

(5)  Allow the disc to come to a complete stop before removing it from a cut, to avoid jamming the disc, and creating kickback.

(6)  A common cause of kickback is a disc that is moving even a little out of parallel to the kerf (that slit in your part that is made by the disc); the problem is multiplied when the disc is deeply inserted into the kerf. It is safer to only try cutting through the material, after the disk begins breaking through the part’s far surface.

(7)  The only relief from torsion kickbacks is provided by Dremel’s EZ-lock mandrel and special cutoff discs; this nearly eliminates torsional forces, making an end-run around that problem. Save the last 1” of their diameters for surface cutting in problem areas, like inside corners.

(8)  Another cause of kickback is the disc bumping into the end of the lengthening kerf. Try to only move the disc counter to the direction that friction inclines it to “walk” along the part, once you start cutting into the kerf; this will help you to avoid bumping the disc against the end of the kerf; always ease into it, to prevent kickbacks. Aside from cutting through the kerf from the right direction, practical relief from bumping kickbacks is provided by smaller diameter cutoff discs. Dremel’s 420 discs are an economical source of suitable small discs.

(9)  When you can, try to cut beside of the cut line, and then grind back to it afterward; this allows you to concentrate on two separate tasks, instead of looking after too many aspects of the cut at one time. After you finish all cuts and remove unwanted material, then start grinding back to the scribe or ink lines with a small stone wheel, or diamond disc. Do not use cutoff discs for grinding; it dangerously weakens them.

On the other hand, small (22mm; 7/8”) diameter imported diamond coated discs (which are much slower cutting than resin bonded discs) excel at precise grinding. Once your coated disc loses the diamond grit from its narrow edge, keep it around for grinding excess material back to cut lines, or sharpening high-speed steel, tungsten carbide, and silicon carbide surfaces. Diamond coated cutoff discs are good for sharpening drill bits and saw teeth; they are perfect for reshaping and reducing silicon carbide grinding wheels and stones.

 

EZ lock mandrel and cutoff disks are one of safest ways for a beginner to surface cut with a rotary tool; they are more expensive than generic cutoff discs, which run in standard mandrels, but considerably easier for a newbie to deal with, for the work needed to build a couple of burners. By the time you use up the disks in one their mandrel and disk kits, you should be well enough acquainted with surface cutting to take advantage of the more economic offers for regular discs and mandrels. You will still find yourself reverting to the EZ lock system for tricky cutting jobs. The special discs that come with this system are 1-1/2” diameters. It is wise to save the last 1” of each disc, rather than wearing them down completely. The small used discs are very handy for making interior cuts in small parts.

    Begin by inserting the EZ lock mandrel all the way into the collet nut on the tool’s spindle, and then tighten the nut. To mount a disk, push the plastic part of the head down against its spring, dropping a disk past the mandrel’s bow tie shaped end piece, and then turn it ninety degrees, to lock it in place.

    You can buy the discs and mandrel in kit form online, and from most large hardware stores. The spring and locking mechanism are what makes this system unique. It eliminates the usual locking screw, so that grinding and sanding wheels can be used nearly parallel to part surfaces, without interference from a protruding screw head. The disc is positively locked, because there is no screw to loosen from vibration, allowing the disc to spin on the mandrel. But most important of all, the spring allows the disc to move out of alignment with the kerf, without creating kickbacks, by nearly eliminating torsional forces; you can order them online, and they are available from numerous hardware stores.

 

Separating discs are standard jeweler’s thin (0.025” thick) 15/16” diameter abrasive cutoff discs, which come as part of most accessory kits. They are too brittle to be practical for most steel cutting tasks, but they are a safer and surer way to cut through the last 1/8” next to a corner hole, than using a larger stronger disc; they are also better for end cuts at the forward and rear edges of air openings; especially when using an angle head attachment. Do not be discouraged when several of them shatter, one after another; they are helping with your learning curve; for the small loss of accessories of little value to anyone but a jeweler.

   Reduce speed a little bit, and be sure to ease into cuts. Don’t bump the disc against the metal, or twist it even slightly in the kerf, or it will disintegrate. Use one of the better mandrels—not a standard jeweler’s mandrel, because even minor overtightening from the tiny screw in a jeweler’s mandrel will shatter these discs. Better mandrels with larger screw heads will allow you to use two discs together; this also helps them to survive the work.

 

Dremel #420 Cut-off discs are 15/16 " diameter, by 0.040" (1mm) thickness, and are rated to 35,000 RPM; they are sold in twenty discs kits for $4.97 through Amazon.com; they are not fiberglass reinforced, but are much more durable for steel cutting than standard 0.025" (0.635mm) thick jewelers’ discs; they have added safety over fiberglass reinforced discs during kickback, and enhanced control when cutting next to inside corners, and through forward and rear cut lines in air openings. These discs are only meant for cutting metals; do not use their sides for grinding. The smaller the air opening the handier these discs become; they are as safe as you can get, and one kit should easily provide enough discs for even a novice to build two or three small burners.

    Don’t confuse these #420 discs with #409 (jewelers) discs, which are only 0.025" thick (0.635mm).

 

Disc mandrels: You don’t want to employ just any disc mandrel for steel cutting. The standard jeweler’s mandrel, which only has a 1/16” standard machine-screw head, was designed for making very short cuts in silver and gold ring bands; not for making extended cuts in steel. There are special mandrels with 1/16” crews that have oversize screw heads, threading into oversize mandrel faces, and similar mandrels for 1/8” and 1/4” arbor holes; these far outperform the minimal screw head variety; you can find them offered through eBay, Amazon.com, and through most jeweler’s supply houses,  Input “SEINC1/16” rotary tool mandrel” to find them quickly. Preamer 1/8” mandrels are excellent for spinning the 1-1/4” diameter fiberglass reinforced aluminum oxide cutoff discs, which are handy for cutting out rectangular air openings on larger tube burners.

 

Note: Poorly finished mandrels, provided along with some cutting discs in some ads, can cause cutoff discs and grinding wheels to wobble. This is a common problem that is seldom correctly diagnosed. Customers incorrectly blame the accessories. What is actually happening is that the mandrel’s face is usually out of true right angles to the shank’s axial center. Or, one (or both) of the flat washers provided with cheap mandrels aren’t perfectly flat. Circular motion on fine sandpaper can flatten washer surfaces, and the mandrel can be spun in your rotary tool, while its forward face is quickly trued up with a diamond coated cutoff disc, or flat file.

[Mikey98118]

Any questions about this stuff? I find it hard to believe that everyone simply accepts my viewpoint...

Whether you just need something illustrated, or want to dispute my ideas, others can only gain from a dialog.

And there's always a chance that someone can trip up the teacher; I always loved doing that when I was a student

[Frosty]

I'd like to Mike but other than a rare typo we're just talking basic shop practices here. I haven't used many if not most of these specific tools so I don't have an opinion of them. And as to using them, our differences would be micro-nitpicking. 

However it does sound like you hold your tongue on the wrong side!

Frosty The Lucky.

[Mikey98118]

Well that at least is an argument of some kind

[Frosty]

Sorry, I couldn't think of anything to discuss so tried for humor. I probably shouldn't have it can be disruptive. 

Frosty The Lucky.

[Mikey98118]

Whats sad is that I was too

[Mikey98118]

3D printer extruder nozzles used as gas orifices are made with nozzles mounted on small brass or stainless-steel tubes; not because they make the very best gas orifices, but because they are the cheapest and easiest to use in SMALL burner sizes.

    .6mm orifice diameters should prove adequate on ½” burners if fine-tuned by shortening with 400 grit sand paper. 3/8” size burners should do even better with the same technique on .5mm nozzles, and 1/4” burner sizes better still with .4mm nozzles.

    Printer nozzles can be purchased in packs with multiple orifice diameters. Such as the Luter 24 pack, with two .1mm (.004”) nozzles; two .2mm ((.008”)) nozzles; two .3mm ((.012”)) nozzles; twelve .4mm ((.016”)) nozzles; two .5mm ((.020”)) nozzles; two .6mm ((.024”)) nozzles; two .8mm ((.031”)) nozzles; and two .10mm ((.039”)) nozzles; $9 through Amazon.com:

    Being a control freak, I prefer to use capillary tubes mounted in MIG contact tips, but common sense demands that the perfect give way to the practical, and that means that my druthers are out of step in the march of progress

[Frosty]

Ain't we a pair!

I've thrown a couple dud jokes today too, I'm on a roll.

Frosty The Lucky.

[ThomasPowers]

Frosty, you forgot to pull the pin first!

[Frosty]

That too. <sigh>

Frosty The Lucky.

[ThomasPowers]

There is a reason why "SPOON" is a decent battle cry...

[Frosty]

Better than OOPS!

Frosty The Lucky.