Circle cutting with oxy acetylene

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Hi I've guys I've been oxy cutting for a year now and have never had to cut a circle. Tonight I had to for my BBQ project. When I did it the molten slag would come behind the hole I cut the way round not causing it to cut all the way through. Just wondering if anyone has any tips to help me. Thanks in advance1 270 wia weldmatic mig welder1 Abel arc welder1 188 bossweld arc and tig welder1 cigweld comet o/a set
Reply:How big is the circle and how thick is the material ?Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Look here first.http://www.eurekaoxygencompany.com/victor.htmBubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Burning is burning, doesn't matter what direction you're going, flat, over head, it doesn't matter. I think your travel speed was to fast, or your tip to small. Here are some tools that really help to make nice circle cuts. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:In the 70's my former employer purchased a torch with a motorized head. You set the size, then fired it up, and let it do it's thing. You didn't have to follow the torch and drag the hoses in a circle. You held the torch steady and let it cut.
Reply:my version
Reply:When I cut a circle, if it's 2" or less, I draw it out, then start in the center and circle the torch around, pretty much burning away everything on the inside until I get to the actual lines. If it's a little bigger, I still start in the center, then move over to just inside of my line and trace it around. Die grinder to the inside edges and a file to finish. I've been meaning to put together a guide of some sort but I hardly ever cut circles anyway.
Reply:Here is a pretty cheap tool made for this, I dont have one I just saw this and bookmarked for later.http://jcaent.com/Page_2.html
Reply:. I made a Lazy Susa...Ok, a Lazy Doug that I rigged up. The torch sits in a saddle(3/4 angle welded on a stick of 3/16 x 1). That gets held to the table w/a welding magnet. Fire it up/adjust. Hold it in the saddle, pull the trigger and turn the work piece on the Lazy Sus.....Doug.Little crap I just drill some holes and then freehand or use pieces of cut off tube-pipe or old drops.Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Farmboy that rig looks good. QuickNeasy !Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:I'm with akabadnews about having to cut out all of the circle if it's a small hole I'm trying to get.   On the other hand, if it is a small disc I am trying to cut out, I generally have to start further out from the actual desired diameter laid out for the disc, and make a large kerf, or even cut it twice sometimes.  It seems that the trouble comes from the fact that all the cutting is being done in a small area, so the heat builds up quickly and that tends to keep the kerf zone too hot, and so the slag remains molten and fuses back into the kerf slit.But if you are not even cutting completely through the thickness of the material, then either your torch tip is too small or you are moving too fast (insufficient preheat time).   If it comes down to insufficient preheat time, you can use the old timers trick of running a few circular passes around your marked circle to heat up the material before you actually start cutting a kerf.
Reply:Invest in a plasma cutter too.
Reply:The circle has a 10cm diameter an it is 1/8 inch material
Reply:My tip is a number 8 the second smallest tip you can get in australia. I have the next size up as well
Reply:You could have been going too slow too.Nothing Ever Got Done By Quitting, Never Give Up.
Reply:I like to drill a small hole 1-8 or 3-16 right on the cut line then go from that point. It really helps on heavier plate,{over 1 inch thick } to get the cut going without blowback.Miller xmt304,  Miller S22 p12, Miier Maxstar SD, Miller 252 w 30A, Miller super32p12, Lincoln Ranger 9, Thermal Arc 181I with spoolgun, Hypertherm 10000 ,Smith torches. Esab 161lts miniarc.
Reply:Originally Posted by GrtpainHere is a pretty cheap tool made for this, I dont have one I just saw this and bookmarked for later.http://jcaent.com/Page_2.html
Reply:This is how I do itDisclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:Thanks tozzi for your input. I've learn so much from this subject and your pics. Thanks again. Sent from my iPhone using Tapatalk
Reply:Here is a link to a cool motorized oxy-fuel torch with circle cutting capability from Koike Aronson. They used to make one similar to this for a plasma torch...although they discontinued that one.Link to video:  http://www.koike.com/portable-soluti...auto-plus.aspxJim Colt
Reply:That's pretty cool but I didn't see a price Jim. Have any idea how much it is?