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View Full Version : modifying an OxyAct torch. advice?



Tony
06-09-2005, 12:20 PM
I have a typical oxy/act cutting torch.
the cutting head is connected to the torch body via 3 small rigid tubes. the look to be brazed in place.

i'd like to modify this torch by adding about 3' of flexible gas tubing between the cutting head and the body.

this would mean cutting the 3 rigid tubes, brazing 6 threaded connectors (3 on each side of the cut) and screwing on 3 (three foot long) flexible tubes.

i'd like to mount this torch head on a machine and keep the valves away from the cutting.

i would use tubing suitable for oxy/act gases. question: since the mixing is done at the cutting head, do i run any major risks (other than leaks from bad connection) by making the mod?

this is an experiment and an oxy/act machine torch is a bit spendy.

thanks,
-tony

Arbo
06-09-2005, 12:51 PM
Should work...Just be sure to keep the hoses supported awway from the flame. If you burn through one, there will be no mistake that it happened!

Tinkerer
06-09-2005, 05:24 PM
I don't know... I'd be worried about burn thru of the feed hoses next to the head. A piece of slag blow back melts and burns rubber. BAD NEWS http://bbs.homeshopmachinist.net//eek.gif I look in to some thing along this line http://www.harriscal.com/2003/2003986machinetorch.asp.
Or get the tip swivel. But I'd stay away from rubber tubing near end of head lots of heat in the cutting zone. But if your determined to do it. I'd test the tubing by clamping some near the head and doing some cutting with to to see how it holds up. But I'd still look for another solution.

CCWKen
06-09-2005, 06:45 PM
As Tinkerer says, I'd be leary of the cutting zone too. You might use the original solid tubing up by the cutting head and then add your flex tube behind that. That and/or some type of shielding to protect the flex tubing.

Any chance of mounting it in a vertical position?

Herm Williams
06-09-2005, 06:58 PM
Another thought would be to get a straight head for your hand torch.
my two cents worth

wierdscience
06-10-2005, 12:10 AM
Stainless braided hoses are the ticket,but a 90* head will not give you the same performance as a straight machine torch.

Here is an idea,why not make your own machine torch? Gun drill a piece of bronze,thread and cut seats for the tip to fit and your valves can be bought as replacements to fit a standard torch.

Since your planning on using it on your CNC rig(mind-reader aren't I? http://bbs.homeshopmachinist.net//biggrin.gif) all you need are mixer valves for the preheat and a solinoid valve for the cutting valve.

Just an idea.

Tony
06-10-2005, 12:57 AM
first inclination was to make one.
but that seems more dangerous than modding an old one.

weird is right, its for the cnc table. my oxy torch is too end-heavy. the weight of the handle/body+hoses would probably cause my setup to 'flex' .. consider the difference in weight between a plastic plasma torch and an all metal oxy torch.

separating the head would be the best bet (i dont even know what a machine torch might weigh) ... but i dont want to do anything stupid.

the key to that tho, is trying to figure out what's stupid, and what isn't. http://bbs.homeshopmachinist.net//smile.gif

-tony

Ted Coffey
06-10-2005, 10:37 AM
Whatever you do make sure not to use tubing or hose on the oxygen side that has any oil residue inside or out. You could have an explosion. We used to use tri-nitro-touluene to clean fittings, tubing, etc. that may come in contact with oxygen. Ask you dealer what cleaner is currently available.

Ian B
06-10-2005, 10:46 AM
Ted,

If you're using tri nitro toluene as a cleaning agent, I'd have thought that explosions from an oil / oxygen mix would be the last of your worries!

You don't mean trichloroethane, do you?

Ian

chipeater
06-10-2005, 12:08 PM
<font face="Verdana, Arial" size="2">Originally posted by Ted Coffey:
Whatever you do make sure not to use tubing or hose on the oxygen side that has any oil residue inside or out. You could have an explosion. We used to use tri-nitro-touluene to clean fittings, tubing, etc. that may come in contact with oxygen. Ask you dealer what cleaner is currently available.</font>

tri-nitro-touluene = TNT http://bbs.homeshopmachinist.net//eek.gif

wierdscience
06-10-2005, 07:54 PM
Tony,I have one track torch with a torch that is only 2-1/2" long x 1-1/2" diameter.

You have to drill three holes,one in the center for the cutting stream and two around the outside for the ox/fuel preheaters,mixing occurs at the control station with the traditonal valves.

As for cleaning and removing oil from the parts and pieces,metal parts you boil on the stove in water.Rubber parts and gaskets warm water and plain ole Ivory soap then dry with compressed air.
The whole oil issue is due to the result of an easily combustable hydrocarbon in a pure oxygen atmosphere.But it's not much of a worry since I'm sure you would buy new hoses and all your seals will be teflon/viton anyway.
If you like I can post some detailed pics of the little torch head I have,it's really simple once you look at it.
Even though it's not real big,it will handle 3" thick steel and make it look like a bandsaw cut,I also have a complete feedrate and gas pressure chart for the various thickness materials,let me know if you want me to post it.

alcova
06-10-2005, 08:07 PM
I's like to see that chart even if he doesn't.

Walt

Tony
06-11-2005, 01:58 AM
wierd,
heck ya, i'd love to see it.

you still have 3 tubes running to the head, right? my concern with building a torch head was the mixing point.

didn't want to mix it "off-board" and have to send oxy/act mixture down a 4' tube. that'd be a nice thin long bomb.

-tony

Norman Atkinson
06-11-2005, 02:21 AM
I got it!!!!

TNT

TNT

TNT

Plop?


Norman

wierdscience
06-16-2005, 12:36 AM
Tony,will do,busy until Saturday a.m.,so probably the weekend before I can get it together.

Oh BTW,in case you are wondering all mixing of gases occurs in the torch head at the tip,the remote valves only set the gas ratio's.

[This message has been edited by wierdscience (edited 06-16-2005).]

Tony
06-16-2005, 01:24 AM
weird, thanks.
no rush. but i'd be really interested to see your setup.

-tony