im adding cutting torch for my cnc machine as i need to cut thicker than 1 inch now for a client

I already have 3 hose machine torch and all hoses.. but the question i have is do i need to buy extra oxygen regulator for cut hose? or just use a tee after the single oxygen regulator?

if i need to have extra regulator do i change the psi for the cut and preheat?

Thanks
Dan

You should use two regs preheat pressure will be lower than cutting pressure

Dan, You may need a solenoid to shut off the cut oxy during pre-heat. Make sure it is oxy safe! Your local weld shop should have cut charts for free that show your pressures. Cut pressure can be as high as 85psi (I think) and the pre-heat is low, usually around 20psi. I can scrounge up the part # for an ASCO redhat that will do the trick for you if you need. There is a company called CalTrol that has a few in stock for under 80 bucks. They are 110vac and plenty of flow (500cfh or there abouts). A three valve set-up controlled by your software would be best if you have the time to build it or will cut with it often.

Cheers!
WSS

okay perfect that was the answer i was looking for (2 oxygen regulator is required)

i already have solenoid valves and they are Rated for use on LP gas, natural gas, fuel, air and other fluids

i will be running flashback arrester on the torch

all charts i had was one pressure for oxygen no pressure for preheat and cut oxygen..

have to find a better chart i guess..

Thanks

im wondering what people do to incorporate a auto lighting system (instead of using a striker to start the flame that way i can have my setup with 3 solenoid and automatically turn off when its done and turn on when im starting a new cut (to reduce the waste of gas)

to incorporate a auto lighting system (instead of using a striker to start the flame

A 12 volt automotive ignition coil will work.

The system pictured has the coil & 12 V supply in the upper control panel with a high tension (spark plug) wire running to an insulated brass rod electrode gap at the torch tip.

A momentary signal to a relay (or push button) to power the 12 V supply will then provide the necessary spark for torch ignition.

Dan,
The valves you are using for oxygen should be specifically for oxygen. ASCO uses a neoprene seal instead of a buna o-ring in there valves. The valve should have a tag or stamp that shows it has been "cleaned for oxygen service". If you use the oil/gas valves you should put flashback protection both before and after the valve. It is the cut line that will most likely be the problem due to the higher pressure. I will post some pics of a gas/oxy console in use over here later today. Also, a high flow flashback arrestor will help the cut line when you want to cut or bevel 2" plus steel. It is hard to diagnose a starved line when everything looks right, the pressure, tip and so on.

WSS

Here are some photos showing a three hose set-up. I hope it can of some use.

Weldtutor, thanks for the info regarding the 12vdc coil! I will integrate that into our CNC machine.

Cheers
WSS

Dan & WSS..
The 12V coil works great for torch ignition.

From experience I can tell you it is not wise to try to adjust the electrode spark gap when the coil is energized!:nono:

Millman52's thread also has some pictures (#5 & #8) HERE (http://www.cnczone.com/forums/showthread.php?t=31133&page=7)in post 74 showing his 3 hose torch & solenoid arrangement.

wss: wow your setup looks really clean i dont think my setup will be that clean..

i found a tread about cleaning inside the solenoid and some black light to check and make sure there is no oil to double check and make sure its safe.. i ordered them long time ago and they have been sitting for long time too..

hope it works..


Weldtutor ill keep that note about dont change the gap of the spark plug while its plugged in coil :)

what did u use for relay to have it go off every 10 sec or how often do you set it for?

Cheers
Dan

also i found a psi chart for preheat/cutting oxygen pressure thought it would be useful for some other people

http://www.fivestargas.com/pages/tools_cutting_tip.asp

what did u use for relay to have it go off every 10 sec or how often do you set it for?


The system I had was a push button start to activate the coil.

A Google search for "momentary relay output" will give lots of choices for relays.

okay i will look it up but what time intervial do you suggest?

10 sec off .5 sec on or that would be too often better to have 30 sec and .5 sec?

Weldtutor, Do you think this would work:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=260409358984

Here are the general specs:
110VAC / 220VAC to 12VDC Power Supply for EM Lock
-Input voltage: AC110-220V
-Output Voltage: DC12V,
-Output Current: 5A
-Output mode: NO/NC(time lag 0-15sec), 2xPush and 12VDC I/P to open
-Operative device: E/M Lock, Access Controller, Exit Push Button
-Dimension: 223x180x86mm
-Built-in Remote control receiver: To open door /w a remote control
-Heavy duty metal case with space for backup battery

what time interval do you suggest?


The torch will take about 2 to 5 seconds to ignite after the preheat gas is flowing.

A relay with an output timed like this (then off) & wired to the preheat solenoid circuit would do what is needed.

WSS
I think from reading the specs you posted & the Ebay listing that a relay is still needed to activate the device????
The 0 to 15 second might be response time rather than output time.

Perhaps another member is familar with this item.

Weldtutor,
Well spotted. The 0-10secs is the time you have to get through before it reverses. It would probably be easier to use an idec relay or some other delay on make timer and hook it it a 110 to 12v transformer.

Getting bit by a 12vdc coil is a blood sport, fun to watch but not participate!

DanOSB, I ran into a couple things today that reminded me of this thread. One is on the high pressure side or cut line, keep it as short as possible. This will keep the post flow to a minimum. The torch I ran today had about three feet of hose after the solenoid and would continue to cut for longer than I liked after switching off. You may have to write some code to do a holding pattern after your cut. The link that Weldtutor referred to showing millman's set-up is perfect, the solenoids are nice and close to the torch. another reminder I had today was when I ran out of high speed tips and had to use gpn's instead of mthn's. The preheat was at least double the time with a non-machine tip. I am not sure what torch you are using but I know Harris and Victor make "machine" tips.

Hope your project is going well.

Cheers

A low tech way around some sort of electronic timer is a small 12V motor (RC car motor) with a cam on the shaft & a set of ignition points from just about anything. Momentary switch to activate ignition motor. Toggle switch to turn power on & off the coil.

You'd get hundreds of sparks per second that way.

Weldtutor,
Well spotted. The 0-10secs is the time you have to get through before it reverses. It would probably be easier to use an idec relay or some other delay on make timer and hook it it a 110 to 12v transformer.

Getting bit by a 12vdc coil is a blood sport, fun to watch but not participate!

DanOSB, I ran into a couple things today that reminded me of this thread. One is on the high pressure side or cut line, keep it as short as possible. This will keep the post flow to a minimum. The torch I ran today had about three feet of hose after the solenoid and would continue to cut for longer than I liked after switching off. You may have to write some code to do a holding pattern after your cut. The link that Weldtutor referred to showing millman's set-up is perfect, the solenoids are nice and close to the torch. another reminder I had today was when I ran out of high speed tips and had to use gpn's instead of mthn's. The preheat was at least double the time with a non-machine tip. I am not sure what torch you are using but I know Harris and Victor make "machine" tips.

Hope your project is going well.

Cheers

The short lengths of line from my solenoids to the torch are also 3/16 line. I get almost instant stop of post flow on the cut line & the preheat goes off instantly when shut down.

I contract for a company that is running a ESAB cantilever machine. I don't know how far down line the solenoids are on that thing but the flame will burn for at least 5-10 seconds befor it finally snuffs out. The cut solenoid is the same way. They have to hold at the end of a cut for 5 sec. or so to keep from gouging as the torch lifts & rapids (crawls actually).

I use Oxweld torches & they have Hi Speed (HS) tips. They do preheat & pierce much better than standard tips. It seems I can never get them to cut as dross free as standard tips though. I don't know what I am doing wrong there.

millman52,
Do you use acetylene or propane? Also do you use liquid oxy or the HP cylinders? I use propane (and HS tips) and have pretty good luck on the dross, I can usually brush it with a wire brush or run a chisel or screwdriver around it to push off the bigger drips or pierce floods. The reason I asked about the liquid oxy is the volume you cut. We will probably cut with the oxy fuel set-up at least 80% of the time. But still only about 6 to 8 hours a week. When it picks up (maybe 20 or 30 hours a week), I think liquid might be more economical. What are your thoughts? Over here we are paying about 13usd per T oxy plus demmurage, I have not looked into liquid cost yet. I know it saves us shed loads on argon.

Cheers!
WSS

millman52,
Do you use acetylene or propane? Also do you use liquid oxy or the HP cylinders? I use propane (and HS tips) and have pretty good luck on the dross, I can usually brush it with a wire brush or run a chisel or screwdriver around it to push off the bigger drips or pierce floods. The reason I asked about the liquid oxy is the volume you cut. We will probably cut with the oxy fuel set-up at least 80% of the time. But still only about 6 to 8 hours a week. When it picks up (maybe 20 or 30 hours a week), I think liquid might be more economical. What are your thoughts? Over here we are paying about 13usd per T oxy plus demmurage, I have not looked into liquid cost yet. I know it saves us shed loads on argon.

Cheers!
WSS

I use acet. preheat time is quicker. I use High Pressure Ox. The gas company I'm with will let me keep as many tanks as I want without demurrage for the 1st 30 days. As long as I have at least 1 leased tank of equal size & gas. I looked into liquid quite a while back. I forget the details but there was something about the tank rent + actual gas usage that the billing could vary. For me it didn't seem to make any savings. Especially since I needed HP tanks for a couple hand cutting rigs anyway.

Cutting 1" & up is what gobbles the ox because cut speeds are so slow. Of course tips are larger too. I usually get by on 10-11 tanks per week max. some weeks 7-8.

millman52,
At 10 bottles a week that is 3300cf of oxy. Assuming they are 330s. A 260 liter liquid is about 6200cf. The rent on a dewr is about $1.50 per day, so the gas would have to be really cheap. With our argon we use a 260 every three weeks (give or take). The problem is the pressure build up over the weekend. Two years ago we never shut down, but know two days of no off gassing causes it to vent a bunch. That is annoying. I run the numbers every year to make sure it is cost effective. It saves us about 45% compared to HP cylinders. We could save a few dollars more by installing microbulk, but that ties you to one vendor for a few years. I like to keep them honest.

I will look into liquid cost next week and post what I find. We don't use enough bottles right now to justify it, maybe two a week.......But who knows maybe the economy will explode next week and we will all need more than can be supplied!

On your 3/16" hose, is it big enough to cut 3" plate? I can see where a smaller hose would drop pressure quicker. We have always used 1/4" around here because that is what my dad used and my grandfather. I have managed to break free a little bit, they both love chevys and lincolns. I prefer Fords and Millers. So I suppose I could use 3/16" if it works.

WSS

millman52,
forgot to mention the acetylene/propane use, If you get a chance to fiddle with propane you will probably notice it is a bit cleaner were the dross builds up and falls off when brushed, it seems more like a plasma dross. The preheat advantage may outweigh the dross clean up though.

We use the R grade hose due to the propane and it feels spongy (for lack of a better word). When you open the solenoid, the hose jumps and swells way more than the T grade. Has anyone noticed this? I was thinking of putting heat shrink tube around it to control the jumping, but I believe LP grade hose has to be able to vent or bleed off.\

Well off i go to swap air compressors. The one I had intended for the plasma is running to much (12cfm home depot job) so I will switch it with my 19cfm Ingersoll Rand. I am hoping that is enough air!

WSS

On your 3/16" hose, is it big enough to cut 3" plate? I can see where a smaller hose would drop pressure quicker. We have always used 1/4" around here because that is what my dad used and my grandfather. I have managed to break free a little bit, they both love chevys and lincolns. I prefer Fords and Millers. So I suppose I could use 3/16" if it works.

WSS

I have only cut up to 2" with the 3/16 hose. I have 1/4" hose from the tanks to the solenoids.

I'm about to find out though I need to burn a chunk of 3 3/4". Although I have no information to support my theory. I'd think 3/16 hose would be good to around 4". I know a company I contract for cuts 8" with 1/4" hose.


LOL don't know what to say about you prefering a Ford over a Chevy!!! At least your dad & grandad tried:devious:

I used to believe Hobart Brothers (before the buy out by ITW & Thermadyne)welding equipment was tops. When it comes to todays welding equipment I'd be proud to own Lincoln, Miller or ESAB.

I'm still running older Linde welding machines 250A & above. The 3 Linde machines I own have been virtually trouble free for years. I can still get most parts from ESAB for them. And for what I do I haven't used anything new I liked any better.

millman52,
The old Lindes were real workhorses! I had two L-tec650CV machines from 1988 that worked until 2005 and 2006. Funny that they both failed so close together. In 06 the electric company replaced the transformers on the poles outside our shop (after the L-tecs fried), I am thinking that caused it as they both fried the center transformer. They had a pure, clean arc that is hard to beat.

My sales rep from the gas company we work with got back with me today and he sharpened his pencil. The HP oxy is $.04 per CF (no dem.) and the liquid oxy is $.0125 per CF + $1 per day tank rent. Basically a 300cf is $12 and a 180ltr (4500cf) liquid is $56. There are other factors to consider: much fewer reg changes, ! delivery charge and fewer bottles to shuffle. However the liquid is heavy! And has a tendency to vent. I'll post an update if I give it a try.

I have managed to work it out so that I have a complete weekend to work on our table! Steel is in and cut, drawings are done. Now to fit and weld.

Everyone have a great weekend!

millman52,
The old Lindes were real workhorses! I had two L-tec650CV machines from 1988 that worked until 2005 and 2006. Funny that they both failed so close together. In 06 the electric company replaced the transformers on the poles outside our shop (after the L-tecs fried), I am thinking that caused it as they both fried the center transformer. They had a pure, clean arc that is hard to beat.

My sales rep from the gas company we work with got back with me today and he sharpened his pencil. The HP oxy is $.04 per CF (no dem.) and the liquid oxy is $.0125 per CF + $1 per day tank rent. Basically a 300cf is $12 and a 180ltr (4500cf) liquid is $56. There are other factors to consider: much fewer reg changes, ! delivery charge and fewer bottles to shuffle. However the liquid is heavy! And has a tendency to vent. I'll post an update if I give it a try.

I have managed to work it out so that I have a complete weekend to work on our table! Steel is in and cut, drawings are done. Now to fit and weld.

Everyone have a great weekend!

I've never tried the liquid myself. I'm sure it's a good deal if you cut heavy material most every day & run your machine at least 5 days per week.

One of my customers that does run a machine torch sometimes 2. 8 per day & 5 days/week tried it. They switched back to compressed cylinders. I don't know what the specifics were but it had mainly to do with the daily rent including weekends holidays etc. + the fact it vented on the off shifts, weekends & holidays. I'm sure they didn't change back on a whim either. I'm sure they ran an actual cost analysis over a period of 3 months or so. They really run a streamlined 1 shift per day manufacturing facility. They really don't use much of anything less than 3/8" thick. & literally semi loads of 8' X 20' sheets of 1/2, 5/8, 3/4,1, 1 1/2" plate.

The only welding machine I have used that I like better than the Lindes is the old Hobarts. The 15 or 20 HP electric motor driven DC welders. I still have a 300A CV (MIG) machine in working order. I just don't like the wire feeder as well as the Linde MIG 35s. That old Hobart will not self thread wire at all. You have to remove the upper drive rollers & thread it then re-install the rollers. Not a big deal but just something else to aggravate you when you run out of wire 15 min from being finished with a job.

Could I trouble you for the ASCO part number. My local ASCO supplier just handed me their big books of ASCO when I asked then for valves. After some pressure they contracted the main supplier who then asked for operating pressures etc. It's a bit frustrating as everytime I visit them they have a new question.

Thought I could reach the destination a lot quicker if I new what the destination was. My current table is an all steel construction and I'd like to use it to cut the parts for my next table which will be dedicated to cutting steel plate. Then I'll dedicate the current one for the wood shop.

Thanks in advance for the help

Here is the part #,
8262G202N
It is 110vac, you will need the proper voltage solenoid for your country, but this will get you real close.

Good luck,
WSS

Thanks a million. It appears they can do 24V DC. I'm keen on using two 12V Batteries like the ones in UPS and Home Security systems. My efforts for now have secured me a conventional cutting torch and thats no fun to use when you want to cut a whole plate.

I'm using the V23 BobCad software and and very impressed as it allows you to tailor your machine to your needs quite well. I've had a few heart ache moments that were more related to my ignorance than the software. But it was during the correction of a heartache moment that I found the Mill Setup program and then discovered what looked like an unending source of possibilities. One being to switch gas on/off etc. The next thing I knew, I was converting my Router to a Gas Cutter. It's been fun so far.

Thanks again