new TIG setup with Miller HF Box questions

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hey guys, hobbyist welder here with minor experience in arc and MIG welding. been meaning to learn to TIG, so i picked up this setup on craigslist recently. i've got a Miller CST 280 tied into a Miller HF-251-1 High Frequency Box. my end goal is to be able to sanitary weld stainless for brewing applications. i've been practicing on mild steel and just want to make sure my setup is done correctly. i have 2ga battery cables ran from the cst280 in DCEN setup (neg into electrode in, torch at electrode out, pos on the work/ground cable). two things i notice about using it is that the HF box clicks consistently while i don't have an arc struck. as soon as i strike an arc, the clicking goes away, but comes back as soon as i release. is this normal? second, when i release the foot pedal completely after welding something, there remains a very small arc from the torch to the steel. it is not hot enough to cause a puddle or anything, but the arc does not release fully after i come up on the pedal. is this normal?anyway, i built this table for a friend for practice and am going to build a welding table next so i have better places to put everything. any information you guys can give me on the setup being correct or not would be much appreciated.pics of setup:table:Last edited by LE ROI LE VEUT; 01-06-2016 at 02:50 PM.
Reply:Sounds like your HF may be constantly trying to fire. I'm sure 7A749 will chime in shortly, he knows a ton about welding equipment, Miller especially.
Reply:Do you have your high freq box set on "start" or "continuous" ?  For DC use it would be on "start"My question though is why are you using one?  Isn't the CST 280 already a tig welder with lift start?Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by MinnesotaDaveDo you have your high freq box set on "start" or "continuous" ?  For DC use it would be on "start"My question though is why are you using one?  Isn't the CST 280 already a tig welder with lift start?
Reply:As far as the clicking, that's not normal. There's a relay inside that unit, I would have to look at the schematic to see exactly what it controls tho. It also uses a fixed time relay for the post flow which should time out around ten seconds. I would have to see and hear it to try and identify the clicking sound. After the machine times out and the gas shuts off, there shouldn't be anything from it until you hit the pedal again. You do have the welder set to remote, right?Personally, I think once you get used to lift/scratch start welding, there's absolutely nothing hard about it. The HF box is just going to provide gas control and a momentary HF charge to start the arc without touching the tungsten to the base metal. It will be used in Start HF for all DC applications, so continuous will not be a factor with that welder you have connected to it right now.I would get a ring connector on the end of those cables coming from the welder. Don't bypass the HF box either, but you prolly already read the directions that cover that. You can smoke the HF box bypassing the ground lug on it. I dunno if you have a real solid connection there or not, it's hard to say. You can remove the cover off the HF unit and try and see if you can identify where the clicking is coming from. My guess is that relay, or possibly the post flow timer block or gas solenoid if there not a good connection to it. Again, hard to say without being in front of it.Can you possibly post a video with sound? That would help. I would just use a torch with a valve and do the lift arc thing. That HF box is worth $350-500 on average.Start with that.Last edited by 7A749; 01-06-2016 at 03:41 PM.Expert Garage Hack....https://www.facebook.com/steven.webber.948
Reply:Originally Posted by 7A749As far as the clicking, that's not normal. There's a relay inside that unit, I would have to look at the schematic to see exactly what it controls tho. It also uses a fixed time relay for the post flow which should time out around ten seconds. I would have to see and hear it to try and identify the clicking sound. After the machine times out and the gas shuts off, there shouldn't be anything from it until you hit the pedal again. You do have the welder set to remote, right?Personally, I think once you get used to lift/scratch start welding, there's absolutely nothing hard about it. The HF box is just going to provide gas control and a momentary HF charge to start the arc without touching the tungsten to the base metal. It will be used in Start HF for all DC applications, so continuous will not be a factor with that welder you have connected to it right now.I would get a ring connector on the end of those cables coming from the welder. Don't bypass the HF box either, but you prolly already read the directions that cover that. You can smoke the HF box bypassing the ground lug on it. I dunno if you have a real solid connection there or not, it's hard to say. You can remove the cover off the HF unit and try and see if you can identify where the clicking is coming from. My guess is that relay, or possibly the post flow timer block or gas solenoid if there not a good connection to it. Again, hard to say without being in front of it.Can you possibly post a video with sound? That would help. I would just use a torch with a valve and do the lift arc thing. That HF box is worth $350-500 on average.Start with that.
Reply:You might wanna remove and check the pedal for a stuck micro switch. Use a meter set to continuity and check between pins A & B. Depress the pedal and the switch will close, release it should open. If it's sticking you'll get continuity all the time. I would investigate that since it won't cost anything to do it.And yes, continuous HF would be used generally for AC current welding aluminum.Expert Garage Hack....https://www.facebook.com/steven.webber.948
Reply:ok guys. have been traveling for work and ran out of gas. picked up a new bottle today and am going to make a video. will post as soon as i'm done.
Reply:here she is! so i have an update on the clicking. it ONLY does it if i have the cst280 set on lift arc. if i change it to one of the stick settings it goes away! i will have a quick follow up video to show that as soon as it is uploaded. disclaimer: my garage is tiny and a mess. i recently moved from houston and don't have my shop anymore. i am building a welding table NEXT, as i know screwing around on my dryer is pretty weak. lol. Last edited by LE ROI LE VEUT; 01-25-2016 at 08:38 PM.
Reply:Bump for vids
Reply:You don't need the lift arc since you already have HF thru the box. The lift arc is probably causing the relay inside the HF box to continuously cycle.That's what it sounds like to me. I've never used a machine with lift arc attached to an HF box before so this was new to me. Just shut it off and run in stick remote (if you have a pedal attached to the HF box)Glad you figured it out.Expert Garage Hack....https://www.facebook.com/steven.webber.948
Reply:Originally Posted by 7A749You don't need the lift arc since you already have HF thru the box. The lift arc is probably causing the relay inside the HF box to continuously cycle.That's what it sounds like to me. I've never used a machine with lift arc attached to an HF box before so this was new to me. Just shut it off and run in stick remote (if you have a pedal attached to the HF box)Glad you figured it out.
Reply:Well without being in front of it it's hard to say. Is the switch on the front of the HF box set to panel or remote?Try disconnecting everything and hooking the door control up to the CST and seeing if you have control of the amperage that way. It will rule out the box causing the problem. Wide open output and lack of any control over it can be bad news. If you have the box disconnected and the pedal connected to the CST with it in remote 14 and it still is putting out full output you may have board troubles.I'm not real familiar with that machine tho. Did the CST work fine before you connected it to the HF box?Double check the switch on the HF box. Make sure it's set to remote. Box connected to welder, pedal connected to box.Expert Garage Hack....https://www.facebook.com/steven.webber.948
Reply:Originally Posted by 7A749Double check the switch on the HF box. Make sure it's set to remote. Box connected to welder, pedal connected to box.
Reply:Well, I dunno man.I just hope your welder isn't going to have the issue without the box connected. That's bad news.Expert Garage Hack....https://www.facebook.com/steven.webber.948