PrecisionPlasma/CandCNC 5X10 table build

[tig-racer]

nice looking system. how do you like the belt reduction setup?

[WSS]

Hi WSS, sorry I was a bit late in replying, I somhow missed your post.

I used 10 ga for both the air bladder and the water tray. I'm sure you can get away with using lighter material as long as the appropriate cross bracing under the water tray and gusset plates inside the air bladder are used. When considering your sheet thickness and bracing, keep in mind that the water alone in the tank weighs alot (if my water tray was full to the top it would be pushing around 2500 lbs.) Then add to that the thickness of the material you are cutting and the total weight on the trays and table can add up pretty quickly. I see your table has 3 cross supports under your slats that will support the trays, you may want to consider adding some longitudinal support between the 3 cross braces to better support the bottom tray due to the added weight of the trays, water, and materials.

I went a bit on the thick side with the material selection for my table so If I decide later to add oxy/acet cutting to the table for thicker materials I wouldn't have to reinforce or redesign the trays.


I use Praxair's migmix Gold (90% argon, 10% co2) when welding all the table parts including the trays. I also utilized the pulsed mig capabilities of my Miller 350P to help limit heat input into the thin sheets. You can use a similar 2 gas composition or use the trimix. Trimix will assist in spray transfer, bead appearance and penetration, but will also make for a hotter arc. I think either of the gas mixes would be appropriate for the job at hand. For wire selection you are fine with 70s6 (aids in welding rusty/dirty steel) or 70s3 with .035, on the trays you could even use .024 if you wanted. I use .035 70s6. Whatever you decide to use, just take it slow and easy by stitch welding. It doesnt take much heat to make a warped up mess. I chose to weld my water tray inside and out for added insurance against leakage but as long as you are confident in your welds and overlap the stitching, the extra welding isn't really necessary. Just make sure to water test the outer tray when you are done welding it.


Brad

Brad,

Thanks for the detailed response. Once I saw those clean welds, I had to ask. I will pick up a bottle of the 90-10 to weld the tray and tank. The welder I will be using is a Dimension 652 with a D74DX feeder. It seems to do well in the low range. I do not have the pulsed-mig capability, so I will go slow.

10ga is stout for sure! I just purchased 4 sheets of 12ga for the tray. This is my second try at it. I started it about a year ago and have learned alot through use. I want to be able to dump and fill quickly for a few reasons, check me if they are not really valid. First, I do not want to fish for parts, I want to dump and grab, then fill again quickly. Second, I do about50% oxy and need to be able to drop the water to about the bottom of the slats. The first design would not allow this very quick.

Thanks again!
Tommy

[Teknition]

nice looking system. how do you like the belt reduction setup?

I havent used the table yet, still in the building process. I have both trays completed now and will be moving on to building the frame this weekend. What I can tell you about the belt reduction units is they are very well engineered and machined. Being totally enclosed units, they will keep out the dirt, grit, and stray water splashes well. As you can see from the build pictures, they are also very easy to assemble and set the belt tension.

Brad

[Teknition]

Brad,

Thanks for the detailed response. Once I saw those clean welds, I had to ask. I will pick up a bottle of the 90-10 to weld the tray and tank. The welder I will be using is a Dimension 652 with a D74DX feeder. It seems to do well in the low range. I do not have the pulsed-mig capability, so I will go slow.

10ga is stout for sure! I just purchased 4 sheets of 12ga for the tray. This is my second try at it. I started it about a year ago and have learned alot through use. I want to be able to dump and fill quickly for a few reasons, check me if they are not really valid. First, I do not want to fish for parts, I want to dump and grab, then fill again quickly. Second, I do about50% oxy and need to be able to drop the water to about the bottom of the slats. The first design would not allow this very quick.

Thanks again!
Tommy

Try a few small test pieces with the trimix Tom, you may not need to switch gases. If it welds fine, just keep an eye on your heat input to the material and I think you will be fine. I've never used the trimix so it is hard for me to tell you which will work best. One advantage of the trimix is you will be able to weld at a lower amperage and still get good penetration.

Being able to adjust the water level in the table does have the advantage of being much easier to pick out your parts as well as infinate water level adjustablity. So if you find you are getting too much smoke out of the table when the water level is at the bottom of the slats, you can always bring it up a bit.

Brad

[WSS]

Tek,

How is the build going? I keep going back to your "obligatory" weld pic, is the lack of splatter from the pulse feature? I do not see any sticky anti spatter. I like the way the weld is equal on both up and flat, it looks like you turned it 45deg to make a "flat weld". Most of the welding we do has to be flat because of the liquid state of the spray. We spray transfer with argon and oxygen (variable) and magnetic transfer/impregnate tungsten carbide grit into the liquid puddle.

WSS

[Teknition]

Tek,

How is the build going? I keep going back to your "obligatory" weld pic, is the lack of splatter from the pulse feature? I do not see any sticky anti spatter. I like the way the weld is equal on both up and flat, it looks like you turned it 45deg to make a "flat weld". Most of the welding we do has to be flat because of the liquid state of the spray. We spray transfer with argon and oxygen (variable) and magnetic transfer/impregnate tungsten carbide grit into the liquid puddle.

WSS

The build is moving along, not quite as fast as I would like but it is progressing. I have alot of the frame done, just havent posted the pics yet. There was no anti spatter spray used when I was welding, just ground the area to be welded clean of mill scale and started welding. If you look real close you can see a tiny bit of spatter but it comes off very easily with one swipe of a putty knife. All the welds were done in the position they are pictured in, verticle welds were done verticle and flat welds were done flat.

The weld picture you are referring to is a horizontal corner weld on the end wall of the tray. I just stuck the gun in there at a 45* angle and pushed the weld along. I have a fair bit of mig welding experience but I'm a little rusty as you can see by the difference in the width of the weld ( a little fatter in the centre). I am using pulsed spray transfer which causes the nice spatter free welds. All the pulse feature does is aid in freezing the puddle in place (very nice for overhead) and also helps limit the heat input to the material. I dont think the pulse has anything to do with the welds being spatter free, its the spray transfer on clean steel that causes that. Try it on yours, grind the steel clean and leave the carbide out. Im willing to bet you will have a nice spatter free weld too. (I would imagine the carbide contamination in your weld is a cause of the majority of your spatter).

Brad

[WSS]

The build is moving along, not quite as fast as I would like but it is progressing. I have alot of the frame done, just havent posted the pics yet. There was no anti spatter spray used when I was welding, just ground the area to be welded clean of mill scale and started welding. If you look real close you can see a tiny bit of spatter but it comes off very easily with one swipe of a putty knife. All the welds were done in the position they are pictured in, verticle welds were done verticle and flat welds were done flat.

The weld picture you are referring to is a horizontal corner weld on the end wall of the tray. I just stuck the gun in there at a 45* angle and pushed the weld along. I have a fair bit of mig welding experience but I'm a little rusty as you can see by the difference in the width of the weld ( a little fatter in the centre). I am using pulsed spray transfer which causes the nice spatter free welds. All the pulse feature does is aid in freezing the puddle in place (very nice for overhead) and also helps limit the heat input to the material. I dont think the pulse has anything to do with the welds being spatter free, its the spray transfer on clean steel that causes that. Try it on yours, grind the steel clean and leave the carbide out. Im willing to bet you will have a nice spatter free weld too. (I would imagine the carbide contamination in your weld is a cause of the majority of your spatter).

Brad

Brad,

Your comment of "grind the steel clean", I am going to let that settle in! Great tip. Getting rid of the mill scale makes sense. You are correct about the clean welds. I did just that today. I carbided some curved grader blades that needed a "straightening pass" put on the opposite side to pull back true before sticking them under the press. They buckle like a spoon.

The pass had the same settings just swithched off the mag feeder. We always grind becuase of paint, most of our stuff shows up already painted. So the long and short of it is practice. I can see the advantage of the pulse there. I will just go really slow to start, practice on a bunch of scrap/drops. My table keeps getting pushed back too becuase it is getting busy again. No complaining,just wish I was further along in the commitment stage of the build then I can justify sticking to it to get it done.

How many gallons do you think your tank is?

Tommy

[Teknition]

Tommy,
I did a quick calculation of the tank and came up with 43.1 cu ft. = 322 U.S. gallons= 2690 lbs. of water.

You can burn thru mill scale with an arc welder and some 60xx series rods but mig welding likes clean surfaces. Practice make perfect and you can use a few hours a night to *practice* on your table

Brad

[WSS]

Brad,

Thanks for the help and encouragement. I managed to get the bladder/tank done with .030 70s6 using 75 argon and 25 c02. I tried .035 but felt I had to move to fast, it welded good but you could not hesitate at all. I have a Miller four roll set-up that would eat the wire at any tip stick. This got old after about ten times so I removed one set of wheels and it worked great after that. I did a soapy bubble test before presseure testing and only had oh....maybe 200 pin holes. Just kidding, there were about 8 touch ups, I did weld inside and out on everything but the lid. It is a 405g tank. I put 4psi of air in it and it held over night with a .25psi loss. WIth water it had no leaks at all. I was very suprised when I tested the output, it only took 2psi to get it to push out fast and high.

Tommy

[Teknition]

Brad,

Thanks for the help and encouragement. I managed to get the bladder/tank done with .030 70s6 using 75 argon and 25 c02. I tried .035 but felt I had to move to fast, it welded good but you could not hesitate at all. I have a Miller four roll set-up that would eat the wire at any tip stick. This got old after about ten times so I removed one set of wheels and it worked great after that. I did a soapy bubble test before presseure testing and only had oh....maybe 200 pin holes. Just kidding, there were about 8 touch ups, I did weld inside and out on everything but the lid. It is a 405g tank. I put 4psi of air in it and it held over night with a .25psi loss. WIth water it had no leaks at all. I was very suprised when I tested the output, it only took 2psi to get it to push out fast and high.

Tommy

Thar she blows!!! lol. Glad to hear you made out alright. Pushing the water out quickly is more related to volume of air rather than pressure unless you are running alot of head pressure. Did your welds turn out smooth and spatter free? My miller is a 4 drive roll machine as well. You should be able to use all 4 drives without problem, just decrease your drive roll tension. I think mine are set around #1. To set yours, engage all 4 drive rolls and back the tension adjusters to 0. Hold the gun back from a block of wood about 2 inches and squeeze the trigger. Adjust the tension up in slight increments until you can just make the wire curl without slipping in the drives.

Brad

[WSS]

Brad, I figured why the wire was crashing! I did not have the tube that goes inbetween the rolls sized right. The one that is in there is for .120 wire and let it spiral too much. I have my finger pointed to it. For some reason I lost the tubes for both the .035 and.030.....I must have ten different size sets in both knurled and v groove. But this small wire has been a learning curve for sure. The side the .030 is mounted on used to have Lincoln's NS3M in .120 on it for grouser work.

I keep looking for updates on your build, how is it going?

Tommy

[Teknition]

Glad to hear you got it figured out Tom, wire feed issues can be very irritating. That .120 is huge wire, the max I've used is .045 metal core and the deposition rate was way more than I needed at the time. Most of the stuff I weld is in the 1/4 inch range and some 1/2 or 3/4 occasionally. My build is on hold for a little bit. I just bought another pickup truck to replace my old one and have been busy putting a lift kit in it and fixing up the body on it. Should be done it in the next few weeks then I will be able to get back at the table build.

Brad