Capping bottoms

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I got a 69 sa 200 and for some reason I'm having trouble on the bottoms when capping.  Its just the bottom from like 530-630.  Undercutting bad.   Tried everything like turning down slowing down but to no avail.  Thing is I don't have this trouble when using a trailblazer or an electric machine.  Any advice???   Can i Change somethin on my machine?   Burning 5/32 and 3/16 5p+    3rd gear and 50 on fine current.  Pipe is sch 80 12 inch69 sa 200
Reply:Tighten the arc, and dont move too fast.UA Local 598
Reply:I tried that and it helped bit still undercutting.  Not sure what's going on.  Could it be my machine?69 sa 200
Reply:Could be the base metal or arc blow? Try moving the ground.UA Local 598
Reply:I wonder if your RPM's are too fast. My 1400 RPM SA-200's stack better than my 1550 RPM SA-200's.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:That's a good observation I need to check that.  Should it be 1400 at high idle no load?69 sa 200
Reply:I tried the moving around part didn't really help much.   I'll try again tomorrow thx for all the input69 sa 200
Reply:Originally Posted by dg09usShould it be 1400 at high idle no load?
Reply:I tried again today and I was able to stack the cap pretty good but still have a little undercut.  I check my ocv and I'm at 91 and 115 at receptacle69 sa 200
Reply:You are in the ball park, technically you should have 90-volts DC at the receptacle on the front of the machine, and 66-volts DC at the welding lead studs at low idle. 88-95 at high RPM on the studs, and 125 to 130-volts DC at the receptacle. If you're not satisfied with the factory settings you'll have to make changes else where.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:K. Thx    Never checked volts or ocv at low idle. I'll check em when I get home69 sa 200
Reply:Originally Posted by dg09usK. Thx    Never checked volts or ocv at low idle. I'll check em when I get home
Reply:Turned my OCVs up to 93/94 and seemed to make a world of difference. Thx for everyones help69 sa 200
Reply:Originally Posted by dg09usTurned my OCVs up to 93/94 and seemed to make a world of difference. Thx for everyones help
Reply:Yea I know I was stumped myself.  My buddy finally called back and told me to turn them up.  I did and ran another cap and no undercut69 sa 200
Reply:I was thinking you'd have to lower the RPM's to change the volt amp curve. I guess by turning up the RPM's you basically did the same thing I was talking about by using the upper half of the fine tune rheostat, getting a wetter flowing puddle. That is what you got right? Is the puddle wetter, which allows you to stack better?Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:I think so.  I see your point tho. It just seemed when I did turn up that it made my puddle worse.  Especially around 3 o clock.  Just wanted fall off the pipe and the faster I went the crappier it looked.69 sa 200