[hmcleay]

Hi Guys,

I've built a few chromoly bikes over the last two years.
To date, I've been using no pulse, just a foot pedal to control the current.
This is my machine: AC DC Pulse Tig Welder Plasma Cutter 200 + 40 Amps - Tokentools Alusync200

No, it's not a high-end machine, but it's affordable, and the company has excellent customer service.

I'm now starting to dabble in pulsing (around 1.5pps, 40% peak), but I'm not sure if my welder is properly designed for this.
It definitely has pulse functionality, but when welding with pulse, the foot pedal actually varies the backround current, rather than the peak current.
I've tried running the background current higher than the peak, but then the machine only puts out the background current.
I'm having difficulty feeling comfortable with this pulse behaviour, since I'm unable to control the peak current.

Shouldn't the foot pedal vary the peak current, rather than the background current?

I'm thinking about adding another foot pedal, connected in series with the existing pulse current knob on the front of the machine.
But then I started wondering whether other machines offer a different means of controlling pulse welding via the foot pedal.
I.e. Would there be any advantage in being able to control the duty via the footpedal, rather than the peak current?

Thanks,
Hugh.

 

[RCP FAB]

I dont know anything about that machine, but the pedal should effect peak, which effects background. IE 40% background: 100 amps peak is 40 amps background with the pedal to the floor. At half pedal peak would be 50 amps, background 20 amps.

 

[ROSKO]

Hi Guys,

I've built a few chromoly bikes over the last two years.
To date, I've been using no pulse, just a foot pedal to control the current.
This is my machine: AC DC Pulse Tig Welder Plasma Cutter 200 + 40 Amps - Tokentools Alusync200

No, it's not a high-end machine, but it's affordable, and the company has excellent customer service.

I'm now starting to dabble in pulsing (around 1.5pps, 40% peak), but I'm not sure if my welder is properly designed for this.
It definitely has pulse functionality, but when welding with pulse, the foot pedal actually varies the backround current, rather than the peak current.
I've tried running the background current higher than the peak, but then the machine only puts out the background current.
I'm having difficulty feeling comfortable with this pulse behaviour, since I'm unable to control the peak current.

Shouldn't the foot pedal vary the peak current, rather than the background current?

I'm thinking about adding another foot pedal, connected in series with the existing pulse current knob on the front of the machine.
But then I started wondering whether other machines offer a different means of controlling pulse welding via the foot pedal.
I.e. Would there be any advantage in being able to control the duty via the footpedal, rather than the peak current?

Thanks,
Hugh.

Personally I would say bead time is going to do far more good than all that fuss to set up a pulser. It's nice and all but plenty of the nicer frames you see are done without. For some it can even become a crutch of sorts. I'd say just keep plugging away and don't sweat it for now.

That said, if you MUST continue down that path I would suggest a few changes to your settings. First- why 40% peak? With that you are getting 40% of whatever your foot is telling the machine the peak is... why not bump that up a bit to 70--80 and set the machine 30% HIGHER than you would for straight TIGing. Say you have the machine set to 100 amps- at 70-80% peak you'll have 70-80 amps avail when you floor it. Make sense? For the PPS 1.5 is so very super slow- how about 9 as a starting point? Mess around with it- there is a weird seizure inducing zone from 30-ish to 90 or so. Where the rate is like visual nails on a chalkboard. I find 100 doesn't bother. Play around with it and you'll find your sweet spot for your style. Poke around on Welding Tips and Tricks - TIG, MIG, Stick and a pantload of other info and you'll find plenty of useful info.

 

[RCP FAB]

The seizure zone tends to be from 4-30 pps. 99.9% of my pulse welding happens between 30 and 90 pps. To put it into perspective, the light bulbs in your house, shop, wherever pulse at 60 pps (AC power, 60hz). Its too fast to see. I can BARELY see 30 pps while welding, its just enough to to be noticed.

Also I believe the 40% peak is TIME not AMPS.

 

[hmcleay]

Thanks guys,

ROSKO, thanks, that's reassuring. I was under the impression that all the 'nicer' looking chromoly welding was done using pulse. But if it can be done with a straight current, then I should probably just sit back down and keep working at it.

RCP FAB, yes you are correct, by "40% peak" I was referring to the duty (time at peak current).

For the record, here's pic of the front panel of my machine.

Knob 1 is the main current control. When using the foot pedal, it works the same as if I was manually adjusting this knob.
Knob 2 is the pulse current control. If this is less than knob 1, then there is NO pulsing. If this is greater than knob 1, then there IS pulsing. Foot pedal has no effect on knob 2 setting.

Knob 3 is pulse frequency. I note that my range is 0.5 to 25pps, which omits any higher frequency pulsing. Most of this range feels fairly uncomfortable due to the 'seizure zone' described.
For this reason, I'm messing around with very low frequency pulsing (basically spot welds overlapping).

Seems like my machine is somewhat limtied in it's pulsing capabilities, and I should probably not bother with it.

Thanks,
Hugh.

 

[RCP FAB]

IMO anything below 30pps is useless (in reality I never use below 50pps), so I agree you should just stick with straight DC.