Marking graduations on the 200DX pedal?

[Joe from NY]

Has anyone marked any graduations on their 200Dx pedal knob? i would like to see photos how anyone has made any markings on theirs to kind of get an idea what amps they are setting on the knob. it is kind of different than what i am used to, a knob with no markings for reference to show what level it is set at.

[Jake98]

I wonder if there's a way to put a 'dummy load' on one so you didn't have to be arcing to see and set the amps? Or maybe Oleg can get us some surplus 'heads-up displays' from the air-force to put in our helmets... ;D
actually, I was reading (here, I think) that you can set the amps in stick mode and see the display.

[sportbike]

Once again, just set the machine, and strike an arc on some scrap, covering with your glove and watch the display. Adjust rheostat. Repeat.

[jakeru]

My super200P also has a current knob on the pedal. I made graduations on the pedal showing the % of power from 0-100%. Nothing very fancy... I think I just used correction fluid! It's OK, given that the pedal just gets kicked around on the floor. I'm sure one could do a much better job, but it does the trick.


If I recall correctly, there were some graduations on it when it was new, but they did not line up with the range of the knob travel. That made it hard to determine how it was adjusted just by looking at the pedal, so I used solvent to wipe off the old graduations, and "redid them" according to their true adjustment range.

Oh by the way, the knob broke (during original shipment of the welder... which was a few years ago.) so I replaced it with this style that is used on many old school guitar amplifiers. The long pointer of this replacement knob is quite functional however, in that it makes it easier to read where the current is set from the perspective of looking down on it from above.

[Joe from NY]

i dont understand why on mine as i rotate the knob on the pedal through the entire range of rotation (without stepping on the pedal) from the 8 oclock position clockwise to the 5 oclock position, the amps displayed on the LED go lower and lower from "023" until they show zero at the 3 oclock position, but then start to go up again until they get to "023" when i reach the 5 oclock position. The zero position is not on the exact middle of the range of the knob.

When i unplug the 7-pin connector from the machine and i put a DVM set to check ohms and put it in the pins of the cable, i get the expected action of ohms reading throughout the range of motion of the knob.

This is a chart of my approximate readings that i measured with my DVM:



Do these readings look correct for a 200 DX foot pedal?

[sportbike]

I think you will be much better suited to check the functionality of the pedal in the system rather than trying to reverse engineer the control logic.

Set up the welder with a piece of scrap material.
Turn the knob to some low setting
strike an arc and push the pedal all of the way down
maintain the arc while looking at the display


Turn the knob to a higher setting
strike an arc and push the pedal all of the way down
maintain the arc while looking at the display

Repeat until you have maxed out the knob.


The values while the arc is not esstablished don't directly relate to anything related to welding.
The actual resistance of the pot does not directly relate to anything related to welding.

The only thing that is relavent, in the system, is knob position to current maximum output. All of the rest is just the method that is used to control the system.

[Joe from NY]

So there is no direct relationship between ohms resistance read from the pedal and amps output? My reason for looking at the issue was the fact that I seem to have hardly any noticeable arc control for the first 70% of pedal travel, then it seems to respond only in the last 30% of pedal travel. I thought maybe i had dead spots in the range of the pedal movement.

Can anyone from Everlast tell me if those values are close to what I should be seeing? If they are normal, then I know the pedal is functioning properly, and it must just be operator error due to inexperience.

[performance]

Joe,
It isn't 100% linear to be sure....but consider this:

Your required foot pedal travel is governed by the relative maximum amp value. At a full 200 amps, your arc response will be much faster, and foot pedal travel required to start and maintain an arc will be much less than a welder set at approximately 100 amps. At 100 amps, your travel will be at least twice as far. And any non linearity (which there is some) will be magnified. At 50 amps max setting, you'll need to theoretically travel twice as far to start the arc than at 100 amps.

[performance]

I wonder if there's a way to put a 'dummy load' on one so you didn't have to be arcing to see and set the amps? Or maybe Oleg can get us some surplus 'heads-up displays' from the air-force to put in our helmets... ;D
actually, I was reading (here, I think) that you can set the amps in stick mode and see the display.

Put it in lift arc mode first and try it. I think I recall that working.

[Jake98]

I chalk it up to one of those things I'll know how to do, when I know how to weld. I imagine it goes something like 'thick stuff, full blast, thin stuff, turn it down a little'. And it's so hard for me to reach the floor anymore, the knob could have boobs on it, and I still don't think I'd be looking at it real close. How's that?

[jakeru]

i dont understand why on mine as i rotate the knob on the pedal through the entire range of rotation (without stepping on the pedal) from the 8 oclock position clockwise to the 5 oclock position, the amps displayed on the LED go lower and lower from "023" until they show zero at the 3 oclock position, but then start to go up again until they get to "023" when i reach the 5 oclock position. The zero position is not on the exact middle of the range of the knob.

When i unplug the 7-pin connector from the machine and i put a DVM set to check ohms and put it in the pins of the cable, i get the expected action of ohms reading throughout the range of motion of the knob.

This is a chart of my approximate readings that i measured with my DVM:



Do these readings look correct for a 200 DX foot pedal?

I know I don't have a 200DX, but here are some measurements I took from my Super200P's foot pedal which like I've shown earlier, has a knob in it like the 200DX.

(Maybe they'll be useful to you, maybe not?)
http://www.hobartwelders.com/weldtal...084#post293084

PS - I looked for the linked schematic of the pedal electrical system, but it appears to be gone. (I think it was on an image server that went down.)

[everlastsupport]

The schematic is in tech bulletins. Looks for a subject with pinouts. I think it is a sticky too. But the 200P and 200DX I believe are the same pedal and just a bigger 7 pin DIN on it.

[Joe from NY]

I know I don't have a 200DX, but here are some measurements I took from my Super200P's foot pedal which like I've shown earlier, has a knob in it like the 200DX.

(Maybe they'll be useful to you, maybe not?)
http://www.hobartwelders.com/weldtal...084#post293084

PS - I looked for the linked schematic of the pedal electrical system, but it appears to be gone. (I think it was on an image server that went down.)

Man, that is funny, you did the same thing to your pedal as I did to mine.