voltage/wirespeed question

[fng]

hello folks,
after having my cousin weld most of my stuff for me i decided i would learn how to weld myself....went looking for a 115v welder for portability (didn't have 220 anyhow) the red 135 plus then checked out the blue 135 and after taking in consideration the spool gun and other stuff decided on the blue...

then read some more about power....decided i didn't want to buy another on right away so was looking at the 210...which is what my cousin has and he does some awesome stuff..(been welding for John Deere for a long time)

at outlet asked about 210...big bucks..back to 135....575.00 no cart...so asked about a 175 i seen in box in corner...somebody ordered last year never come and got...it has cart and i can have it for 630.00 just 55.00 more than 135 so i got it....took home wired 220 and have had my cousin walking me thru it..lol...

anyhow the here is the question... if you have two controls voltage and wire speed why would they tie wire speed into voltage? to prevent burnback into the tip? and it a guy knows that a voltage increase speeds up wire why can't he just take it into consideration and cut it a little if he thinks it warrants it?
am asking this question cuz if i know why its tied in it might make it easier for me to understand and adjust accordingly....
thanks
fng

[Jmb]

fng,
I think you may be confusing voltage with current/amps.
Adjusting the wire feed speed will adjust your current. In simple terms, voltage is used to "push" the current through the circuit.

Miller has a very good GMAW book included in their student package for $25.00 that explains the different settings, transfers, gasses, wires, etc. The information can be very helpful to a beginner.

Miller Student Package Link

[Dan]

Did you purchase a Millermatic 175?

[Roger]

Originally posted by fng


anyhow the here is the question... if you have two controls voltage and wire speed why would they tie wire speed into voltage?
fng

To save money.

[Dan]

Originally posted by Roger
To save money.

Now Roger,

Its supposedly done to help keep the arc more stable for the inexperienced operator In reality, it does do this, but tuning the arc in is sure a pain when the voltage is variable. This is why in there current states i would definitely choose a HH 175 over the MM 175. the HH 175 is just so much simplier to operate, and has a very good arc.

[fng]

in order......

jmb,
nope not confused two dials on millermatic 175 ..top controls wire speed and bottom voltage....with wire speed at 10 and voltage at 1 ...wire speed is slow but still there....crank voltage up to 10 and wire speed increases dramatically while wire speed dial still at 10....so they are tied together...wire speed tied in to voltage...even tho it can be made much faster by using the wire speed control dial at the same time (voltage at 10 and wire speed at 100 and away she goes..lol) ...kinda seems like overkill ...i figure must be to prevent wire from burning back into tip and the wire speed dial is just for fine tuning?

dan,
yep millermatic 175 for 630.00 with cart..

roger,
i don't understand the saving money part...duplicated effort with still having separate wire speed control

granted i don't know what i'm doing yet....but after listening to my cousin it doesn't seem impossible to learn...what we figured works best is making one move at a time to get the desired result (meaning adjusting one parameter)...so if we turned up voltage we turned down the wire speed just a bit to comensate for the increase in wire speed upping the voltage caused...making two adjustments to change one thing ..that being the voltage...anyhow got some scrap and have a few things to practice then onto another step....
thanks for all the replies and and all appreciated...
later
brian

[Sundown]

Originally posted by fng
,snip>
roger,
i don't understand the saving money part...duplicated effort with still having separate wire speed control <snip>

I think it might have cost a bit more to set it up like that, IMHO

Originally posted by fng

<snip>granted i don't know what i'm doing yet....but after listening to my cousin it doesn't seem impossible to learn...what we figured works best is making one move at a time to get the desired result (meaning adjusting one parameter)...so if we turned up voltage we turned down the wire speed just a bit to comensate for the increase in wire speed upping the voltage caused...making two adjustments to change one thing ..that being the voltage...anyhow got some scrap and have a few things to practice then onto another step....
thanks for all the replies and and all appreciated...
later
brian<snip>

You might want to concider taking very good notes while testing. If you design a small spreadsheet and jot down all the changes you make [as you make them], soon you will have settings [for the MM175] for all metal thickness and joints types that you are using. After using these for some time you will know what the settings are and will not have to consult your charts.

[Portable Welder]

I say dont worry about the wire speed being off when you adjust your votage, take notes and eventually you will learn your settings, but since you dont know let me give you some advise.
Voltage is how you set your heat, so set your voltage depending how thick of metal you will be welding, then get a pc. of scrap the same thickness as you are about to weld on, hook up your ground and start welding with one hand on the gun and the other hand on your wire speed Knob, adjust your wire as you weld and listen for your sweet spot and then you are ready to weld.
Note: never turn the votage knob when welding, this would eventually hurt your machine, but it os ok to adjust your wire when welding to find your sweet spot.
When loading a new spool of wire alot of people do not know how tight to adjust the drive roll tension, put the new roll in, feed it through the liner and when it comes out the tip you want to grab the wire at the tip and adjust the drive roll tension at the point of where you can just barely? stop it.
I think if you follow these steps you will at least have a properly set machine.

[fng]

george,
good advice.....will be a challenge given my ADD with paperwork tho...

portable welder,
thanks good to know.....

later
brian

[Dan]

For the record, the MM 175 is a variable voltage machine, so it is perfectly fine to adjust the voltage while welding. You shouldn t adjust the voltage while welding with a tapped voltage selection machine.

[fng]

did some more reading....didn't realize i shoud have refered to wire feed tracking......my mistake....
thanks
brian

[Roger]

1. Some MIG welders use welding current to power wire feeder.

2. Some MIG welders use seperate windings on welding transformer to power wire feeder.

3. Some MIG welders use seperate transformer to power wire feeder.

Which of the above is cheaper to build?
Which of the above doesn't provide steady wire speed when welding rusty metal?
Which of the above is silly on infinite voltage MIG welder?
Which of the above is used by HH175 HH135, MM135 and MM175.

Dan, I will guess voltage tracking wire speed compensates for voltage changes while welding. The little MIG welders don't have as flat voltage curve as needed with constant speed wire feed.