www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

Welding
Goto page 1, 2, 3  Next

Post new topic   Reply to topic
  Author    Thread
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  
Welding

hmmm odd, i must be especially stupid today or that old thread with some welding discussion in its gone.

but anyway, with MIG welders, i got a few questions. do you have to cut the excess wire off from the handle thing before you do each weld, and if you hold the wire too close to the welding job will it arc across?

how far should i hold the wire away from the item.. i was just laying some quick tack welds to see if the thing was working and had it like 10mm or so away and just waited for the wire to sort of un reel into the metal... pretty sure thats the wrong way to do it Very Happy
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Sun Jan 29, 2006 5:57 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Big AL
Experienced Roboteer


Joined: 16 Oct 2004
Posts: 436
Location: roleystone perth. WA


 Reply with quote  

from what i got told by my metalwork teacher you are "ment" to cut the tag bits of wire of before you weld but thats so the wire when you pull it out to change to different types of wire you dont rip the teflon inside the feeder line with jagerd edges.

as for ten mm way from the job i think that what i was doing and just pushing it toward the job and a way from me at the same time (if you get my drift) till it started welding
_________________
For West ausies interested in robotics email me at: theoneshrug@hotmail.com
OR
dragoonarie@gmail.com
best quote ever:: "Those Gas-Turbine style warehouse heaters arent illegal, and neither is remote controlling one as far as I know."

Post Sun Jan 29, 2006 6:13 pm 
 View user's profile Send private message MSN Messenger
DumHed
Experienced Roboteer


Joined: 29 Jun 2004
Posts: 1219
Location: Sydney


 Reply with quote  

usually it's easier to start welding if there's only 10mm or so of wire coming out the end, which can be cut, or just hold it against somewhere you're not working on (but is connected to the welder ground) and press the trigger and it'll blow it off Smile
The other way is to open the lid and wind it back to save wire Razz

There's no power to the tip until you press the trigger.
_________________
The Engine Whisperer - fixer of things

Post Sun Jan 29, 2006 6:27 pm 
 View user's profile Send private message Visit poster's website MSN Messenger ICQ Number
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

I got all my welding knowledge from books, so don't count on it being totally accurate Wink :

You are using gasless wire so its OK to have the wire poking out further from the nozzle - 10 to 15 mm is about right. further out and its harder to steer the wire. Too close

I find its better to clip off the drop of melted ali before starting a fresh weld.

Position the wire just above the start of the weld before you press the trigger. The closer the better, but not touching. With gas welding, I hold the wire further back so there is plenty of Argon cover before the arc starts.

With aluminium, you need to angle the torch in the direction of the weld so you are 'pushing' the wire into the weld in the direction you are welding in.
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post Sun Jan 29, 2006 8:38 pm 
 View user's profile Send private message
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

With a gas mig, you push the weld. With a gasless mig, you pull the weld.
_________________
https://www.halfdonethings.com/

Post Sun Jan 29, 2006 8:39 pm 
 View user's profile Send private message
Big AL
Experienced Roboteer


Joined: 16 Oct 2004
Posts: 436
Location: roleystone perth. WA


 Reply with quote  


quote:
There's no power to the tip until you press the trigger.


the one i was working with has power without the trigger being pressed, the teacher made a hude deal about it then jammed the tip onto the job to show us that he was right. he was wrong,it welded with the trigger open
_________________
For West ausies interested in robotics email me at: theoneshrug@hotmail.com
OR
dragoonarie@gmail.com
best quote ever:: "Those Gas-Turbine style warehouse heaters arent illegal, and neither is remote controlling one as far as I know."

Post Mon Jan 30, 2006 12:45 pm 
 View user's profile Send private message MSN Messenger
ffej
Experienced Roboteer


Joined: 22 Jun 2004
Posts: 595
Location: Kurrajong, NSW


 Reply with quote  

Must have been faulty then, MIG's arent hot till you press the trigger.
_________________
Jeff Ferrara
fb@ffej.net

ffej.net

Post Mon Jan 30, 2006 12:50 pm 
 View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
DumHed
Experienced Roboteer


Joined: 29 Jun 2004
Posts: 1219
Location: Sydney


 Reply with quote  

yep, and since I sold this particular welder to glen I know for certain that the trigger works properly Smile

Incidentally, when I got it the trigger was pretty dodgy and intermittent, so I replaced it with a new switch.
_________________
The Engine Whisperer - fixer of things

Post Mon Jan 30, 2006 1:24 pm 
 View user's profile Send private message Visit poster's website MSN Messenger ICQ Number
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

ohhh swung $145 and got an auto welding helmet and a bit more gasless wire.

then took out some 3-2mm steel and went to town on it.



thats the best one i could manage. too slow a wire speed and it would sort of spit and often jam up but any faster and the wire would just pile up behind the weld. plenty of practice shall make perfect!!

and andrew is 1 or 2 the highest power setting on the welder? im inclined to think it may be 2?

and yep no power before the button gets pushed
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Mon Jan 30, 2006 6:33 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Big AL
Experienced Roboteer


Joined: 16 Oct 2004
Posts: 436
Location: roleystone perth. WA


 Reply with quote  

can't you adjust the amps/power going thought the wire? the higher amps should compinsate for the faster speed. (I think) the slower wire speeds are for thiner jobs that need less heat to stop it from blowing hole thought it
_________________
For West ausies interested in robotics email me at: theoneshrug@hotmail.com
OR
dragoonarie@gmail.com
best quote ever:: "Those Gas-Turbine style warehouse heaters arent illegal, and neither is remote controlling one as far as I know."

Post Mon Jan 30, 2006 8:54 pm 
 View user's profile Send private message MSN Messenger
ffej
Experienced Roboteer


Joined: 22 Jun 2004
Posts: 595
Location: Kurrajong, NSW


 Reply with quote  

I find its usually easiest if you adjust the amps first, then set the wire speed mid weld till you get a constant buzz, rather than spluttering or burn back. If then you decide the weld penetration is wrong, adjust the amps in the desired direction and repeat the previous step.
_________________
Jeff Ferrara
fb@ffej.net

ffej.net

Post Mon Jan 30, 2006 9:45 pm 
 View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
DumHed
Experienced Roboteer


Joined: 29 Jun 2004
Posts: 1219
Location: Sydney


 Reply with quote  

this welder has two switches for amperage.

There's a 1/2 switch and a min/max switch.
Full power (90A I think) is with the switches in the 2 and max positions.

For that sort of steel I'd use full power and adjust the wire feed rate as suggested till you get smooth welding going on.

The trick with MIG is that once you have it working you have to be quite fast and accurate. I was never very good at it Smile

That welder's wire feed tends to be a bit uneven, but maybe just lubricating the motor and gearbox will help it a bit. It seems that there's not enough reduction in the gearbox so there's not much torque available at low speeds, which causes uneven feed rates whenever the reel doesn't unspool perfectly.

It could possible be improved with a PWM style speed controller rather than the series variable resistance transistor setup.
If you're really ambitious you could replace the motor with something better and it'd probably be quite a good welder.

That said, most of it's probably just practice Smile

Being gasless it'll never be super pretty, but it is possible to join metal together with it Smile
_________________
The Engine Whisperer - fixer of things

Post Mon Jan 30, 2006 11:49 pm 
 View user's profile Send private message Visit poster's website MSN Messenger ICQ Number
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

I don't know about that particular welder, but most MIGs have a tension adjustment on the wire feed roller. If there is one on the welder, it may be set too low and cause uneven wire feeding. If it was set WAY too high it might also cause problems by loading the motor down.
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post Tue Jan 31, 2006 10:25 am 
 View user's profile Send private message
DumHed
Experienced Roboteer


Joined: 29 Jun 2004
Posts: 1219
Location: Sydney


 Reply with quote  

it's pretty hard to overtension this one.
You can hear the motor speeding up and slowing down with the wire feed, so it's not slipping.
It just doesn't let it spin fast enough at normal wire speeds to give enough torque.
_________________
The Engine Whisperer - fixer of things

Post Tue Jan 31, 2006 10:26 am 
 View user's profile Send private message Visit poster's website MSN Messenger ICQ Number
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

just got back in from welding, its working great now Smile

ended up wasting like 5m of wire but finally have it all in the machine and working properly. the wire feed does get a little shaky if theres a kink in the wire, so i might see if i can get a drill motor in there

heres a few parts of welding, tell me if there okay or not Smile



i think the white stuff is the slag? well anyway that blocks the weld out a bit but thats the best one i could do. it looked like i welded both of the sides so it got good penetration.



theres another good one. i welded it too high so it got like no penetration in the bottom panel. practice makes perfect lol



same deal



lol ran out of stuff to weld....

another thing i noticed is that 90 amps is still enough to punch holes through the 4mm steel i was practicing on if your not careful... im still playing about trying to get the weld right. am i right in guessing it should look welded on both sides even when you weld it on one?

might also look at adding in a fan if thats okay andrew (it wont fark the machine up or anything will it?). where abouts do you think i should wire one in? on the 12v side or the 240v side?

oh yes and it was getting hot with that non stop welding, does it have any thermal cut offs or anything or should i just stop welding every 10 minutes ?
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Wed Feb 01, 2006 10:44 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 1 of 3

Goto page 1, 2, 3  Next

Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.