Common Mechanical Wire Feed Problem Causes & Fixes

1. Mig Wire Spool not turning smoothly

   Depending on the type of Spool Hub your Mig Welder has:
   In the case of an Industrial type Spool Hub. The wire spool not turning smoothly can be because the spool brake is too tight.
   In the case of a DIY type Spool Hub. It may be that the Spindle the Wire Spool turns on has become badly worn, or dirty. It may also be that the Wire Spools label is catching on the Hub as the Spool turns!
   

2. Mig Spool Overruns spilling wire into the machine

   If you have an Industrial type Spool Hub it’s most likely the Spool Brake is too loose. You will need to tighten it enough so the Wire Spool stops as soon as the Feed Motor stops, but not so tight that the Feed Motor struggles to turn the Wire Spool.
   If you have a DIY type hub, you may have lost the spring that provides tension on the Wire Spool.

3. Mig Wire is Jerky coming off the Spool

   This may be a poorly wound spool of wire, try manually pulling the wire through your Torch and see if the wire is still jerky coming off the spool. If it is a poorly wound spool there’s not a great deal you can do about it. They sometimes get better as you use the wire, otherwise, you might need to change the spool for a better one!

4. Feed Rollers Slip

   There are quite few possible reasons for this:
   a) You may be using the wrong sized groove for your wire, check this!
   b) The Roller may be worn, in which case you will need to replace it.
   c) The Roller Groove may be dirty and part filled with fine metal dust, clean it thoroughly!
   d) The Spool Brake may be too tight (as discussed above).
   e) There maybe problems further down the line, which we’re coming to!

5. Feed Roller Tension

   If the Feed Roller Tension is too high, the Mig Wire can be distorted, especially if you’re using Flux Cored (Gasless) Wire!
   Feed Roller Tension that’s too high can flatten the wire a little so that instead of being say 0.8mm diameter and round, it becomes 0.7mm x 0.9mm and Rugby Ball shaped. You’re then trying to push a 0.9mm wide wire through a Mig Tip in the end of your Torch that was made for 0.8mm wire!
   I’ve written a separate blog article on Feed Roller Tension and produced a video if you prefer to watch rather than read.

6. Guide Tube Blocked

   Mig Welders with Euro Type Torches have a Guide Tube between the Feed Rollers and Torch.
   This Guide Tube is typically around 4-5mm in diameter and sharpened like a pencil at both ends.
   Over time, metal dust can build up in the guide tube, causing the wire to part, or fully, jam.
   Remove the Guide Tube and either replace, or clean thoroughly so wire passes through unimpeded.

7. Blocked or Damaged Torch Liner

   Torch Liners are usually either Plastic, or Metal.
   Plastic Liners wear very quickly, so if wire feed problems are caused by the Torch Liner, a plastic liner will need to be replaced.
   If your Torch Liner is metal (looks like bicycle brake cable coated in plastic), it may have become partly blocked by copper dust from the Mig Wire. This can usually be resolved by removing the Copper Mig Tip at the end of the torch and blowing the Liner out from both ends with an Airline.
   If blowing the liner out doesn’t cure the problem, remove the liner and check it’s not kinked, if it is, it will need to be replaced.
   Some DIY Mig Welders have a small additional liner in the Torch Neck. These are often only fitted to torches that have a Gas Valve built into the torch handle. If you have one of these, also check this.

8. Mig Tip in poor condition

   The Copper Mig Tip at the end of your Torch is what transfers welding current onto the wire, so it’s important it’s in good condition.
   Check you have the right size of tip for the wire size you’re using!
   The Mig Tip can become worn and/or blocked. This can cause the wire not to feed through it very well and/or lead to poor transfer of welding current from machine to wire. This in turn can cause the arc to “stutter”, which can be misinterpreted as a wire feed problem.
   If the condition of the tip is in any doubt, replace it to eliminate this as a possible cause of problems!

9. Too Little Gas Flow

   We all know the main reason for using gas is to protect the weld pool from oxygen in the air. However, the shielding gas also provides “Gas Cooling” for the end of the Mig Torch.
   If there is insufficient Gas Flow, the Mig Tip can become very hot.
   When metal gets hot it expands. As the metal expands, the hole through which the wire is feeding gets smaller, potentially causing the wire to then jam.
   A key pointer to this being the problem is if wire feeds OK when you first start welding and the end of the torch is cold, but becomes problematic as the torch parts get hot!
   This is also more likely to be a problem when using flux cored (Gasless) wire!