Modifying off the shelf parts - better to hack or make from scratch

Attached are photos of some common sewing machine parts. The two silver items are parts that often break in the middle. The important areas of these parts are the pointed area. I am not sure of the type of metal used, but they are slightly bendable. If one of these breaks, can I tig it back together successfully?

Next items are common feet for sewing machines. The shaft area are what mount to the machine, the bottom is what I am looking to modify / remake. They are hardened all the way through and it is super hard. Not sure of what value since I don't have a tester. I want to change the bottoms to accommodate different types of products. Can I cut the bottom part off and reweld the new design to it? The only part that really wears is what comes in contact with fabric ( bottoms ) Time is always short for me so I dont want to have to make these from scratch. The set of standard feet is about 8 bucks.

I am working of a miller sync 250.

Thanks

Jason

two more photos.

I see no problem with welding either part. As for the new "soles" for the feet, if your weld is far enough form the sole, then hardness of sole may be unaffected by welding heat. You might also consider pinning or bolting soles to feet. Pictures of the new "soles" you ned might help.

For the slender parts, sure, you can weld them, but getting them as strong or stronger than new is another story. That depends on the original material, heat-treat, process, filler used, pre-heat, post-heat-treatment, and whether there is room for you to make them fatter where they broke. All those questions might be better addressed by making your own from scratch.

Jason, it's always sort of dicey to weld hardened material, especially when you don't know the material (and even if it's a weldable alloy). For the feet, can you retain enough of the existing bottom to get a good adhesive bond to your new custom shape? (Perhaps together with pinning?)

Welding fatigued material can be pointless. Even if the welds perfect another crack can appear darn quick within mm of the repair. its a similar issue on excavator arms. There comes a point were replacement with new unfatiqued metal is the only viable solution.

Awesome idea of pinning a replacement. Here are examples of what I am trying to make, but these types of feet only work with cording ( decorative stuff that goes on upholstery items ) up to 1/2" where I need to work with cording that is 1 inch thick.

CONSEW 206RB 225 226 PIPING WALKING FOOT SET of 6 PAIR | eBay

The other parts shown in silver usually break because of operator error. The only purposes of these pieces are to move thread in the sewing operation. A photo of similar type items is attached with thread in the proper place. Tension is pretty small.

Replacement costs on something like the silver parts is from $25 to $85. Some low volume ones are in the $150 range.

I would love some ideas on how to set the Synrowave 250 up to handle this.

Thanks

Jason

Jason, there are surely materials testing labs in LA. Look for "materials lab" or "certification lab" or the like. They ought to be able to test your samples and tell you the chemical composition, from which the "name" of the material can be found. They also ought to be able to test the hardness.

Given that information will inform your welding procedure, etc.

I would bet a few bucks that the thread loopers are a plain carbon steel.

If the failures are operator error, the rest of the part will probably not be fatigued.

Tig would be the way to weld them, but I would do it with oxyacetylene and a spring straightened-out for filler. Real easy to burn high-carbon steel.

Only problem with welding is that they will come out annealed near the weld. Little parts like those would be easy to quench-and-temper with bernzomatic (propane) torch and a coffee can full of water. Draw to blue everywhere but the end that carries the thread, leave it straw there.