some comapnies are providing hand welding tools by using battery
Your caliper piston is not returning and you are technically riding with your brakes on. You fix it by taking the caliper off.remove the bleed valve and working the piston in and out a few times and a little cleaning would help a lot.
You might, given your additional details, have twisted the forks. But even though the impact was on the other side, first check the disc by raising the front end, and spinning the front wheel and use a pencil to measure the distance from fork leg to disc.
Get 6 pieces car battery and connect them in series with thick copper bars. Now it has 72 volts and workable current about 150 amperes. Good enough to replace the AC welder. 85AH car battery shall give you not more than 90 minutes welding work.
