How to change the needle, it won't stay in place

When using this slippery thread it is possible you need to change things a little. To change I mean you will have to stay with a straight stitch and place your needle at the left side of the plate. It may need to be placed on the right if the hook is rotating the opposite direction. Give it a try both ways to see which way works better. Anyway, you will need to stay with a straight stitch. When you first attempt to bring your bobbin thread up you need to hold on to the upper thread.

It is stuck on bar tack...change the mode to normal, reset then try again

if the machine is still under warrenty, take it back
if it's not under warrenty, take it to the place you bought it from & tell them

it's very possible that the machine is out of time & needs to be serviced at a sewing machine shop

the screw & the needle clamp may have to be replaced

the machine may need to be serviced to see why the needle position won't
move

Firstly check that needle has been placed into the needle holder the right way, ie flat shank to the back. If you look closely at the needle there is a cut away at the back called the "Scarf" and this must face to the back of the machine as the rotary hook swings through there and catches the thread to make each stitch.

Also, check needle is fully up into the housing.

There is some good trouble shooting tips and tricks on this website. http://www.sewusa.com/Sewing_Machine_Repair/Sewing%20Machine%20Troubleshooting.htm

So check needle is in the right way, check threading up is correct and thread is in the needle eye. If none of these resolve the issue, then it is possible you knocked the timing out when you broke the needle. Remember, never drag fabric as it is stitched, let the machine feed it, you just guide it. Dragging is a sure fire way to break a needle.

If timing is out, (you can see info on what this means on www.sewusa.com site too) then you probably need to take it for a service to address this issue.

needs a new needle clamp screw & possibly the needle clamp too

try sewingpartsonline.com

By reading your problem I think you have bent the needle shaft as changing the needle does not help. I think you need a repair/service person. Did you use a larger sharp needle when stitching? Top stitch needles are very good, also titanium coated as the tips stay sharper longer.
Sorry I don't have a nicer solution.
Ellie

on my overlocker, its the screw in the front; it obviously works by pushing onto the needle head. Perhaps you've loosened it too much ?