My Juki TL2010Q does not break needles except when I sew any kind of thickness then the needle bends toward the left and of course breaks. Is it the tension when using on thickness?

Check under the needle plate for a build up of lint and dust.

On what

Check that you are using the correct needle for your machine--a needle of the incorrect length will most likely hit where it shouldn't. Then be sure to use a heavy enough needle so it will not bend when stitching heavy fabric. Next, do not pull or push the fabric when stitching as that will tend to bend the needle. If those check out, then there is most likely a timing issue where the needle is arriving at the wrong time. Best to take it for service.

...

of course but how thick are the goods u r sewing and hopefully u r using the right size needle. u need a no. 22 for heavy goods. yes your hook timing could be off and if u continue to break needles you will damabe the hook, fine emery paper will take any burrs off the hook. slide plate that covers the hook and turn wheel slowly and watch the needle and hook interplay. unthread needle for this. the hook should be about 1/16 from needle before the needle starts to rise.. good luck on setting the timing i can't even do that. since its a walking foot mach. i doubt the timing is off!!

Hai, I think your thread very old or thick. Please putting some drop oil in thread. If your cloth lighter, you use small size needle and new cotton or silk thread.

Needle breaks
1.the needle is damaged
2.the needle is not correctly inserted
3.wrong size needle for the fabric
4.the wrong foot is attached
5.the needle clamp screw is loose
6. Top tension is too tight
7. Machine could be out of time


The needle thread breaks

1. the needle thread is not threaded properly

2. The needle thread tension is to tight

3. The needle is bent or blunt

4. The needle is incorrectly inserted

5. The needle thread & the bobbin thread are not set under the presser foot when starting to sew

6. the threads were not drawn to the rear after sewing

7. The thread is either to heavy or to fine for the needle

A broken needle can put your timing out, you need to find a sewing machine tech...

The MOJ-3916 industrial m/c has a chainstitch looper that picks up the thread off the needle. As it passes across the needle check that the point of the looper almost brushes the needle as it passes thru the scarf (flat scoopout above needle) And of course the long groove of the needle should face the operator nice and square not cocked.
Also check that the looper point is smooth with no hook burrs.
The tesion on the looper thread should be set with just a little drag , no tension as such.
The egg shaped rotay takeup on the side should start to rise to pull thread juat as the looper begins it's travel back towards the left direction.
Hope this helps
Ken

Make sure the needle is in correctly. On most machines the flat part goes towards the back of the machine. Also make sure you are using the correct size needle for the type of thread and fabric you are using. Thicker fabrics such as denim and upholstery fabrics will require a thicker needle, like a 100 (16).

Are you using the correct type of needle? have a word with your needle supplier and explain the problem. Different threads and different thickness material need different top and bottom tension adjustments.
Can I suggest sew one thickness material at a time with tension adjustments for that thickness. Then change the tensions and do a batch of thicker material.