Take-Up Spring
Don’t forget about the take-up spring!
It's small, it's unobtrusive, it's inexpensive, and it "rocks-a-lot".
The take-up spring on your Longarm is an important component to ensuring stable tension on the thread as the needle oscillates vertically while the hook is rotating creating the magic of a "stitch" 40 or more times a second. If your machine has 10 Million stitches on it, the Take-up spring has bent 20 million times - 10 million forward and 10 million backwards...and...just might be tired/damaged and ready to be replaced.
The spring below came from a clients machine who had verified all tension settings, had me check timing which was OK, but was having intermittent shredding of thread along with occasional skipped stitches. A little sleuthing with my trusty magnifying endoscope found discolorations on the bend of the spring, running a thread past it found rough edges, and replacing the $5 spring put the quilter back in business. This particular spring had oscillated 46 million times (machine had 23 million stitches).
In case you are wondering – the Take-Up Spring is typically on the right-front of the Longarm, and will be never the Take Up Lever that the thread routes through – here is an example:
So...when to change? I have not been able to find guidance online from major longarm manufacturers, but a couple of professional quilters I know have posted they change take-up springs proactively quarterly or so. Having replaced several that were broken or damaged, my opinion is every 10-15 million stitches (often in tandem with service interval) is an appropriate time for replacing - also - if you quilt a lot I would advise to keep a spare spring around - they are easy to replace and they never break at noon on Wednesday when the shop down the street that keeps them in stock is open...
Track the activity of your take-up spring and make arrangements to replace it before it breaks or starts shredding thread.
Do you have questions on this topic or a suggestion for another one you are interested in?