Intermittent Stitching Due to Encoder Problem
Intermittent stitching at certain points on the Frame?
You could have an encoder cabling problem.
I have posted on the Longarm-Tech Facebook Page several times on encoder issues - usually the machine can't detect either Front-to-Rear motion (Y-encoder) or left-to-right motion is not detected (X-encoder). The issues are usually simple - a "tire" came off one of the encoders, the bolt holding it (Y-axis) is too-tight not allowing the spring to push it into contact, or the communications cable came unplugged.
I recently ran into an intermittent stitching issue that was a real pain to track down - the Quilter had a 12 foot Frame using a machine with a 20 inch throat. The machine would stitch just fine until it was at the last 3 inches or so of the space towards the rear - and then would have frequent skipped stitches, long stitches, and general stitching ugliness - see Picture 1.
The Quilter and I spent about 30 minutes stitching in various areas, watching the encoder tire to make sure it was spinning, looking for lint, thread or other gunk on the encoder tire or track all for naught - every time the machine was pushed near the rear of the quilting space it could not stitch accurately - only other time I have seen something similar was a Y-Axis encoder where the track it rode on was a little humped in the middle and the spring was too tight - when the machine was close to the front or the rear the encoder tire was not spinning - but in this case every position we checked the tire was spinning.
Next move - onboard diagnostics....
Picture 2 show the diagnostics screen - most machines have these - at the end of the post I will include a link to one popular machine - web searching will undoubtedly find your particular machine's location.
When the encoder is tested (in this case the X-axis) the machine beeps slowly as motion is detected - but - you 𝘮𝘶𝘴𝘵 go slow - too fast makes a continuous tone. As I started moving the machine left-to-right I started at the front of the quilting area and moved an inch back after getting good tones for a foot or so - lo and behold - as the machine got near the back - the motion stopped being detected - WHY?????
I had the Quilter do the same operation while I watched the encoder in the rear - I could not see anything wrong, but did notice the cable connecting the encoder to the machine would bend in different looser or tighter bends depending on where the machine was front-to-rear. I had the Quilter move the machine to the front - verified encoder motion was being detected, and then I bent the cable into the orientation is was normally in at the rear of the quilting area --- and ---motion stopped being detected - so now we know what but not why.
Pictures 3 and 4 show the top view and side view of the entry point on the encoder for the communications cable.
Picture 5 shows what close inspection of the encoder found - the grommet that secures the communications wire to the encoder housing was partially pulled-out, and the wire was also partially pulled out of the grommet - something obviously "yanked" the encoder wire (suspicion is the vigorous tail of a golden lab but "Boomer" would neither confirm nor deny any knowledge of such an incident..) but still no obvious damage that would cause intermittent motion detection at certain positions of the carriage.
The culprit was finally revealed when the encoder housing was disassembled and the grommet was slid back on the cable - revealing one of the 4 wires was broken - the jacket on the cable was keeping the broken pieces in contact when the carriage was to the front or middle of the quilting area, but the orientation of the bend at the rear caused the wire-sections to lose contact and therefore not be able to tell the machine when motion was detected – Picture 6.
Since this Quilter runs a business and had quilts stacked up for delivery before Christmas, I repaired the encoder on my workbench to get her back in business the same day while a new encoder was ordered (fortunately under warranty) and a few days later I went back and installed the replacement.
The quilter asked me - if the encoder could not have been temporarily repaired was there any way she could continue turning out projects either free-motion or Pro-Stitcher, and the answer is "yes" but with a caveat - she could quilt in Manual mode as the encoders are not needed but then the Quilter becomes the "Stitch Regulator" - so you might want to practice some in Manual mode just-in-case. (My wife loves manual mode for simpler patterns as the machine is much smoother and quieter without the stitch-regulation speeding up and slowing down the needle speed).
You will note I did not name the brand or machine - these encoders are used on several different machines from a couple of brands and the problem is not vendor-specific.
This is the second problem with a damaged encoder cable at/near the entry point to the encoder that I have run into in only a small number of machines - I have communicated with the manufacturer who advised me they were aware of the issue and have made an engineering change which will hopefully prevent the situation in machines made after it is implemented.
Hope you don't run into this issue - but if you do there is now a new arrow in your quiver to help troubleshoot and resolve the issue more quickly.
Helpful link: HQ Avante Diagnostics video
Do you have questions on this topic or a suggestion for another one you are interested in?