skipping stitches on only one needle

[Mama Kass]

Needle number 7 is sewing out with tons of skipped stitches in both column and fill stitches. I have recently lubed the thread feed rollers and needle bars; it stitched fine right after having done so. I've changed my needle and tried various slight adjustments to the needle angle. I doubt it's caused by flagging, thread feed settings, or digitizing because it sews out fine on another needle. What am I missing here?

[Rod or Sharon]

Mama Kass,

Double check to be sure your thread is passing through that little black cover over your thread feed roller. That would cause it. If that isn't it, check your threadfeed drive gear to be sure no grease got on the roller part, and if so, clean it with hot soap and water, dry it off, re-grease it and put it back in. Any grease on the roller can cause issues too. Let us know...
Sharon

[Greenwing]

Also double check and be sure the needle is in correctly.
scarf to the back, thread channel to the front.

I know you said it is in right.
but I have driven 90 mins one way to help someone that was having the same issue, I walked in turned the needle around then went home.
She insisted she had it correct.
not so much.

[Greenwing]

also make sure it is all the way up in the needle bar.

[Rod or Sharon]

Mama Kass,

If this appears to only be specific to one needle ( #7 ) then the firs thing I would check very closely would be the Pinch roller and the inner thread feed roller. I say this because I know you primarily use "metallic" thread with what you do. This can wear grooves in the rollers faster than regular thread.

Check to see if a groove on either the pinch or inner threadfeed roller is present. This would mean that the thread is not being pinched tightly enough and it could be slipping.

Also, what is you closest and furtherest needle designation for your hook timing. When was hook timing last checked?

Rod Springer

[Mama Kass]

OK, here's what I've found:
-needle scarf to back and all the way inserted (although I wouldn't have put this newbie mistake past me right now)
-washed and re-greased thread feed and pinch rollers and then switched those from needle 7 with those from needle 12, which sewed out fine and happens to be my closest needle
-I do have what I would call skid marks on my rollers but no grooves like they show in the photos; besides the rollers worked fine on another needle.

I sewed out the same design on both needles - 12 fine, 7 not so much.

Ipso facto...it's probably my hook timing, which was in the back of my mind but something I didn't want to face because I hate doing it. I don't know my farthest needle since this isn't listed on the machine and I've never had reason to figure it out, but I have a sneaking suspicion it's needle 7!

So thanks for all your help; I'll let you know if the hook timing solves it.

[Rod or Sharon]

Mama Kass,

You really do not need to know the farthest needle, even tho it would be nice to know, to do the hook timing. Always use the closest needle, which you say is # 12. When checking , use the timing location target # also found under the tabletop with the closest needle designation.

The left and right position should have the "point" of the rotary hook just barely peeking out the left side of the needle. The forward/backward needle position ( needle guard gap ) should be touching but not touching the backside of the needle and that means just close is not close enough. ;-))

Just thought I would refresh your memory in case you may have forgotten some of this...

Good luck..

[Mama Kass]

I have it all written out in my own words because it was a pain going back and forth from my computer to read the instructions and then back to Red to make the adjustments. I just really dislike doing it - very persnickety.

[Mama Kass]

OK, I just checked my rotational timing and my needle to hook gap. Yes, I used the closest needle at the rotational setting indicated on my machine. The hook is just barely peeping out to the left of the needle. The gap is virtually nonexistent; I can see no space and if I bring a thread up between the needle and the hook it forms a "V" before it pops. The closest needle is also the one which had a good sew out in my test on Saturday.

Do I need to be looking for the dreaded cracked gear?

[Rod or Sharon]

Ok, sounds good so far....

The cracked drive gear would be a common denominator to all 16 needles, "but it would not rule out that the internal gear on #7 that meshes with the main drive gear is broken." Lift the pinch roller lever, remove the pinch roller, remove the little face plate cover and then remove the inner roller. Use a flashlite and check down in the pocket to see if there is any thread build-up that might keep the roller/gear assembly from turning. Also spin/turn this gear by hand ( you can reach it from the back side of the needle case ) and watch to see if the gear tracks true and does not wobble from side to side. If it does, then it is cracked/broken around the hub and would need to be replaced.....( not an easy choir to do without some training ) :-{

The other possibility is that the "needle depth" has slipped, i.e. the needle bar may have slipped up thru the clamping stud either from an inadvertent hoop strike, needle break, or just the needle pounding up and down in dense material, dense design, etc.

Mama, as a quick check, run your needle case over to the # 16 position and lay a straight edge across the points of all the exposed needles. If #7 is higher than the rest, that would be an indication that it is not going down far enough to allow the rotary hook to pick up the thread in the scarf area. Number 16 needle should be the "only" needle that is lower than the rest at this point so pay no attention to it during this quick check of needle depths.

Let us know how this check goes, it could be a distinct possibility this is what the problem is so check very carefully...it does not have to be off much to cause a problem.

Rod Springer
Amaya Tech & Trainer

[Mama Kass]

Gears look fine and move freely. All the needles line up except #16. There was a 6" piece of metallic thread wrapped around the gear and hub for #7, but it wasn't tight and didn't seem to cause any binding effect; I was able to pull it right out.

My next step is to repeat a test pattern that shows up the problem I've been experiencing on #7 and see if it happens on any other needle. Maybe all this fiddling with stuff will have cured the problem.

[Rod or Sharon]

That 6 inch piece of thread may have been having a Chinese finger trap thing going on too...as the shaft rotated, the thread may have started to bind tighter???? You at least found something!! and it was on #7....

[Mama Kass]

All the needles sewed out with acceptable appearance on the front. However, out of all the needles only #7 did not have an even column of bobbin thread on the backs of the columns. The metallic thread showed from side to side in quite a few places and looked a bit loopy, so something is till rotten in Denmark. I think pulling out the Chinese finger trap helped but didn't completely solve it. Since I rarely use all 16 needles at once, my solution for now is just to avoid #7.

Thanks for all your help.

[Rod or Sharon]

The next thing now is to check the X-axis cable tension. It is not as easy to adjust on the Reds as it is on the XT series, but....the cable may have stretched enough to start affecting column registration. Check out you tech and parts manual for X cable tensioning....let me know if you have questions ;-))))))

[Mama Kass]

Many years ago Hugo walked me through doing the adjustments by pulling the cable a bit tighter through the clamp at the end of it, behind the black panel on the left. I really don't think it's a column registration problem because I've experienced that before. I also have done an AMPASS fairly recently and the columns looked fine. It looks more like the bobbin thread is being missed leaving missed stitches and loops.