Birdnesting

[lrsbranding]

What am I missing? We have a Tajima TMFX II-C1506 and a Barudan BEVT Z1501. The Barudan will sew all day long and never birdnest. The Tajima will drive me crazy with random nesting. It will randomly birdnest on the bottom side on any one of the heads with any color and with any type of fabric. It will do this several times then run great for a while. The stress of waiting for it to eat a Nike drives me crazy. I don't know what to check. It happens regardless of the bobbin tension. I use a Towa gauge and have tried anywhere from 1500 to 2500 mN. It will do it with either prewound paper bobbins or magnetic. I have replaced all the bobbin cases, I have sprayed the hooks with cleaner. Don't see any damage. Have set the hook timing with the RhAT Tool. The I and FOX tests look good and the machines sewing quality is good. Can the felt disc's on the upper wear as to still sew good but not enough friction to stop the pull through? Is this just a normal problem for this machine? We can't turn our back for a second. Makes it hard for one person to hoop and sew.

 

[WildWestDesigns]

What am I missing? We have a Tajima TMFX II-C1506 and a Barudan BEVT Z1501. The Barudan will sew all day long and never birdnest. The Tajima will drive me crazy with random nesting. It will randomly birdnest on the bottom side on any one of the heads with any color and with any type of fabric. It will do this several times then run great for a while. The stress of waiting for it to eat a Nike drives me crazy. I don't know what to check. It happens regardless of the bobbin tension. I use a Towa gauge and have tried anywhere from 1500 to 2500 mN. It will do it with either prewound paper bobbins or magnetic. I have replaced all the bobbin cases, I have sprayed the hooks with cleaner. Don't see any damage. Have set the hook timing with the RhAT Tool. The I and FOX tests look good and the machines sewing quality is good. Can the felt disc's on the upper wear as to still sew good but not enough friction to stop the pull through? Is this just a normal problem for this machine? We can't turn our back for a second. Makes it hard for one person to hoop and sew.

How new are those needles?

Does this occur in smaller areas that are packed with thread?

Bare in mind too, if it is happening in small areas, not all machines can handle the same sizes. Not all machines can do as wide of a satin stitch, not many can go as small with a stitch as well. You will get sporadic good quality, some good, some not.

Your bobbin case could also be worn out as well. Those things don't last forever.

I imagine that your Tajima is a 6 head. Step or servo motor?

Barudan's just do plain better then Tajimas though. A lot more you can do with the digitizing pattern that also helps out with quality that you can't do on other machines.

 

[lrsbranding]

Thanks for the help. Using new needles, new bobbin cases. It has step motors. It has happened on small stitches but mostly happens on the large stitches when sewing the underlay. I don't know what the term of bird's nest exactly covers but it's not just loose jumbled up stitches on the back. It will wrap the thread around the tab on the bobbin support and basket, fill up the knife area with thread and suck the garment into the needle plate. I first thought the thread was catching on the bobbin case pigtail but I don't see that.

 

[WildWestDesigns]

Thanks for the help. Using new needles, new bobbin cases. It has step motors. It has happened on small stitches but mostly happens on the large stitches when sewing the underlay. I don't know what the term of bird's nest exactly covers but it's not just loose jumbled up stitches on the back. It will wrap the thread around the tab on the bobbin support and basket, fill up the knife area with thread and suck the garment into the needle plate. I first thought the thread was catching on the bobbin case pigtail but I don't see that.

It sounds like a tension issue. I would also check your upper tension as well. Have you swapped thread types? Gone from Polyester to spun cotton and/or rayon (or metallic etc)? Or any combination thereof? Typically when I have that issue, tension (upper) is too loose. Or even used puffy in a previous project that tension was adjusted, but not adjusted back for regular embroidery?

Bird's nesting really just covers then jumbled up stitches (at least that's all that it's been associated with when I first started doing this many moons ago).

 

[lrsbranding]

I had just checked the upper tension last week before it birds nested again. I haven't checked it with an upper tension gauge. I go off the I test. I presume that the I test would be fairly accurate. The only thing I can think of is that the felt tension discs are worn enough that they don't have enough holding power. Don't know if that is even a possibility.

 

[WildWestDesigns]

I had just checked the upper tension last week before it birds nested again. I haven't checked it with an upper tension gauge. I go off the I test. I presume that the I test would be fairly accurate. The only thing I can think of is that the felt tension discs are worn enough that they don't have enough holding power. Don't know if that is even a possibility.

Well, I have replaced those over the years, but typically in something like this you are looking at upper tension, upper thread not through take up lever, incorrect pathing of upper thread, bobbin tension, hook timing needs to be adjusted. Even fabric bunching can cause this.


Going back to timing. On step motor machines, timing has been a known issue on these compared to servo motors when you start getting more then 3 heads. The ones that are most affected are the ones that are furthest from the motor. Machines like these typically need a little more TLC then servo motors. Our step motors are mainly single heads, some specialty (sequin embroidery). Multi-heads are servo and that's what I would suggest for anyone getting more then a 2 or 3 head machine. Or network a bunch of single heads together.

On checking the pathing (threading) of the upper path, look at it carefully. Sometimes the thread can just get a little out of whack that it looks good from a quick visual glance, but it's out of whack just enough that it doesn't have pressure throughout the thread path. There is a trouble spot like this on Barudan machines, but it will cause constant false thread break errors, not really bird's nesting.

 

[millenniumgirl]

Birdnesting?

I, too, am having issues with this. I just bought a brand new machine and it sewed perfectly during the "training" and now, when I do hats, the thread from the bobbin just turns into a mess underneath. Shirts and test swatches are fine. Just not hats. Any tips. I bought an entry level Highland machine fyi.

 

[WildWestDesigns]

I, too, am having issues with this. I just bought a brand new machine and it sewed perfectly during the "training" and now, when I do hats, the thread from the bobbin just turns into a mess underneath. Shirts and test swatches are fine. Just not hats. Any tips. I bought an entry level Highland machine fyi.

That could be poor digitizing. Hats, particularly structured hats require a different sequence. Although, unstructured hats you can get away with more things, not with structured (which is what most people want it seems).

EDIT to Add: Are you doing anything else with the hats? Puff etc? that might dictate a change in tension "levels"?

 

[millenniumgirl]

No puff or anything like that. I haven't messed with the tensions at all. I did lighten up on the density of the stitches, didn't help. I'll try re-digitizing it for a structured hat. Thanks for the feedback. It's much appreciated.

D

 

[WildWestDesigns]

No puff or anything like that. I haven't messed with the tensions at all. I did lighten up on the density of the stitches, didn't help. I'll try re-digitizing it for a structured hat. Thanks for the feedback. It's much appreciated.

D

Are you doing any designs that have really small areas that you trying to do satin stitching in as well? Smaller you go, sometimes you have to change stitch types to work in that smaller area (or larger area as well, but larger is easier to deal with then smaller). Most machines have a certain min/max stitch width when it comes to satin stitching. Not all are the same. Try to measure out the smaller areas and see if you cross over that smaller threshold. Might have to try to go to running stitches. Bad thing is not all machines have the same min/max values, but it should be in the manual, if not there, tech support for Highland should be able to tell you. I have no experience with those machines (seen them around though), so I couldn't tell you what it would be.

Also it could help using a smaller needle, light weight thread and/or slowing down the machine. That's if it's a design related issue. Since it's only affected hats, that would be my first call. What about thread types? When doing hats, have you switched from say rayon to poly or to spun cotton? Those can dictate a slight change in tension. I would try to stay away from the spun cotton threads though.

 

[LUV DEM TIGERS]

I had just checked the upper tension last week before it birds nested again. I haven't checked it with an upper tension gauge. I go off the I test. I presume that the I test would be fairly accurate. The only thing I can think of is that the felt tension discs are worn enough that they don't have enough holding power. Don't know if that is even a possibility.

The "I" test does not tell you if you have proper tension. It just tells you that the correlation of the tension between the upper tension and the lower tension correspond. If both or too tight, you can have a successful "I" test. If both are too loose, you can have a successful "I" test. If both are perfect, you can have a successful "I" test.

 

[WildWestDesigns]

The "I" test does not tell you if you have proper tension. It just tells you that the correlation of the tension between the upper tension and the lower tension correspond. If both or too tight, you can have a successful "I" test. If both are too loose, you can have a successful "I" test. If both are perfect, you can have a successful "I" test.

Yes and no. In order for it to have a perfect I test with both tensions being too tight or too loose, they have to be still in balance with regard to that tension setting and with the fabric/thread/needle. I personally have never seen where both were too tight (or loose) make a perfect I test and a smooth running machine/stitch out. It has to be a very good "marriage" of every variable to do that. Something that is hard to do as the top thread tension would more then likely be even tighter or looser then the lower tension just due to ease of changing the tension especially during stitch out.

I'm not saying that it couldn't be done, although, like I said, I've never encountered it. Usually something is throwing it for a loop if the settings are out of whack. Typically if it's too tight or loose, sometimes the bobbin trimmer won't even work right and you'll get those error codes as well, with the trimmer still sticking out. There is typically something else that will let you know that something isn't right.

Although, the absolute best thing would be to have tension gauges and that would preclude a lot of speculation as to if everything is in balance, especially if you use different thread types (both upper and lower).

 

[Laz0924]

The Tajima upper tension gage is not very accurate, gets you in the ballpark but I wouldn't depend on it's accuracy. The Towa bobbin tenstion gage is pretty good I set mine at 25 gr and the upper for ploy at about 140 which is higher than rayon about 110 start with that then do a test sew. Also you should not run caps faster than 700spm.

 

[WildWestDesigns]

The Tajima upper tension gage is not very accurate, gets you in the ballpark but I wouldn't depend on it's accuracy.

The tajima upper thread tension gauge requires some finagling that can skew the results if you don't quite do it just so. It can be off by a pretty good margin depending on how you hold your mouth it seems at times.

 

[lrsbranding]

I would presume that if the bobbin tension is set correctly then you could set the upper with an I test. I don't know how to calibrate the Towa bobbin gauge other than comparing the results with a drop test. I have an upper tension gauge but question the accuracy of it. Perhaps I'm using it wrong. I run the thread through the needle then down through the presser foot then pull towards the front. As for the birdnesting, is it possible that if the raceway between the rotary hook and bobbin basket gets gummed up that the basket won't float loosely enough to let the thread pass around the basket stay? Last week I concentrated hook wash into to raceway and blew out with air. Didn't see anything come out but now the bobbin baskets run much quieter and haven't had any problems since. I used LB5 for a month or so to lube the hook but other than that only used Tajima's oil. Is it possible the LB5 caused problems?

 

[lrsbranding]

Never mind. Didn't solve the problem.