Brother LS2-B837 Sews Forwards But Fails in Reverse.

[LunarConcepts]

Hello,

 

The above mentioned machine was recently serviced. Since its been home, I have used it about 2 hours running heavy nylon belts with great results. It was then set up with a binding attachment and has seen minimal time just sewing some binding across maybe 50 2" pcs of webbing. The issue I am having is that it will sew forward with no issue but unpredictably it will not sew in reverse without trying to wrap the top thread up into the hook area or pluck strands off the braid causing them to pile up in the needle hole.

The big change would be that I started binding a layer of Cordura and Diamond Ripstop edges together so my tension is down about 3 turns from where I was. I even went back to my previous settings and would say its only slightly better with thicker materials and more tension. I am using the same needle and thread though all this.

When sewing and reversing with speed it seems to do better than when I'm just walking through starting a seam and want to back-stitch 3 or so stitches. Sometimes its great and others it nests up so quick you cant react. You can sew through four layers of binding tape up and back 5" and not have an issue. The first back stitch on your project and BAM!

When sewing through material it is audibly louder with  a clank, clank, clank in reverse. Without thread and material the machines sounds the same in both directions.

Hook timing looks solid. reverse is just something I never had to play with so I don't know what to go after. Could the reverse "stop" have something to do with it? The machine came to me where the stop set that the stitch onnly revers at about a 3 length where I stitch more in the 5 range so I did lower the stop to better match the forward stitch length.

Thanks for your suggestions.

[Diyer]

Put it back to what you were doing before it was serviced.

Check for any changes- different noises etc. Check if it does reverse as it should.

If it doesn't, or there are noises that were not there before the service, there are two possibilities.

1.The servicing has introduced a fault somewhere- ask exactly what they did.

2.Something has come loose or out of adjustment, since the servicing, but not neccessarily as a result of it.

I would be inclined to look at the parts book if there is one, to see what is involved with reverse.

You could also unthread the machine, and see if reverse is still a problem. I do not know your machine, but what I am suggesting is basic fault finding routine.

[LunarConcepts]

Thanks for your reply.

The machine went into service because it was in desperate need of a tune beyond set the timing and go. The machine would nest thread no matter what. The machine came back after service at Keystone and ran great. I'm looking for the  tip as to why it sews great in forward and only messes up in reverse. It runs smooth when not actually threaded. There is something with either the thread deleivery or take up that is only happening when the R-lever is pressed.

I have run the gammit of upper and lower tension to see if more or less would make a difference with no real favorable result. It does seem slightly better with more tensions or keeping the speed up. The proble is I am sewing inside of a 9x3x3" bag and you just cant go that fast.

Thanks again!

[mikesc]

If Keystone did the service..why not ask them ( phone ) what might be going wrong, they know your machine far better than anyone on a forum?

Edited March 18, 2017 by mikesc

[LunarConcepts]

3 hours ago, mikesc said:

If Keystone did the service..why not ask them ( phone ) what might be going wrong, they know your machine far better than anyone on a forum?

They are not in till Monday and this forum is filled with a very knowledgeable, and in the past, helpful crowd.

[brmax]

I agree wait till monday. 

On a trouble shoot the issue sounds to start with tension change to a binding operation. Thats something we all have to struggle and learn to do. Or its seems in my cases anyway always the new task or weird materials make the need to change.

I am hesitant in saying much on the reverse adjustment as im not familar, though it looks to be very similar to a singer 211 in looks. So im real curious as the procedureu

 

Floyd

 

[LunarConcepts]

Ill certainly give them a call. The service was 5 months ago. This wasn't a situation were I got home and a  day later and the machine just started acting up. It wasn't used much as its not my primary machine I use for business now.

[Docado]

If i was having this problem, i would try sewing in reverse first, on a test strip of course. If it was stitching correctly in that direction, I would start stitching in the forward direction over the top of previous stitches (reverse). If it them birds nests or messes up, it would appear to be more related to needle size than the reverse direction. In that case I would change to the next size larger needle. If there is not enough space in material where needle pierces along with thread being doubled up in same hole, it may cause problem you are having. Hope this helps.

[LunarConcepts]

1 hour ago, Docado said:

If i was having this problem, i would try sewing in reverse first, on a test strip of course. If it was stitching correctly in that direction, I would start stitching in the forward direction over the top of previous stitches (reverse). If it them birds nests or messes up, it would appear to be more related to needle size than the reverse direction. In that case I would change to the next size larger needle. If there is not enough space in material where needle pierces along with thread being doubled up in same hole, it may cause problem you are having. Hope this helps.

Docado, Thank you! I was gonna just stay away from the problem today and avoid the headache. Your post prompted me to sit back down and look at it again. I went ahead and swapped up two sizes on the needle. I noticed that my bobbin was getting low and just figured I'd take care of that while be blood pressure was still down   I started out on a 12" double layer of bias tape and noticed that the top tension was real high. Figured it was the larger hole the needed was making and made the appropriate adjustments. I went back and forth on that 12" pcs probably 30 times randomly throwing in back stitches.  It was running like a champ!

For education purposes, I threw the 19 needle back in place of the 21 (T90 thread) and it also sewed perfectly. I then threw the original bobbin in and it all went south! Turns out, I have better then a handful of bobbins that are "sticky" in the case and I just happen to have 3 of them in a row. Its a vertical axis machine and certain bobbins I have are getting pinch between the backlash spring and the bobbin hold down arm. some move freely up and down against the backlash spring tension but still drag on the hold down arm right where it folds over and contact the corner of the bobbin hole. You really notice how inconstant and jerky the bottom tension is, with the bad bobbins, when you pull on the bobbin thread when it isn't laced through the bottom tension spring.

I have always sewn heavy webbing on this machine. I image that I never experience the problem prior barbecue I was always sewing with such high top stitch tension that it just overcame any lower tension inconsistencies.

Thanks again for suggesting a helpful course of action.

[Docado]

Congradulations! Glad you were able to get everything worked out. Thank you for reply back and on how you were able 

to fix problem.