Rookie issue with Techsew 5100

[TES]

15 hours ago, Wizcrafts said:

On my Cowboy CB4500 and my friend's Cobra Class 4, both of us can back off the top tension disks spring to the point that there is no tension at all. This is the same lack of tension we get when we lift the feet all the way with the hand lifter knob, or foot lifter pedal. When you lift the feet does the tension drop to, or close to zero at the disks?

If the tension can be set to zero at the top disks, can the same be done by backing off the beehive spring on the bottom roller? Standard procedure is to wrap the thread around the bottom roller 1.5 turns. Check the tension as the thread exits the bottom roller.

Move on to the check spring. Is the spring able to move up and down as the take-up lever moves up and down? Inspect the inside of the loop at the end of the spring to see if it has a burr, or is somehow pinching the thread.

Inspect the thread hole in the take-up lever for burrs.

Inspect the lower thread guides, including the thread hole on the needle mounting clamp.

You need to figure out where along the thread patch the tightness is coming from. Maybe it is the spool itself. Is it cross-threaded? Once you are able to set the path to zero tension, balance the top and bottom. You should be able to back off the bobbin tension to a bare minimum and balance the knots.

Make sure you're using the best thread and needle combination. Consult this needle and thread chart.

Partial victory!

I went out this morning and took the bobbin shuttle out and cleaned everything. I polished all of the surfaces with 2000 grit and finished off with 2500 grit sandpaper. I could definitely feel the corrosion when rotating the bobbin shuttle....No more though....it is now polished up and smooth as silk.

I made the first stitch and it did the same thing (top thread looping around), but it was a much, much looser loop. I loosened the two top tensioners and changed the EPS to stop in the needle UP position. It has worked flawlessly ever since...Flawlessly in that the top thread doesn't catch or loop in the bobbin shuttle.....I still can't figure out completely why the little knots are showing. I have the bobbin thread as tight as it can go and the top thread is now no as tight as it was. I think that the tightness was caused by this: on the tensioner where you make 1.5 turns the last half turn of thread was laying on TOP of the bottom thread. I rethreaded and passed the half turn INSIDE the first turn....now the thread tension seems to be much smoother. All of the tension issue I think was from the bottom roller (1.5 turns)....

When you lift the feet does the tension drop to, or close to zero at the disks?   Yes sir, when I lift the foot, most all of the tension on the top thread is gone. 

I thought that tightening the bobbin tension would pull the knots down toward the back of the work....

I am going to order new needles and thread today. I did change the needle yesterday to a 23....but I only have the Tex207 for thread (machine thread).

The back stitches look perfect....front stitches have the knot showing...please see below.

My preference is that I like to see the stitches, meaning I like a heavier thread when possible....The thread I am using now says Techsew Tex207. Based upon the chart, I should be running a size 23 needle.

What brand of thread and needle do you recommend? I'm brand new at this...

 

I thank you all again for your help.

 

Tom

 

[AlZilla]

Looks like your sewing a single layer. I wonder if the bottom thread disappears when you sew 2 layers together?

[TES]

5 minutes ago, AlZilla said:

Looks like your sewing a single layer. I wonder if the bottom thread disappears when you sew 2 layers together?

That is two layers....but they are probably two -three oz layers.

[kgg]

41 minutes ago, TES said:

What brand of thread and needle do you recommend?

I find Schmetz needles work the best in my machines. Buy a brand name like A&E and stay away from the cheap Chinese stuff particularly the 8 oz spools. Buying a brand name thread will save you a lot of frustration. I use A&E (www.amefird.com) thread in either bonded polyester or bonded nylon.

28 minutes ago, TES said:

That is two layers....but they are probably two -three oz layers.

I think this is just to thin of leather to allow proper seams appearance for a Class 441 machine. If this is the thickness you are going to typically sew I would suggest getting the narrow feed dog and needle plate that @RockyAussie came up with and also refer to @Wizcrafts article on dumbing down a Class 441 machine (  Dumbing down a Cowboy CB4500, Cobra Class 4, or similar harness stitcher ( https://www.rw-leatherworks.com/blog/2019/02/dumbing-down-a-cowboy-cb4500-cobra-class-4-or-similar-harness-stitcher.html )).

41 minutes ago, TES said:

The thread I am using now says Techsew Tex207. Based upon the chart, I should be running a size 23 needle.

No, for V207 thread which is Tex 210 the needle should be a #24 and in thick / tough / sticky materials you may have to go up to a #25 needle. The #23 needle is for V138 (Tex 135).

kgg

Edited May 28, 2023 by kgg

[TES]

43 minutes ago, kgg said:

I find Schmetz needles work the best in my machines. Buy a brand name like A&E and stay away from the cheap Chinese stuff particularly the 8 oz spools. Buying a brand name thread will save you a lot of frustration. I use A&E (www.amefird.com) thread in either bonded polyester or bonded nylon.

I think this is just to thin of leather to allow proper seams appearance for a Class 441 machine. If this is the thickness you are going to typically sew I would suggest getting the narrow feed dog and needle plate that @RockyAussie came up with and also refer to @Wizcrafts article on dumbing down a Class 441 machine (  Dumbing down a Cowboy CB4500, Cobra Class 4, or similar harness stitcher ( https://www.rw-leatherworks.com/blog/2019/02/dumbing-down-a-cowboy-cb4500-cobra-class-4-or-similar-harness-stitcher.html )).

No, for V207 thread which is Tex 210 the needle should be a #24 and in thick / tough / sticky materials you may have to go up to a #25 needle. The #23 needle is for V138 (Tex 135).

kgg

Many thanks for this information....EXACTLY what I needed. 

 

Thanks again for all of your comments.

 

Tom