Consew 206rb stitch length not adustable question

[olivermarks]

I've got a strange issue with my consew 206rb where I can no longer get my stitch length longer than about 1/8th of an inch. This is after tuning up to stitch thick leather with heavier thread. I had adjusted tension at bobbin and top tension and the stitch length got really short when I overtightened. I'm getting shorter sections of stitches sometimes within a longer section of sewing.

I'm using Coats star nylon 16 pt tex 210 207 with Schmetz Leather Industrial Machine Needle Size 22 - 135x16 TRI, DPx16 D

Can anyone tell me what to adjust, oil or other adjustment to get the full stitch length again? The feed dog goes to the back of the plate looking down on it but doesn't travel to the maximum amount forward, I'm wondering what to adjust to get maximum travel. Thanks!

[kgg]

5 hours ago, olivermarks said:

I'm using Coats star nylon 16 pt tex 210 207 with Schmetz Leather Industrial Machine Needle Size 22 - 135x16 TRI, DPx16 D

Before you go fiddling around with the machine change your needle to match the thread. The needle should be a #24 or in thick / tough material a #25.

A good reference chart for thread and needle combination : https://www.tolindsewmach.com/thread-chart.html

kgg

 

 

[Quade]

Stitch length is set by a mechanism that controls the feed dogs and needle swing. If it didn't do this before the "tune" I'd suggest someone messed up when tweaking the machine. 

1 - I'd probably flip the machine up and try to move the feed dogs by hand with the foot up and needle out of the dogs.   See if there's any slop in the movement.  The feed dogs should be held tightly in place and shouldn't flop around. 

2 - Set it to zero and longest stitch length and observe the feed dogs and needle swing. Does it change properly with no cloth or threading in place?  You can measure the movement of the feed dogs to determine what the stitch length is set to. 

3 - The fact it's intermittent makes me think something is loose or sticking.  Off the main lower shaft is a lever which reaches into a joint which makes the feed dogs move as the machine is cycled. There's a clamp that clamps this mechanism to the feed dog shaft.  The symptoms suggest to me this clamp might be loose.  The reason I think that is that even with the intermittent stitch length, the needle and feed dogs remain in time. Which tells me that the problem is likely before this shaft. This shaft moves both the dogs and needle movement. 

The 206RB used the same mechanism for changing stitch length as the Singer 211 machine. 

 

Edited March 19, 2023 by Quade

[olivermarks]

Thanks for the input.

I may go down to T135 if I can find a good dark.brown color. I know I'm a little undersized on the needle for the 210 thread (It may be a 23 not a 22, Not near machine right now to check). I was testing the Bison leather I'm sewing, which is quite soft, but practicing on similar quality scrap leather. 

I had some leather underside tension issues and did a lot of tweaking of the bobbin as well as the topside tension when I was setting up for heavier material and thread, it is sewing pretty well at the short stitch length right now, but I'm not going to do any top stitch visible sewing on the final product until this is resolved. (It's a bench seat and door cards for a '30's truck)

I checked the feed dog for slop yesterday - I usually put blue Permatex thread locker on the two screws to make sure they don't work loose - and checked the the timing etc. I think the stitch length has been compromised for a while, I just didn't realize it until I started experimenting with tension and length.

The feed dog goes all the way 'back' in it's rectangular enclosure under the needle 'throat' area, but not all the way 'forward' coming back towards me facing it which makes me think something is out of kilter mechanically, but I can't figure out what to adjust, where. 

I did loosen and experiment with the feed dog assembly on the left of the bobbin side, and looked at the cam in the 'fork' (F & H in this pic).

Also the stitch length lever, which is on maximum, was moving slightly when I started sewing which made me think something may be sticking at the wheel end of the machine. I was wondering whether to go in from the top of the machine and check the alignment described in this vid:

 

 

 

[Quade]

I just took a re-look at the 206RB manual and now think I must have looked at the wrong manual.   The mechanism is completely different than the 211.  So my advice was mostly pointless. Sorry. 

[1hp]

this video may help:

 

[olivermarks]

Thanks, i haven't watched these videos in while there's some good info on feed dog longitudinal positioning at 10:00.

[olivermarks]

I'm still grappling with the stitch length issue, spent time today trying to figure out what has changed. The machine is the original 206RB.

Is the large screw head in the image below on left an adjustment point? I didn't want to loosen it until I did further research.
The stitch length lever is barely moving the shaft. You can see the feed dog moving in this video as I move the stitch length lever, it is only moving in the center of the slot. I'm assuming maximum stitch length = maximum feed dog movement?

 

 

 

 

Edited March 25, 2023 by olivermarks

[shoepatcher]

The feed dog looks wrong.  It should be all the same height front to back on it.  Check the adjustment screw underneath to adjust height of the feed dog.  it has 4 motion  feed meaning feed dog comes up, moves back, drops down and then comes forward to complete the cycle.  i would remove the throat plate and take a video of the feed dog moving.

glenn

 

Edited March 25, 2023 by shoepatcher

[Quade]

Quote

The feed dog looks wrong. 

It does look funny. I wonder if it's because he's not cycling the machine but just changing the stitch length?  I'd like to see  a full cycle of the machine manually advanced so we can see what the dog is doing.  

I consider it normal for the feed dogs to move as the stitch length is changed.   I've never seen a machine that didn't have that.  The stitch length adjustment is directly tied into both the feed dog position and speed and the needle rocker arm that moves the needle fore and aft.  

[olivermarks]

The feed dog looks a bit weird in that video because I hadn't adjusted it back after changing height etc to see if that was the issue. I'm still unclear what shifted and why so I no longer have max stitch length. At least I'm learning more about the wheel end of the machine!

The forward and reverse stitch lengths are identical, i don't wan tto mess that up too. The machine is also sewing ok, no major issues.

Edited March 26, 2023 by olivermarks

[olivermarks]

Can anyone tell me what will happen if I loosen these two fasteners marked with the two arrows?

They are the base of the stitch length lever.

 

 

I am still trying to get the maximum stitch size back! My machine is running like butter - I've reset just about everything to tolerances but still not getting the maximum length. I have been sewing with the stitch set at max, and occasionally the stitch length lever gives a little jump when I start sewing, which is odd. Still trying to figure out what, where, how...

I don't speak Spanish, this video seems to be talking about what to adjust, not 206rb but looks useful?
 

Thx

 

 

 

Edited April 1, 2023 by olivermarks

[Gump]

I have a Consew 227r that uses the same lever set up, and on the inboard end of the lever is a set screw that holds the adjustment lever in place. On mine the shaft can slide in and out, changing the amount of available adjustment. I slid mine in and now have 5 spi. My machine also has the handle pointing the other way with grip ribs pointed up, so your machine may have been tinkered with before.

[1hp]

looks like photo in manual.

[olivermarks]

Thanks. 

do you mean the adjustment inside the machine behind the stitch length lever circled below? I'd better take that apart and check it

 

[1hp]

looks like they mean move lever to desired stitch length and tighten knob "M".

[Wizcrafts]

33 minutes ago, olivermarks said:

do you mean the adjustment inside the machine behind the stitch length lever circled below?

NO! The stitch length is set by the knurled round nut ON the stitch lever, on the outside of the machine. Turn it counterclockwise to increase the maximum stitch length, then pull the lever down to set that length. turning the knurled nut clockwise will shorten the maximum stitch length and move the lever further up.

[olivermarks]

50 minutes ago, Wizcrafts said:

NO! The stitch length is set by the knurled round nut ON the stitch lever, on the outside of the machine. Turn it counterclockwise to increase the maximum stitch length, then pull the lever down to set that length. turning the knurled nut clockwise will shorten the maximum stitch length and move the lever further up.

I've been using the knurled 'M' round nut for years to change stitch length. It's one of the most basic functions on the machine. The issue is that the functionality of the stitch length mechanism isn't working properly and I'm still trying to figure out why.

[Wizcrafts]

22 hours ago, olivermarks said:

The issue is that the functionality of the stitch length mechanism isn't working properly and I'm still trying to figure out why.

Maybe these manuals will help, if you don't already have a copy.

 

Consew_204RB-1,_206RB-1,_208RB-1.pdf consew_204_206_208.pdf

[Quade]

Trying to picture in my head how moving the stitch length lever up and down changes how much the feed-dog bar rotates.   Does it change how much the forked rod, that goes into the upper shaft eccentric moves up and down? Or is it back and forth? 

I'd probably try to observe how changing the stitch length lever changes how much the feed dog shafts rocks back and forth.   The forked rod goes around the upper shaft eccentric so it much rock back and forth when the main shaft is moving.  Somehow this is converted into up and down movement of the lever connected to the feed dog shaft.  The amount it rocks up and down is controlled by the stitch length adjustment.  Putting it in reverse must make the feed dog shaft move in reverse. 

I imagine examining how that linkage works would show why you're not getting max throw which would be max stitch length. 

 

Edited April 3, 2023 by Quade

[Gump]

Yes, the circled set screw inside the head allows a slide to move in and out. Mine would only give me 7 spi, and I moved the shaft farther in, and it allowed for more adjustment on the knurled knob.