Inconsistent stitch length Ferdo Pro 2000

[jrk65]

Not sure how "I" messed up this machine. Yes it was operator error.

If you sew a straight line at same speed it sews wonderful, speed up or slow down and the stitch length begins to shorten, may or may not come back to normal.  If you stop at a corner and let needle go to bottom and start up 1/4 inch then lift presser foot and turn project the next stitch will be very long followed by 2 or 3 normal then it will start to shorten again.

Current needle is 25/200 with bonded nylon 277 thread.  Have tried dozens of thread needle combos,  learned a lot, didn't fix problem.

I have watched numerous videos of threading 441 type machines.  There are several different opinions about this topic.  I have tried them all.  Some seem to give more thread tension than is necessary.  None fix my problem.

Also have spent hours with thread tension.  It is not the problem.  I also found some old style, steel Juki type bobbins.  Not the problem.

I have tried a bunch of pressure settings for the presser foot.   Some with heavy marks in project, not the problem.     Currently have the smooth plate and needle guide  that Ferdco uses.   That is not the problem.  

Gets worse with very thick (max thickness) or in a couple layers of soft chap leather  4/5 oz each

I have checked belt tension, not slipping. Machine is well oiled and bobbin shuttle etc. are clean and lubed.

I have spent hours with the UWE Grosse videos on timing.    As stated, if you start of in a straight line it sews like a dream.  Very nice top and bottom thread.

This project is 10/12 oz veg tan and 5 oz chap; 277 bonded nylon, 25/200 needle

 

 

 

 

[kgg]

29 minutes ago, jrk65 said:

This project is 10/12 oz veg tan and 5 oz chap; 277 bonded nylon, 25/200 needle

Any chance of a couple of photo's of your thread path to the needle? Have you tried moving up to a #26 needle with the V277? Have you tried installing the bobbin so the thread comes off clockwise rather then CCW?

kgg

[jrk65]

28 minutes ago, kgg said:

Any chance of a couple of photo's of your thread path to the needle? Have you tried moving up to a #26 needle with the V277? Have you tried installing the bobbin so the thread comes off clockwise rather then CCW?

kgg

thanks for asking: as I posted, I have used dozens of poly and nylon, 207 and 277 threads, and needle combos,  Ive tried all the different combos of half wrap to full wrap to one and a half wraps around the tension disks.  I have not, put the bobbin in reverse or clockwise. 

[Patrick1]

Enlighten me @kgg on why you would change the rotation of the bobbin except for adding another problem as in screwing up the spring.

[kgg]

1 hour ago, Patrick1 said:

Enlighten me @kgg on why you would change the rotation of the bobbin except for adding another problem as in screwing up the spring.

Sometimes parts become weak with use and having the thread spool off the bobbin in the reverse direction can overcome the shortfall.

kgg

[Wizcrafts]

Remove the throat plate and check if the feed dog screws have come loose.

[Patrick1]

@Kgg, I'm still not enlightened. What parts become weak? Are you talking about the tension spring? If so replace it. Running the bobbin in the clockwise direction will eventually damage the bobbin spring. Sounds like some kind of folklore with no mechanics to it.

[kgg]

4 minutes ago, Patrick1 said:

What parts become weak?

The spring, poor bobbin tolerances, etc. This is used to help determine if the problem lies within the bobbin hook shuttle. If by reversing the position of the bobbin stitches become better you know where the problem lies.

kgg

[jrk65]

Thanks for the questions/suggestions.

This is a fairly new Shuttle/bobbin case.  Stitches are perfect top and bottom when it sews.  More than likely  not a tension problem, which running the bobbin backwards would be likely to address.

There is no feed dog, as I mentioned in my post I'm running the Ferdco system of a smooth plate and needle guide but no feed dog.  This is not the problem, I know of dozens of these around and they sew nicely.  At some point recently, this machine did too!

After further investigation I am leaning towards Needle/Walking Foot Timing

Thanks for your interest in my troubles

[RockyAussie]

13 hours ago, jrk65 said:

There is no feed dog, as I mentioned in my post I'm running the Ferdco system of a smooth plate and needle guide but no feed dog.

Does this machine not have a needle guide down under the needle plate? I believe that on most other 441 class machines that this part is where a feed dog is normally in place and what @Wizcrafts is suggesting is that you check that this

part has not come loose.

As for the needle/walking foot timing I have to wonder why it would be right most of the time and not other times. I would first check that the back walking foot lifts smoothly and easily without any catching This pic shows a screw that allows the roller to be tighter or looser to the guide for the back walking foot - 

and then also that there is no excessive slop in any of the linkages that connect to the front walking foot and needle bar assembly. Make sure that the connecting rod coming off of the cam on the end of upper shaft has not come too loose or worn out. Many many operators do not do a good enough job of lubricating those knuckles on these rods. They do have oil holes in them and most people do NOT oil them. No video or even most manuals show all of the holes that should be oiled on these machines. Simple ...if it turns/revolves it should be oiled. 

Edited March 12, 2023 by RockyAussie