Transition Of Thickness

[reddevil76]

I have a bifold design which has an inside area where it transitions from 3 layers of 3 oz to 2 layers.

Now, I know a walking foot can handle the transiting layers. However, what happens when the transition is underneath? (feed dog side)

Also, during the demo (when I was buying it), we did try sewing 2 layers of 5-6oz and transiting to 1 layer. And when it went to 2 layer, the stitches started to have knots below. I was told I would need to fiddle around to sew different thicknesses. How do you deal with needle and bobbin tension when the project you are sewing has different thicknesses? I can't possibly be changing tension in the middle of a project?

My machine is arriving in a few days, but I can't wait to gather some info before I jump into it... sorry..

[reddevil76]

Also, stitch length changes when the thickness of the project changes.

How to maintain a constant stitch length with a project of varying thickness?

[Wizcrafts]

What type of machine are you referring to RedDevil? The stitch length variance you describe always occurs on top feed only patchers. Is the machine a Patcher?

If so, your only recourse is to pull the material back as the foot feeds it, giving it a little assist. How much this helps depends on how worn out the feed mechanism is. A factory tight Singer Patcher cannot give better then 5 stitches per inch, and this would be into about 1/8 inch of leather. This drops as the thickness increases, unless the foot pressure is rather light.

This behavior can also happen on a needle feed only machine, or a double feed machine without a feed dog, but under high top pressure.

[reddevil76]

What type of machine are you referring to RedDevil? The stitch length variance you describe always occurs on top feed only patchers. Is the machine a Patcher?

If so, your only recourse is to pull the material back as the foot feeds it, giving it a little assist. How much this helps depends on how worn out the feed mechanism is. A factory tight Singer Patcher cannot give better then 5 stitches per inch, and this would be into about 1/8 inch of leather. This drops as the thickness increases, unless the foot pressure is rather light.

This behavior can also happen on a needle feed only machine, or a double feed machine without a feed dog, but under high top pressure.

Hi Wiz, I bought a used Pfaff MA 1245. It's a walking foot machine. It is rated to sew 207 top and 138 bottom. But during the demo, we managed to do 277 top and bottom, so I snapped it up.

[Wizcrafts]

Hi Wiz, I bought a used Pfaff MA 1245. It's a walking foot machine. It is rated to sew 207 top and 138 bottom. But during the demo, we managed to do 277 top and bottom, so I snapped it up.

If you continue using #277 thread in that machine you may wear it out in no time at all. You may wish to consider replacing critical bearings and moving parts in advance. See if there is a titanium coated hook available for it. Use the best needles money can buy; not Organ brand, with the longest amount of needle below the eye. The slower the taper of the needle, the less stress it places on the machine as it pounds through the dense leather, with a very large needle and thick thread, with which it was not designed to sew.

[reddevil76]

If you continue using #277 thread in that machine you may wear it out in no time at all. You may wish to consider replacing critical bearings and moving parts in advance. See if there is a titanium coated hook available for it. Use the best needles money can buy; not Organ brand, with the longest amount of needle below the eye. The slower the taper of the needle, the less stress it places on the machine as it pounds through the dense leather, with a very large needle and thick thread, with which it was not designed to sew.

Hi Wiz, it was actually reconditioned and destined for export to Vietnam. There were several units, and when I expressed my interest, the dealer pulled out one unit for me. The dealer said he has changed all the wear and tear parts and included a brand new table and servo motor.

I brought a friend along who has been working with leather for 6-7 years, and he told me it is very likely the dealer is telling the truth looking at the machine.

I am probably going to sew about 5-6 wallets a month, and using #277 top/#138 bottom for only 2-3 of them. Most of the time, I would use #207 top.

Now I just hope I can learn how to control it (the lowest setting on the servo is too weak) and work with transiting thickness. With handstitching, I always plan where all my stitches will land, to the dot. Using a machine will be a totally different ball game for me.