Newbie questions (lot of them!)

[RaSk]

Hey!

I'm Alex from France, I've discovered a new passion for upholstery and I want to transform this hobby into a business as soon as possible.
My goal is to make upholstery for cars and motorbikes. I'm using only vinyl fabric for now but I hope someday to start using real leather! 

I have watched probably more than a dozen hours of YouTube videos (if Cechaflo is here, you're a god!), and bought the Lucky Needle course. I've also got probably 30+ hours of sewing and 30 hours of patterning experience for now.

I've got a lot of questions regarding upholstery, sewing, and sewing machine, to avoid separate topics I decided to post them all here (my biggest current pain is slow stitching).
 

1. Machine - I bought a Durkopp 239, it's a walking foot single needle. Was it a good choice? I can't really get my money back and I also don't understand the differences between all those walking foot machines.
2. Slow stitching - I have a Juki servo motor (JK-513-A) and a needle positioner. My current issue is that I can't do "less than 1 stitch point", it is binary: needle up or needle down. But I can't do an approach using my foot like Cechaflo does in a lot of his videos. Have I been tricked by the vendor who told me the servo motor was the best for my use? I tried using the M0 parameter (no synchro) but I still can't get it to work as I expect. Now he is telling me that I should buy an EFKA servo motor that is more expensive than the machine itself. I've seen Uwe's video with a thumb controller, it seems amazing, but can I do it with my current brushless motor? My first guess is that the needle positioner itself his blocking the wheel in up/down position, but the vendor seems to insist that it's not the case.
3. Presser foot lever - My foot lever behind the machine is very hard. Is there something wrong? It is a bit easier when I use my knee on the "under the table lever", but if I release it it's like a 10kg force that seems to be realeased.
4. Bobbin thread - I've read around here and seen on some videos, that it's better to use the same thread for the needle and the bobbin. I've also heard that you can use a thinner thread for the bobbin and it will make a better seam aspect. What is your experience regarding that last statement? And what are the downsides/benefits of both solutions?
5. "Reversible" sewing - As I'm borrowing the small CNC from my wife (Cameo 4 Pro), I was trying to digitize some patterns and then draw seam lines & cut on the backside of the vinyl with some nice results. Following the previous question, if I use the same thread for the bobbin, is there a world where I can sew from the backside of the vinyl? Mostly for a purely decorative seam, like drawing something on the back and stitching it from the "back" side. My understanding of lockstitch makes me think it is possible.
6. Felled seams - I don't know the correct terms for this question, but I think I do 99% of the time "felled seams". I'm doing small stitches for the "inside" seam and as long as I can in the "decorative" / strengthening seam. I have some questions: is it normal that the "decorative stitch" seems so hard? Would a bigger foot help me, a bulky one, like the one that comes with the Sailrite Ultrafeed? My current foot seems thin on the right side, and I'm probably sewing too close to the seam as I can see the "inside" seam a bit appearing. Is this the case? How can I improve my felled seam?
7. Open seams - I've seen some designs done with only "open seam" or a mix of them, basically skipping the decorative seam. They seem nice in some designs, but what are the downsides of doing that?
8. Presser foot guide - I've also bought (by recommendation of the vendor) a presser foot with an edge guide, exactly this one but 3 times more expensive, to do the decorative seam mentioned above, my issue is that it does small stitches. I've tried reducing the spring tension but still not very effective. It's probably not a good idea to use it for felled seams, is it?
9. Curves - I've been improving my curves skills but I still have a lot of difficulty with very sharp curves (like a 90° angle in 3cm / 1,2 in). I can do them "properly" (read "acceptable") maybe 1 out of 4 or 5 times, including a lot of relief notches and manual sewing (hand on the wheel, as I can't do approach, see question 2). Is this even possible? Or should I change my designs? Any tips? I've tried stapling but it's not really compatible with stress relief notches.
10. Patterning notches - I try to add as many notches as I can (maybe too much), but in general, do you recommend adding notches inside the curves and/or before/after?
11. Curves on curvature - When I do patterning, I'll have two pieces (let's say A and B ), but sometimes I end up with: A straight + B curved, A curved + B curved in the same direction, or worse A curved + B curved but in opposite direction. I guess that it comes from the curvature of the model (like concave or convex parts), but I still can't get my head around it. Am I doing something wrong?
12. Stress relief notches - Following the last question, I try to use "tension" relief notches (only small perpendicular cuts) as it's easier for me to do and foresee. I still rarely use "compression" relief notches (triangles to have less material and avoid wobbly material), should I use them more? In which case? For the "tension" relief notches, I find it easier to cut a lot of them thinly (like 2mm), it seems to help but the downside is that I can't use staples. Is there any reason I shouldn't do this (cutting thin tension relief notches)?

Sorry for the long post, here's a baguette and a glass of wine for your time: (oops can't include emoji, but the intention is there <3 )

Merci!
Alex

Edited July 5, 2022 by RaSk

[dikman]

Whew! Anyhow, welcome to the forum RaSK. The only one of your questions I feel even remotely qualified on commenting on is #2. It seems to me you would be better off without the needle positioner as then you will decide where the needle stops. There should be a setting in the servo menu to disable it. If you want really slow speed then fit a speed reducer pulley, this will let you crawl the needle if necessary, the downside will be a loss of top speed but with leather this isn't usually a problem. I doubt if a "better" servo will help as a needle positioner is designed to stop either up or down when you stop, regardless of the servo type.

I tried a positioner but didn't like it as it would sometimes put a stitch where I didn't want it (not good in leather!).

#3 I'm not familiar with your machine but it sounds like you have too much spring tension on the presser foot? Many machines have an adjustment knob/wheel/screw on top to vary the tension.

[SARK9]

2 hours ago, RaSk said:

........my issue is that it does small stitches. I've tried reducing the spring tension but still not very effective.

With many of the **import** presser feet I've purchased, the installed length of the foot assembly can be wildly variable, and your foot motions may be totally wrong in terms of the presser foot's lift timing and height, as well as the walking foot's actual usable loading of the work against the feed dogs for transport. This is usually a trivial adjustment on the Singer 111w** type machines, but I have no firsthand on the 'Adlers. There are several Adler owners that will know if that adjustment is similar to the Singer/Juki/Consew walking foot mechanisms, and if so, its well documented on member Uwe Grosses' excellent videos.

-DC

[toxo]

Welcome to the forum Alex.

I have the same machine and can do a stitch at a time simply by changing the handwheel for a bigger pulley. Very cheap to do. The needle positioner is very useful once you get used to it. I also have those presser feet with the spring guides, again useful in their place but they don't dictate the stitch size. Thats adjusted by the reverse lever.

[kgg]

14 hours ago, RaSk said:

Bobbin thread - I've read around here and seen on some videos, that it's better to use the same thread for the needle and the bobbin. I've also heard that you can use a thinner thread for the bobbin and it will make a better seam aspect. What is your experience regarding that last statement? And what are the downsides/benefits of both solutions?

I normally use the same size thread on the top and in the bobbin. Sometimes you want to highlight your top seam but don't need the additional strength that will be provided by the same size thread in the bobbin. The main thing to remember is the strength of the seam will only be as strong as that provided by the smaller thread.

 

14 hours ago, RaSk said:

Slow stitching - I have a Juki servo motor (JK-513-A) and a needle positioner. My current issue is that I can't do "less than 1 stitch point", it is binary: needle up or needle down. But I can't do an approach using my foot like Cechaflo does in a lot of his videos. Have I been tricked by the vendor who told me the servo motor was the best for my use? I tried using the M0 parameter (no synchro) but I still can't get it to work as I expect. Now he is telling me that I should buy an EFKA servo motor that is more expensive than the machine itself. I've seen Uwe's video with a thumb controller, it seems amazing, but can I do it with my current brushless motor? My first guess is that the needle positioner itself his blocking the wheel in up/down position, but the vendor seems to insist that it's not the case.

I would turn off the needle positioning then add a speed reducer pulley between your servo motor and the machines hand-wheel or change the size of the machines hand-wheel pulley. There are pulley size calculators out there that would help with sizing the hand-wheel for a given motor and pulley speed.

Are you binding the edges of the material??

14 hours ago, RaSk said:

Felled seams - I don't know the correct terms for this question, but I think I do 99% of the time "felled seams". I'm doing small stitches for the "inside" seam and as long as I can in the "decorative" / strengthening seam. I have some questions: is it normal that the "decorative stitch" seems so hard? Would a bigger foot help me, a bulky one, like the one that comes with the Sailrite Ultrafeed? My current foot seems thin on the right side, and I'm probably sewing too close to the seam as I can see the "inside" seam a bit appearing. Is this the case? How can I improve my felled seam?

If you were doing a lot of felled seams I would invest in a flat felled seam attachment.

kgg

[Wizcrafts]

16 hours ago, RaSk said:

Presser foot lever - My foot lever behind the machine is very hard. Is there something wrong? It is a bit easier when I use my knee on the "under the table lever", but if I release it it's like a 10kg force that seems to be realeased.

16 hours ago, RaSk said:

Now he is telling me that I should buy an EFKA servo motor that is more expensive than the machine itself.

You should back off the pressure screw on top of the left side of the head, over the presser bar. This screw pushes down on a coil spring that pushes on the outside foot. There may also be a second, smaller screw adjuster over the inside foot that can be backed off.

Perhaps your brushless digital motor is dependent on the needle positioner due to the way it was set up at the factory. If you want to change motors, look for an analog brush motor with a speed limiter knob, like the one on this page.

[RaSk]

Hey guys! Thanks for all the answers.
 

18 hours ago, dikman said:

It seems to me you would be better off without the needle positioner as then you will decide where the needle stops. There should be a setting in the servo menu to disable it.

I've tried disabling the needle positioner (the M0 parameter, M1 is "synchro activated") but it doesn't seem to have much effect besides stopping less accurately the needle. My guess is that the needle positioner, even disabled on the servo motor, has still a mechanical effect on the shaft/pulley, but it's a newbie guess.

17 hours ago, SARK9 said:

With many of the **import** presser feet I've purchased, the installed length of the foot assembly can be wildly variable, and your foot motions may be totally wrong in terms of the presser foot's lift timing and height, as well as the walking foot's actual usable loading of the work against the feed dogs for transport. This is usually a trivial adjustment on the Singer 111w** type machines, but I have no firsthand on the 'Adlers. There are several Adler owners that will know if that adjustment is similar to the Singer/Juki/Consew walking foot mechanisms, and if so, its well documented on member Uwe Grosses' excellent videos.

-DC

Here's a picture of the difference in stitch length: on the right max length with regular foot assembly and on the left various tries with the edge guide presser foot (reducing loading, reducing spring tension, etc.).
Now that you've pointed out, I've noticed the foot assembly is not aligned with the feed dogs for transport...... Is that it?!
Also my regular foot assembly has teeth underneath, and the edge guide presser foot has none.

 

17 hours ago, toxo said:

Welcome to the forum Alex.

I have the same machine and can do a stitch at a time simply by changing the handwheel for a bigger pulley. Very cheap to do. The needle positioner is very useful once you get used to it. I also have those presser feet with the spring guides, again useful in their place but they don't dictate the stitch size. Thats adjusted by the reverse lever.

Thanks for your reply. So you would suggest a bigger pulley and keeping the needle positioner? I've measured my current pulley I think it's between 70 and 80mm, so I'd guess 75mm.

 

5 hours ago, kgg said:

I normally use the same size thread on the top and in the bobbin. Sometimes you want to highlight your top seam but don't need the additional strength that will be provided by the same size thread in the bobbin. The main thing to remember is the strength of the seam will only be as strong as that provided by the smaller thread.

 

I would turn off the needle positioning then add a speed reducer pulley between your servo motor and the machines hand-wheel or change the size of the machines hand-wheel pulley. There are pulley size calculators out there that would help with sizing the hand-wheel for a given motor and pulley speed.

Are you binding the edges of the material??

If you were doing a lot of felled seams I would invest in a flat felled seam attachment.

kgg

Thanks, makes total sense for the bobbin suggestion! I think I'll keep it simple and use the same thread for both.

After watching some videos on pulley reducer it seems that it would do the trick.
Regarding the calculator I think this is the one: https://www.blocklayer.com/pulley-belteng.aspx
Are there standard dimensions I can/should use?

Regarding the stitching I'm doing, this is what I called a "felled seam" but I'm not sure it's the correct term.

 

4 hours ago, Wizcrafts said:

You should back off the pressure screw on top of the left side of the head, over the presser bar. This screw pushes down on a coil spring that pushes on the outside foot. There may also be a second, smaller screw adjuster over the inside foot that can be backed off.

Perhaps your brushless digital motor is dependent on the needle positioner due to the way it was set up at the factory. If you want to change motors, look for an analog brush motor with a speed limiter knob, like the one on this page.

Thanks. While doing my pressure foot testing, I've almost unscrewed completely the pressure screw and it's a bit better now. 
My motor is still almost completely new so I guess I'll go for a speed reducer pulley solution for now, but thanks for the suggestion.

 

 

 

I've recorded this video of what happens. The worst part is sometimes when I'm trying to do 1 stitch, it does 3 or 4 very quickly.
I first thought it was my foot sensitivity issue, that I wasn't used to it. But I've tried manually, like adding grams of force, but still almost impossible to do 1 stitch.

 

Edited July 6, 2022 by RaSk

[toxo]

Those presser feet with the blades are meant to be used on an edge.

This is the enlarged pulley on my Durkopp Adler 69  (Similar on the 239).  It's 270mm diameter with a 40mm pulley on the servo motor. Total cost about £50 iirc. Note the needle positioner doing it's job.

 

[SARK9]

3 hours ago, RaSk said:

Here's a picture of the difference in stitch length: on the right max length with regular foot assembly and on the left various tries with the edge guide presser foot (reducing loading, reducing spring tension, etc.).
Now that you've pointed out, I've noticed the foot assembly is not aligned with the feed dogs for transport...... Is that it?!

Have a look at:   About 3:12 for a couple of things to check. At the point in the cycle where the presser foot should be holding the material down, try to wiggle it from side to side to check the hold down force. Also test when the presser foot lifts to see if the walking foot is pressing the material to the feed dog firmly,  and its moving in unison with the needle & feed dog. You may need to reset the heights & timing as is shown in the video to accommodate non-OEM feet and different materials.

-DC 

 

[dikman]

Have you tried reducing the overall speed in the servo menu? This should make it easier to control at slow speed, but to get accurate slow speed control you need to fit a speed reducer of some sort. Replacing the handwheel with a larger pulley, as toxo suggested, performs the same function as a speed reducer, I've done this on several machines. 

Your servo appears to be a fairly generic design, nothing special, but these really need some sort of mechanical speed reduction to get the control that most of us want for leatherwork. I'm surprised that the seller didn't suggest this.