Is this rough texture normal?

[imon]

Today I received a Juki 1541 Walking Foot. I'm still waiting for my Guttermann Mara 30 Polyester to arrive next week (which will likely be my preferred thread).

In the meantime, I've been practicing with Realm Bonded Nylon (40s) which I happened to have on hand, on 2.0–2.4mm (5–6oz) Veg Tan doubled up.

Photo A shows the top of the leather I have practiced on:

1. Stitch Length 5, Needle 19 (120)
2. Stitch Length 5, Needle 23 (160)
3. Stitch Length 6, Needle 23 (160)
4. Stitch Length 6, Needle 23 (160)
5. Stitch Length 6, Needle 23 (160)
6. Stitch Length 4, Needle 23 (160)

Photo B show the bottom of the leather. However, in each case I'm left with this unsightly rough impression where the needle penetrates through.

My question: Is this normal behaviour on an industrial sewing machine? If so, I'll stop obsessing. If not, I'd love some advice on how to minimise the effect.

Note: I appreciate that I haven't quite dialled in the tension yet, but I'll address that tomorrow. I didn't have much time to try it today.

[Northmount]

42 minutes ago, imon said:

Today I received a Juki 1541 Walking Foot.

Moved your post to leather sewing machines.

You appear to be using a standard conical point needle best suited to fabrics.  Switch to a leather point that cuts a small slot rather than blowing out the bottom side.  More members will be along with similar comments.  You can do some research in this forum about what needles to use.

 

[Tigweldor]

a 160 size needle is way to big for Tkt 40 thread - the 120 needle is already on the big side - ideal would be 110 - but in leather one size bigger is not bad.

https://www.tolindsewmach.com/thread-chart.html  - Guttermann Mara is a German thread - so use the (Ticket) under Thread Size and then the needle according to it.

And like Northmount already said - use a leather needle on leather.

 

Greetings

Hans

Edited March 25 by Tigweldor

[imon]

Thank you both for the advice.

By "leather needle", do you mean diamond needles like the Schmetz Diamond Point Needle (https://www.ae-sewingmachines.co.uk/products/schmetz-134di?variant=54843275346300)?

[Tigweldor]

Yes , you can use the diamond point on leather - it aligns your thread in a straight line.

Or you can use a 134 LL (slot facing to the left) or a 134 LR (slot facing to the right) 

Just make sure that the needle size corresponds with your top thread size - or you will produce large "well holes" with a tiny thread coming out of them - like your 160 holes in the pic.

Since these needles don´t cost a fortune - I would buy all types and then decide which style of produced look matches your project best.

Say you want to shorten sleeves on a leather jacket - you would use a LL on one sleeve end and then a LR on the other sleeve end - or the diamond point for both. Might not sound like much - but a picky/knowledgeable customer will see such little details. If not - point out what extra care and effort you took for the small price he is paying.

You can also use a slightly smaller thread size in your bobbin - has the advantage of getting more thread onto the bobbin = Tkt 40 on your bobbin and Tkt 30 for top thread. That is how I handle it on my machines.

Hope that helps you out

 

Greetings

Hans

Edited March 26 by Tigweldor

[imon]

@Tigweldor Thank you for sharing your knowledge. I've ordered a range of needles to try, as you suggested. I look forward to seeing the results 🙂

[kgg]

3 hours ago, imon said:

By "leather needle", do you mean diamond needles like the Schmetz Diamond Point Needle (https://www.ae-sewingmachines.co.uk/products/schmetz-134di?variant=54843275346300)?

No, do NOT use a system 134 needle for the Juki DNU -1541 and Juki DNU-1541S they are made and setup for a system 135 x 17 x (needle size) for fabric or 135 x 16 x (needle size) for leather, check you manual. Here is a good reference chart for needle size vs thread size. ( https://www.tolindsewmach.com/thread-chart.html ).

I would also suggest:

i) reducing the presser foot pressure as it appears the pressure foot is imprinting the leather needle plate hole into the leather.

ii) increase the bobbin tension using the drop method of setting the bobbin tension.

kgg

 

[imon]

@kgg It was explained to me that the 134 DI is the equivalent to the 135X8 DIA. The former being a European designation and the latter being USA/Asia. The manual says 135, and it's an Asian manufacturer. So, I think it's ok? 🤷‍♂️ The regional differences are super confusing.

[Tigweldor]

Here is what Schmetz says - and they are a needle manufacturer : 

System 134R is generally used in single needle lockstitch industrial sewing machines. It is also known as 135x5, 135x7, 135x25, 1901, DPx5, and DPx7. 

 

The R after the 134 stands for Rundspitze = round point = for farbrics

The L suffix stands for Leder = leather

LR = Leder rechts = leather right side slot

LL = Leder Linkes = leather left side slot.

 

 

Edited March 26 by Tigweldor

[kgg]

44 minutes ago, imon said:

The manual says 135, and it's an Asian manufacturer.

 

Here is a screen shot of the spec for the Juki DNU-1541 series:

My understanding is the system 135x8 is not designed for walking foot machines made for drop feed machines. It is a slightly shorter needle which may require you to adjust the needle bar as well the hook to the needle timing.

Needle selection reference: The Thread Exchange by Juki model ( https://www.thethreadexchange.com/miva/merchant.mvc?Screen=CTGY&Category_Code=needle-systems-juki )

The equivalent to a system 135 needle for leather, 135x16, is the DPx16 and 135x1 NRTW.

The equivalent to a system 135 needle for fabric, 135x17, is the MR, 3355 MR, DPx1 MR, DPx17

Why not use the correct system needles recommended by the manufacturer, needles are cheap and save yourself the problems / headaches associated with other then recommended needles.

kgg

Edited March 26 by kgg