Motor recomendation for Juki 1541

[ozleather]

Hello! I would like to learn professional automotive upholstery and leather-working.

My plan is to purchase Juki 1541 and purchase a 12 coil motor separately. I assume that the Juki provided motor is 6 or 9 coil motor. 12 coil motor is supposed to provide a higher torque and should be smoother. 

I came across Reliable SewQuiet 6000SM, 120V, 550W, digital speed controller, 60mm pulley, 7.8 lb, made in China.

I wonder if this is a good idea and if there is any other motor I should consider. 

Any thoughts or suggestions are appreciated. 

Thank you! 

 

Edited June 25 by ozleather

[kgg]

42 minutes ago, ozleather said:

I wonder if this is a good idea and if there is any other motor I should consider. 

Since you are in the US the Sailrite Workhorse is the same motor ( https://www.sailrite.com/Sailrite-Workhorse-Servo-Motor-110V ) at $299.95. 

The problem with any of the brushless servo motors is the high startup rpm's which is typically around 500 rpm and with both the Reliable and the Sailrite it is 400 rpm. This can create startup "jump". To help smooth out the startup "jump" of the brushless motors as well as slowing down the machine while giving more torque install a speed reducer pulley and replace the servo motor pulley with a 50 mm pulley. Typically the reduction is 3:1 (6" large pulley and a 2" small pulley).

I would suggest you forget about the Juki DNU 1541 and purchase the Juki DNU 1541 "S". The Juki DNU 1541 has no safety clutch.

kgg

 

[ozleather]

The situation about motors is very confusing. Juki does not state any information about the motor they include with 1541. Some retailers install their motor, some motor, and some claim that they provide with the one Juki provides. Are all these servo motors brushless?

 

[ozleather]

51 minutes ago, kgg said:

I would suggest you forget about the Juki DNU 1541 and purchase the Juki DNU 1541 "S". The Juki DNU 1541 has no safety clutch.

One retailer told me that the "S" version with the safety clutch, when new, the spring is too strong and it does not engage when it suppose to. With age, the spring gets weaker and engages even when it is not suppose to. The non-S version is cheaper by $75 which is not that much but I hate to spend it if it does not work well. 
What do you guys think? 

[kgg]

20 minutes ago, ozleather said:

The non-S version is cheaper by $75 which is not that much but I hate to spend it if it does not work well. 

The safety clutch when it kicks in protects a lot of internal parts from getting damaged. Depending on how badly you screw up usually it is just a matter of resetting the safety and you are sewing again.

If you jam the machine up and I think most of have at some point jammed a machine up the repair cost of the damaged parts will be be a lot greater then the $75 you "saved". 

As a side note my Juki DNU -1541"S" hates items less then 5mm thick and much prefers thicker items with V92 thread as a minimum top and bobbin thread size.

20 minutes ago, ozleather said:

One retailer told me that the "S" version with the safety clutch, when new, the spring is too strong and it does not engage when it suppose to. With age, the spring gets weaker and engages even when it is not suppose to.

Find another retailer one with experience doing leather work.

1 hour ago, ozleather said:

I would like to learn professional automotive upholstery and leather-working.

What are the items you want to sew, how thick of leather and with what size of thread as a flatbed machine may not be your best option?

kgg

 

[ozleather]

My main focus is automotive upholstery but I would like to learn how to do things from leather. I am thinking of belts, bags, probably made from not the thickest materials. 

You suggested a speed reducer pulley and replace the servo motor pulley. Are you referring to a speed reducer showing on the picture below?



 

[kgg]

2 hours ago, ozleather said:

I am thinking of belts, bags, probably made from not the thickest materials. 

Keep in mind:

i) Items like belts / wallets are best done on flatbed like a Juki DNU-1541S or clone.

ii) Items like bags are best done on a cylinder arm machine like the a Juki LS-1341 or clone.

iii) You can turn a cylinder arm machine into a flatbed machine by installing a flatbed attachment. If this is going to be your only machine I would suggest seriously looking at this option.   

2 hours ago, ozleather said:

Are you referring to a speed reducer showing on the picture below?

That is one style of speed reducer typically referred to as a box style. You can also get the more common pedestal style. Both have their pro's and cons but do the job, speed reduction. Here is a photo I copied from Toledo Industrial Sewing Machines ( https://www.tolindsewmach.com/motors.html ) 

The motor shown in your photo is a brushed servo motor, good uncomplicated work horses.

kgg

 

[ozleather]

Thank you! This is what is now my understanding:

1. Brushless servo motors have a high startup rpm's so it is recommended to use additional speed reducers with a smaller motor pulley. Brushed motors do not require speed reducers.
2. Likely motors that come with 1541 are brushed - This is my assumption 
3. Getting "S" type, the safety clutch is recommended 
4. Items like bags are best done on a cylinder arm machine. You can turn a cylinder arm machine into a flatbed machine by installing a flatbed attachment. 

I think I will go with 1541S and with whatever brushed motor it comes with to learn the trade. I can always upgrade the motor to brushless later if I see the need (after some paid job 🙂 ). I will focus first on items I can do with 1541S. There is lots to learn.

Thank you for your help! If I missed anything please let me know. 

[kgg]

9 minutes ago, ozleather said:

Brushed motors do not require speed reducers.

Incorrect. They typically have a lower startup rpm but depending on operator skill, startup rpm, manufacturer you may require a speed reducer regardless of servo motor type.

If you are going to be sewing leather the needles you will need are 135 x 16 x needle size. Your machine will come with a 135 x 17 x needle size for fabric. Here is a good link to a chart showing needle size versus thread size vs thread strength ( https://www.tolindsewmach.com/thread-chart.html ).

Don't cheap out, buy brand name needles and thread. Always buy two spools of thread, one for the top thread and one for the bobbin. That way you can fill a bobbin while you sew without having to un-thread the top thread to wind a bobbin.

kgg

[ozleather]

Perfect! Thank you!