Juki 8500

[SewVic]

Hi I am new to leather working and was able to pick up a Juki 8500 for $325.00 (in almost new condition) - so couldn't pass that up! I do have a couple questions I hope you can help with. I plan on sewing Horse bridles and breast collars with double 7-8 oz leather. I did modify the presser foot to get both pieces through nicely - but I am having a hard time slowing it down - and end up shooting the leather out the back - hehe!

I would like to know what type servo motor to get and possible places to get one. Also, what type needles and thread would be best.

PS - LOVE this site!!!

[Wizcrafts]

Welcome to our Forums, SewVic!

You have bought yourself a very high speed garment sewing machine, with a self oiling system. This machine is best used with thin, soft material, under 1/4 inch total thickness. It is designed for use with thin sewing thread, not exceeding #69 bonded nylon. The needle system is correspondingly thiinner than walking foot machine needles. You will be lucky to get it to sew leather with a #20 needle, and #69 thread.

Still, you might be able to cheat and up the thread and needle size a bit (to #138, with a #22 needle max).

I definitely know where you can get a super servo motor that will improve your sew-ability. It is called the SewPro 500 GR and it is sold by Toledo Industrial Sewing Machines. Many of our members use this motor on our walking foot machines, myself included. When purchased for leather sewing it comes with a 50 mm (2") pulley. It has built-in 3:1 gear reduction and a speed limiter knob on the back.

Your current motor is probably equipped with a 4 inch pulley, for the high speeds required in cloth garment work. Since the 500GR sits closer to the table than a standard clutch motor, you will need to subtract an inch more than otherwise, when buying a new, much shorter v-belt. For every inch of difference in pulley diameter, you need an inch shorter belt. Thus, if the original pulley is 4" and the new one is 2", on the SewPro motor, order a 3" shorter v-belt with it. This assumes that the original belt is set in about the middle of the motor tensioner bolt. If the existing belt is sitting near the bottom of the bolt, subtract another inch for the new belt.

With the SewPro 500GR installed you will be able to sew under 1 stitch per 3 seconds. It is capable of extremely slow sewing operation and doesn't drop out with a shudder, like some of the cheaper servo motors do. With this motor and a heavier top tension coil spring (and possibly a heavier pressor foot spring and heavy duty feed dog conversion as well), you will be able to penetrate 1/4" thick veg-tan or bridle leather, using a #22 needle and #138 top thread.

Considering what you paid for it, you have little to lose when you destroy the machine sewing leather bridles. Hopefully, you can sew enough of them to get your money back. Then, buy a walking foot machine that is made to sew heavy leather.

Edited June 26, 2011 by Wizcrafts

[KAYAK45]

"you have little to lose when you destroy the machine sewing leather bridles."

Wiz, that might be a biiiit harsh! LOL

Even if true.

The sewpro is sweet at slowing your machine. I have two servos and love them!

Keep you current machine for canvas or something light and get a walking foot leather machine. See post, after post, after post. on garment machines used for leather.

I also bought a high speed, self oiling, garment machine, a Singer 251-3 that I like for other than leather and boy is it fast.

Good luck

Kevin

[SewVic]

Welcome to our Forums, SewVic!

You have bought yourself a very high speed garment sewing machine, with a self oiling system. This machine is best used with thin, soft material, under 1/4 inch total thickness. It is designed for use with thin sewing thread, not exceeding #69 bonded nylon. The needle system is correspondingly thiinner than walking foot machine needles. You will be lucky to get it to sew leather with a #20 needle, and #69 thread.

Still, you might be able to cheat and up the thread and needle size a bit (to #138, with a #22 needle max).

I definitely know where you can get a super servo motor that will improve your sew-ability. It is called the SewPro 500 GR and it is sold by Toledo Industrial Sewing Machines. Many of our members use this motor on our walking foot machines, myself included. When purchased for leather sewing it comes with a 50 mm (2") pulley. It has built-in 3:1 gear reduction and a speed limiter knob on the back.

Your current motor is probably equipped with a 4 inch pulley, for the high speeds required in cloth garment work. Since the 500GR sits closer to the table than a standard clutch motor, you will need to subtract an inch more than otherwise, when buying a new, much shorter v-belt. For every inch of difference in pulley diameter, you need an inch shorter belt. Thus, if the original pulley is 4" and the new one is 2", on the SewPro motor, order a 3" shorter v-belt with it. This assumes that the original belt is set in about the middle of the motor tensioner bolt. If the existing belt is sitting near the bottom of the bolt, subtract another inch for the new belt.

With the SewPro 500GR installed you will be able to sew under 1 stitch per 3 seconds. It is capable of extremely slow sewing operation and doesn't drop out with a shudder, like some of the cheaper servo motors do. With this motor and a heavier top tension coil spring (and possibly a heavier pressor foot spring and heavy duty feed dog conversion as well), you will be able to penetrate 1/4" thick veg-tan or bridle leather, using a #22 needle and #138 top thread.

Considering what you paid for it, you have little to lose when you destroy the machine sewing leather bridles. Hopefully, you can sew enough of them to get your money back. Then, buy a walking foot machine that is made to sew heavy leather.

Thank you -that's what I needed to know. I figured the 325 wasn't bad if I was careful and could get a few out of it to get me going....I JUST missed out on a Consew 206RB that was really inexpensive. Now, will I be able to use that servo motor on a 206RB when I find one - providing I don't blow that up too

[Wizcrafts]

"you have little to lose when you destroy the machine sewing leather bridles."

Wiz, that might be a biiiit harsh! LOL

Even if true.

Good luck

Kevin

Unfortunately, it is true. The take-up lever system, the shuttle and feed system, not to mention the various gears and bushings, are simply not beefy enough to hold up for long, under the pressure of sewing thick, or hard leather, with or without thick thread and a large needle. Add the #138 thread and a #22 or #23 needle and the pounding inflicted when penetrating 16 ounces of veg-tan leather will wear out the machine in very little time.

[KAYAK45]

Now you get some good news.

Yes the sewpro will migrate from almost all machines to others without anything but maybe a different belt. It's that simple.

Sew (SP) if you buy one now for your current box and get another, it will go across.

[SewVic]

Now you get some good news.

Yes the sewpro will migrate from almost all machines to others without anything but maybe a different belt. It's that simple.

Sew (SP) if you buy one now for your current box and get another, it will go across.

I know, I know I did read all the threads about the machines - but with money being a big factor right now and my fingers sore from handstitching I needed a cheap way to heal up my fingers for a week or so

I am glad to hear the servo will swap over when I move to a proper leather machine.......thanks for the input.....now back to lurking and reading and oogling all the fabulous pictures!

[Yarndiva]

I just wanted to add that I use this model of sewing machine every day and it's a wonderful worker on lots of fabric types. Like has been said, I haven't used it on leather.

[Wizcrafts]

The main differences between cloth and leather sewing machines are the feed system, take-up mechanism, tensioners, pressure spring(s), bobbin size, stitch length, oiling system and size of the gears and bearings.

There are self oiling high speed machines that run out of oil at critical points when operated with slow speed servo motors.These machines have an oil pump that is designed to be spun at a certain RPM and above. Slow speed motors used in leather work don't create enough oil pressure to feed oil to all of the extremities.

Garment quality industrial machines have thin take-up levers and connecting rods, keeping the weight down in the head for higher speed operation. They also have vertical axis bobbins, which support higher speeds.