Juki LZ 586 questions

[Nairbg]

I have just purchased my first industrial type sewing machine. It needs a little attention and I need some direction.

First, on the back of the main casting toward the drive side there is a small vertical mounting boss cast in. It has 2 threaded holes, one over the other. I cannot determine the size or thread pitch of those holes. They are close to 6mm but they are finer than the expected 1mm tgread pitch. Anyone know what this size/pitch is?

Second, my information to date suggests that a #18 needle and Tex70 thread are the largest that this machine can handle. I'd like to go heavier. Has anyone any experience/information on going heavier with this machine?

[kgg]

4 hours ago, Nairbg said:

First, on the back of the main casting toward the drive side there is a small vertical mounting boss cast in. It has 2 threaded holes, one over the other. I cannot determine the size or thread pitch of those holes. They are close to 6mm but they are finer than the expected 1mm tgread pitch. Anyone know what this size/pitch is?

Those are for mounting the upper belt cover and they are 15/64-28 L=10.

My understanding is that machine is a high speed drop feed zig zag machine for fabric installing a larger needle will probably cause problems. What are you planning on sewing????

kgg

[Nairbg]

I was planning to sew car seat upholstery and some canvas.