Changing The Needle Gauge on a JUKI Industrial Sewing Machine
Posted by Cutting Sewing Room Equipment Staff on 11/15/2019 to
One of our clients needed to know how to change out the needle gauge on their Juki offsite. We put together the how-to-instructional video below. We thought some of our other customers might find this transcription helpful too. The video is below the transcription text at the bottom of this page.
Step 1. Open the saddles to change out the Feed
Here we are changing the gauge from a standard quarter-inch to an inch and a quarter. Instead of the standard feed, we'll change it too. The first thing we have to do is open the saddles up. So you have to lean the machine back. When you turn the handwheel, you'll see the two collars on the saddles left and right. You have to loosen them both, but don't loosen the knife cam, at the collar shaft itself. Loosen both screws on both sides. And then you'll loosen the saddle itself. On the top, engage all 4 screws, and then you can move your saddles out to allow getting your new feed in, to line up your needle chuck. You loosen them and then you can move your chuck and the entire saddles out. Everything moves together. Once you get them out of the way, use your 4mm allen wrench to snug them back down so they won't move. Now you have your saddles out where you can put your feed in.
Step 2. Change the needle chuck
Now you have to take your faceplate off and take the top off to change this needle chuck. Now you must use a 3/32, long, allen wrench. You've got to go down through the needle bar to the bottom. Leave your allen inside of the machine so you can tighten the screw - start right back. Loosen the old chuck from the screw in the bottom. (here we show the one we are changing to, and the one that came standard). Pay attention to the pin in the needle chuck that locates on the needle bar slot. After you get the feed in, you insert the needle chuck. Push up and tighten the screw up. Leave your allen inside of the machine so you can tighten the screw - start right back. And when you get it tight, remove the wrench. Now you'll insert your needles into your chuck. Place the long grove to the inside, and scarf to the outside. Insert your other needle so that you can line up your chuck. Place the long grove to the inside, scarf out. So when you bring the needle down to meet the feed dogs, you'll notice that it's crooked. It's not inline with your holes in the feed dog. This is why you have your faceplate open. Now loosen the screw on the needle bar, but do not loosen it completely. Snug it so your needle bar won't move up and down. Now get a wrench and you can turn your needle bar to get it centered. So now you're squared. If you don't do this, when you try to tighten your hooks, the needle shanks will be skewed. You need it straight across, dead even in the holes, on both sides. The needles are not touching the insides of the feed holes now. Snug the needle bar screw back down. Now take the feed back out so you can re-time the hooks.
Step 3. Re-timing the Hooks
We will take the feed back out to retime the hooks. Remove the two allen screws. Bring your needle bar down. You'll notice the far distance from the needles. Both hooks are out of time. The needle bar has to rise 2.5 mm for timing. Now we'll move our saddles back in and get them close to the needles and then we can re-time the hooks. Lean the machine back. We'll do one side at a time. Loosen the top allen screws. Loosen the 4 mm screws on the timing collar. Now we'll move our saddle. Now we'll come back around and get our 2.5 mm rise. Now we can turn the hook. Snug one collar screw. You want it all the way up against the guard to ensure no movement. Snug the other screw and then we check our rise. It's perfect on the inside. Now we'll hold the saddle and snug the top allen screws. So now we have our distance set on our inside hook, and proper time. We have 2.5 mm rise on the needle bar. The hook point comes in right above the eye. That's good. Now you'll tighten everything down on the inside of the machine. A note about not having to set the undertrimmer: If you only move the collar you won't have to set the undertrimmer now. Because the, if two dots on the hand-wheel are lined up, the feed cam will be right for your knives. So when you are moving it, don't move the cam, but move the outside collar instead. Now if you have everything snug, you'll do the same thing on the outside. They have to come in at the same time.
Loosen the 4mm screws on the collar. Then we'll move this saddle in. You'll want to line this hook up, because you've already got it timed, and bring this one to the same time. They should be right across from one another. The left hook turns counterclockwise. The right hook turns clockwise. They both have to come into the needles at the same time. Make sure the hook doesn't bump the needle. If so, bump the saddle back out just a little. Once the hook points are in the center of each needle, you can once again tighten the 4 mm screws on the collars. Then on the hook saddles. And now when you turn it, you'll notice that both of them (hooks) are coming in at the same time. Got our rise at 2.5 and both hooks come in at the same time. Go back to the bottom and check to make sure that you have everything tight. These need to be really tight. They are made to slip so they won't break the hooks. Double check your hook saddles. When you tighten these up check your hook timing again because it will move. Now you can let the head back down.
Step 4. Put it back together
Now you can put your feed back in. Be sure to put your feed in with the teeth away from you so it pulls, not pushes. The screws self align as you tighten them. Double-check the alignment with your needle bar. It should be perfect. And that's it. Just put your plate back on. Put your new throat plate on. Put the new bed slides on.