Boss Tippman Tension?

[barbiesdude]

Just got a used Boss in good condition. Went by the manual on threading and tension to the best of my newbie ability. When stitching, every couple inches it advances the leather but then pulls it back making a short stitch. Any ideas on why this is happening? Doesn't seem to be a timing issue it seems like maybe to much tension somewhere. Thanks

[Chief31794]

A couple of things that helps with a Boss, 1) Make sure you are pulling the lever all the way down and pushing it all the way up every time. Do this methodically and don't try to go too fast. 2) Needle alignment and size. Make sure you are using the right needle and not just the recommended one in the charts, test it on your thread to make sure it moves very easily, then when installing the needle take extra care to ensure the needle is absolutely straight and that the kerf is on the side that the set screw is on. There are no marks for alignment so you have to do it by eye but if it is "twisted" slightly it will pull stitches short and even skip stitches due to binding the thread. Hope that helps, if you still have trouble I would call Tippman during business hours, they are more than happy to work with you to get it going correctly.

Chief

[Dwight]

Take a couple of pieces of scrap 6/7 or 7/8 leather, . . . put them in place for your sewing, . . . flesh side to flesh side.

You need about 5 inches of thread from the needle and the bobbin.

Take the thread out of the needle, . . . and sew a "line" of holes into the leather.

Inspect the leather on the bottom, . . . looking for marks from the downward pressure of the presser foot. They should be there, . . . faint, . . . but should be there.

Turn your machine around, . . . pull the plastic piece off the back. Look in the upper left hand corner, there is a rod there going left to right, and it has a collar around it. That collar has to be spaced so there is a 5/8 inch blank piece of shaft to the left of the collar. This needs to be pretty precise.

After you have done all this, . . . check your bobbin, . . . looking down into the bobbin holder, . . . pull the string, . . . it should turn the bobbin counter-clockwise.

Check your needle, . . . there should be a trough on the needle's left side, . . . and the thread hole needs to be 90 degrees perpindicular to the travel of the leather when being sewn.

Now, . . . re-thread your needle, . . . leave out about 5 inches on both needle and bobbin, . . . grasp it in your left hand, . . . and begin sewing with your right hand.

Gently, . . . with about the same pressure you use to turn on your turn signals in your automobile, . . . really very little pressure, . . . but gently apply pressure to the leather you are sewing. Push it away from your as you sew.

That should give you some decent stitches.

If all that does not solve your problem, . . . loosen the bobbin tension screw, . . . and unscrew the two top tensioners. Take off the thread from the tensioners. Start screwing down the adjusters until you see contact made with all the tensioner parts. Use a black sharpie and make a mark on the top of the knurled knobs so you can tell where you are, . . . turn both down 1 1/2 turns.

Try some stitches, . . . you should get good stitches, . . . but everything pulled up to the top of the leather pieces.

Tighten the bobbin screw up until you feel it contact, . . . turn it in one full turn, . . . try some more stitches. They should now be below the surface of the top layer.

Adjust until you get tight stitches on the top, . . . tight stitches on the bottom, . . . and the meeting of the two threads should be very near the middle of the two layers.

Let us know how this worked for you.

May God bless,

Dwight

[TwinOaks]

Too much presser foot pressure can cause the leather to push down into the needle slot on the bottom. That little 'pooch' of leather can clog up in the slot and cause 'drag' that prevents the leather from moving correctly. When it pooches out 'far enough' it'll interfere with the loop being pulled into the hole, lifting the leather a little...which makes the whole thing 'jump' ahead to where it needs to be.

This can also be caused by a dull needle that blows out the leather on the back side instead of neatly puncturing it.

Too little presser foot pressure can cause it to move backwards when the needle lifts to reset.

[barbiesdude]

Thanks all, It will be a few days ubtil I have time to sew again (braiding projects to finish), But I will check the things you suggested and report back. I appreciate the time in answering my post.

[photoshutter]

I have two tips for Boss, first power handle has tendency to unscrew bolts, I just added second screw to the post from side, problem solved, second little problem is tension nuts also unscrew from time, just add any 1/4" contra nut on top from any hardware store, I added some cabinet hardware.

[trekster]

Really good tips, especially putting the extra bolt in the handle. I have to watch mine, because it does have a tendency to work loose after several stitches.

Far as the tension screws loosening, I have not experienced that problem yet. However, I have heard of putting lock nuts on top as you show. The thing that confuses me about that is, my Primary Tension post (the one with green felt) does not have any threads protruding out from the top of the knurled nut, so there are no threads to screw a lock nut onto. Am I trying to run with too little tension on my machine? My stitches seem to look okay, top and bottom.

Also, in your second picture, I'm curious as to what that "gadget" is just in back of your Primary Tension post? It is purple, as I see it. ???

[photoshutter]

Oh, it's LED light with Velcro attached, Thanks.

[trekster]

Now that is cool! I see in this picture that you've added a chrome handle to the upper-most part of the casting. You've made some nice mods to your machine. How old is it? Serial No. ???

[photoshutter]

8 years old, Thanks.