CowboyBob

If you were to push the rod behind the tension unit & then lift the foot up does it (the rod) move towards the tension unit?If it does the all you need to do is bend the bracket it contacts on the backside of the tension unit to adjust it to open the discs.If it doesn't move you should inspect the release guide as it might need to be replaced.

You have a good idea BUT he'll need something stronger like a 2x6 for a bottom brace to hold all the weight of the arm hanging out the leftside of the stand.

Nothing to worry about,it held an oil wick that is probably long gone & when oiled properly not needed.

If you want a chainstich machine for canvas get a 300W.

This is a Singer model 552 they were made for gloves,pants & lingerie,single needle 2-spool that makes a chainstitch.The seller made think because it's large it will sew what he claims but it is not for sewing anything heavy esp leather where you'll have the loops of thread on the bottomside.

Sounds like a bent needlebar.Loosen the screw on the clamp inside the head & then spin the machine & see if it stops the bind.If so get a new needlebar.

The H3 has 11mm foot lift,the B=medium materials & s is for cloth.

The thinnest leather this will handle is 10 oz or 4mm using size#138 thread,it should sew up to 1/2",32oz or 13mm

Main differences are the 7-33 has a larger bobbin & 2 feet that walk,this model has a single jump foot & they thread different.

On the second tension unit marked #23 wrap the thread around it 1 & 1/2 times.

Sure wished I could help,I've never seen this model before.This Singer looks alot like a Chandler darner(which parts aren't available for either) but the bobbincase looks different.

Just tighten them all the way in & loosen 1/8 of a turn @ the most,too loose & they'll fall out & they won't hold the stitch length.

Maybe you have the little screws on what we call the gib too tight on the stitch length adjuster,I wouldn't change the shaft if I were you.If you oil & run the machine some it will probably loosen up.With the pressure foot down they will have a tight spot in them when they push the foot up,is it still have a tight spot when you lift the foot?

A rare one for sure,I like the pedal,it does look a bit like the 206.Nice Find!!

That "divit" will be at different positions @ different stitch lengths.Also it wouldn't hurt to put some oil in the stitch length cam to make it work smoother.

Back in the day I used to sell both of these when they were new,can't remember the price but the serger is great for 2-3 layers of lightweight shirt or dress material & maybe 1 layer of thin canvas but the cutters won't cut anything much heavier that that.

Some of these had that guide when the bobbin winder was built-in on top of the machine

No,they both have been sold.

We always use the 45mm & no one has ever complained they run too fast.LOL

Turn your spindle all the way in ,take out screw BB,turn screw CC all the way in until it stops & re-install screw CC will make your stitch length longer. If you use the shorter 135x5 needles you won't break as many as the longer 135x17. If you sewing canvas the double row feed dogs will work better.

I hate to tell you ,your either overlooking something OR it is out of time,because if it was in time it would be sewing.Once in a while the pin on the top cam(belt pulley breaks) the end of the screw on the pinion gear can also break.As you turn the machine the needle bar goes down ,starts to come up ,goes & then when it goes up the 2nd time is when the point of the shuttle should be above the eye of the needle.

It's the top part of the saddle that needs to be milled,not the hook bushing hole.The larger hooks are taller the the small ones ,the top hook bushing needs to be milled also,an easier way is to buy a Juki 563 saddle which sometimes popup on Ebay.You'll also need the Juki 563 Take Up lever.

From what I can see it looks like the correct one,which is short on this model of 45K

Are you sure there's enough slack in the foot lift chain(or wire) from the pedal to the lifter arm on the backside?