Scroll saw experts I need help please!!!

[Thirdyfivepickup]

So I recently acquired a Rockwell 40-440 24” scroll saw from my Dad. I’m not sure how old it is but it’s in pretty good shape. Saw runs nice and seems pretty smooth.

The problem I’m having is that it keeps destroying blades. I thought I had it figured out but I can’t quite get a blade to last.

Does anyone know how to properly set up the blade so it doesn’t get pretzeled?

Also there is a knob up top and a handle by the belt that I’m not quite sure what to do with. I’m wanting to start making some signs and other artwork and could really use this saw functioning correctly.

 

[Rick_Br]

The knob on top of the upper plunger is used to adjust blade tension. If I'm remembering right you turn the motor by hand until the lower plunger is at the topv of its travel./Insert the blade in the lower plunger about 1/2". Lower the upper plunger so you can insert the blade in the upper jaw about 1/2" and then pull the plunger down to the desired tension number - I usually use 12 to 14.

I would suggest you go over to vintagemachinery.org and search for a manual. If you can't find it I will get you a link

Rick

 

[cvairwerks]

The other thing is make sure you are installing the blades with the teeth pointing down.....The saw is designed to cut on the downstroke only, same as a bandsaw. Don't know how many times where I've gone to use a scroll saw in a open shop and found the blades installed teeth up.

 

[Maui]

Yep, if the blade tension isn't adjusted properly you will snap blades. I've had the same blade mounted in my vintage Delta/Rockwell scroll saw for more than a dozen years, and it still cuts beautifully.

Maui

 

[rlitman]

Wow, I've never seen a machine like that! You've got a variable speed drive that Delta made famous on their drill presses on a scroll saw. The lower knob is to adjust the pulley size, which changes the speed. That's incredible!

I grew up using a single speed Craftsman branded version of this machine. The spring tension adjustment up top should be set so that at the piston's top of stroke, there's still adequate tension on the blade, but not so much that at bottom of stroke the blade's ears get ripped off.

Once you get past that, blade breakage is mostly caused by pushing the work too fast, or sideways (that's the biggest issue). If the blade is curving, you're pushing too hard. In the middle of a cut, stop moving, hold the workpiece still and shut off the saw. Then let go of the workpiece. If it moves sideways, you've got to work on your form.

Also, these sorts of saws don't work well with the finest of scroll saw blades.

 

[Thirdyfivepickup]

The knob on top of the upper plunger is used to adjust blade tension. If I'm remembering right you turn the motor by hand until the lower plunger is at the topv of its travel./Insert the blade in the lower plunger about 1/2". Lower the upper plunger so you can insert the blade in the upper jaw about 1/2" and then pull the plunger down to the desired tension number - I usually use 12 to 14.

I would suggest you go over to vintagemachinery.org and search for a manual. If you can't find it I will get you a link

Rick

I have been installing the blade that way but I haven't touched the tension knob.

The other thing is make sure you are installing the blades with the teeth pointing down.....The saw is designed to cut on the downstroke only, same as a bandsaw. Don't know how many times where I've gone to use a scroll saw in a open shop and found the blades installed teeth up.

definitely had the blades pointed downward.

Yep, if the blade tension isn't adjusted properly you will snap blades. I've had the same blade mounted in my vintage Delta/Rockwell scroll saw for more than a dozen years, and it still cuts beautifully.

Maui

Ok, I'm going to download the manual and play with the tension. Hopefully that will make things work.

Wow, I've never seen a machine like that! You've got a variable speed drive that Delta made famous on their drill presses on a scroll saw. The lower knob is to adjust the pulley size, which changes the speed. That's incredible!

My gut is telling me that this thing is spinning too fast. Well at least it feels that way to me.

I grew up using a single speed Craftsman branded version of this machine. The spring tension adjustment up top should be set so that at the piston's top of stroke, there's still adequate tension on the blade, but not so much that at bottom of stroke the blade's ears get ripped off.

Once you get past that, blade breakage is mostly caused by pushing the work too fast, or sideways (that's the biggest issue). If the blade is curving, you're pushing too hard. In the middle of a cut, stop moving, hold the workpiece still and shut off the saw. Then let go of the workpiece. If it moves sideways, you've got to work on your form.

I had blades break the second I switch the saw on... I Had 1 blade that lasted a little while but eventually broke. I don't feel I was pushing too hard or putting a side load on the blade. But who knows...

Also, these sorts of saws don't work well with the finest of scroll saw blades.

The saw came with maybe 4 dozen blades. My father said a lot were cut from a bandsaw blade. Maybe 1/4 wide... I'll try and take a pic of the blades when I'm home.

Thanks for the tips so far. I'm looking forward to getting this saw up and running so I can finally start some projects I've been wanting to do. I'll see what Vintage Machinery can help me with.

I also plan on doing a freshen up on the saw... that will probably have to wait until spring though.

 

[rlitman]

Well, too much tension can break a blade. So can too little.
If the blade isn't pulling up faster than the piston on the bottom rises, it can get compressed, and that will break it quickly.

1/4" is fine. 1/8" blades should be fine too. When I said the finest of blades, I'm talking about the wire thin stuff you'd put in a jeweler's saw frame.

So, does the upper spring loaded piston move smoothly? If it's sticking, that could be a problem.

And maybe you are just moving too fast. Try slowing it down all the way, and then increasing the speed a little at a time.

 

[Thirdyfivepickup]

Well, too much tension can break a blade. So can too little.
If the blade isn't pulling up faster than the piston on the bottom rises, it can get compressed, and that will break it quickly.

1/4" is fine. 1/8" blades should be fine too. When I said the finest of blades, I'm talking about the wire thin stuff you'd put in a jeweler's saw frame.

So, does the upper spring loaded piston move smoothly? If it's sticking, that could be a problem.

And maybe you are just moving too fast. Try slowing it down all the way, and then increasing the speed a little at a time.

I'll try to slow it down. I just hope I don't run out of blades before I figure it out.

 

[Thirdyfivepickup]

Here are some of the blades I’ve been playing with... just making sure they look ok