Auto Body Sheet Metal Fabrication: Is Scroll Saw Cutting Practical?

[Scottl]

it all works
as long as you can actually manage to clamp it sufficiently
(the real skill in fabrication)

Exactly. Fit the scroll saw with a floating hold down similar to a die filer and it will be safer to use although likely slower than a band saw.

 

[MrCreosote]

on rust repair, you ususally cut it large by about 1/2" and end up scribing a line then trimming the body back to that line with a cutoff wheel.

I make the precision cutting on the patch, not the body - the body will have obstructions making scribing and cutting precisely difficult.

Cutting the body is a different set of problems than cutting the patch. Cutoff wheels do not cut curves. I've used carbide burrs to "hog out" the bad metal. Then I cut a template from a "pizza box" and transfer to the patch metal where the precision cut is made.

When welding sheet, sharp corners are avoided at all costs since they produce distortion. A square patch is the worst - circular the best. I became acutely aware of this when doing oxy-acetylene patch welding. Same applies to MIG and TIG but to a lesser degree. NOTE: The nice thing about o/a is that when done properly, there is usually no grinding the weld to speak off - a few "draws of a file" in some places.

 

[IceCzar]

cutoff wheels will cut curves BUT
you have to alter both the angle of cut and the diameter of the cutoff wheel to pull it off
cut short then grind to the final diameter ( convex or concave ) tighter the radius and thicker the material the harder it gets
( and the further away from the final line you need to be)

 

[William Lynn]

Get a genuine Beverly shear and don't look back. Used may be hard to find, but new ones are available. Mittler Bros bought the business a while back and are made in the USA.

 

[MrCreosote]

cutoff wheels will cut curves BUT
you have to alter both the angle of cut and the diameter of the cutoff wheel to pull it off
cut short then grind to the final diameter ( convex or concave ) tighter the radius and thicker the material the harder it gets
( and the further away from the final line you need to be)

I've used cutoff wheels in angle grinders a lot. They have their place cutting out rusted body panels, but I usually end up with the die grinder carbide burrs. It's also different applications: cutting the body, and cutting the patch.

I've also just thought of how a metal cutting blade in an oscillating tool might work. In particular, the ones with the "extended cutting end wings" can be "oriented perpendicular" so that it works just like a saber or Sawzall - which is kind of intriguing. This could be very good for cutting the body.

I need to find out if it is possible to make super slow fine trimming cuts with a Pilot Arc plasma cutter. I know w/o PA not possible.

 

[eKretz]

Get a genuine Beverly shear and don't look back. Used may be hard to find, but new ones are available. Mittler Bros bought the business a while back and are made in the USA.

I bought my Monoset tool and cutter grinder from Beverly Shear. At least, from the guy who bought the building and contents when they quit the place. They had a big old K&T or Milwaukee vertical in there and a couple shapers too. One of the shapers was set up with a curved template follower, using what looked like a small car leaf spring to keep the head/tool tracking tight to the template. As the shaper stroked back and forth, the tool was moved up and down in an arc as it followed the template. So, fun fact: the original curved Beverly Shear blades were machined on a shaper!

The fella who'd bought the place, Miles, was a musical instrument maker and repairman. He had some NOS Beverly Shears for sale too. At the time, after buying the tool grinder I didn't have enough $$ to grab one of those too or I absolutely would've.

 

[MrCreosote]

UPDATE (1 month later)
RE: Nibblers: How to see the scribed line:

All that I ever saw obscure it with the die. I thought about chamfering the die to gain sight of the punch on the scribed line.

Today I was in Harbor Freight and saw their $80 nibbler which did just that. Now you have to get you view angle pretty low, but it possible and far better.

It is 18ga and the punch diameter is much great, maybe over 6mm instead of the 4.4mm of the Buffalo that I have (one of the clones.)

While I believe I have found replacement punches for min (pulled head off cutting 16ga), I'm going to try and chamfer like the HF Chief:
HF Chief Nibbler
NOTE: The idea of giving HF $80 for an air tool is not going to happen. (ever since the lawsuit and the plethora of phoney baloney brands)

 

[MrCreosote]

Good grief, just found the Neck Industries Trace-A-Punch duplicating nibbler.

This think works off templates (can be card board which is what I do (!) )

And then there are the "square punch" nibblers as opposed to those that "pull" the round punch. You can clearly see punch.

I definitely have to get one of these.

 

[Bherzog]

Good grief, just found the Neck Industries Trace-A-Punch duplicating nibbler.

This think works off templates (can be card board which is what I do (!) )

View attachment 390054

And then there are the "square punch" nibblers as opposed to those that "pull" the round punch. You can clearly see punch.

I definitely have to get one of these.

Sears Dunlop is sears lower quality tool. If it last thru the first piece, I don’t if while much longer.
Bruce