Punching Thin Metal Sheet - Triangular Punch Hole

[larry4406]

How would one punch triangular tabs in a piece of stainless sheet? Below is a picture of the spark ground for the igniter for my Wolf BBQ-362 gas grille. Parts are extremely expensive and near obsolete, so I was thinking of making these. I believe the sheet stock is around 1/16" +/-.

The spark ground is the hat-shaped metal piece. There are 3 metal punch locations. These punches (like an old style can opener) create a pointed tip where the spark from the electrode jumps thereby igniting the burner. There is also a tab on one end to hold that end on the electrode bracket while a screw is used on the other end. The igniter mounts vertically in the electrode bracket and comes up in the center of the spark ground (see last picture).

I don't have accurate dimensions yet (summer project) but in the picture, the background grid is 1x1" and the screw is 1/2" long for reference. The tab punching looks to be the most challenging aspect of this.

I would need to make 6 of these and perhaps some spares.

 

[PCustoms]

What do the tabs do?

The shape might just be for ease/speed in production. You might be able to make it easier for a few pieces

 

[OccupantRJ]

The stainless from the factory is likely to be a 1/4 hard material for stamping and forming. Unknown stainless might be a bit difficult to work with, so at least be aware of that.

 

[larry4406]

What do the taps do?

The shape might just be for ease/speed in production. You might be able to make it easier for a few pieces

The tabs (not taps) are grounds where the spark from the electrode jumps to. Think spark plug where the spark from the center electrode jumps to the tip.

I thought about not doing the punched tabs at all and instead just using a stainless screw with a nut that I could adjust in and lock to set the spark gap.

 

[larry_g]

If the 'points' of the tab are just a ground lug for the piezo to arc to I would be tempted to bend up the metal and run tek screws through it to replace the tabs.

On edit, if just the tabs are eroded on the existing piece run the tek screws into the existing metal.

lg
no neat sig line

 

[bwringer]

Agreed, a screw would work just fine as a piezo spark "destination". This ain't a McLaren race engine.

You could use a grinder to fashion the tip into a point if you're feeling fancy, but that's certainly optional.

 

[larry4406]

I’m not even sure I have any of the spark ground straps anymore.

Most if not all are simply gone after 25 years.

The last pic I posted was an internet pic not mine.

 

[PCustoms]

The tabs (not taps) are grounds where the spark from the electrode jumps to. Think spark plug where the spark from the center electrode jumps to the tip.

I thought about not doing the punched tabs at all and instead just using a stainless screw with a nut that I could adjust in and lock to set the spark gap.

Typo/autocorrect. Fixed my post

I would definitely use a stainless self tapper, or if I felt fancy and adjustable screw as you described

 

[no704]

Why not just use a generic Pizzo sparker?

 

[larry4406]

Why not just use a generic Pizzo sparker?

I will be using an electrode like you show. My grill uses rotary spark igniters not push button.

But the electrode tip needs someplace for the spark to jump to. It is not simply a lightning bolt thru the air.

The spark ground with the prongs are the targets for the spark to jump to.

Need to complete the circuit if you will.