Spoilboard hole pattern, grid or offset?

[madsb]

I’m getting ready to cut my first full-size spoilboard for my Shapeoko XL. Since I’m in metric-land, I’m looking at 50mm hole spacing and 8mm holes for my threaded inserts.
All of the Shapeoko MDF spoilboards I’ve seen have had a regular grid structure, like this one:

However, I’ve seen some aluminum fixture plates where the rows are offset

Have any of you created your spoilboards with offset holes? What are your thoughts on it?

[neilferreri (Neil Ferreri Ω)]

No matter how you do it, the holes won’t be in the right place.

I rarely use my threaded inserts, but I use 8mm dowels for alignment on most jobs.

[WillAdams (William Adams (Carbide 3D))]

I’ve agonized over this sort of thing, and have determined that the next time I do threaded inserts, I’ll machine holes through the spoilboard and into threaded insert board as/where-needed, and then finish drilling the threaded insert board and then install the threaded inserts from underneath to that I’ll be confident each hole is used at least once.

[gdon_2003 (Guy Donham)]

The thing about uniform spacing for your spoil board is you can make jigs to hold irregular or special shaped objects. I made some minimalists wallets out of glued up veneer and I made a jig to hold the thin and flexible material down. I also made another jig to hold down some round knobs so I could carve on the top of them. Both of these jigs had holes in them so I could bolt them down on my 2 inch grid of holes.

This jig was to vcarve on some engine cover knobs for my Thunderbird. The knobs were tall so I need to put some spacers on the bottom of the jig and because they were round I cut a slot and put a threaded insert in and a bolt to clamp them in place.

This jig was used to cut very thin veneer and it was held flat. The second picture are the pieces cut out after using the jig.

So having an even spacing it is easy to make jigs for special purposes.