Filling in Hole

[john schnyderite]

I made a desk top and routed out a 4.5" circle for a wireless charger to mount from underneath. It is about 1/8 or 3/32 thick in that area, which I'm worried about structurally. I was thinking about trying to fill it in a bit. Even thin plywood would probably add too much thickness to charge reliably, so I was thinking about just adding a 1/16" layer of wood glue in the bottom to firm things up a tad and make it sound less hollow. Any better ideas?

[Jamie Buxton]

Do you water-based wood glue like Titebond? That's a bad idea. As it comes out of the bottle, the glue is about half water. A sixteenth inch of it will bulge your thin wood.

You can buy thin plywood from vendors which serve the aircraft model community. For instance, https://www.nationalbalsa.com/birch_plywood_s/58.htm has 1/8", 3/32", 1/16", and even 1/32" birch plywood.

[John Lanciani]

If it’s 1/8” I think you’ll be fine but I think the best way to ad some strength would be to bed a piece of fiberglass fabric in epoxy in the void.

[Kory Cassel]

I made a desk top and routed out a 4.5" circle for a wireless charger to mount from underneath. It is about 1/8 or 3/32 thick in that area, which I'm worried about structurally. I was thinking about trying to fill it in a bit. Even thin plywood would probably add too much thickness to charge reliably, so I was thinking about just adding a 1/16" layer of wood glue in the bottom to firm things up a tad and make it sound less hollow. Any better ideas?
Search 'potting electronics'. There are different compounds for different applications. Some are focused on vibration dampening, some are geared toward your problem. The harder epoxy mixtures will certainly add any strength you need but be careful with bleed through. You may want to research the proper releasing agent so you can remove/replace the charger in the future if needed. I agree that yellow wood glue might cause a problem. Good luck!:)

[Gary Ragatz]

No experience with wireless charging, so I don't know what thickness would be acceptable. I wonder if you could epoxy a thin piece of polycarbonate (maybe ~ 0.10") to the underside to stiffen things up?

[john schnyderite]

Epoxy sounds like a great idea. I have some west systems I'll add later on today to strengthen the thin area a bit. Thanks for the advice. Once i get it where I want it and confirm it charges, I'll hot glue the charger in.



Search 'potting electronics'. There are different compounds for different applications. Some are focused on vibration dampening, some are geared toward your problem. The harder epoxy mixtures will certainly add any strength you need but be careful with bleed through. You may want to research the proper releasing agent so you can remove/replace the charger in the future if needed. I agree that yellow wood glue might cause a problem. Good luck!:)

[Patrick Varley]

Not sure if it's too late, but instead of using a off the shelf charging pad, I would just buy a Qi charging coil unit like here: https://www.adafruit.com/product/2162 (You could also probably scavenge the coil and PCB out of the charger you already have)

Then I'd probably mount it to the top of a wood inlay that glues into the pocket you created. This way you'll get the support on the thin area of wood, but also minimize the distance between coil and phone which determines whether it will charge.

We're I designing this, I would have routed out the recess on the top, placed the coils in the recess with wires out from below, then used a thin decorative inlay to cover the coils. It has the added benefit of letting you know exactly.where the charging spot is. Though this is obviously a design choice that may not have fit with what you're doing.

[Floyd Mah]

Why don't you just put a bracing piece of wood under your wireless charger to keep it near the desktop so that there's no void between the two opposing surfaces. A 1/16" piece of wood is unlikely to add any strength if you were to successfully glue it in. A piece of plastic might be stronger and can be epoxied in without trouble.