I’ll be making a display for a wedding. Basically, the words “Mr & Mrs” will stand on the head table at the dinner. So, I want the letters to stand by themselves without extra support on the back, so I’d like to cut them out of two layers of 3/4" MDF. Can I glue my MDF together and cut it all the way through, or should I cut each one separately and glue them together after that (and then sand forever to make the edges flush)? To cut through 1.5 inch material, will I need a special bit, or will the regular 1/8" bit from inventables cut that deply?
Those starter bits giving up to 0.80 inch cut. On or over this size wouldn’t work. If no blade ends starts rubbing against the edge, starts squicks and heating up bit, possibility breaks. Some 1/8" long bits on eBay you can find. I’ll post if I can find the place I purchased.
You’ll definitely need a long bit for that, you’d only have 1/2" or less clamped in the spindle and run a larger risk of snapping the bit.
The cutting edge only needs to be 1" long or so, with a much longer shank, if you can keep the dust and shavings from building up in the cut, but you run the risk of the shank rubbing and burning the edges, as well as damaging the bit.
I’d also suggest using a bit that’s 1/4", if possible. You’ll have a big problem with dust and shavings being ejected out of 1.5" of MDF, and I can tell you from experience that trying to vacuum dust out of a 1/8" cut is difficult. You don’t want the dust to build up in there, so if you choose to use 1/8" you will want to pause the cutting every few times around and use a small pick or tool to pull as much as you can out.
Something like this.
We just actually cut one of these and lent it to our friends. It was cut out of 3/4" MDF. It seemed to stand up fine, although it wasn’t on the head table so maybe if the table was bumped it would fall over, but I’m not sure.
Unless it was specifically requested to be 1.5", you might be fine with just 3/4"! Let’s us know how it goes!
Put a flat plate as a base just glue and screw.Maybe in clear plastic?
If you have it cut two copies, you could also have it cut some 1/4" alignment holes and use dowels to align it. Then glue them in, cut them near-flush, and sand flat.
I’ve made a bunch of these signs that my wife sells. I was making them with a scroll saw, but could hardly keep up with demand. It’s probably the biggest factor in my buying the x-carve. I always just use 1/2" material (usually baltic birch ply for the strength when the fonts get thin) and put a 3/4" pine base on the bottom to help it stand.