I was going to post some photos, but my camera's batteries needed recharging, and then when I went to load them into the graphics PC, all the Adobe software required updating, so I haven't got around to it till today.
The router bit was new, and I check the chuck to make sure it was centered, but as you surmised, I did try to take off more than 1/2mm at once, which worked fine when testing on the MDF, but obviously way to much when used on the much harder and dense Maple of the neck.
The instructions state to center the router bit over the edge guides, guide roller, then loosen the adjusting bar till you have the desired depth of cut, which is exactly what I did.
It says nothing in the instructions regarding recommended max depth of cut, if it had I would have followed those instructions and made multiple small passes.
I think the scant instructions that come with this unit [especially the use of the straight edge guide] are in urgent need of a revision.
I imagine there wouldn't be a problem when using the much smaller router bits for removing wood for inlay, as it would be removing far less wood at any one time, it's when using that larger biding router bit that the vibrations become so much that the whole unit can shake itself to bits.
Live and learn as they say.
I've tried the wood filler route over the last few days, and it doesn't seem to be a suitable option, even if I impregnated the filler with glue to harden it, I suspect it would eventually just fall off the headstock in one large mass, taking the binding and any finish with it.
I suppose the other option is to first remove the wood filler I have applied, then cut some Maple or Basswood 2mm veneer I have to shape, and gluing that to the oversized binding route, then filling in any gaps with wood filler, then gluing in the binding.
At least it should give the binding a more substantial base to adhere to, and be less likely of disintegration should it receive a knock, which I have never known a guitar not to suffer from eventually.
I'll post photos in the build diary, as it's been ages since it's been updated....pity this happened, as the Blonde shellac finish on the body has come up really well.
http://www.buildyourownguitar.com.au...?t=4988&page=2