Resonator build

[WeirdBits]

The truss rod counter-acts string tension, so when you have a back bow or convex neck the truss rod is too tight and is bending the neck backwards. Your current back bow may be fine when under actual string tension but for the purposes of building and setting up it is best to have the neck as straight/flat as possible, and then re-adjust the truss rod when the strings are on.

In your case, with the truss rod being too tight, you need to loosen it gradually and allow the neck to hopefully ease back to nice and straight. Looking from the headstock end down the neck you need to loosen the truss rod by turning it counter-clockwise (lefty loosey, righty tighty) BUT only by 1/4 of a turn at a time. Then let it sit for at least a few minutes, check it, and repeat if needed. Don’t rush it, as wood and glue and the various densities of material take time to settle and adjust after each tension change. For me, if I need more than 3 or 4 quarter turns then I’ll probably leave it overnight before re-checking and adjusting it further. This is particularly true if the kit/neck has travelled a long way or between very different climates (heat, humidity etc), as they really do need time to acclimatise. Neck pocket tightness, neck bows and general fit can all change significantly as they settle and adjust to the new environment.

It’s possible that while adjusting the truss rod it could start to feel ‘loose’ with no effort to turn it, don’t panic. These should all be double-action truss rods, so if you loosen it far enough it will transition from ‘pulling’ backwards with tension to ‘pushing’ forward with tension into a concave or front/up bow. If at ANY point the truss rod adjustment becomes really tight and difficult to turn then stop and do not apply any more force. Count how many 1/4 or whole turns you have made and let us know. If the truss rod isn’t adjusting easily or worse if you strip its thread then the neck could be headed for the bin.

Slowly, slowly does it, and good luck.

[Tgraham]

Thanks Scott, I have turned it to the feeling lose stage the curve has lessened and yes I will recheck in the morning after a settling period.
Thank you

[fender3x]

I think the post from Tim and from you must have come in while I was writing mine. Nice to know he stands behind the product.

The convex does not look to extreme. My guess is that the Weirdbits method will clear it up. With regard to the neck's looseness in the pocket, I keep some veneer around for just such things. We had a member for a while (Simon) who taught many of us that veneer has about a gazillion uses, but one of the principal ones is just the issue you are having.

[Tgraham]

Woke up eager to see how the neck responded - happy to report it looks much better than yesterday morning. It will be interesting what it does when strings are on and tuned. So I’ve learnt more about truss rods thanks guys.

Trevor the dent, I think won’t be a problem it’s just a small one as per photo - and yes I’m getting better at loading photos to, the dent is a perfect match for the corner of the saddle slot in the spider. Better packing for transit is needed, the spider was in a light foam sleeve and just floating around inside the body thus able to bang around during shipping hence the dent.

I will try the spider sitting on a table saw flange today to see exactly what’s going on there. Just looking at it it seems one leg in particular is curved down. Will watch StewMac video again and again. Should the whole thing be flat.

So many questions about building this thing I.e. is the saddle in 2 parts and is it notched for strings to sit in, how high is the tailpiece supposed to sit.
There will be more I’m sure
Cheers
graham

[Tgraham]

Veneer for shims hmm I’m sure there’s some at the men’s shed.
Thanks fender

[Tgraham]

Made a “jig” to try to make the sanding of the lip for the cone as even as possible. Double sided tape to hold sandpaper on. Started with 180 grit will see how that goes then go finer.

[fender3x]

Great idea! Simple and effective.

[Tgraham]

Replogle Resos is a great site for resonator information

[Tgraham]

Finally got the spider sitting nicely on the cone so time to put a couple of strings on the check for rattles and buzzing, went ok I can’t detect any resonator bugs. Also got a good idea of the height the action - very high, good for slide but a bit high for picking, will think on that for a while.

Question specifically for TD - did you try the saddle that came with the kit or did you just go with the wooden one?

Haven’t decided on colour yet - possible blue or green will experiment with those options on scrap timber.
Cheers
graham

[Trevor Davies]

Finally got the spider sitting nicely on the cone so time to put a couple of strings on the check for rattles and buzzing, went ok I canÂ’t detect any resonator bugs. Also got a good idea of the height the action - very high, good for slide but a bit high for picking, will think on that for a while.

Question specifically for TD - did you try the saddle that came with the kit or did you just go with the wooden one?

HavenÂ’t decided on colour yet - possible blue or green will experiment with those options on scrap timber.
Cheers
graham

Hi Tgraham,

I did try the kit saddle! See Link.

BTW, my old acoustic has that style of saddle. It is designed for 4 wound, 2 non-wound, acoustic strings. I'm using normal electric strings (so only 3 wound!).

My action was a bit high. But I did not lower the nut action as I wanted it setup for slide. The action is tricky on a resonator. It seems like the action is set at the end by filing/sanding the base of the bridge so that it sits lower in the spider. Also, having all six strings on will also compress the spider/cone assembly and lower the strings a bit more.

Your picture of the action does look a bit high. Just checking, is your neck straight? Is the nut action too high? Is the bridge seated correctly in the support?

Something to consider: if the bridge is not on the spider (so the strings are on the support only) would the string action be too low? At least then you know the action can be raised by the bridge to a good height!