Fixing the string height issues of a Ran Crusher

[Antiproduct]

Hello everyone,
I need the collective help of sso.org!
My Ran Crusher has been acting up for about a year now and I finally have time to address the problem.
I first noticed it when I set the neck straight, but still had to set the screws on the bridge to maximum to get a halfway usable string action. Interestingly, only the higher frets from the 15th fret onwards were playable, all the others were too high. However, the neck was still set straight.
In the meantime, however, another problem has crept in, which is possibly related to the string action. Ran does not use normal wood screws with direct screwing, but lock nuts with which the neck is fixed. This seemed to me to be an ingenious system at first, but now the nuts push out of the neck, creating a gap between the neck and the body and making the neck angle completely wrong, and with it the string action. I tried to show it on the photo, but due to the angle of the shot it doesn't come across so well, hence the DirtyPuma lines.

I think I should solve the neck screw situation first. Does it make sense to glue the nuts in and if so, which adhesive should I use? I would classify myself as handy, at least I'm not afraid to fix my own stuff.

 

[Asdrael]

Yeah the neck inserts pulled out so you can't set the neck properly.

You could try carefully screwing the inserts back in (usually a rather large Allen key) but it might just be that the wood has become a tad lose around them, so you'd only delay the problem.

A solution would be to super glue them in but that's s a bit bandaid. If anything else is wrong you are screwed (lulz). More elegantly you could redrill one size larger for new inserts and that would be perfect. Or plug, redrill etc.

The real question though is why are they pulling out now. They shouldn't be doing that. A possibility is that the screws are too long for the inserts and tightening them too much tried to rip the insert out. Double check that before you do anything.

 

[odibrom]

... please post a pic of the neck part that sits under the neck pickup.

 

[Antiproduct]

Yeah the neck inserts pulled out so you can't set the neck properly.

You could try carefully screwing the inserts back in (usually a rather large Allen key) but it might just be that the wood has become a tad lose around them, so you'd only delay the problem.

A solution would be to super glue them in but that's s a bit bandaid. If anything else is wrong you are screwed (lulz). More elegantly you could redrill one size larger for new inserts and that would be perfect. Or plug, redrill etc.

The real question though is why are they pulling out now. They shouldn't be doing that. A possibility is that the screws are too long for the inserts and tightening them too much tried to rip the insert out. Double check that before you do anything.

I have already gently reset the inserts twice with a hammer, but they have pulled out again each time.
I suspect that the wood has dried out and contracted slightly so that the inserts had room to slide. The screws are definitely not too long. Without washers, I can "completely recess" the screw head.
What do you mean by "if something else is wrong"?

... please post a pic of the neck part that sits under the neck pickup.

Sure!

 

[Asdrael]

Wait those are "hammer in" inserts? Typically you want to use screw in inserts, especially in this type of wood.

If they really are hammer-in (typically used for plastic), I would simply swap them out for regular wood ones that should have an external thread. But you need to make sure that they are fine for the existing hole size and that you can screw them in straight. I see that you are in Germany, I can recommend Rampa Muffe for this. Their SK/SKD line is awesome.

 

[Antiproduct]

Nope, these are hammer-in inserts. I just hammered one out and took a picture. It looks like metal inside the hole now but I think they sprayed it with graphite or something like that to hammer it in easier?

 

[Asdrael]

I am out of proper ideas for this one, sorry man. I think they are just too lose now.

I would take it all out and replace by a proper wood (threaded) insert of the right size, but that would likely require some redrilling best done with a drill press. Or super glue everything and hope for the best.

 

[Yul Brynner]

You need those furniture type inserts with the barbs that grip into the wood. But you'd have to remove the fretboard because they need to mount from the top side of the neck.


What are dirty puma lines?

 

[Antiproduct]

You need those furniture type inserts with the barbs that grip into the wood. But you'd have to remove the fretboard because they need to mount from the top side of the neck.


What are dirty puma lines?

I would rather try to glue the original inserts in or use different threaded inserts like Asdrael suggested I think

The DirtyPumas reference is from here https://sevenstring.org/threads/ngd-rusti-guitars-lotus-1-headless.354881/post-5436472
Read the whole thread and you will get it

 

[Asdrael]

I built my guitar with Rampa SKD inserts. You can get them at Sautershop:

RAMPA - Muffen

Verschiedene Typen an Rampa Muffen. Ideal für den Frästisch Bau. Einschlagmuffen und Einschraubmuffen. Große Auswahl. Jetzt im sautershop bestellen.

www.sautershop.de

Obviously, mind the screw size, hole diameter requirement, length etc. They are meant to recess slightly by themselves when you tighten them in, that should fix your issue. But they need to be screwed in straight!

 

[odibrom]

I think that @Asdrael 's solution is the less intrusive and probably the only one a non luthier guy could go with without external help.

Looking at the photos I asked for and the the following one I'm amazed at how RAN was so well considered in the guitar community. Those are simply the wrong wood inserts to use in this type of joint where tension stress is heavy. It is obvious that these inserts would sooner or later slide out of their hole, more so if they sprayed grafite into the hole. The guitars looked nice and well built, but damn, that's a novice kind of mistake, and a terrible one as well because it can cause unstable tuning and structural problems later on.

... remind me to not look ad RAN guitars in the used market.

 

[Antiproduct]

I will start looking into other wood inserts. I will probably document it here. It's not an unfixable structural problem but I agree that this should not happen AFTER building a reputation as a builder.

I got this guitar in 2015 and they stopped shipping guitars in..2017? 2018? Maybe they stopped giving a shit around then as I can't find anyone with similar problems online.

 

[Lemonbaby]

I built my guitar with Rampa SKD inserts.

This. For M5 screws.

 

[oracles]

I've pulled both my Crushers apart and they both use the proper inserts, so this is very surprising to see, sorry you're having issues with this.

Agreed that the SKD inserts seem like the least intrusive option, they should work out great.

 

[MaxAidingAres]

Id say hammer them in and maybe a dab of super glue/ epoxy just to hold it in place. maybe some loctite?

otherwise you would have to remove the bushings and upsize to a larger wood insert and maybe upsize the neck screws if needed

 

[Antiproduct]

The Rampa inserts have now arrived and I have installed them.The result is not as nice as I had hoped, but less ugly than expected.
I opted for SK30 inserts and in retrospect would have preferred to use the slightly more expensive SK330 for a straighter screw-in. Due to the relatively short screw-in distance of around 10 mm, it was possible to screw the inserts in slowly by hand using the Allen key. A quarter turn, readjust, turn again a little and so on.
The inserts are not 100% straight, but you can still tighten the neck bolts.
Rampa recommends a pre-drilled hole of 10-10.5mm. Ran's holes are 10mm, although in hindsight I would recommend 10.5mm as unfortunately some of the wood bent upwards when screwing it in. Nevertheless, I was able to tighten the neck flat.
At the moment I'm letting the neck sit with the contact pressure, checking the neck again and trying to straighten the curved wood a little if necessary, and then I'll put strings on again to see if my problems with the string height have been solved or reoccur.

 

[odibrom]

The Rampa inserts have now arrived and I have installed them.The result is not as nice as I had hoped, but less ugly than expected.
I opted for SK30 inserts and in retrospect would have preferred to use the slightly more expensive SK330 for a straighter screw-in. Due to the relatively short screw-in distance of around 10 mm, it was possible to screw the inserts in slowly by hand using the Allen key. A quarter turn, readjust, turn again a little and so on.
The inserts are not 100% straight, but you can still tighten the neck bolts.
Rampa recommends a pre-drilled hole of 10-10.5mm. Ran's holes are 10mm, although in hindsight I would recommend 10.5mm as unfortunately some of the wood bent upwards when screwing it in. Nevertheless, I was able to tighten the neck flat.
At the moment I'm letting the neck sit with the contact pressure, checking the neck again and trying to straighten the curved wood a little if necessary, and then I'll put strings on again to see if my problems with the string height have been solved or reoccur.

Cool, good to know this is progressing well enough. Don't forget that you still have the option of taking the guitar to a good tech guy.

 

[Antiproduct]

Cool, good to know this is progressing well enough. Don't forget that you still have the option of taking the guitar to a good tech guy.

For sure, I won't do anything outside my capabilities to this guitar haha
Anything that involves frets has to be done by a professional. They are hard to find however... maybe the guys from Gamble guitars, they are from my home town.

 

[Asdrael]

The Rampa inserts have now arrived and I have installed them.The result is not as nice as I had hoped, but less ugly than expected.
I opted for SK30 inserts and in retrospect would have preferred to use the slightly more expensive SK330 for a straighter screw-in. Due to the relatively short screw-in distance of around 10 mm, it was possible to screw the inserts in slowly by hand using the Allen key. A quarter turn, readjust, turn again a little and so on.
The inserts are not 100% straight, but you can still tighten the neck bolts.
Rampa recommends a pre-drilled hole of 10-10.5mm. Ran's holes are 10mm, although in hindsight I would recommend 10.5mm as unfortunately some of the wood bent upwards when screwing it in. Nevertheless, I was able to tighten the neck flat.
At the moment I'm letting the neck sit with the contact pressure, checking the neck again and trying to straighten the curved wood a little if necessary, and then I'll put strings on again to see if my problems with the string height have been solved or reoccur.

Sounds like a good step forward already. I would have gone for the SKD and not the SK as they have a small lip, so that when you screw them in they recess and bring the wood around down flush more easily.

What you could do if you want to be anal about it is very carefully sand flush the wood that "popped up" or straight out switch for a SKD. Anything more I would bring to a tech to to maybe step up to a M6 and drill accordingly (then you'd need to be extra careful of truss rod and potential carbon reinforcement).

 

[pondman]

That system is designed not to work