PDA

View Full Version : Bridge Posts for Floyd Rose Bridge - How tight?



gamahucher
03-09-2017, 12:21 PM
Exactly how tight should the bridge posts be in the body for a Floyd Rose bridge? I'm up to the stage of putting the bridge on and following what Adam did on the video, I go to tap the posts home in the holes and I'm sure they are too tight. In fact I can see a crack starting from one (see photo) so I'm a little reluctant to just drive them home. I'd rather pull them out and ream the hole out a little, but to what? And more to the point, how do I get it out now?Thanks in advance. Warren
22063

mjg
03-09-2017, 12:55 PM
I had the same experience - I only widened them enough to to remove the paint that had sprayed in them, and they split the wood both vertically and horizontally when I hammered them in.

Could you screw the bolt in to give you a bit more length, and see if you can wobble it back and forwards a bit to loosen it and get it out? Of course you'd want to be careful to not make the cracking worse, and to not bend the bolt.

What I ended up doing was hammering them all the way in, then using some thin super glue to wick into the cracks. I had one crack like the one you are seeing form, and another appeared under the other pin, running horizontally to the bridge earth wire hole.

gamahucher
03-09-2017, 01:07 PM
Well, I ended up getting them out just using a hammer with the claw covered with cloth against the body with some ply protecting the finish. To me, if it's cracking, it's overstressed and the wrong size. As it is, because it has cracked, I'll probably have to use some CA glue to limit the damage. Therefore I think I'd be better reaming it out a bit and maybe using some epoxy when the insert is re-inserted or replacing them with other inserts - as long as the internal thread is the right size for the bridge post.

gamahucher
03-09-2017, 02:31 PM
just a bit further, the insert post has a diameter of 10.3mm and the predrilled holes in the body are 9.2mm. That means over a millimetre difference which sounds like a huge amount. My son used to work in an engineering shop and he tells me the outside diameter of 10.3 suggests a hole diameter of 10mm. Thoughts anyone?

gamahucher
05-09-2017, 10:54 AM
Well, for what it's worth (surely someone else has a similar problem) trying to fit a 10.3mm post into a 9.2mm hole will cause damage anytime. I had a quick chat to an engineer and he suggested the ideal size into wood would be the diameter to the bottom of the flukes on the insert post. That way the post is held by the flukes and you're not trying to compress the surrounding wood excessively - which leads to cracking. It was really difficult to measure the diameter to the due to the calipers not having a fine enough edge to fit in between so in the end we decided on a very sharp 10.0mm drill turned by hand in a drill press to keep it vertical. This worked a treat and the posts then tapped in just like Adam did in the video. Hope that helps people.

wokkaboy
05-09-2017, 11:26 AM
glad you had a good outcome Gamahurcher.

mjg
05-09-2017, 03:42 PM
Good to know. I'm sure others have had the same issue. Something to be added to the instructions that are being compiled?

Simon Barden
05-09-2017, 06:24 PM
From a visual inspection, the bottom of the posts are often a slightly smaller diameter than the basic inner diameter of knurled section, which leads me to think that the holes are probably based on the thinner part.

I'd always try and use a press or a clamp to slowly push the inserts in rather than tap them with a hammer - even a soft faced one - as the extra over-pressure caused by the hammer blow can increase the tendency for the wood to crack. I'm not saying an over-sized insert wouldn't crack even if slowly pressed in, but even if the holes were a better size, too severe a blow might still cause some cracking, as there's not a lot of wood around the back end of the hole.

Buchanfarmer
01-01-2018, 06:59 AM
Hi folks. Am having a small problem hope you can help sort out please. Have tapped in the mounts. But Adam says tsp in until they are level with the top. Well the screw tops are still 5mm above and top of the mounts are at surface level of the routed out area where they fit. The screws are now finger tight.
Please how much further do I tap them in?
Is 5mm above the top surface area of the screw heads significant?
Doug.

DrNomis_44
06-01-2018, 04:39 PM
Hi folks. Am having a small problem hope you can help sort out please. Have tapped in the mounts. But Adam says tsp in until they are level with the top. Well the screw tops are still 5mm above and top of the mounts are at surface level of the routed out area where they fit. The screws are now finger tight.
Please how much further do I tap them in?
Is 5mm above the top surface area of the screw heads significant?
Doug.


The threaded inserts that the posts screw-into should be level with the wood that they tap into.