Disaster?

[blackalex1952]

I was routing a slot for a saddle. I wasn't quite "in the zone" for this move...I had ignored the faded scribbling on my saddle router jig which said originally "USE PLUNGE ROUTER ONLY!!!"
It had faded since the last build, and due to a bout in hospital, I had suffered an extended break from the workshop. So, basically, I have routed a saddle slot, the trimmer base which runs against a fence kicked and necessitated another pass for a wider saddle to hide the ding that the trimmer caused (read, I caused it ha ha). Then, to make matters worse, I misadjusted the router depth and cut through the soundboard and just touched the rosewood bridge plate on the inside of the guitar.
My repair plan at this point is to glue a piece of spruce to the bottom of a rosewood inlay which will fill the saddle slot, then glue the inlay into position. Then re route the slot to the correct width and depth...using, of course, my plunge router base. It is both heavier and more accurately adjustable.
The concern is, what effect, if any, could this have on the sound of the guitar? Given that I have carved a slot in the spruce then repaired it??? The bridge, bridge plate, soundboard and bracing, at least at low frequencies, seems to act as an integral unit to drive the soundboard. But what of long grain short wavelength vibrations in the soundboard, given that the repaired break in the spruce soundboard is directly under the saddle? My take is that it won't be a noticeable issue. Kicking myself for a silly avoidable mistake, and certainly not at all pleased, especially towards the end of a build...Cheers Ross

[johnparchem]

I think you are good; whats a thin strip of top relative to the mass of the bridge? Just a thought, if you are OK with the current width of the saddle slot, glue in a strip of rosewood just thick enough to give you the correct slot depth into the slot. Then there is no need to reroute. You have it easy with the bridge plate in place.

[Mark McLean]

Yes, I know you feel bad. We have all done things like this that are a mistake born out of fatigue or stress, and should have been preventable. But I agree with John that this is entirely fixable. All of your trouble is in that narrow slot, and it is entirely reasonable to glue some material in there to make a solid floor to the slot and a good connection to the soundboard and bridge plate. Just go ahead - and don't beat yourself up about it.

[blackalex1952]

Thanks, guys, for the replies. Yes, I don't expect any problems now the repair has been successfully executed. It would be nice to be able to source router bits ie end mills which match the thickness of the bone bridge blanks.
Also, does anyone know of a source of 3 degree taper bridge pin reamers other than Stewmac...preferably an Australian supplier. Cheers! Ross

[kiwigeo]

I always use a cutter of smaller diameter than the final slot width. I use the Stewmac slot cutting jig and adjust the width by fractions until I reach the correct width for the saddle.

Plenty of 3 degree reamers on Ebay but quality probably varies. I got mine from a European supplier.

Thanks, guys, for the replies. Yes, I don't expect any problems now the repair has been successfully executed. It would be nice to be able to source router bits ie end mills which match the thickness of the bone bridge blanks.
Also, does anyone know of a source of 3 degree taper bridge pin reamers other than Stewmac...preferably an Australian supplier. Cheers! Ross

[kiwigeo]

A plane landing is a "controlled stall"..........making a guitar is a "controlled disaster"

[blackalex1952]

Martin:

A plane landing is a "controlled stall"..........making a guitar is a "controlled disaster" :mrgreen

Yes. There is also a saying in aviation:"The outcome of any manoevre shall never be in doubt"!!!!
Aslo:

I use the Stewmac slot cutting jig and adjust the width by fractions until I reach the correct width for the saddle.

Half my trouble is caused by my home made jig which is a bit tricky to adjust in small increments. It seems, to me, that a trimmer is a bit on the heavy side for this kind of work and a Dremel too lightweight...I have never seen one of these slots accurately cut with hand tools alone.
Cheers! Ross

[kiwigeo]

Cutting a saddle slot is probably a perfect job for Dremel...it's about the only job I use my Dremel for. The Stewmac jig is overpriced of course but it does allow you to set the slot angle and then "creep up" with the cutter position.

Half my trouble is caused by my home made jig which is a bit tricky to adjust in small increments. It seems, to me, that a trimmer is a bit on the heavy side for this kind of work and a Dremel too lightweight...I have never seen one of these slots accurately cut with hand tools alone.
Cheers! Ross

[blackalex1952]

I'm a little concerned re the power of the Dremel for the right size bits, which are also hard to find. At least where I live. I do have one Dremel router bit, but it's very easy with a bit that size to overheat. I mainly use the Dremel for inlay work. But DEFINITELY open to a source of the bits that you use for saddle slots.-
R

[kiwigeo]

Most of my small cutters I think came from Stewmac or LMI. I think a few I got from Carbitool here in Australia - their service is pretty good.

I'm a little concerned re the power of the Dremel for the right size bits, which are also hard to find. At least where I live. I do have one Dremel router bit, but it's very easy with a bit that size to overheat. I mainly use the Dremel for inlay work. But DEFINITELY open to a source of the bits that you use for saddle slots.-
R

[56nortondomy]

I use a 4mm bit I got on ebay in my laminate trimmer, I rout mine before I attach the bridge.
Wayne

[TallDad71]

To be sure I never did see the point of cutting a slot after fitting to the top, unless it is a repair, of course. Is there one?

[kiwigeo]

For me it's the best way to ensure that saddle to nut measurement is as accurate as possible. Installing a bridge with slot already cut introduces possible inaccuracies if the bridge moves just a fraction during glue up.

To be sure I never did see the point of cutting a slot after fitting to the top, unless it is a repair, of course. Is there one?

[blackalex1952]

I have used both methods to route the slot, both on and off the guitar. The saddle blanks I have average around 2.8mm wide. So not quite 4mm! Easier to establish the correct intonation by routing the slot on the instrument. I wish I had 4mm to play with but at the moment I don't. Do you make your own bone blanks or purchase them? Cheers! Ross

[Bruce McC]

Hi Ross

For router bits/end mills try Adam's Bits on eBay.
Based in Melbourne I think.

[56nortondomy]

I get my bone blanks off ebay Ross, they come from the UK, I contact the seller when I need them and he does an order for me. Wayne