Jazz bass Mod becomes Build?

Amazon delivered a 300mm x 4mm drill bit today. It was very impressive the way the stainless steel sleeve stabilized the angle. The slop has dropped from about 6 degrees of play to about 1 degree of play. That seems pretty acceptable. I managed to get it two ways.

One of the two 6mm guides they sent is worse than the other. I'd throw the bad one away, but maybe I'll drill it out to use with a 1/4" bit.

I got the 1-degree-of-play with the 4mm bit first by using the better 6mm guide with the stainless steel sleeve.

I also discovered discovered I could get pretty much the same using the 8mm guide. In this case I used the stainless steel tube and then the plastic shaft from a Bic "round stic" pen.

Attachment 46032

I noticed that the shaft OD is exactly 8mm and the ID is 6mm. It worked great. Not really necessary since at least one of the 6mm guides to work, but interesting nevertheless ;-)

Great that the sleeve has reduced the angle variation - I think +or- 1 degree is very acceptable.

Funny about the pen tube - great find!

So far, I am thinking that your approach, along with a test using some scrap wood, is still best. The only thing I may have contributed is the idea of using the stainless steel tube.

I tried my "15" degree jig again today, using the sleeves and a 4mm bit. I drilled two tests holes in a 2x4 piece of lumber--one on the 8mm and one on the 6mm side. So, I now know, that stabilizing with the stainless steel sleeve, the 6mm hole drill a 19 degree hole, and the 8mm side drills a 17 degree hole.

This prompted me to do some measurements, and to get out a calculator to see what angles I would need. Distance from the center of the bridge to the control cavity is 135mm. The control cavity is 30mm deep. So the maximum angle I can use to get to the cavity is 12.5 degrees. If I go from the bridge to the bridge pickup cavity it's a bit better... 60mm of run, 20 mm of drop...that's 18mm. One side of my jig will work for that. TD's will also work.

I think the moral of the story is that the next time I do this, I need to be ready to make--and test--a jig. I don't think I am going to be comfortable drilling until I can get it right on a piece of scrap lumber.

That may not be too long. I just found a bass body (p-bass this time) for $25 on AliBaba. I have an idea about making a headless bass using the neck from the SX that I will have left over after this bass... The body should arrive shortly after I finish some refinishing on this and a couple of other projects...

If you want a cheap fairly accurate way I just use some painters tape and some off cuts and a long series, about 300mm long 3mm diameter drill.

I use 2"/50mm painters tape that I use on the finished painted surface as I found placing it on bare wood would sometimes move. I run a bit of tape from the cavity where the hole will finish and run past where the hole will start. I mark where the hole will enter the body and drill a 3mm hole about 2mm deep. I run a line from the hole centre to where it will break though into the cavity and back as far as the tape goes. I use this to align the drill to where it should enter the cavity.

I make a template for the angle but measuring the length from the hole to the cavity and then what the depth is from where the drill enters the cavity to the body surface which gives me the angle. If the angle is 15 degrees I keep the piece that is 165 to use to set the drill angle. I place the long drill in the shallow drilled hole and using the template on top of the drill and I use super glue to glue a block that the drill sits on while I drill the hole. That's it.

Clamp the body to a bench and I use a battery drill and I rest the drill on the glued block and start drilling from the 3mm hole I drilled earlier and while standing behind the drill I can just align the drill by eye following the line I placed on the tape. Always make sure you clear the drill by pulling back and clearing the drill as sometimes if you try and force it through it will make the drill wander, not so much in softer woods but in harder woods you can damage the drill.

I have used this method on about 8 guitars and have never had any problems but do it how ever you want but if you do different lengths and depths then you may need a jig for each guitar.

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Originally Posted by Dikkybee007

If you want a cheap fairly accurate way I just use some painters tape and some off cuts and a long series, about 300mm long 3mm diameter drill.

I use 2"/50mm painters tape that I use on the finished painted surface as I found placing it on bare wood would sometimes move. I run a bit of tape from the cavity where the hole will finish and run past where the hole will start. I mark where the hole will enter the body and drill a 3mm hole about 2mm deep. I run a line from the hole centre to where it will break though into the cavity and back as far as the tape goes. I use this to align the drill to where it should enter the cavity.

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I like the sound of this method, and am pretty sure I get it up to here.

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I make a template for the angle but measuring the length from the hole to the cavity and then what the depth is from where the drill enters the cavity to the body surface which gives me the angle. If the angle is 15 degrees I keep the piece that is 165 to use to set the drill angle. I place the long drill in the shallow drilled hole and using the template on top of the drill and I use super glue to glue a block that the drill sits on while I drill the hole. That's it.

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I am not sure I understand this part. Do you have a pic of one of these that you've made?

So this is what I am thinking that you use... Make a small block that is the same height as the distance between the top of the cavity and where you want the hole to come out. In this case 25mm. Glue the block to a piece of scrap wood so that the distance between the edge of the block and the edge of the piece of scrap is the same as the distance between control cavity and the shallow hole you drilled that will be under the bridge (in this case 125mm). Clamp the jig to the body so that the drill bit lines up with the shallow hole and rests on the jig as at the bottom of the drawing below?

Attachment 46038

If that's right, it's ingenious. Quick, easy, no math...and it would work with any angle. I haven't seen this anywhere before.

Sorry I haven't been able to log in since I made the post.

I normally just use some 2" / 50mm painters tape and glue the block in place with some super glue directly to the tape. I have found it works as long as you don't hit the block hard with something heavy and it is easy to remove. I also do it once I have the finish applied as the tape sticks much better.

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Originally Posted by Dikkybee007

...I normally just use some 2" / 50mm painters tape and glue the block in place with some super glue directly to the tape....

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Attachment 46047

That's even simpler. I like it! I have another body on the way, so it's about time I begin to understand. Some days the lights come on slower than others ;-)