Drilling a String-Through Body

[mkern]

My first build-from-scratch turned out pretty good for a first attempt and now I want to avoid some of the pitfalls.

I could use some advice on how to drill the holes through the body for the strings. My drill press is too small and can only reach a few inches. Last time I drilled, I did it free hand and its pretty apparent I did so from the positioning of the ferrules on the back.

I would like to hear how other people drill the holes perfectly perpendicular through the body. I'm thinking of making a jig but perhaps someone knows of a thing-a-ma-jig from Home Depot that would help.

Thanks.

[Jack Wells]

If you plan to continue building guitars, I suggest you plan on buying a 12 in. drill press sometime in the future. Until then you could use your drill press to make a jig for drilling the holes. Terry Downs uses a jig made from a metal block. He has posted a detailed drawing of the jig. I'll try to find it. I see no reason why you couldn't make one out of hard maple.

Found it .............

Terry Downs' String Through Drill Jig

[Albert J]

"General Tools" makes a tool called a "Precision Drill Guide" pn. 36/37 for use with a 3/8" or 1/2" hand held electric drill. That is what I plan on using when I get to that point.

I was typing while JWells was posting. I like the jig better. I know what I will be making tomorrow on my too small drill press.

[Jack Wells]

There's a thread here somewhere where Terry posts pictures of using the jig. The jig is attached to the body using a couple of the bridge mounting holes.

To insure your ferrules line up straight, I suggest you only drill the two outside holes all the way through from the front. Drill the four inside holes about half way through. Flip the body over and use 1/8 in. drill bits or dowels through the two outside holes to position the jig. Then drill the four inside holes to meet the holes you started from the front.

Even with a drill press, a 1/8 in. drill bit can drift a little if you drill all the way through from one side.

[JohnPurdy]

Mkern,

Do you have a bench type drill press that has a pipe from the base that slides into the drill about 3" or 4" from the chuck, secured by allen set screws? If so I may be able to help you!

john

[mkern]

Jwells: thanks for the suggestion on the jig. I have a piece of 1x1x6 aluminium I can use as the jig. Also, the suggestion about the drilling sequence is very good. Thanks so much!!

[mkern]

Originally Posted by JohnPurdy

Mkern,

Do you have a bench type drill press that has a pipe from the base that slides into the drill about 3" or 4" from the chuck, secured by allen set screws? If so I may be able to help you!

john

Yes, that's exactly what I have. From your picture, your drill press looks like a floor model; mine is a table top model but has the same tube and allen set screws.

[JohnPurdy]

No, that is just photographic trickery, it's a bench type too.

Actually I have two of them, the other one is right behind the one in the picture and is the one I modified. I'm at work now and don't have pictures to explain what I did to modify it. Also you should know I just did this last weekend and have not tried it out but after you see what I did I think you will agree that there is nothing to keep it from working. The mod is also completely reversible.Well here it goes, if I can't explain it well enough I can shoot you some pictures this weekend.

First, using a level mark a line on the support tube even with the bottom of the chuck. Next take the drill off the stand by loosening the allen screws, then unbolt the stand tube from the base(mine has 3 bolts). Measure from the top of the tube where it went into the drill to the line and the o.d. of the tube. Now you need to go to a Steel tubing supplier and get a piece of pipe with the same o.d. the length you measured. While your out you need 3 U bolts of the diameter of your pipe long enough to fit around 2 pieces of pipe. I did this on the weekend when the pipe suppliers were closed so I went to home depot and got a piece of galvanized pipe that was a little to big and brought it home and spent a couple of hours with a belt sander making it the right size.I wouldn't recommend doing it the way I did it!!! Ok, back to to the mod. Slide your new piece of pipe into the drill and secure it with the allen screws. Then bolt the support pipe back in place. In this next step you may need some help. Sit the drill on top of the support pipe with the new piece of pipe in front of the old one and get the clamps on it. Before you tighten it down center it up, then tighten. Next check to make sure the drill is perpendicular to the table, I had to shim mine front to back with a piece of folded up aluminum foil, and adjust the table tilt a little(you should probable adjust the table tilt before you start and then check it). You can drill a new clearance hole in the table to keep from dulling your wood bits.

After all this you gain the o.d. of the pipe from the chuck to the support, if I remember in my case it was 1 3/4", so it went from 4" to 5 3/4" which I think should be enough to drill the string ferrules.

Let me know if you have any questions, I hope this helps.

John

[edd677]

I too have the same problem with my drill press being too small. That sounds like a great idea but it would really help if you could post up some pics of the rigs.

[Jack Wells]

This is the way I invision JohnPurdy's drill press mod. Great idea there John.

......

[edd677]

Wouldnt that add only like 2 inches though?

[JohnPurdy]

jewlls,

You've got it. The details are that the drill sits all the way down so that the old support pipe sits on the edge of the lip that it used to go into. And the new pipe goes all the way to the bottom of the chuck for more support, you won't be using the space behind and above the chuck anyway. I also used 3 U bolts, and the top U bolt had to be turned nuts facing the front to keep it from interfering with the motor being able to pivot, and still get it as high as possible. I also think if I had gotten the correct pipe size instead of whittling my own I probably wouldn't have had to shim to get the drill straight.

edd677 I'll try to take some pictures this weekend.

John

[JohnPurdy]

It will add the o.d. of the pipe, mine was 1 3/4'. Gets you to within a 1/4" of a 12" press, which seems to be enough to drill the hardtail strat I'm working on.

John

[edd677]

Yeah, my press only has 4 1/4 inch of depth. The pipe on mine is 1 9/10" and i guess a tele needs 6 inches of throat? Should just take me close enough. Just got back from the machine shop and they are going to turn me a piece of steel tube to fit in the morning.

[JohnPurdy]

Here are the pictures of the drill press.

http://www.tdpri.com/forum/attachmen...1&d=1238255678

[JohnPurdy]

I have no idea how I got the pictures to come out like that???

[mgdesigns]

If standard sized pipe would work, how about using 2 pieces of say 4" long pipe nipples, and a single piece of the length of the original stand, and 4-90 degree elbows? That way you can make the throat as deep as need be by replacing the horizontals. I'll sketch it up and post it.

[JohnPurdy]

I couldn't find the correct size elbows and pipe to do it that way. But I did it on the weekend and only looked at Home Depot, a pipe supply might have the parts.

John

[mgdesigns]

Also, an option might be to use those elbows used on handrail assemblies call "Keyclamps" I believe. They use tubing and have elbows that utilize setscrews.

I found this website so everyone knows what I am referring to:
http://www.svl.ie/index.php?pid=107&cid=83

My only concern with u-bolts is if they start to slip and slide. Maybe a set collar below the lowest u-bolt to prevent downward travel?

[Jack Wells]

I think it's probably best to not have horizontal pipe and elbows because of the weight of the drill press head.

If you have concerns about slipping, you could squeeze some silicon into the area where the two pipes meet. However if those U-bolt nuts are torqued down tight I don't see slipping as a problem.