Here is the flute blank all glued up and drilled through at 5/8 inch ready to go. I had Wade Carpenter of Webfoot Custom Calls make up a custom mandrel to spin up flute blanks on.
Here are the dimensions of the mandrel, using one of Wade's MVS mandrels as a guide:
I start with a piece of sacrificial wood drilled through 5/8 and slide it on the mandrell, then the blank, followed up with another sacrificial block. Now is when you line up the marks for the grain... Then I crank down the nut on the threads and lock the blank onto the mandrel very tight. This works slick! The blank never moves on the mandrel, it's rock solid and ready to turn. I love doing call this way, as I can turn the entire call as one piece and never worry about matching up the two halves.
Now, turn it round, then remove it from the mandrel...
Now we are going to counterbore. Here are my tools. On the top is a custom drill bit for step drilling barrels all in one shot. It was made by River Mallard and is made to my bore specifications. The bottom shows my 7/8" and 3/4" pilted counterbores with a 5/8" pilot for boring blanks. I used these for years before I broke down and had a custom bit made. I still use the 3/4" to drill the exhausts for the gut-sert. You can buy these from Enco. I also have a 1 inch drill chuck on a #2 morse taper for holding the big counterbores.
Test fit to make sure the 5/8 inch pilot will go all the way through the blank without binding up. If it does, remove it with a small rod and take the blocks to the internal bore sander again until the pilot slides right through.
Then chuck up the blocks and drill the counterbores. MAKE SURE YOU DRILL THE RIGHT ENDS!
First the barrel:
Then the exhaust. Use the 3/4" counterbore and drill in three inches or so. This creates a small sound chamber inside the exhaust (past the end of the gut-sert) that aids in getting the back pressure for the flute to run good.
Remove from the lathe and glue in the gut-sert. I use a .625 bore gut-sert that fits Webfoots flute guts. Let it cure overnight.
Now the fun part.
Assemble the barrel and exhaust, line up the grain, put it back on the mandrel and crank it down tight (I used a new sacrificial piece on the end of the exhaust and put some CA glue on a void that needed some strengthening). Pull up the tailstock and get it ready for turning.
Now turn the entire call, don't worry about shaping the mouthpiece and exhaust end quite yet.
Now for the sanding. THIS IS CRITICAL. Don't get in a hurry or skip steps, the sanding is what makes the finish pop and is worth every bit of time to do it right all the way through. I can't stress this enough (SO I USED GREAT BIG LETTERS)..
I usually start with 150 grit. Turn on the lathe, sand the call smooth, turn off the lathe and go back hand sanding the entire blank WITH THE GRAIN. Don't miss any spots or the next higher grit of sandpaper might not take off the rough part.
Then turn the lathe back on and repeat with 220 grit. Turn it off and hand sand again.
Then 320 grit, 400 grit, 600 grit, 800 grit, stopping each time to hand sand with the grain.
Once I get it to 800 grit, it's time to burn some lines in the call. I use a piece of guitar string tied to some wood blocks. I like to hide the joint between the barrel and exhaust with a burn line. It makes it really hard to see where the call comes apart...
After the lines are burned, I go over the call once again with 800 grit to sand away any excess burned wood and contuinue sanding using 1200 and finally 1500 grit. By then the wood is starting to take on a glass like shine and feel to it.
Now it's time to finish up both ends. Take the call off the mandrel and take the mandrel out of the collet chuck. Here are the two blind mandrels I use for flutes. The little stubby one was made by Wade Carpenter and measures just a hair below 7/8 inch in diameter. A 7/8 drilled blank just barely slides on it tightly. The other is a .610 piece of steel rod.
For the barrel, I use a single layer (or two) of masking tape at the lathe end off the stubby mandrel. It helps to hold the blank firmly once you slide in on. Turn on the lathe, if the blank wobbles a bit, turn off the lathe and rotate the blank on the mandrel a litttle bit, usually you can find a spot where it runs pretty true.
Then I sand the bore and the mouthpiece, AGAIN BOTH ON THE LATHE AND THEN BY HAND WITH THE GRAIN. Same grits, 150 all the way up to 1500. I just roll up a piece of sandpaper to do the bore...
Now for the exhaust. Put the steel rod in the collet chuck. It should be long enough for it to go through the gut-sert, through the sound chamber, and then back into the 5/8 inch bore about halfway through the call. Put a layer of masking tape around the rod next to the collet chuck and slide on the exhaust, over-running the masking tape to get a firm grip on the call. Turn on the lathe and check for wobble, and adjust it by turning off the lathe and turning the blank a bit. Play with it a little and you can get it to run pretty true.
Turn the bell on the exhaust. I like to get it opened up most of the way with a small scraper and then go back and open it up all the way with sandpaper. Less chance of once of those oops moments where you catch a tool and destroy the whole exhaust this far along. I'll use a very aggressive 80 or 120 grit to get it started and then shape it and refine the inside as I move through the grits. Once again, stop each time to sand with the grain.
Guess What, your done making the flute and ready for the finish room.
So here you go folks........
I hope this helps you all. I'm glad I can share back what I have learned here.
Thanks once again to all my mentors and friends who have helped me along the way.
All The Best!
Doug Nelson
aka gooseforsupper