Tapped M30 Thread in Kwila

[Kidbee]

Inspired by Brendan Stemp's Youtube video of his resin and gumnut sphere, I invested in a threaded live centre from Vermec. To hold the spheres for completion I had to make some jam chucks that fitted the head stock and tailstock ends. The first thread I turned was in hoop pine and it was unsatisfactory. I found some kwila in my timber pile and it woodturns very nicely (like a big block of hard cheese). I initially drilled a 1 inch hole and then made it larger using a skew to accommodate the large tap. The correct drill size is 26.5mm but my hole was a fraction over 27mm when I measured it. As you can see by the photo the timber took a crisp thread with minimal chipping. I tapped the thread copying a Youtube video as well which is also listed below but I used a normal metal tap from McJing.

Brendan's video
https://youtu.be/NLyreMoRoeE

Mike Peace video
https://youtu.be/G0yD8J4HyhA

[Pat]

Tapping threads in Timber is fun. Run some super glue over the threads to strengthen them, as it sound like you will be using the jig more than once.

I find with the harder woods, the closer to "official" clearance hole the better, in softer wood, I can go up to 0.5mm smaller.

[powderpost]

Try this, glue two 19mm discs together and go into the side grain. Makes a better glue chuck because you are not gluing on to end grain. Still good if you are using a spigot and jam chucks as well, and it doesn't matter what wood you use.

Jim

[Fallen Woodwork]

I have also purchased a Vermec threaded live centre
One of the uses will be to turn and sand spheres and the like with a wooden tailstock threaded cup

I will be using hardwood to make one or two cup sizes.
A 2nd hand Intermediate M30 tap is on its way up from Perth.
Thinking of drilling and wonder of its preferable to have 26.5mm drill
What technique do those who cut threads use to bore holes ready for tapping?

Are end grain or side grain cups better for cutting threads?
I will be drilling all the way through the cup as the tap is INT

[Pat]

Thinking of drilling and wonder of its preferable to have 26.5mm drill
What technique do those who cut threads use to bore holes ready for tapping?

Are end grain or side grain cups better for cutting threads?
I will be drilling all the way through the cup as the tap is INT

Side grain, dosed with CA, as close to 26.5mm as possible.

[Fallen Woodwork]

Thanks Pat
Can anyone recommend where to buy a reasonably priced reduced shank 26.5mm drill bit in Australia?

Have looked at the usual Oz retailers. Not wanting to pay over $100 for a sutton
McJing; whilst they stock budget priced 30mm tap they only have 25 and 27.5mm drill bits - reasonably good price though
Would rather not ebay a Chinesium bit that might get here before February but thats looking to be the only budget option
Suppose I could always widen a 25mm hole with a gouge or carbide scraper

[Bushmiller]

Thanks Pat
Can anyone recommend where to buy a reasonably priced reduced shank 26.5mm drill bit in Australia?



FW

If you are only drilling into timber, you could use an oversize spade bit (28mm may be the nearest, but even 30mm will do - Just a little more cutting)). Mark out with a sharp scribe both sides and cut or grind close to the line maintaining the same angles: Finish with a file. Don't worry if the bit has spurs and you lose them in the narrowing process. I have done this before. If you have bought budget bits you may need to sharpen them but this too is easy enough.

The only word of warning is to find some way of identifying that the bit is now less than the original marked size!

Regards
Paul

[Pat]

I have had success with both 25mm, 1" and 26mm drill bits. If you are pedantic, use a 25mm and a skew to get to the final dimension. Most woods are more forgiving than metals. Plastics need to be on spec.
Always chamfer the access.

[Fallen Woodwork]

Hey thats a great alternative to a fluted bit :2tsup:
Thanks Paul, that will be better than widening an undersized hole and cheaper than a 26.5 fluted bit.
I should be able to source a 28mm spade bit locally for the trifecta - will just have to take my time to file the shoulders down evenly

[Fallen Woodwork]

Thanks Pat - do you mean that you can tap a 30mm thread using a 26mm bit without widening it? That would be easy too.
I used to be pedantic, now I just want to get stuff done ... a close to the best way possible with my limited skill level :wink:

[powderpost]

I have been making my own wooden face plates for a while now. I glue two discs together and bore a 25mm hole in the side grain and tap a 30mm thread in with a 30mm metal tap. The face plates are re-usable a number of times and can be shaped to suit the job at hand. Cheap too :U

Jim

[Pat]

Thanks Pat - do you mean that you can tap a 30mm thread using a 26mm bit without widening it? That would be easy too.
I used to be pedantic, now I just want to get stuff done ... a close to the best way possible with my limited skill level :wink:


With timber, bore a 25/26mm hole and tap it.

[Fallen Woodwork]

Thanks Jim and Pat
A 26mm spade bit through side grain it is. I am tempted to try Pauls idea for comparison
Thanks all

[turnerted]

Make sure you cut a recess on one side to fit the shoulder on the headstock spindle .
Ted

[Fallen Woodwork]

Good pointer thanks Ted. I'll post my results when everything arrives

[powderpost]

Make sure you cut a recess on one side to fit the shoulder on the headstock spindle .
Ted


Hi Ted,

After I glue and thread the "face plate" boss, I mount it on the headstock and true up the face, so that it will fit properly. Then I turn the "face plate boss" around and then true up the second face. Now I glue a third disc of appropriate size to the boss, that disc becomes the face plate. The face plate is then shaped to suit the job at hand and can be turned off and replaced when needed. I have been doing this for five or six years now, succesfully.

Jim