Threading Jig, 16 tpi, from UK

[Peter Fabricius]

Hi All;
I ordered it on 3 Sept and it arrived today 11 Sept 2012.
My new Threading Jig cuts threads 16 TPI both the inside and outside threads and I made a very small box with a threaded lid as soon as I had it in the shop.
The box is 2.25" diameter and 1.25" tall.
I am liking this already!!!
Peter F.

Note for Mike Pearce: You will now hear more about this model as I work it, on day one it cut perfect threads. All I had to do was get my head around the size of the two parts to be threaded. I was initially a little challenged about the ID and OD to be cut into the lid and box.
Now, I think I have it.... The threads are 1mm deep so if you cut the male threads first and then measure to the bottom of the threads and add 2mm for the lid--- then you are good to go.
More to come over the nest little while.
Note I use threaded (1 1/4" x8tpi, Beal Tapped, for my Nova DVR XP) glue blocks to hold the blank. One blank, parted for lid and box and then threaded. Part off the glue blocks and finish the bottom and then the top on the Stronghold #1 long jaws.
Available from ebay, "boffin53" is the seller. $120.00 plus shipping $30.00

[Dale Miner]

Interesting! I just built a shop made unit myself that mounts in the banjo. This is the first commercially available one that does that that I am aware of. The one I built is also 16 tpi.

As to the difference between ID and OD, I found that having a difference of .070" works out just about perfect. On a threading chart, the tap drill for a 3/8" -16 tpi is 5/16", or .062" difference. My first try was with a .062" difference, and it seemed by the time I took a roughing cut, and then followed it with a clean up cut to get sharp threads, the threads were a bit loose. I changed the process to .070" difference, and am pleased with the thread apprearance and fit. I cut the threads with the roughing pass to leave a small flat spot on the top of the threads, put a light (very light) run around of thin CA on the threads to harden the wood, and then take another light cut to leave the threads without any flat on top. A quick touch with some 320 grit, and they threads are finished.

The more dense homogoneous woods are better choices. Blackwood, cocobolo, boxwood, and most of the rosewoods thread without the run around of CA. Domestic hardwoods like pear, apple, osage orange, and hard maple do well with the CA trick. I haven't tried walnut or oak, but doubt they would thead well even with CA unless a more coarse pitch was used.

[Reed Gray]

I never liked chasing the threads with CA. Too messy, and always seemed to be some left over. I did find that if I chased the threads when half way cut or so with some soft wax/oil mix, it lubricated the wood for a smoother cut. I keep a tooth brush (magnetic base type for electric toothbrush) handy for doing this.

Also, I was told that there was no way to align things so you could have the two halves line up in the same place every time, and some times you have to remove almost 1/16 inch on the shoulder to get the grain to line up. Well, I found a way. Before threading, I line up grain for the top and bottom pieces, and make a pencil register line on the blanks. Then when mounting on the jig, that line goes to 12 o'clock. I slide the piece up to the thread cutter, and use a 1/2 inch thick piece of plywood as a spacer block. This starts the threads cutting in the same place every time, and I do this with both pieces. With my set up, and my Klein jig, if I have the register mark on the lid at 12 o'clock, the pieces line up just a hair past even, so if I back off the lid and have the register mark at 10 to 11 o'clock, I end up with needing to adjust the shoulder to allow maybe 1/8 of a turn, or 1/64th of an inch to get the grain to line up. Critical here is to make sure the thread part on the male piece is EXACTLY 1/4 inch. I use one of the mini 6 inch rules and with good glasses can get that to less than 1/32 of an inch.

Not sure if I explained that so it can be understood, but with the 1/2 inch spacer block, and a 1/4 inch lip/spigot on the male part, it is repeatable, and if you have to remount to cut threads again, you don't have to eyeball it to get things to line up.

robo hippy

[Dale Miner]

I never liked chasing the threads with CA. Too messy, and always seemed to be some left over. I did find that if I chased the threads when half way cut or so with some soft wax/oil mix, it lubricated the wood for a smoother cut. I keep a tooth brush (magnetic base type for electric toothbrush) handy for doing this.

Also, I was told that there was no way to align things so you could have the two halves line up in the same place every time, and some times you have to remove almost 1/16 inch on the shoulder to get the grain to line up. Well, I found a way. Before threading, I line up grain for the top and bottom pieces, and make a pencil register line on the blanks. Then when mounting on the jig, that line goes to 12 o'clock. I slide the piece up to the thread cutter, and use a 1/2 inch thick piece of plywood as a spacer block. This starts the threads cutting in the same place every time, and I do this with both pieces. With my set up, and my Klein jig, if I have the register mark on the lid at 12 o'clock, the pieces line up just a hair past even, so if I back off the lid and have the register mark at 10 to 11 o'clock, I end up with needing to adjust the shoulder to allow maybe 1/8 of a turn, or 1/64th of an inch to get the grain to line up. Critical here is to make sure the thread part on the male piece is EXACTLY 1/4 inch. I use one of the mini 6 inch rules and with good glasses can get that to less than 1/32 of an inch.

Not sure if I explained that so it can be understood, but with the 1/2 inch spacer block, and a 1/4 inch lip/spigot on the male part, it is repeatable, and if you have to remount to cut threads again, you don't have to eyeball it to get things to line up.

robo hippy

I tried wax when hand chasing, and did not see much benefit, at least with domestic hardwoods. I will give it a try milling the threads and see how it works.

The explanation about timing the threads makes sense to me. One caveat I think would be that the 1/4"male thread length works for thread pitches that are evenly divisible by 4. 18 tpi would require a bit of calculation for the male thread length. Thanks for the timing tip, I will give it a try next time. My first piece using the jig, the lid became tight just past grain alignment. A hair to much on the shoulder, and rats! another full turn to make it right. Amazining how when there is a lot to go, a heavy cut makes almost no change, but when near the end, a whisper thin cut is to much.

[Reed Gray]

Timing the threads... Good name, though I am totally unaware of that name, that explains it well. For adjusting the shoulder for the proper fit, I use a skew with a convex grind and a tiny honed burr in a negative rake method. You can get it pretty close to perfect that way, and 320 or so grit abrasive on a flat surface (table saw bed) on the lid for the perfect fit.

Thanks!

robo hippy

[Harry Robinette]

Could we get more info as to were you got it. I looked up every thread thing on ebay and can't find anything.

[Dale Bright]

Could we get more info as to were you got it. I looked up every thread thing on ebay and can't find anything.

Harry, type this into the search function on the bay: WOODTURNING LATHE 16tpi THREAD CUTTING TOOL / JIG

Dale

[Harry Robinette]

Thanks Dale I got it now.

[Mike Peace]

Peter, I know you will enjoy using that threader. Look forward to reading more about it as you get to using more.

[Joe Bradshaw]

I guess my E-Bay function does not like for me to find this thread cutting jig. It tells me that there are 0 matches.

[John Keeton]

I guess my E-Bay function does not like for me to find this thread cutting jig. It tells me that there are 0 matches.

Joe, try this search string - WOODTURNING LATHE THREAD CUTTING TOOL

[Joe Bradshaw]

I finally found it. It looks very interesting. I just wish that the inventor would have put a little more information about post sizes in his write-up. I guess that I will have to email him. Thanks for your help John.