Threadcutting.

[Davyboy]

Hi again,

Some time ago I mentioned a threadcutting jig for threading box lids & the like. For all those interested, the device is now available on eBay. I have one, & it is so easy to use, a boon for those, like me, who cannot get on with thread chasers. It fits into the lathe banjo & will cut internal & external threads with ease. I know the Klein jig & the Baxter jig are both available in the USA, but are very expensive, & this jig is available at a fraction of the cost.

 

[stevebuk]

any chance of a link the item??

 

[Bodrighy]

Here you go Steve

Pete

 

[stevebuk]

thanks pete.. :lol:

 

[Davyboy]

Thanks Pete, I'm not very good with computers etc. Haven't a clue how to post a link I'm afraid.

 

[wizer]

I by chance came across this earlier. I'm not entirely sure if I understand how it works? It only does one thread pitch?

The seller needs to supply more information and video is pretty much expected these days.

 

[Davyboy]

Yes wizer, the jig repeats the thread into the wood, but I have a feeling they will supply other threads to order. I have one & it's easy to use, you merely turn your box, or whatever, to the right size, then remove the chuck with the work still in it, mount the jig into the tool stem holder with the spindle nose facing the lathe headstock, fit the chuck/work to the jig, put the cutter into the headstock, line up the jig & start threading. Do the male section first, then measure the root diameter of the threaded bit, which will then give you the correct internal diameter for turning the female section. It probably sounds complicated, but in actual fact it is so easy.

 

[wizer]

What's your connection to the seller? How did you get one before they came to market? Can you show us some better pics than the single one on the ebay sale?

 

[Davyboy]

Hi Wizer,

Thought you might ask that. Some weeks ago, I bought a ball cutting tool from this seller, & whilst communicating via email, I happened to tell him about a jig that I made up about 18 years ago to cut threads, although mine, which I still have, fits on to the lathe bed & is about twice the size. I got the idea from a photograph in a woodworking magazine at the time. I suggested that he might like to consider making one for the general market so that it would be available to all. They made up a prototype for me to test, which I still have, so I can most certainly vouch for it's use. I have absolutely no financial interest whatsoever. Hope that answers your query

 

[Davyboy]

Oh Wizer, I'm sorry, I don't have any photos I'm afraid, but if you like I can email you some instructions, which might give you a better idea of how it works, if I could have your email address, as I don't know how to send attachments on here.

 

[Paul.J]

It would be interesting to see some photos of what it can do.
If you want to have go at uploading some piccys there is an how to at the top of the front page in CHJs safety and how to post.
If i can do it i'm sure you will be able to

 

[Davyboy]

Hi Paul,

I'm sorry, I have one phot of a trial I did on a scrap piece of olive wood, since I'm a duffer at uploading, give me your email address & I'll send what I've got to you & maybe you can post them eh? :lol:

 

[shedhead]

I think this is the same people i bought the sphere cutting jig from a few years ago. I must say that the sphere jig is very good.
Do i have this right, the thread jig fits into a 1MT.
A demo DVD was supplied with the ball jig. This was to me very helpful to get me started.
I would like to get one of the thread jigs but as i am a bit thick with working out new "toys" it would be good if a DVD was given with this jig. I would buy one then.

 

[Turn It In]

Hi All,
I have been busy recently and not had time to contribute to threads on the forum. I have read this thread with some interest as my friend Boffin53 has been perfecting his latest wood turning accessory with some trials down at my workshop where we have deliberately made use of my Fox midi lathe so as to assure any interested party that the jig can be used on a small lathe as well as any larger machine.
I can see you are all in need of some WIP photographs and therefore i have turned the embrio of a box to show how the threading jig is set up and operated.
This picture shows the cutter adjusted to cut the external thread on the male lid section.

Here is a close up of the cutter and timber

This picture shows the overall set up of the jig on the lathe

The next photo shows the set up for cutting the internal thread in the base of the box.

I have included a further picture of the jig set up for internal threading.

This is a close up of the cutter which is supplied in a MT1 arbor which i have secured in a MT1 to MT2 converter sleave to suit the Fox lathe. Also a view of the threads cut internally.

My final picture shows a close up of the two halves screwed together and a further shot of the cutter.

I hope these photographs tell most of the story but to clarify first turn your box or other project and thread the male thread first by mounting the chuck on the jig, visually aligning the threaded shaft with the lathe bed and carefully touching the area to be threaded onto the cutter with the lathe stationary.
Advance the top slide by slacking the clamp screw (Bristol Handle) and knowing the top slide adjusting screw is 1mm pitch advance the adjusting knob by half a turn for the first cut.
Start the lathe ensuring you keep well clear of the rotary thread milling cutter and slowly advance the work onto the cutter and watch the thread appear. Un wind the job back to the beginning with the cutter still running and when clear release the clamp screw and advance the adjustment by a second half turn. This gives full thread depth .

Measure the thread root diameter and open the internal part to be threaded to this diameter. Adjust this piece so that the cutter touches the inside of the box and repeat the procedure for external threading.
After two passes the thread is complete and a light sanding of the thread peaks on both parts will help to stop the threads biding as will a little soft polish.

I do hope that this information has clarified the process.
Regards,
Ian

 

[dickm]

Looks a brilliantly simple device. One query - how do you make absolutely sure the milling cutter stays in the taper? Is there any sort of drawbar to hold it in?
(If not, it might be a worthwhile suggestion for the maker)

 

[Turn It In]

Hi ****,
The taper is simply tapped in with a mallet and does not have a draw bar.
There are several lathes that do not have a hollow head stock and certainly those with motorised heads do not. I have given it a good run and even at 3000 rpm as I am running the cutter it always has to be knocked out to release the tapers.
But good point.
Regards,
Ian

 

[robo hippy]

Since the box bottom and lid are in a jig that mounts on the banjo, how do you make sure it is lined up dead square to the cutter? If there is any taper in either threaded piece, you won't get a good fit.

robo hippy

 

[Davyboy]

Hi ****,

I have been using Morse taper fittings in lathes for over 40 years & during that time, I have never known one to come out during use. I know that there are drill chucks on the market with MT fittings with drawbars, but the other end of the MT taper fitting usually has a stub taper which fits into the chuck body, these have nothing to hold them in, but I have never known one to work loose.

 

[Davyboy]

Hi Robo,

The jig is aligned visually with the lathe bed, or you could use a square or some other gauge. I have always aligned mine visually & have never had any trouble. When cutting the thread on the second piece, stop the machine & check the fit before demounting from the chuck. It really is very easy.