Wooden Thread Profiles

[RayG]

Hi Peter,

I actually have one of those adjustable spade bits... somewhere.... I looked for it, but like most stuff, I've put it somewhere safe...

Anyway, here is the finished 5 tpi version, I need to do a bit of work on the lathe change gears to get the 3 tpi I really want.



That's a 12" ruler and a 1 3/4 forstner bit just to get a sense of the scale, also that picture was taken before I milled the cutting slots.



Test run in a bit of pine. I welded a 3/4" drive socket on the top, so I could use a standard socket bar.



Close up of the tap and thread in a bit of pine..



Thread quality is fair to middling, I haven't tried to sharpen the cutters yet, so a bit of lubrication and sharp cutters, should be ok...

Now to make the thread box.

Regards
Ray

[IanW]

Ray - for Pine, I think the result looks fine. The internal threads in cross-grain are very strong - the screw threads are always the bits that break, if anything gives. Though these wooden screws are amazingly tough - I have not had any failures that weren't due to a fault in the wood, and I often lean quite heavily on my tail-vise screw.

I would not get too carried away with the 'cutters' - just make sure they are reasonably clean-edged, with either zero or a little negative rake, I think you'll find it will do a splendid job in any decent hardwood - but you'll be a little bluer in the face than after driving it through the Pine.

The 3 tpi production model should be the goods. (I'll be wanting to borrow it to try it out!).

On second thoughts, I think I made enough 2" screws a year or so back to last 2 lifetimes. I made some for other folks, so did a few extra, since I had several suitable bits of wood available. It's like that - once you get the threadbox set up & working nicely, you are reluctant to dismantle it!

Cheers,

[Basilg]

Hi Peter,

I actually have one of those adjustable spade bits... somewhere.... I looked for it, but like most stuff, I've put it somewhere safe...

Anyway, here is the finished 5 tpi version, I need to do a bit of work on the lathe change gears to get the 3 tpi I really want.



That's a 12" ruler and a 1 3/4 forstner bit just to get a sense of the scale, also that picture was taken before I milled the cutting slots.



Test run in a bit of pine. I welded a 3/4" drive socket on the top, so I could use a standard socket bar.



Close up of the tap and thread in a bit of pine..



Thread quality is fair to middling, I haven't tried to sharpen the cutters yet, so a bit of lubrication and sharp cutters, should be ok...

Now to make the thread box.

Regards
Ray

Ray

That looks a very professional job , & I look forward to seeing the Thread Box. I have a few things that I would like to do with wooden threads & I am trying to convince myself I need a lathe.
I am very surprised that " somewhere safe " location is not full up, I must have a stack of stuff stored there.

regards

[simonmags]

One of my mates has a meatl lathe and I have occasional access to a wood lathe, any tips for someone thinking also of making a wood vice, twin screw or single screw?

Cheers