Links to wooden thread stuff
Hi MA, these are the threads I could find quickly. They are all started by me - I'm not blowing my own trumpet, I just seem to be the wood-thread tragic of this forum.... :)
1. A very early thread (rather sparsely illustrated).
2. A better introduction to the topic with more pics.
3. Making the ancient style tap.
4. Making handscrews.
5. Making bar clamps.
6. Some other applications for wooden screws
That will get you started. At the risk of more blatant self-promotion, here are a couple of videos of me performing:
Tapping
- and threading.
There are other videos on the web, and possibly other heads on the forum that I didn't find, so if anyone has anything to add, go ahead. If you like, I will put all the links together as a sticky, for future reference..
Cheers,
5 Attachment(s)
Larger threads for the leg vise.
I don't post often so hopefully this is OK. I Thought I might post my experience to assist others there are several threads on this threading business (sorry couldn't resist). I researched for ages on what method to use for my leg vice screws 2½" at 2 threads per inch in my future Moravian workbench (instead of my B&D workmates). I came to the conclusion that for a wooden thread this size the easiest method for me with tools I had available was as per Carter's Whitling on youtube Carter's Whittling - YouTube . He goes into a lot of detail about sizing and each stage of the process. This is very similar to the AWR article and videos on YT noted in several posts here and Ian's knowledge of course. A "thread box" this size seems only to be available from a German manufacturer great quality product but best part of AU$2k!
I did my prototype in scrap pine which I knew might chip but its a prototype to see if I could do it. The tap part was easy (used an old file for the tooth) and heat treated etc. The follower was just a piece of tin in the pine block. The thread wasn't that bad but as other comments in other posts suggest setting the 90º router bit in the correct spot to cut the thread on the screw took about a foot of practice thread. Front to back was the easiest but getting the depth just right to cut a thread that fitted the nut without binding but not too sloppy took a couple of goes.
The hardest bit for me was making long accurate dowels at 2 and 2½" diameter and cutting holes at 2" and 2½". Hole saws are not accurate enough. So forester bits it was. I tried two methods for the dowels router bits and turning spindles on the lathe. I was aiming for accuracy (which it turns out is not that necessary). The router method was OK using a jig shown by the Wood Knight on YT but still leaves slightly flat surfaces. The tricky thing on the lathe is accurately turning a spindle 2-3' long. Turns out a chair makers rest is what I needed so there is no need to keep moving the normal short rest - that will be for the production model.
Learnings -
- the dowels do not need to metal machine grade accuracy they just need to fit the holes with a few thou gap. I will do these on the lathe as I can make the spindles fit the holes with sanding. The router method still requires sanding and may not match the holes. Spinning 1" and 1¼" roundover bits are not for the faint hearted even on a cast iron router table and are fiddly to get even and accurate over that diameter (unless you have an expensive router I guess).
- 90º not 60º is right for wood I have seen a research paper somewhere (edit found and added) doing the destructive testing to confirm answers the profile questions earlier possibly.
- Getting 3"+ starting timber (straight fine grain hardwood) is also not easy so my first was laminated seems to be no problem.
- Pine did give tear out but I wasn't particularly slow or careful feeding the blank through the cutter (once it worked I was excited and just went for it!).
- I will set up entry and exit guide holes prior to the cutting rig to improve accuracy and figure out a way to evenly turn the dowel feed.
- To answer the question over on another thread I cut the nut by the push method and drew back to clear cuttings in a gap between the follower and the nut being cut.
I did this a while ago whilst I search for suitable hardwoods here in WA of this size. I can get Jarrah as they demolish old houses and the beams tend to be 3x4". Just have to get bits that are gum free and straight grain. Hopefully it doesn't chip like the pine did. My bench will be from some Tuart I've picked up at the wood show wet so has been drying for 4 years now so soon. I might have enough of the 4x4" left to turn these - denser than Jarrah and gum free. The larger pergola post jarrah will be good for the hubs. Maybe I will look for some dry Applewood from down south.
With any luck I can get this going to make a screw or two especially as American imports tend be be best part of US$130-300 (not really the issue just the achievement is satisfying). Maybe by the end of the year. Any further suggestions on timber we can source in WA for this would be great, maybe it's not that critical using the router method. Don't need great lengths just larger diameters.