kogatana Posted November 8, 2006 Share Posted November 8, 2006 Hello How would you make the tools (tap and die) to produce threads in wood? Is this a blacksmith type of job (at least the heat treatment should) or more the one of a moulder or machinist? Ludo Quote Link to comment Share on other sites More sharing options...
Strine Posted November 8, 2006 Share Posted November 8, 2006 Mmmm. I too wanted to make threads in wood. I thought a great big nut and bolt would make a great toy for my toddler. I managed in the end but sadly by that time he was a strapping eighteen year old. You need to make the tap first so you can use it to make the die. Depending on the size of bolt make a suitable tap by either forging three or four blades onto a shaft or use a more modern approach if you like. No doubt you've seen many taps and have an idea of the size. At this stage make the flanges parallel and the right diameter for the job. This diameter will be the diam of the stock you intend making the bolt out of. Explained in a different way...the tap should be able to fit nicely into a pipe with an ID of the above. This means the top of the flange needs to be rounded. Now that it fits neatly into the pipe, make a solid cylinder by filling the flanges with clay, car bog or what ever and shove it back down the pipe. Remove and let dry. Now you have a solid cylinder with four strips of steel showing at the surface. Next step. on a piece of paper, accurately draw a square with a width and height equal to the circumference of the tap. Divide the top and bottom of the square into 12 divisions. Draw a line from the top left corner of the square to the first mark on the bottom of the square. Call this a pitch line for want of a better term. Draw lines parallel to this first pitch line by drawing lines between the corresponding marks on the top and bottom of the square. Eventually you will run out of marks... just draw another square and carry on. Wrap the paper around the tap blank making sure the square lines up and lo and behold you have a continuous thread line around the blank at a pitch that works pretty good in wood. Scribe through the paper onto the steel strips. You have now marked the thread line as it passes over each flange on the tap. File each flange between these marks with a 3 corner file...parallel with the marks on either side and such that the top of the file is level. File away until you are left with a sharp peak without filing away the mark. All that is left now is to file down the leading end to create a taper. Let us know when that's all done and we can look at the die which I hasten to add will require some forging Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted November 8, 2006 Share Posted November 8, 2006 traditional woodworkers would use a screwbox and tap. Normites would use a router and jig and a tap. Quote Link to comment Share on other sites More sharing options...
the_sandy_creek_forge Posted November 8, 2006 Share Posted November 8, 2006 There is a book available, but I am not sure how available it is in your neck of the woods. The book is by Roy Underhill, a rather famous American woodworker who has his own long running show on many public television stations in the U.S. I am not sure which book contains the instructions for the wooden screw tap and die, but a little internet research would probably reveal the exact publication. My own personal opinion is to buy all of his books. Even though I focus alot on metal being a blacksmith, they are still wonderful reading. -Aaron @ the SCF Disclaimer: Neither myself or the Sandy Creek Forge are in anyway affiliated with Roy Underhill, it's just my personal opinion. Quote Link to comment Share on other sites More sharing options...
kogatana Posted November 10, 2006 Author Share Posted November 10, 2006 Strine, Interesting! What is this wood you used to make the bolt and nut? It does seem that your tap and die did a great job (well you did the job). So if I read you well, this first lesson is for the tap. While reading you I've drawn the following schematic. Is that what you mean? Now my question is how to you make the 3 or 4 blades sharp so that they cut wood? Are they really blades or should we see them more as scrapers? Aaron, Yes I've heard about Roy. I wished I could watch his shows, it would be a great idea to make them available on DVD! Is there any address where to send him this suggestion? I will check in which book he explains the process. irnsrgn, I know about thread boxes, but I wanted to make myself the size I want. And check out this link: prices are in the 100s of euros range.Wood thread cutting tool and Dowel Maker Ludo Quote Link to comment Share on other sites More sharing options...
Strine Posted November 12, 2006 Share Posted November 12, 2006 kogatana Your interpretation looks good to me. The wood is redgum. This link describes the species in more detailhttp://www.anbg.gov.au/cpbr/WfHC/Eucalyptus-camaldulensis/index.html It was from a peice laying around in the shed. Ant dense, close grained hard wood should work allright.how to you make the 3 or 4 blades sharp so that they cut wood It is the face of the triangle forming the tooth that is "sharp" not the pointy bit at the top. Quote Link to comment Share on other sites More sharing options...
kogatana Posted November 28, 2006 Author Share Posted November 28, 2006 I have found the book from Roy Underhill, and a lot is explained exept I couldn't really understand how to forge the tap. The author mentions using a U shaped fuller to form the "blades". What is a fuller, and how should I do then to get the "blades" onto my steel cylinder (or bar stock)? Ludo, Taiwan Quote Link to comment Share on other sites More sharing options...
Strine Posted November 28, 2006 Share Posted November 28, 2006 A simple fuller can be made from a piece of round bar. Hold it over the work and hit it. Behold..it leaves a dent. For your tap however you may need to get a bit smarter. You will need a bottom fuller as well and a means of holding everything steady. Two round bars hinged together somehow will make a fine top and bottom fuller that can sit in the hardy hole. Best advice I can give is to work it out with a piece of modelling clay using the tools you intend to work the iron with. Bon chance and keep us posted Quote Link to comment Share on other sites More sharing options...
henerythe8th Posted November 28, 2006 Share Posted November 28, 2006 Sometimes we forget about what the object is... ...and I may be confused. Not abnormal for me ! If the goal is threaded wood, not making the tool to do it then check out:http://www.leevalley.com/wood/page.aspx?c=2&p=41791&cat=1,43000 you might have to cut and paste... Sometimes it's also prudent to look at different ways to tackle the same job. The link could provide inspiration for making your own. To purchase this tool is a bit spendy--but it may be worth the time... H the 8th Quote Link to comment Share on other sites More sharing options...
kogatana Posted November 28, 2006 Author Share Posted November 28, 2006 Strine, Ok, I get it now. I think the trick is also to find the appropriate size and shape (tapered bar or not tappered, cylinder, how thin/thick) versus the size of the tap to make, isn't it? I'll try to experiment. henerythe8th, Well my goal is to actually make the tap and then hopefully the die. I know the link you mentioned, but the equipement requires a router that I don't have. And if you go back to my previous post on the topic, you'll see a link to some tap and die that are prohibitively expensive. Wood thread cutting tool and Dowel Maker Ludo Quote Link to comment Share on other sites More sharing options...
Strine Posted November 30, 2006 Share Posted November 30, 2006 I've been thinking about this all day and can't think why this won't work. Forge the two parts, slot them together and join with a welding heat. Allow a bit for loss and forge or file to final shape. Cut the teeth as previously described. Main point is there's no pesky fullering to do:) Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted November 30, 2006 Share Posted November 30, 2006 Geez, pictured are a commercial screw box and tap. 1. The screwbox with attached guide. 2. Guide removed showing the aluminum insert thread, the slot at the right top is where the square cutter bit is put and the brass bolt above is what secures it in place, The notch at the top is for the shavings to exit. 3. The Companion Tap. 4. A close up of the tap with a hollow center for chips to exit. The above set is for 1.25 threads, I have another one for 3/4 threads. Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted November 30, 2006 Share Posted November 30, 2006 detail of 1/4 inch square cutter for the screw box. it wouldn't let me open the manage attachments now. more than one way to make your point, I guess. Quote Link to comment Share on other sites More sharing options...
Strine Posted November 30, 2006 Share Posted November 30, 2006 Geez??????? Quote Link to comment Share on other sites More sharing options...
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