Tuesday , February 20 2018
Home > Lathe Projects > New Project: Plans for a Collapsible Nested Scribe

New Project: Plans for a Collapsible Nested Scribe

Here’s one of those beginner projects that I just love. I’m all about making my own tools, even if they can be purchased for a fraction of what it costs me to make them in terms of man-hours. Why? Because I get a renewed sense of satisfaction every time I reach for a tool that I’ve made. My handmade tools are a constant reminder of how satisfying this hobby can be.

Mike White from the Franklin Technology Center in Joplin Missouri sent in this set of plans for a nifty collapsible scribe. What’s neat about this particular scribe is it’s ability to collapse down and nest inside itself. It reminds me of those hammer/screwdriver combos where the screwdrivers are nested inside the handle of the hammer. However, like many combination tools the ham-driver was never a good hammer or a good screwdriver. It was a mediocre combination of both. But I digress …

This scribe design solves the problem I have with my current $5 scribe – it protects me from getting jabbed with the point when not in use. Sure my $5 scribe came with a protective rubber tip. But I lost it within a few days somewhere in a pile of swarf. With this setup I’ll be able to slip my scribe into my bib overall pocket next to my scale and never poke myself!

My only question for Mike is what method do you recommend to harden the scribe? Keep in mind that people making the scribe may have no experience whatsoever in hardening. So an explanation of the cheapest/easiest/safest technique would probably be best.

Mike also shared plans for a machinists hammer (ball peen style) which I’ll post in a few weeks. Thanks for sharing your plans with us Mike!

If you’re an instructor like Mike and you’d like to share your student plans with the site, please feel free to submit them using the “Submit Your Plans” tab at the top of the page. I’ll provide a link (and thus free publicity) back to your school or website. Every submission helps this site grow. Thank you for your support!

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About Tyler

Tyler is a hobby machinist and 3D printing aficionado. He teaches computer programming and web development at Highline College near Seattle. Tyler founded Projects In Metal in 2008 because he was frustrated by the lack of free plans available for hobby machinists.

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35 comments

  1. TylerYoungblood said:

    Here's one of those beginner projects that I just love. I'm all about making my own tools, even if they can be purchased for a fraction of what it costs me to make them in terms of man-hours. Why? Because I get a renewed sense of satisfaction every time I reach for a tool that I've made. My handmade tools are a constant reminder of how satisfying this hobby can be.

    Mike White from the Franklin Technology Center in Joplin Missouri sent in this set of plans for a nifty collapsible scribe. What's neat about this particular scribe is it's ability to collapse down and nest inside itself. It reminds me of those hammer/screwdriver combos where the screwdrivers are nested inside the handle of the hammer. However, like many combination tools the ham-driver was never a good hammer or a good screwdriver. It was a mediocre combination of both. But I digress …

    This scribe design solves the problem I have with my current $5 scribe – it protects me from getting jabbed with the point when not in use. Sure my $5 scribe came with a protective rubber tip. But I lost it within a few days somewhere in a pile of swarf. With this setup I'll be able to slip my scribe into my bib overall pocket next to my scale and never poke myself!

    My only question for Mike is what method do you recommend to harden the scribe? Keep in mind that people making the scribe may have no experience whatsoever in hardening. So an explanation of the cheapest/easiest/safest technique would probably be best. Mike also shared plans for a machinists hammer (ball peen style) which I'll post in a few weeks. Thanks for sharing your plans with us Mike!

    I used some stoody torch applide hardface rod for the tip and have not had to do anything to it in about 20 years! Just my 2 cents worth, hit your local welding supply for one rod it will make lots of tips.

    If you're an instructor like Mike and you'd like to share your student plans with the site, please feel free to submit them using the “Submit Your Plans” tab at the top of the page. I'll provide a link (and thus free publicity) back to your school or website. Every submission helps this site grow. Thank you for your support!

    [Image Can Not Be Found]  Scribe_Plans_from_Mike_at_Franklin_Tech.jpg (169.4 KiB, 39 hits)


  2. What's it called? Stoody torch? I'm not sure if that's a typo or something I haven't heard of before. 

  3. Hello, I am new to the site and new to the lathe. I just purchased a Grizzly 12×36 and thought this would be my first real project. I have turned tapers but nothing to a point and as thin as the scribe. I have completed the body and cap and really enjoyed it. However, for the life of me I cannot figure out how to turn this scribe. I figured it at 3* and I turned down the 2.5″ of stock to .250. As soon as I touched the stock at the 3* degree angle with cutter it bent. I have tried 3 times now with no luck….

     

    Anyone willing to share some knowledge with a total newbie?

     

    Thank you!

  4. Car99r, welcome to the site. You ask the very question I have. I've tried to figure it out but had the same luck you have.

    Sammy

  5. sammy95 said:

    Car99r, welcome to the site. You ask the very question I have. I've tried to figure it out but had the same luck you have.

    Sammy

    Sammy,

    I have been searching for hours for any videos or tutorials on turning such a fine point with no luck. Hopefully someone who has made this can chime in here?


  6. There are enough experienced people on this forum that I am sure we will see the answer soon.

    Samm

  7. I'd get it close enough then use a file to finish the point.

  8. I'll see if I have any suitable high carbon steel and look into this for you.

     

    But for now, consider the relationship between speeds and feeds. In this instance that's the speed the workpiece is rotating at, and the feed rate at which we apply the tool.

    Because of the fact that any given RPM the 'periphery' speed of a workpiece is determined by the diameter on a small narrow taper the speed of the surface passing a cutting tool can be very low indeed. 

    A problem of perception can then occur. Whilst our chuck may be spinning at 500 rpm and would be fine on sensible diameter, with the point of a thin taper this could place needs of RPM's in the thousands to achieve the same cutting speed for a 1″ bar say. So what can happen is folk feed in the tool at a 'normal' rate, but the material is not passing the tool quickly enough so digs in and it all goes pear shaped. Tiny diameters need huge RPM's.

    Tools have to be sharp, very sharp, and with as small a contact patch as possible. So rough tools, forming tools, and finishing tools are usually out, we need fine sharp points. This reduces the friction, and subsequent force needed to make a cut.

    Also consider, in the case of this particular need, the nature of the point design. In the pictures it appears to be a single taper to a point, whereas most commercial scribes have a secondary angle on point. This secondary angle forms the actual scribing tip, and is usually ground on, the same way a centre punch should be ground, with the grinding direction in line with the axis of the tool. I'll cover that some more when I've had a fiddle.

     

    Finally, think out of the box.

    If you're using the the whole taper length protruding from the chuck and expecting it to work, revisit that. A lot of machining tricks are about the application of common sense. So, in this instance, try this:

    If our taper is, say, two inches long. Allow the first 1/4″ to stick out of the chuck and turn it down to a fine point, leaving it slightly oversize. Then loosen the chuck minimally and pull out a further 1/4″ without rotating the workpiece, turn down this section to the taper to marry up with the first piece turned. Follow this with a 1/2″ bite and repeat, finally perhaps the last inch can be done to finish the roughing down. To finalise it and blend the sections finish with abrasive cloth over a file in the normal safe way. By using this method the vulnerable overhang is reduced to a place where it won't matter so much due to the increasing diameter being cut, if at all. Some experimenting with the size of bite may be needed, but it'll work far better than trying to turn the whole thing down in one setting.

  9. Jerry, i agree with you, increase speed, and decrease overhang. Perhaps you might also have luck with a tool post grinder as well. i ground a needle jet screw for my model diesel out of an old 1/16 drill bit. i stuck my Dremel tool to the tool post, it seemed a little roughneck but it worked nicelySmile. just make sure to not over heat things, and keep that dust out of the ways!Laugh

  10. Commercial scribers are certainly ground, it's the best way at the end of the day, but it can be done on a lathe……………….

     

    Here's some 'Silver Steel' 6mm diameter, a high carbon tooling steel suitable for heat treatment. It's been mounted leaving me clearance to machine down the first 1/4″ or so, the rest of these photo's are in sequence as the workpiece is pulled out of the chuck for each stage, to the last showing the levelled surface. The spindle speed was 1,500 RPM for all operations, feed was by hand off the compound slide angled to 3 degrees, cutting tool was a regular HSS RH knife tool, just quickly dressed before starting, no lubricant:

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    I then put on a typical grind for the very tip:

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    Finally here's a micro shot showing the tip alone. A couple of things to observe here. Go back to the last of the sequence shots…looks quite shiny doesn't it? This goes to demonstrate a side issue regarding surface finishes. It might look smooth, but that's an illusion created by the reflection of light off the walls of thousands of grooves that resulted from the surface dressing. When the surface is seen this close it's not such a bright picture. In fact the surface is pretty rough at this magnification.

    But, on top of that look at the ground tip. That's the kind of surface finish that results from a 'fine' grit bench grinder wheel. Not so fine then, and this is why stoning comes into play when grinding cutting tools.

    Whatever, for a scriber this is ideal. it still has a tiny round on the very tip, and a real needle point will just be too fine to survive, and indeed too fine to see as a mark, it measures about 0.004″ in diameter at the tip (a bit of a lottery measuring tapers on this scale). To aid perspective on scale, the bottom edge of the ground point is on a diameter of approximately 0.038″. Note also the direction of grinding on the tip. Doing it this way removes possible concentric grooves which can be a starting point for fracture, and as the wheel grinds from the tip down the shaft there's no worries about raising a burr.

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  11. Jerry,

     

    That is great my friend. I plan to try this again tomorrow morning using 3/8″ drill rod. I have yet to turn anything at that speed but going to give it a shot. Thank you so much for the tutorial and taking the time to do this.

     

    I am loving this website so far. 

  12. Cool, but do take care, you're working close to the chuck, so use a carriage stop if you have one for a bit of added safety. Keep the cuts small, get that tool sharp and dead on centre. 

    Let us know how you get on.

  13. Jerry said:

    Cool, but do take care, you're working close to the chuck, so use a carriage stop if you have one for a bit of added safety. Keep the cuts small, get that tool sharp and dead on centre. 

    Let us know how you get on.


    Thanks Jerry!

     

    No carriage stop so I just moved compound in to closest I could get and still clear chucks and marked a line. I knew this would be as far as I could go when turning. Worked great and your method worked great.

     

    I got so excited that it was working that I forgot about my mark for stopping at .250 in diameter and blew it on the first try. Therefore I started a second one and went fast and easy. I still have to finish it tomorrow so no pics today but working great!!!

     

    Thank you

  14. OK, all good. Looking forward to seeing the result when you're ready.

    We've all done that jumping ahead thing, I can't remember how many times I've whisked a part out and undone the chuck just as I remember there was something else to do! Embarassed

  15. Well, here is my finished result.

     

    This is the first thing I have ever turned, threaded or anything…lol So please bear with me.

     

    I finally got the taper down and then had to part the tool off. When I did it hit the carriage and bent the tip a little I was able to straighten back some but afraid of breaking it until I get it hardened which I have to read up on.

     

    I also didn't like how thick the handle was right beforethe cap. When holding it like I was going to scribe something it felt odd so I turned it down just a bit more and polished it. (No measurements, just what felt good in my hand)… I am very happy with my results. Maybe once I get better on the machine I can give it another shot…lol

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    I wish I would have made the cap narrower too…

  16. well done car99r congrats on  you accomplishments  a job well done! Cool

  17. Very nice work. Good photos, too! Nice way to join the group-

    Kevin

  18. Nice work Car, looks great.  I'm sure that this is a tool that you'll remember making for many years to come.

  19. Thanks for the comps guys!

     

    Now to find another small project I can make using the lathe only. I don't have a mill so limited on what I can do.

     

    Also,

    Is it possible to harden this drill rod material here at home using normal stuff I have. No oxy torch but I do have one of the MAP torches.

    I was told cherry hot then quinch in clean oil, once cool then bring temp back up to golden straw color and let cool again. Sound about right?

  20. you could always put together wheel forge and either use charcoal  or if you have acces to hedge (osage orange) use it . ive melted alum  on a hedge fire before

  21. or something like this

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  22. Well done, great stuff!

    Catching parts to save them from damage can be tricky, i'll bet everyone on this forum has had to dig around the swarf in the tray at one time or another. It's actually quite a tricky thing to do safely, and it's difficult to recommend a particular way. Some folk use trays with foam linings, but then the part can bounce out and if it hits the chuck that real bad news, other use their hands which is my way, but the risks with that are clear. Probably the best way is a simple tray that can be held from a safe distance. CNC machines use little catchers for transfer to exit chutes.

    To straighten fine points place the sides of the taper on to a flat surface, with the held end off the side, and roll it. If it's real bad another piece of flat material can be held on top and use that to roll the part.

    Quenching in water is the usual way for hardening. The quenching medium dictates the cooling rate, the longer it has to cool the more the exited carbon atoms can make their way back to the place they came from when the steel was cold, so by quenching fast we trap those carbon atoms after they adopted their position in the middle of the cubic structure that steel molecules form when heated. The more we can trap the harder it is.

    The second stage is to temper the steel to remove some of the brittleness, and for that what you suggest is fine. This process does undo a little bit of the hardening process, but without it the tip of a scriber is going to be very prone to breaking.

  23. Nice Job Car!

    One thing I noticed was your pictures were full size (I edited them so that they are 300px now, with the ability to click and expand to full size). 

    The reason that this is a problem is because the forum software doesn't deal with oversized images well – it messes up the word wrap.

     Image Enlarger

    Just to be clear, you don't have to change the size of your photos at all, you just have to make sure that the software knows what their original size is before you insert them. 

    In the image above you can see that the dimensions of the image are larger than the 300px limit, and that's ok. You just need to make sure that these dimensions aren't blank. If they are, click on one of them and they should autofill. 

    The image might still show up as a full size image, but as long as the dimensions were properly filled in it will be resized to 300px wide once you hit “Post New Reply”. 

    Here's how it looks in the editor window – before posting the new reply. Notice how the image is still shown full size. Once I post the reply the image will be resized to 300px wide. 

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    I hope that helps. Thanks for sharing your first project with us. I'm glad it turned out so nice!

  24. Thanks Tyler

     

    I actually just hosted them on photobucket and inserted the BBCode from there. I noticed they were too big and tried to resize through photobucket but still did not work. For now on I will just use links since it is so much easier… haha

     

    Nice site you got going here too!

     

    I run http://www.thechopperunderground.com which is one of, if not the largest motorcycle chopper forums on the net. Roughly 15,000 members worldwide but we use IPB software instead of wordpress. I will try to get used to this software and hopefully more projects to come.

  25. Please don't post links instead of actual photos, lots of people have trouble viewing the linked photos (I assume because they are using older browsers) but nobody seems to have trouble viewing the inserted photos. 

    I reinserted your photos using the same photobucket links you used originally. The software can detect the size of photobucket and flickr images just like it can an image uploaded directly to the site. It's just that sometimes you need to click on one of the dimensions boxes to get them to autofill. 

    It's a double edged sword. It's nice that the sofware can resize the images for us, but it would be better if it worked 100% of the time. 

    Anyway, don't worry about changing the image sizes (unless they are over the 5mb limit). They can be 1200×800 and still work with the forum software, as long as the forum software knows that they are 1200px wide. 

    I took a look at your forum, it's big! When did you start it? How long has it taken you to grow it to that size?

  26. I will give it a shot the next time I post some Tyler.

     

    The site is huge and keeps me rather busy. I took it over from the previous owner about 7-8 years ago with 1400 members. We are now featured monthly in The Horse Backstreet Choppers magazine plus here and there in a few others. We are working on yearly meets throughout the US and possibly even other countries.

     

    You can read a bit of the history here. http://car99r.blogspot.com/201…..ndcom.html

     

    Now, someone give me another project to do…haha I really want to make the spring center but no mill or end mills to cut the slot. I will head over the that topic and find out what my best choice would be.

     

    Thanks to all of you for the encouragement and kind words. If I knew working with the lathe was so much fun i would have bought one years ago… haha

  27. Hello, I am new to the site and new to the lathe. I just purchased a Grizzly 12×36 and thought this would be my first real project. I have turned tapers but nothing to a point and as thin as the scribe. I have completed the body and cap and really enjoyed it. However, for the life of me I cannot figure out how to turn this scribe. I figured it at 3* and I turned down the 2.5″ of stock to .250. As soon as I touched the stock at the 3* degree angle with cutter it bent. I have tried 3 times now with no luck….

     

    Anyone willing to share some knowledge with a total newbie?

     

    Thank you!

  28. When turning the taper, chuck the material deep into the jaws, so there is only a very small amount of it poking out, Make sure that your tool tip is on centre, and that it is sharp. Good luck.

    Pics?

  29. Hi Soccerkid, welcome!

    Instead of turning the whole length of the scribe down to size at once, try turning a half inch or so, and then sharpen the tip. After the tip is to the point you are looking for, you can turn the rest of the scribe in .5″ increments until you've got the entire 2 or 3 inch tip turned down to size. Each time you want the part sticking out of the chuck no further than necessary to make the cuts. So start with .600 sticking out, turn .500 of that down to your .200 diameter (or whatever it is), then turn that .200 diameter to a point. Then loosen the chuck, pull the part out another .500 (so now there is 1.1 of it sticking out of the chuck) and turn another .500 of it down. Repeat until you've turned the entire piece.

    The only issue with this approach is that you'll have a hard time matching the final pass of each half-inch section. But you can get close and polish out the rest once the entire piece is turned down to size.

    The reason your piece was bending is because it was sticking out too far from the chuck without support.

    The other option would be to turn the part as you have done already, and then support the end in a steady rest near the tip, but far enough back so that you can cut the tip.

    Hope that helps!

  30. Another way to do it would be to centre drill one end, then chuck the entire length plus a little more, with a dead/live centre in the tailstock, you could then turn it down to the right dimension as long as you don't take too deep a cut, it should be fine. then part off the bit with the centre drill in, and turn the taper on the end, et voila :P

  31. Sorry, I wasn't envisioning the taper when I wrote my approach above, I was thinking more along the lines of a punch, not a scribe.

    But for a scribe the process could be accomplished in essentially the same way. Since you'd have a hard time using a steady rest (due to the taper) go ahead and turn the first half inch or so at a taper until the tip comes close to a sharp point. Then pull the part another half inch out of the chuck, keep the taper angle the same, and turn the part until your second taper matches the first. Now you have a 1″ taper. Keep going until it's long enough.

     

  32. All right. When you make the actual scribe piece, cut it at 0° from the shoulder to maybe 3/4″ out and taper the rest at 2-3° except for the very tip. Cut this at around 30°. I also made my piece a little heftier to avoid too much bending. But go ahead and let it bend some. Just wear your safety glasses and don’t over-do it. Run it really fast at 1000-2000. When it bends too much for your liking, slow it way down between 200-500 and finish with a rough file. Then use a fine file until sharp. Then feel free to polish with Emory paper and buff. :)

  33. So you got yours done then? Excellent. Picture?

  34. So you got yours done then? Excellent. Picture?

    I would but I don’t know how to post them. I already tried to copy/paste. They aren’t anywhere ion line either so I can’t add URL either.

  35. There's a link in my “signature” below that talks about posting pictures. There are written instructions as well as a video walkthrough (for those of us who are visual learners). 

    You can't copy/paste the images (as you've already found out). You need to upload them to the site's using the insert image button. But the FAQ will walk you through that. It's easy once you get the hang of it.