Regarding the knurling process. 1st, it is a slow speed operation so choose a back gear if you have one to get a slow surface speed. 2nd start the tool with only a 1/4 to 1/3 of the knurl wheel engaged. You may also include a small "lead in angle" to the tool to progressively cut the knurl. 3rd from this starting point engage the knurl to depth. 4th with the knurl now running in it's own groove traverse the length required while washing away the chips with plenty of coolant. Lastly the mark of a well formed knurl is to undercut the basic diameter and chamfer up into the knurl. In any case I don't personally like knurling tap wrench handles because after a longer tapping session the knurl is rather hard on the hands.
If the knurl ends up too rough, you can always do a skim cut on top and knock the top edges off the knurl. It will retain the grooves, so you still have some grip (though it will be slightly less than before, still better than no knurl), but the sharp top edges will all be removed and much easier on the hands.
That's what I found as well. The 'pressure' knurling tool I have has a 1-1/4" shank! (I used to have a big Colchester) getting a mini lathe was a shock when I saw how tiny it was but has worked out real well for smaller hobby parts
I concur with others that the clamp type knurling tool works better on small lathes. They are simply not stiff enough to manage the load on push type tools. Clamp types keep much, if not most, of the knurling forces within the tool rather than transmitting it to the lathe tool post. Also, others mentioned getting the diameter close to the pitch circle of the knurling. This helps on small lathes as well. It doesn't need to be perfect but helps. I have created a simple spreadsheet that does the calculation and use it particularly for course knurls.
Certain diameters of material will form different patterns with a knurling tool. Think of it as a gear where one of the gears (the work piece) has one and a half teeth. That will result in a double cut (fine knurl). There are calculators online for this.
I was coming to say this. I didn't realize this and why my knurls were all out of whack, until I saw this mentioned in a video by some machining channel (Sorry, I don't remember which xD)
You can do a good knurl and a double tracked knurl on the same diameter by using different styles of approach. Going straight to full depth and feeding from the side makes it harder to double track a sharp knurl. If you're doing a coarse but shallow knurl, then even this doesn't help, you just have to calculate
Great result. I love that you recreated the 100 year old one even down to the measurements. I hope you keep those tap wrenches together and they are both used in another 100 years.
I work an hour from the Starrett factory. Yard sales in the area can be exciting. I have a set of Starrett tap wrenches that I love, yours looks similarly well made
The few tools I have from my dad ( he died when I was 9 yr old) I re-surfaced. On the few chizzes and punches, they have mushroomed heads, I left that part. He was a tool maker, Mom sold all of his measuring tools as I was to small. Re-machine that tap wrench, chase the threads and knurls. You will be glad you did as you will be going through the same steps on the same steel that he did 100 yr ago.
Knurling patter: You have to calculate the scope of what you want to knurl. It should match the knurling wheels (distance tooth to tooth). If you want the uneven look on both parts you need at least the same factor on both. Perfect knurling means calculating, but there are online tools...
I have couple cheap chinese tap wrench. Those are with coarse thread. I think fine thread is better because when coarse thread handle turns even a littlebit, tap is loosen. Here spring helps. Good job!
I like the two different knurls. Since they are different in other ways, like diameter, I think it looks cool like it is supposed to be that way. Anyway, a fine knurl is so much nicer in the hand anyway, it is not like you need massive grip security on this tool. 👍
A few machining channels have recently made clamp style knurlers from kits. Pretty interesting builds because of some challenges due to some of the supplied parts at final dimension but rough surfaces, so to have a nice finish, they had to make lots of adjustments.
Awesome project, love how you mix some old school techniques, with new school! It always bothered me watching you cut heavy materials with a hacksaw, but I get it. Always great content, I may have to make one of these myself
Knurling is like cutting teeth on a gear, you need to have the parts diameter close to right to get a whole number of "Teeth". Where it looks like you've made a really fine knurl, it's because the part's diameter was almost exactly half a tooth off sized, so after the part had turned 360' the tool started trying to cut a valley into the peak it started forming before. It's hard to describe, but I hope you get the drift. There's all sorts of maths you can do to ensure you get perfect knurl every time, but I can't be bothered with that. I just press the knurling tool against the workpiece just hard enough to leave marks, and turn the spindle 360' by hand. If the first and last marks are really close to being in the same place it'll work, and I start to knurl the part. But if the marks are really out of alignment, I'll take a tiny skim off the surface with a file to change the diameter slightly, and check again. Usually you'll be good to go after only doing this once or twice. It's well worth having a play at this on some scrap, just to get a feel for how far out it can be and still produce an acceptable knurl. Oh, and one last thing. Fine knurls are a lot less prone to this than course ones. The fine ones just seem to be a lot more tolerant to this.
There is also a online knurling calculator you just have to input your knurl wheel diameter and some other stuff and it will tell you what the nearest diameter to take the stock to and you will get perfect knurl 100% of the times. Also maybe use the tool at low speed
@@suhasdilwale1260 Well, I suppose if you WANT to get all technical and precise about it....... 🤣 TBH, most of the stuff I make for fun has a tolerance dictated by the finish I got. If it's at the diameter I was aiming for, but the surface finish looks more like a screw thread than a precision turned part, it goes undersized. If it's a part that needs to fit into something else, I'll then aim to make the hole in that undersized too. 90% of the time it doesn't matter to me. It's all about the fun of making things for me, and I find no fun in making something again just because my little lathe chattered like a couple of old women in the supermarket, and to fix that I need to go 0.5mm undersized. 😏 For some reason this makes me think of some hinge pins I rushed my way through when I built my utility trailer. I'd already made the pins, and was drilling out the cup parts to fit on them. The drill bit I was using cut WAY oversized and the pins were a sloppy fit. Not wanting to waste anymore material on remaking the pins, I quickly diamond knurled them, and turned the tips of the knurl down to the new cup bore diameter. They've worked fine like that for several years, and if anyone notices and mentions it, I brush it off by saying "Oh, that? They're relief channels to keep the grease evenly distributed within the hinges". 😁
Next project. Make a clamp type knurling tool. These work brilliant on a small lathe - even on stainless. I’m no machinist but the one I made works great.
The tool turned out great! I love that you do it right and heat treat it as well. I had a craptastic Chinese tap wrench that was garbage. I bought a Starrett tap wrench to replace it. It was like going from a broken down junky car to driving a Ferrari. Night and day difference.
Awesome result dude! Very functional and looks great too. One of those tools that I know I need to make (for the same reasons) but am yet to do. You might've just inspired me
Good job. mrpete222 (Tubulcain) just did a two-part series on knurling you might find helpful. Looking forward to sometime seeing you clean up your grandfather's tap wrench so it can be put in a place of admiring :)
Knurls usually leave a slightly jagged edge when pressing a knurl onto a raised boss. I prefer to finish the small diameters on either side of the boss after I've knurled so they clean up the edges.
Many have already noted that a pinch knurler is what you need, and it's an ideal shop-build tool project. Some have mentioned that several youtubers have built the Hemmingway Kits version. It's elegant but way over complicated. You can design a much simpler version that will work very well. I'm eager to see what you come up with. And get some medium pitch knurling rolls. They're ideal for machine handles and much less prone to double- or triple-tracking than the coarse ones, though not immune.
I did some reading on zinc fumes. Apparently, they're far less dangerous than people think. Don't get me wrong. it'll give you one helluva cold, for at most, a day, basically, but after a while, your body just kinda uses the zinc. it is a nutrient. there are no known long term health effects. (probably because, unlike other smokes, the body can easily clean up every bit of it)
when you said the twist drill wnadered off center at 9:15 it looked more like the entire part shifted. Though it might also have been the camera moving idk.
Outstanding video! Check out the Hemingway knurling kit. Simple enough that you don't need to buy the kit. Draw it up yourself and you can make it for whatever size knurls are most easily available to you. Important to source high quality knurls. It would also make a great video idea.
According to this old Tony. When it comes to knurling you want to flood the knurling tool as much as possible. But in your case that tool looks like it's putting a lot of pressure on the tool post. So I think your assessment is correct that you need a replacement that does not put so much pressure on the tool post
Nice job on tap wrench, I made a copy of the smallest Starrett and will be making the medium size one of these days. For a knurling tool, look up Tom’s Techniques here on RU-vid, he shows one that works really well. I made it last year and my knurling improved immensely. He has drawings for it on his website too under the projects section.
You did an excellent job. I also made several of those for myself and customers. As can be seen on my channel. Would love to restore your Granddads one to its former glory. Best regards.
You did a great job. If I may provide input regarding knurling, there’s a few things to remember. Slow RPM, depth of cut between 0.015 to 0.020” each pass until you achieve the desired result and most important, lots of oil with a brush to clean the knurls as they are being made. Gilles
Wow your great great grandfather would probably be ashamed his tools was let go like this. I just made one just like it a while back and it took quite a bit of time to make it. I would be pretty upset to see mine like that. Took to long time to make not to take care of it. You should see if you could restore it or bring it back to at least useable condition. You did a good job on the one you made.
I'm a machinist in a food plant. 99% of my work is stainless steel, mostly 303 and 304. Ever try knurling that stuff? I gave up and made a cheesy cut knurler. It only took about 15 minutes to build and it takes two passes but it works so much better. I'll prob never try conventional knurling on stainless again.
The style of knurling tool you used applies a surface pressure that is directly dependent on the pressure that the cross slide can develop and the rigidity of the part being knurled. Whereas the clamp style knurl-er is independent of the cross slide or part as it develops the surface pressure totally by the pinching action and how rigid the knurl-er is made. The clamp style knurl-er doe snot place any loads on the cross slide nor doe sit cause the part to deflect away from the knurl-er. These are a much better option.
From what I learned about knurling, 1. Dont use a live centre, Can damage centre,due to side pressure 2. Use feed, not hand 3. Start about a third of knurl wheel on job, 4.use oil, 5. low rpm
This is a compliment ive watched a good bit of your videos now... the fsct that you can make any kind of part with any kind of precision on the machines your useing is blowing my mind... i see runout and wobble general movement in almost all your videos... Like i said compliment id love to see you machine on some good well made machines... keep up the good work and good videos...thanks
Cheers mate. Yeah there is usually some wobble here and there. Its a pretty basic lathe and it can only do so much. One of these days ill get something else.
@@artisanmakes sorry it seemed rude but i ment it as a compliment i struggle on work machines that company paid for lol... you have a good eye and do amazing work.
You don’t want knurling that has formed a sharp diamond pattern as it hurts your hands - the tap wrench that came with my Hare and Forbes set was so sharp it drew blood and I had to knock the tips off the knurling on a linisher . Ditch the push type knurling tool and buy or even better make a clamp type - push type knurling tools are only good on big industrial machines . Tap wrench came out great and will give you a lifetime of reliable service !
It turned out very nicely. You will always have problems creating coarse knurl patterns with a bump or push type knurler on a small lathe because of the lack of rigidity which is required to bully a push knurl into a component. As others have said a scissor type knurler is the ideal type for smaller machines like yours. Just one final thing i wanted to share is that I have never bothered with tempering a case hardened mild steel item such as this because the case depth is only shallow and the core stock is already soft even after quenching.
If you use the live center and no stepped soft Jaws your part needs to have a turned on clamping feature to ensure the piece does not back up into the chuck
The clamp styles do help however they aren't perfect either. One of the tricks I have found is to place the knurls on to the piece then back away the cross slide and tighten the scissor type knurl tool just a small amount then bring the cross slide back in while spinning the piece by hand until the knurl wheels are on top and bottom, give it two or three rev. and inspect the pattern and if it's not wanting to track correctly I take about .001 off the piece and try again. Usually I can hit it on the second or third try if not the first time around, once the pattern is tracking correctly while still turning the piece by hand I tighten the knurl tool some more and get the pattern deeper into the piece and once that is done I can power knurl the rest and keep a good pattern.
If you've never tried evaporust, you need to try evaporust. It'll remove the rust from your family heirloom while leaving all of the character it has gathered over the years intact.
Nice tapping tool. Knurling seems to be a problem for you. The tool used puts tremendous radial pressure on the spindle shaft, it is better with a light lathe to use a clamping knurling tool. The way of working also plays a role, once the diameter to be knurled has been turned off, then knurling the entire piece and then removing the excess knurling. This way you get a nice start and end of the knurling.
The rust on your grand dads tap wrench looks like it laid in water or in a damp place on papers, we go to local scrap yard alot and see that same sort or rust pattern where some tool sat in a toolbox that was in a damp or flooded location, but very nice new one, sure he'd be proud of you 👏
Can I recommend Evapo Rust to clean up the antique wrench? Don’t know its availability in Australia, but it’ll keep the part as close to original as possible. It’s so gentle, really only attacks the rust and that’s it. Unlike citric acid, wire brush or sand blasting it won’t eat away at the details. I guess electrolysis might be good too, but I’ve never used it.
I have a really neat tool called a handy knurler, you may want to look it up. A clamp type knurler would be superior though. Great video, thanks for showing me what is possible with your equipment. Now i want ot make one of these tap wrenches 😂.
i hope you can find a scissor-style knurling tool, since that will eliminate almost all toolpost-tool pressure, and allow you to control the knurling depth in far greater detail, and use the power feed
The issue with your knurling is possibly your speed, I do mine at between 40 and 80 RPM, and use a fine feed for it, also the clamp style knurler is better for smaller parts, to use the push style you need to support the free end with a live or preferably dead centre.
Nice work. I found the thin handles really make the hands/fingers ache, gettin old I guess. Grabbed an old broom handle and bored it out to to press over existing handle grips.
For getting rid of the zinc galvanisation, powdered/granulated citric acid dissolved in water is quite good, and you can easily make the acid stronger if needed. Not the fastest process, but definitely one of the safest.
Great little project. That style of knurling tool is just garbage they never give a good knurl and put a lot of stress on both the workpiece and your lathe. Definitely get one of the clamping style knurlers.
For the future You can just grind or sand off the galvanized layer down to shiny steel with a flap disc etc just becarful cause you don't want to breath the zinc dust either 👍 you can also just grind off the inferior where you're gonna weld with a small sanding drum on a die grinder or dremal 👍
That knurler should work better than what you're getting out of it. Sure, it's not at all ideal, but still. Probably you have to get the tail stock with a center in there to support the work so you can really push on it.
You need to slow down your knurling speed a bit. It should be done dead slow, plenty of oil & always hand feed if you’re doing any length. Power feed forces it out of sync & can ruin it. Definitely invest in (or make) a clamp knurling tool too, they’re so much better. Great idea for a video 👍
could you have a couple of adjustable free-spinning nylon cylinders held by a very sturdy support on the other side of the cutting tool to counter the deflection of the part?
I might be wrong but I feel that on your great grandfather's tool the flat was milled deeper on one side than the other so that he could stamp his name into the handle.
I think there is a calculator for ensuring the diameter of your stock matches the diameter/number of teeth on your knurling wheel. @InheritanceMachining might have mentioned it.
