Making a steel thumbwheel, plus some great lathe tricks
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- Опубліковано 1 жов 2024
- Slightly longer video about making a thumbwheel to make my mill knee crank easier to take on and off. Also a lengthy side bar (in the middle) with a couple of measuring tricks for the lathe - covering digital caliper usage (thanks Myfordboy), and balanced cuts (thanks Carl White and Stefan Gottewinter).
/ craigsworkshop
craigsworkshop.net
Nice work Craig. I think Joe Pi does that trick with the rule to find the offset for the parting tool. 5=prime number.....uber nerdy! 😃
anything to do with joe pi or robrenz will make your head hurt 😂
Thanks Preso. I think you are right!
Agreed Ian :) but in a good way!
Nice collection of tricks Craig! It's kinda humorous, being from America, when you said 1/4-20 I said #7 just one of those things you know by heart here.
I know what you mean :) After I cut a few threads of a particular size, I'll hopefully learn the numbers by heart too. Cheers for watching! Craig
Good job Craig. Works OK. I would have just coarse knurled it to match the graduation ring further in on the shaft. Either way it only has to be finger tight. Cheers Rob
Cheers Rob
Good job Craig. That's one sexy looking thumbwheel mate ;-)
Cheers Aaron. I think my best work is behind me now. Lol
Gday Craig, the knob really looks good, definitely better not going as deep with the end mill, the polishing bug has bitten I see which is awesome, things don’t go rusty as easy, that’s a big plus, I’ve been doing the same deal with the digital callipers for some time now and it really is a big help, take care, Matty
Cheers Matty. I kind of mixed up two separate tips in one segment. Should have kept the caliper-zero tip separate from the balanced cuts tip - it would be less confusing! I've been doing the zero thing for ages too but a lot of people don't seem to use that method. In combination with the imperial -> metric thing, it's a great timesaver.
The balanced cuts thing is great for hitting a target dimension pretty precisely. You can use an indicator on the cross slide for even more accuracy of course.
Cheers, Craig
@@CraigsWorkshop You could also use an angled top slide for micro-adjust - old model engineer's trick.
@@paulwomack5866 Absolutely. I did a video about extending this same trick to also convert mechanically between metric and imperial. Check out my last year video with the #tipblitz19 tag. Good fun if you like workshop tricks 🙂
Great little modification. I hate washers on things I have remove frequently. Always drop them.
God bless
Stay safe
Same here Anthony! I like the style of boots and nuts that have a built in raised washer section for that reason too. Thanks for watching! Cheers, Craig
G’day Craig, thanks for the good tips and that knob came out very nice. Cheers, Peter
Cheers Peter, you're welcome!
Great channel Craig, thanks for sharing. Only just found you from over at Matty's. Looks like I've got some interesting catching up. I prefer knobs like that, especially if they're small. With oversized stock I drill a hole circle then turn the OD down into the hole circle, same result.
Hey Dave, welcome! Good idea with the oversize blank - Craig Tate recently made some just like that over on his channel. Thanks for dropping by and I hope to see you in the comments in future. Cheers, Craig
Your next project is to make a spring loaded tap follower for your lathe and mill. Easy to make and you will use it every week. Even with the tap just started in the work it is all too easy to snap a tap off reaching over the top of the lathe with your tap wrench and putting side pressure on the tap.
The other thing to be aware of is that all is not what it seems with electronic digital measuring tools. At first glance you might say that your digital calipers read to 0.0005 inches...that's what it says on the read-out. Remember digital devices are an all or nothing proposition. If your calipers read a zero or five in the last displayed digit the caliper you can at best only be certain that the actual dimension being measured is the value displayed +/- 0.00025 inch. Generally if the dimension has to be held within +/- 0.005, use a micrometer. You can do closer work with a caliper, but you have to be careful and check against a known standard size (checking against gage blocks is preferred).
Also every time you zero the display the mechanism can only read the signal blocks that are a given distance apart.. it can't interpolate between blocks. The pick-up will pick the nearest block and display that as zero . In the example before with a zero or five as the last digit displaye it can be +/-0.00025 inch from where it actually is.
As a practical matter all of this doesn't matter most of the time, but is a factor when you start working in the +/-0.001 range and you should be aware of it.
Nicely made video and if you polish anything (including things like my head) it usually looks better.
Cheers From NC/USA
Hey Ace road holder. Brilliant information thanks. I will have to give that a slower re-read to make sure it all sinks in. Good idea on the tap follower. I have many little projects like that to get on with. Thanks again, I hope to show you a tap follower build in a future video. Cheers, Craig
Nice job! I like the fluted idea, much better than a knurl.
Thanks Nigel
Yah, morning coffee in the shop.
Cheers
Morning! Hope you find it entertaining/useful. Cheers, Craig
@@CraigsWorkshop
Morning in Canada
Craig's Workshop Very! Thanks!
@@mumblbeebee6546 Great!
Thanks for the tips. Very handy to know. I really like the process you used to design the number/spacing of the flutes. I too find that aesthetically pleasing.
Cheers from Canada
Thanks for the great comment :) I am pretty happy with the design too. I reckon I'll probably end up using these proportions in future projects. One variation that I want to try is an external radius where the chamfers are, but that's just an idea at this stage.
I like the heavy chamfer on the fluted knob
I will have to add that to my future knob designs!
Good work
Cheers Tom
Very nice fit and finish. Thanks for sharing.
Thanks Steven!
Nice. I'll be stealing this idea, thank you :)
No worries - that's why I made the video :)
Hi Craig ,
Could you let me know what measuring tools you do have as i'm sort of downsizing the work i do to sub 50 mm which will be covered by my beloved mitutoyo mic or starrett digital mic both 0-25mm and my moore and wright 25-50 mic . Maybe i can help you out with some gear ?
Hi Ian, I will send you a message! Thanks
Can you email to email@craig9 dot com ? Or I can email you if you let me have the address. Thanks again, Craig
Craig's Workshop
Hi Craig,
I have sent you an email with some photos of the mics .
@@ianbertenshaw4350 Thank you Ian - I have just replied!
Nice job! Now that's one less tool hanging around your workspace 😊. Really like how you did those scallops, they look great! You will be copied lol. Thanks for sharing! Cheers
Thanks :-) Yes, please do copy. Cheers, Craig
Cool knob, I like the heavy chamfer and 5x flutes.
Thanks. The more of these I do, the less I think I need straight knurls on the shopping list 😁
@@CraigsWorkshop I find knurling a pain these features are a fun way to avoid it. It's a pain cause I have a small lathe. too much load for the push type knurl, hard on the bearings and chuck. And the cheap overarm pinch knurl I have it a piece of shit.
I've got a fairly crappy pinch knurler too (angled knurls) but I far prefer theae flutes too. It takes longer, but I think worth the time.
You've got a nice locking knob Craig, so much easier than having to employ a screwdriver. Great job, enjoyed the machining. Tony
Thanks for the compliment Tony 😂 Cheers for watching! Craig
Beautiful work Craig and well explained, looks like its meant to be there. Now just spend 12 months and bring the machines finish up to match. Also congrats, knocking on the door of 1000 subs. It will be a great milestone to reach and well deserved.
Cam
Thanks for the support Cam! Almost at 1000 subs is a bit of a surprise and has come up quickly! With the machine refinish we'll have to see. Preso (Mark Pressing) is doing a cracking job on his bridgy. Cheers, Craig
Nice knobs Craig, I like your technique of keeping notes, too many times I find I am "re-inventing " the wheel so to speak. I was wondering about 5 scallops at first, but you apparently nailed it when comparing to the DTI holder, and the chamfers perfection. thanks for the video, I enjoyed it immensely, cheers!
Thanks Howder - glad you enjoyed it! Sometimes the notes can be invaluable. It's finding the right page that's the trick. Needs some kind of index. Cheers, Craig
Goood for you, and good luck
Thanks Brian
Works great in use-handle mode, but when you're reversing the handle to save space, it looks as if the knob either needs to be a little larger in diameter to sit nicely ON the teeth, or a little smaller to sit INSIDE the teeth. It looks a bit on the edge as it is.
Since your lathe can't turn it larger, smaller seems the "go to" option, if I'm seeing it right.
(freeze frame at 25:46)
Oh - and Abom79 has been banging on about equal cuts for years.
Thanks for the Abom reference. Also you're totally right, I will shrink it down to fit within the castellated section. Just need to turn up a temporary aluminium collet first to hold the five lobe shape In the chuck. Don't reckon the three or four jaw will cope well with all the flutes and bumps.
Love the caliper zero trick. For accuracy and for working between imperial and metric. Cheers friend.
Definitely. Minimising metal arithmetic, and conversions, is great for minimising errors, and doing the balanced cuts is great for hitting a target dimension. Thanks for watching Bruce. Cheers, Craig
Hi Craig , nice knob . Cheers .
Thanks lol!
Nicely done Craig, and because my shops also small, it took just once walking into that knee handle to make a habit of reversing it when it's not being used. However the end shaft for my mills knee was never drilled and tapped like yours is. But it's a definite project for the future I think. A very good idea and well demonstrated.
To expand a bit on Aceroadhandlers comments below, and unfortunately this is going to get a bit long. And sorry but I work and think in imperial measurements. But metric measurements would make no difference to any of this. Since I've had a bit longer to pick some of this up maybe it will help.
Most decent caliper brands will come with a user manual, there well worth reading through since a lot of what I'm posting here is already in them.There's three distinct and separate metrology terms anyone with a home metal shop should know and fully understand what they actually mean. "Accuracy", or what the tool can reliably measure to every single time. And that accuracy is directly linked to it's "Repeatability". And that repeatability has a great deal to do with the tools overall mechanical design, it's built in precision and the quality it's made to and with. Without that repeatability the tool can't be accurate since the measurements would seldom be the same. A soft mild steel digital caliper that was only roughly machined and not hardened and ground would be just about useless as an example. Then there's the metrology term "Resolution" that most get confused about. A tools resolution simply means how many digits there are to the right of the decimal point. A .001" reading micrometer has a resolution of one thousandths of an inch. But that resolution or last digit number is also NOT that tools accuracy or repeatability level and should never be confused with those. So while your calipers do show a resolution down to that 1/2" thou. The calipers themselves simply can't measure that well other than by pure random luck once in awhile. And random correct measurements that aren't repeatable or something you can count on aren't usable since you simply can't know which are or aren't correct. Logically there not repeatably accurate to that high level no matter what the displays resolution reads. So in my shop that 1/2 thou digit is just ignored on my calipers since it's basically meaningless for the following reasons.
The design and the mechanical components calipers are made with, and the very slight but important clearance required to allow the sliding jaw to even move can also allow a small degree of tilting movement in the tools sliding jaw unless it's correctly used. Yes there are take up screws that allow reducing those clearances to a bare minimum and there usually located just to the right of the dial or display and above the beam of the caliper. There are still small but unavoidable clearances on even brand new tools no matter how well adjusted they are. It's not hard to add a bit of closing pressure and change the measurement by a thou or more.So a caliper's mechanical design alone just doesn't allow measurements to be made reliably to less than maybe a thou or two on even the very good one's. To get better than a calipers average level of accuracy, the far stiffer frame and much more rigid inline components of a micrometer are required. There's also a world wide agreed to metrology standard that the tools being made should fall within an allowable + - one count of it's smallest division or it's resolution to pass it's accuracy and repeatability certification. So a brand new tool being checked in a well known brand name factory can be incorrect up to that + - one count and still pass it's accuracy and repeatability specifications. Almost all of the better metrolgy equipment I've checked (Mitutoyo, Starrett) using fairly expensive Mitutoyo gauge blocks has so far fallen roughly in the middle or around half the maximum allowable deviations. One indicator was at about 80% of the allowed in a few places. A further issue with digital equipment is there's also the rounding off errors. Your displays 1/2 thou reading simply means the tool is reading the measurement as being somewhere between .0003" and .0007" of that 1/2 thou number. That's up to a possible 2/10ths on either side of being correct right there. And what the display is showing does not take into account those unavoidable mechanical issues previously mentioned.
There's another metrology term, "Uncertainty of Measurement" and there's also the now generally accepted industrial practice that metrology equipment should be at least ten times more accurate as the highest accuracy specification for your parts is. In other words to measure and be certain of your measurements to .001" all your measuring equipment should be accurate and make repeatable readings to .0001" to then be 100% sure your parts are within a tolerance of .001" And that 10ths" level of accuracy still comes with the same allowable deviation of that + - one count. That's part of the uncertainty. And yes I do know high accuracy parts to low 10ths numbers are made every day using 10ths resolution equipment. That also takes a highly developed sense of touch and more than a bit of continuous practice. And there's still more uncertainty than if they were using higher accuracy equipment. It's not impossible, just a lot harder. So there's also the users extremely important technique while using any measurement tool. And the higher the accuracy the more important that well practiced technique becomes. But since this is about calipers. While thumb wheel equipped calipers can measure parts using it, Mitutoyo themselves advocate it's a better practice to either close a calipers jaws against smaller parts by using your thumb and fore finger to lightly squeeze the jaws closed and using as closely as possible the exact same pressure and finger position on the jaws each time. For larger parts where that doesn't work then gently closing the jaws on the part using two hands. That thumb wheel if used incorrectly can exert pressure in the wrong area at the top of the moving jaw and that can very slightly tilt that movable jaw. The further out on the jaws the measurement is being taken the more possibility there is of having less accuracy.For round parts then closing the jaws with your fingers or both hands further down on the jaws and opposite of where that round part is touching the jaw faces is a more consistent technique as one example. Trying to measure anything with just the tips of the jaws is really inaccurate due to even light pressure magnifying it's effect at the top of the jaw and again possibly tilting it a measurable amount.That thumb wheel is mostly meant for making fairly quick adjustments to get close to your part size. Yes most do use it to measure with and I used to do the same, but it's still a bit less accurate and I've proved that's true to myself.
I made a point of checking my brand new solar powered Mitutoyo calipers when I first got them against my gauge blocks. They really were and still are the tightest yet smoothest calipers I've ever had in my hands. Under the best and most controlled conditions I can manage and using the best technique I know on those gauge blocks, then these calipers seem like they can be trusted to being within about .0015" of being correct on those gauge blocks every single time. Yes the calipers can do a bit better, maybe even to a thou. But that .0015" is my trust limit under those ideal conditions.Measuring parts still in the machine and during less than ideal conditions, variable surface finishes, part temperature etc.? Then maybe .003" at best. For myself if it's got to be accurate to less than about .005" I use a micrometer. This is already far too long, but I'll add there's ample and mechanically logical reasons the inside jaws most calipers have are even less accurate. And especially so as the holes being measured get smaller. Measuring and being certain of those measurements to even .001" is a whole lot tougher than most with home shops seem to think. And no off the shelf Starrett, Mitutoyo, Mayr and for sure other cheaper calipers can do so 100% reliably in average shop conditions.
Thanks Turning Point. This is great information. I had previously read about, and understand the difference between resolution and accuracy - but it's great to get another persons take on it, to cement it into the brain. But the section on uncertainty of measurement is a new one on me. And no, I don't trust internal calipers in round holes :-) I have some good telescoping bore gages, and now some small hole gauges - which themselves are another delicate feel-based friction-based tool which take a bit of time to learn. Repeatable results with those are a function of skill rather than just owning the right tool for the job. And - perhaps surprisingly - even with something as coarse as a tape measure you can get large errors from not holding the thing perpendicular to the faces you're measuring etc. I've seen people "measuring" with some comical setups. :)
At the time of recording this thumbwheel video, the best measuring tool I had for that size was those mitutoyo digital calipers. With all calipers, I'd previously noticed that if I squeeze harder, they "measure" smaller, so it's definitely a delicate operation, and I know I can't go in hamfisted and clamp down on the thing and expect repeatable results.
Since making that video I've been lucky enough to receive some larger size digital mics (also mitutoyo) from an exceptionally generous viewer. These have a resolution down to microns (0.4 ten thousandths, or 40 millionths), and they have clutches on the spindles, which give good repeatable results, so my uncertainty (hopefully) should be one order of magnitude coarser than microns? In other words with the 1 micron calipers, I should get a good repeatable accurate result, if I am measuring and working to hundredths of a millimetre (about 0.4 thou)?
I will cut and paste your comment into a file and re-read it again to make sure I'm not missing any golden nuggets of information. Thanks for taking the time to write such a well thought out and informative comment!
Cheers,
Craig
@@CraigsWorkshop I've had to do a whole lot of research about metrolgy for a long time simply because I've got no one to actually teach me so I got forced into it.
I've also got 1"-4" Mitutoyo digital mikes that I've had for some time. Yes there very good and you'll love them. But they should be 50 millionths resolution unless there different than mine. I think you'll find accurately and repeatably measuring to 10ths still isn't quite as easy as it looks even with them.There's enough variables between what's holding your ears apart and the micrometer anvils to make it a bit less than simple. Getting down to .4 thou shouldn't be too bad though. And they are a big help. I've tried covering the display with a post it note and checking various random gauge blocks to test myself and small measurement variations can show up if you don't do everything as well as possible. So it still takes practice. The calipers are always my most used tool and they get me close and then those mikes get used when needed. Just be sure to use SR -71 battery's and not the LR type, the lifespan is about 3 or more times as much.
To measure those telescoping hole gauges I found it a big help to either buy or build a decent micrometer vise. I did buy the Mitutoyo 156 - 101 version, but for what they are there a bit expensive. Hold the mike in the vise, set one end of the telescoping gauge against the micrometers fixed anvil and sweep the other end of the gauge past the advancing anvil until you get a light drag as the gauge end goes past it. Juggling the mike in one hand, adjusting the measurement with a finger and sweeping that gauge past the micrometer face is for me slower, a bit less consistent and tougher. Probably a real machinist wouldn't need that crutch, but I do. :-) My mikes have a ratchet thimble and for the best consistency Mitutoyo recommends using the same number of slow clicks for each measurement. If the accuracy requirements are high enough it can sometimes make a small difference. It's a habit for me now so I don't even think about doing so.
Great tip with the conversion and the cuts it is a great tip thanks, you gave some awesome tips in this video nice project screw i like the finishes on it thanks for the video
Thanks Joe - glad you enjoyed and found it useful. See you on the next one! Cheers, Craig
Meaty! 💪🏼
No jokes about meaty knobs please Yuchol. Lol
Good looking useful addition to the mill crank.
I get hooked by one of mine almost every time I'm not careful, hahaa.
That balanced cut approach to accurate final size is just too simple, isn't it.
Takes the stress right out of it.
Thanks Carl. I will not forget the balance cut method. It's simple and elegant and dead useful. Thanks for letting me in on the secret. Hope you don't mind I've told the world :-)
No worries mate,
I think anybody machining deserves to know how to easily achieve desired sizes.
Me too! Cheers Carl.
Love the way that thumbwheel looks. The chamfer really adds to the look
Thanks Craig - It could also be something to add to your own thumbwheel repertoire! Cheers, Craig
@@CraigsWorkshop I will definitely keep it in mind
Thanks
You're welcome Paul. Thanks for the comment.
Very clever! I’ll be sure to start using the full advantage of my digital calipers now. Quite simple, but something I overlooked. Thanks Craig.
Thanks Daniel - I'm pleased you found something useful.
All the trendy machinists rave about their dial calipers. I think they are nuts. Digitals are the bomb.
Agreed. Especially with worsening eyesight and reduced capability to do mental arithmetic :-)