I might paint a green band on the shaft near the handle that only showed when the pin is pulled out, just so I wasn't standing there thinking, "Why won't this thing start?" Nice project!
If you reduce the diameter between the detents, you will reduce the force required to switch between them, and therefore the tendency to overshoot. I got the impression that it was a bit stiff, in that regard, so I think you could reduce it a fair amount and still have a good positive detent.
@@troglokev Maybe, but then you reduce the strength of the end stop as well, which is not desirable. But at least you would have less force, and thus more control.
A very good solution, worked with a speed chuck many years back on a very large turret lathe, it had a foot brake spindle lock which screamed like a stuck pig every time you used it.
I think everything you did worked I've been thinking about buying a metal lathe I was leaning toward the Grizzly lathe but like a lot of issues I'm still looking. I appreciate what you've been doing to fix things keep up the good work.
James, just wanted to say Thank You again for an excellent project. When I first saw the videos on the spindle lock, I thought it would be nice but seemed a bit difficult with the precise long hole and the large radius for the spindle. Fast forward 3 months with a new set of reamers and I figured I would give it a try. I printed your 3D parts and test fitted everything; it was perfect. Made the parts per your plans, excellent information. Not as difficult to make as I thought and turned out great. The only thing I need now is a surface grinder so I can make things look as pretty as your parts. Anyway, thanks and keep up the informative videos for the average guy with a hobby tool shop.
I admit I kinda like the spring-eject idea, but I wasn't particularly worried, I just sorta aesthetically prefer it or something. You clearly prefer this, though, and that's fine. Just gotta fix those grooves so the ball stops the pin. :) Fun project! I might have to ponder doing something like this...
I'm sure it won't be an issue, but I would probably have a fear of accidentally bumping the handle or hitting it with something so I would likely add another locking detent with a push or pull pin so that you need two hands to engage it. But you also made sure that it doesn't eclipse the edge of the machine so bumping into would be pretty unlikely. Very cool project to watch!
Replace the 4mm ball with a "bullet" made from 4mm round steel. You can adjust the shape of the round nose on the bullet to be smaller radius than 2mm, so you get better safety. Also, the bullet can be longer than 4mm, allowing you to get deeper engagement on the shaft (if you cut the shaft grooves deeper).
use a microswitch as an interlock for the locking pin to disable the VFD, its another electronics project and best yet you can use that same interlock circuit for a lathe stop later if you like
Agree the variable speed lathe will not generate enough torque to cause problems if power is applied when the pin is engaged. For those with fixed gear lathes where the engine starts at full torque there may be problems. Suggest a little feature creep on the electronic screw... pin position interlock. Disable power to the drive motor if lock pin is engaged. Another project? 😉
On a bigger lathe, if you drilled those holes, oil would flow out of the gearbox. My 10ee has a spindle lock, the PM1236T does not. I should use my surface grinder more, looks nice ground.
Possibly try machining down the body of the pin between the chamfers? That way the ball starts deeper in the groove, and doesn't need to wait for the spring to push it in, and will hit the unchamfered sides at a steeper angle.
Great video as always , thank you. At about 18:30 I was curious about how you knew it was OK to just drill through the headstock casting? Mine has some gears and an oil bath back there.
The only way you can truly align a tailstock with a headstock is to place both a true center in the headstock spindle and a true center in the tailstock spindle or quill and take a cut at both ends of a shaft and compare. I have an Edge Technology tailstock alignment bar to use in place of a turned shaft in my lathes and even though it is claimed to be hardened and ground it is not as accurate as turning both ends of a shaft for comparison. If you use anything on the headstock side of things, i.e. chuck, collet, or etc. you are compounding or magnifying error. Something the long dead machinists knew, but seems to be forgotten in many cases.
You also need to run your indicator over the top of the shaft at both ends to measure how much your tailstock has dropped. On worn lathes they can drop (wear) quite a bit.
You should have some sort of warning sticker in a bright colour on the lathe behind the handle that only shows when the pin is engaged in the spindle. As an automatic warning not to start the lathe
I believe you want your ball "sunk" into the detente deeper than its radius, which would make the resulting pressure on the ball working to press in further into the detente (where it has no place to go) rather than out of it, when you try pushing it past the stop. The sloped side should still be able to climb out of the detente, I think. If all else fails, one can of course always use TWO separate spring-loaded "detente pins" that do not rotate in their shafts and are chamfered only on the side they are supposed to disengage on...
I was wondering if a limit switch might be needed to disable the lathe spindle when locked, but... a live test doesn't lie! :D Great project & Video as always; learned a lot about the spring detent too; I definitely want some of those for an upcoming project
Knipex is usually pronounced differently. The Germans say "nii-pex", a lot of other Europeans call it "nip-ex"....... The K is silent like in "knife" 😁 Your machining is great, im a woodworker so it astonishes me the accuracy people like you work to 😆 looks like ive found a new machining channel to satisfy the OCD side of me 😁🤙
I can't tell you how many times I've started the lathe with the spindle lock engaged. It slips on the belts and squeels like a bitch. A safety lockout was always part of the plan but you know how those jobs end up on the back burner once the thing works...
Even if you did leave the pin in, speaking from experience the belts will slip on the drive pulleys, so you still have a little protection in that end as well.
You could do a version that used a cross pin through the shaft, a slot inside the block that the pin moves in, a couple of magnets to hold in either the locked or retracted positions. You wouldn't have any issues with it slipping past the ends of travel. The pin can even be floating if you cap the open slot. Not very adjustable for locking force, but very simple.
I was concerned about starting the lathe while it was locked but as you showed there’s no issue. The VFD just doesn’t have enough torque at slow speed.
I was interested in how you would deal with power-up-with-lock-engaged as well. Seems you happened into an elegant solution. Frankly, I'm surprised you didn't over-complicate it. I use the back gear to lock the spindle when changing chucks, and half the time I forget to disengage. The motor usually spins up and the belt slips. (I don't use a belt tensioner, the motor's weight provides belt tension, and a crude clutch effect.) That hasn't been a problem, but it can't be good for the belt and I go "Oh $#/+!" every time. I'm considering mounting a microswitch actuated by the back gear to inhibit the motor. But then I'd need an override switch for when I actually use back gear. Adding something to sense when the bull gear lock pin is out is just getting too complicated. So it wouldn't be a complete poka-yoke, but close enough.
Now you know why you keep the old lantern style tool holder that is on the shelf. Quick change tool holders are very useful, but their bulk gets in the way sometimes.
@@KennyEaton603And that's why you keep cemented carbide and high-speed steel cutting tools in your toolbox. In the home shop I gave up on insert tooling. Way too expensive whereas cemented carbide is a 1/3 the price and lasts for years. In commercial work it is a different story. You have the horsepower and machine rigidity to make carbide work as it is supposed to.
@@aceroadholder2185 agreed! I run a lot of inserts, but plenty of brazed carbide and HSS as well. I regrind a lot of my inserts as well, after seeing Stefan Gotteswinter do it.
So on to the mark 2 version. The locking shaft has a rack gear cut into it and then the handle has a gear. Movement is by gear motion, there are detents on the lever shaft to hold the in and out positions. The other possible version would be a toggle design, much as the one Luger used on the 1908 design.
Guess you could wire a position sensor to the spindle lock , so it detects when it's engaged. Then a simple circuitry could make that led BLINK or BRIGHTER or both if you accidentally turn on the VFD while lock is engaged. Or who knows. Go silly. Air Horn if you engage while lock. Nice and simple project. For me it'd be good enough to know that the VFD can't shear the pin :) And after days using this, you'll get used to it.
And I'd have to assume that since that's not gonna be doing much in the way of spinning at high speeds I don't think putting the center in then extending the stock is going to have any effect on its function. It's just a pin. A very fancy pin, but a pin none the less.
Interesante, lo que no me ha quedado nada claro, como se desconecta la parte electrica? seguramente lo ha explicado pero mi nivel de ingles es muy bajo... Gracias maestro por mostrarnos un excelente trabajo
Nicely done, but I'm a little puzzled that you started out with a drilled center that, as one of your references, should be perfectly true by definition - and then cut it off and drilled the other end, being concerned by drills wandering.
Nice work, man I'm worried about the possibility that chips may have fallen into the gearbox. And you could consider a switch to disable the power when the static lock activates.
James, I knew there would be safety concerns with the pin-stop. I had thought a lockout switch should be recommended for those that might not have the same exact configuration as you.
Configuration doesn’t really matter. It can’t be engaged while spinning, and it can’t start spinning while engaged. I suppose you could round over the end of the pin a bit in case you try to engage it while spinning.
0.1 deg out of level 😱 how do you live w/ yourself! J/K. Amazing video James. You've managed to captivated me with two videos on a spindle lock. Glad you were able to show what happens if you forget to take out the lock. Would the result be different if there wasn't a VFD? Also will all VFDs behave that way or was there an option/feature that needs to be enabled.
Nice build James, as we could already get used to from you ! Did you consider using any security circuit breaker in this lock to avoid switching on the spindle accidentally with a locked spindle lock?
If cutting the grooves deeper to prevent overshooting the pin on removal doesn't work, I'd put a cap screw in the head stock to block it coming out all the way.
love your content! Very educational! Question: at 9:01 you say "You really shouldn't put taps in a drill chuck", what should taps be held in if not drill chucks? Sorry if its a noob question! I'm a complete amateur
man, you did a great job on that. you ended up with a built in safety because of the vfd. that was a very happy accident lol. however, put the original motor setup back on it. and flip the lathe on , it will be a different story. i do like your way better though.
Turned out great! There's an easy way to idiot proof that, why not just mark where the handle is engaged and not engaged? A quick little sharpie marks and you're good. If you really want to, you could scratch in marks also.
So the grooves should be a little deeper than half the diameter of the ball. This way the square shoulders of the grooves would stop over-travel of the pin. i am sure you know that. Or, you could replace the ball bearing by a short pin that you'd machine, that'd have a 45 chamfer to accommodate the chamfers on the pin but shallow enough to catch the square part of the groove.
I wonder if you could turn the spindle lock into a safety feature that prevents the spindle from starting by turning it into in electric switch. Edit just saw that the VFD does not power up - never mind :)
Suggestion: add two vertical sharpie lines vertically on the side of the headstock case, in line with the center of the T handle and extending a quarter inch or so above and below the handle in each position. Then you can tell at a glance which position the handle is in. A paint marker might be better than a sharpie, less likely to wash off.
I must admit, I did not like the video…it was too short 😬 You make great videos sir. I learned a lot of neat stuff watching you. Keep up the great work and shutting down the negativity 🤘🏻
Just out of curiosity,,,, how many tools have you had jam and exploded? How big was the hole in your ceiling ? On the serious side ... Thanks for sharing ... Stay safe and well ...
Did you think to check the center of the pin? Given the length:diameter ratio, you're probably turning a barrel shape. The middle of the bar will flex away from the cutting tool, giving a larger diameter in the center. I ran into this turning a piece of 1.5" 1144 about 18" long. The middle was bowing out by a couple thou.
this depends on your DoC, the deflection is directly proportional to the cutting load so you often make this stop being a factor by allowing yourself a final 1 thou spring pass
@@PaulSteMarie depends on both the tool and the material - Carbide is prone to chatter on spring passes as carbide rips rather than shaves, Sharp HSS tools or inserts however can do final spring passes happily
I would absolutely add a microswitch interlock to prevent the lathe from spinning with the lock engaged. All it's going to take is bumping that pin and not noticing it to destroy that belt.
The test at the end went about as I expected, anticlimactic. Having the same VFD that I set up based off your video, I had a pretty good idea what would happen. If you do read this, have you changed/improved any of your VFD settings over time?
I have tried to start my small hobby lathe several times with the spindle lock engaged and nothing happens. It's only a 0,75 kW motor with a VFD and it just squeals until I stop it. I could install a micro switch to interlock the motor with the spindle lock but I don't see it as a big enough problem as it is.
This spindle lock has one minor issue. Maybe acceptable on a prototype. It does not 'lock' into position when opened. You don't want it sliding into lock position when the lathe is turning under no circumstances. This could be solved, when the shaft has to rotate 180° (handle up/down) to slide it or to lock it into position. Handle down for locking as gravity is on your side. Your ball + spring hold is not a lock.
Why not drill some blind holes in the back (locking) collar of the chuck and make a "C" spanner to tighten/loosen it. The modification and manufacture would make interesting content.
