Note: it is a good idea to disconnect the leadscrew when milling on the lathe or exceeding 1K RPM spindle speed. This prevents feedback from the spindle through the change gears and wear and tear at high RPM. Cheers Rob
Rob - Years ago when I was first getting into machining as a hobby I had a 7x10 mini lathe from the same SIEG factory that this one is from. While you are correct that engaging the half nut will prevent the carriage from moving (kind of) it doesn't actually lock the carriage in place. Almost all lathes made after the 60's have a neutral position to prevent the lead screw from spinning - I use the feature to reduce noise and gear wear. However, most other lathe manufacturers also include a carriage lock. I think after you use this lathe for a period of time you will discover why so many extremely intelligent people have spent so much time engineering a proper lock. A real lock provides actual repeatable precision in facing cuts and most importantly it greatly reduces chatter in these small lathes.
Also, thank you for all the videos you have been making for so many years. I have definitely learned a lot from you. I'm a professional machinist now and you were one of the great sources of information that got me here.
It is not at all "totally-locked" in real terms, it still has a significant amount of "wiggle" from the drive bearings, and half-nut clearance, not providing a stiff and chatter-free lock...yes, for some applications, ok, it's not moving, but it does have play in it when locked that way. In short, the folks who want a carriage lock, probably want more than just stopping the carriage feeding.... IMHO
For most people who just wants to lock the carriage for facing, it does the job fine. For anything more serious like milling it won't be good enough. Cheers Rob
Used this method for a over a year until I got my mini mill. First thing I made on that mill was a carriage lock. This works, but having an actual lock makes a world of difference, especially in parting operations.
Yep been doing that from day one ! if you want to totally lock the carriage so it cant move in either direction 'simply run the carriage up to where you want ,lock the half nuts (tumble gear in neutral ) then pre -load it by turning the carriage wheel so it tries to feed the carriage towards the chuck then run the tailstock up against the tailstock side of the carriage and lock it down . If you need some more clearance for the tailstock (so it doesn't hit the workpiece etc) simply use a packer like a 123 block sitting on the bed between the carriage and the tailstock base as this will make the tailstock sit back further along the bed away from the chuck. The finish on the machine looks good and if they are doing them for the price that was in your link in the last video pretty good value .
Not really a positive saddle lock, there will be backlash in the half nuts, you would need to be careful if doing accurate compound slide work that the saddle carriage didn't move within the backlash.
@@Xynudu Actually it is Rob, you have the dial on your compound slide, if you take the backlash out the same direction every time you will come back to the known tool position. However if the saddle inadvertantly moves it is unaccountable, even if you push it back or forward with the handwheel to take up the backlash you never know exactly where your tool is. I suppose you could put a dial gauge on the saddle to ensure you maintain position but a positive saddle lock gives you peace of mind that you are not losing position when working solely from compound slide.
I'm now confused that was how we were told to do it as school. Tbh it could not be more obvious. Also one of the gib adjusters is a plain screw just tighten and it locks solid.
I just bought a mini lathe. Was looking for the carriage lock. I did use the half nut lock on my first try and thought it may damage the thread. So I found this video. Thanks n
Hi Dan. This method is used by many mini lathe owners and is not my idea, or a new idea. It will not harm the leadscrew when used sensibly. OK it's not totally rigid, but then nether is any cross slide with backlash, so the facing results will be the same. For parting off it will still work, provided you apply a bit of carriage handwheel pressure in one direction to take up the slop. People that criticise what is a simple, cost free solution really are missing the point. Cheers Rob
@@Xynudu You probably recall my comment in the previous vid Rob - the BS that worries me is in the materials and workmanship. The BS in the literature and what people say can be overcome with sufficient research and a good dose of weariness. :) So, for example, I prefer to listen to you where I can trust what you say. Its rare thing in our Internet world, where opinions are touted as fact and even outright lies are peddled.
this was something i thought could be used to lock the carriage but the little bit of slack that it has made me think it wasn't intended for that. ive only had my lathe now going on 3 months so its been a learning experience for me from day one but this make me rethink that. i was actually looking into adding a lock to mine until i stumble onto this video an i think i'll actually try this now an see how well it actually does. i guess as long as u make sure any slack it may have is taken out it shouldnt have any issues. thanks for making a video on this cause i would have continued thinking it was not the best option an would have ended up drilling an tapping to make a lock but id rather not if i can avoid it.
Glad you found it hekpful. It works fine for facing and can do parting off provided you keep pressure on the carriage handwheel in one direction to counter any slop that is present. Alternatively you can use the tailstock to apply pressure. Many mini lathe owners use this trick and it serves them well. You can make a dedicated carriage lock, but there is no simple/easy way to do this. I personally wouldn't bother unless I had absolutely nothing else to do, and you really need a mill to do a good job. Cheers Rob Reply
Like Craig Roop, that was the solution I came up with to lock mine. So glad you validated it. I was afraid that since no one was mentioning it, that I was doing something obviously stupid that would damage my machine. Whew...
You hit the nail on the head Mark. You can't damage anything doing this. The half nuts are made to take a large cutting load, so facing will be a piece of cake. Correct solution. Cheers Rob
This is a perfectly workable solution for a small lathe. I don’t think it’s that people don’t realize the halfnuts can be used that way. I think it’s because “mods” videos are so popular on youtube that youtubers are looking for any excuse to make a mod and put up a video.
Its a good idea and I have used this method, but there is still freeplay movement as can be seen when you rock the carriage wheel back and forth. I found for milling etc you do need a proper carriage lock for precision. You can buy them on Ebay or easily make them up. They lock the carriage absolutely solid and there is no chance of damaging the leadscrew and half nuts in the event of a crash or anything.
Hi Steve, yes it's got limitations, but most people will only face with it. Not many will do milling. So it's a handy trick for the average Joe. Pull up way blocks are a lot better, but looking at the cross slide I don't see any place to incorporate that common design. So unless you want to make up or buy a bridge type pull up clamp there aren't a lot of options. Gets people thinking though, which can only be a good thing. Cheers Rob
Excellent idea, Rob. However, I wonder if backlash in the half-nuts and/or leadscrew might not become an issue, due to normal wear and tear. Also, exact positioning of the carriage is limited by the leadscrew thread pitch; can't just lock it anywhere while the leadscrew is stationary.
Hi Daniel, it's much the same as slop in the cross slide nut. You have to use the top slide as normal to position/feed in the cutter. No different to a pull up locking block. Cheers Rob
Hi Rob, interesting thinking. So that's the lathe and your brain well and truly out the box! Merry Christmas to you and your family from 'Up Over' mate. Cheers, Jon
Hi Jon, same best wishes to you and yours. Stay healthy and well over there. Looks like we might get a half decent Xmas day down under - it's been 40 C + the last few years. I will have a Shepherd Neame 1698 for you and my other UK uploaders. Cheers Rob
@@Xynudu Thanks Rob, I would like to say I would have a Fosters on your behalf but unfortunately can't drink the stuff (to gassy). Will have a single malt or three instead. Cheers, Jon
I discovered this method soon after setting up my lathe, but I also added an adjustable end stop to the leadscrew to remove the end float, with a small plate and 6mm screw with locknut. Careful adjustment can result in zero carriage movement and still allow the leadscrew to revolve freely.
Hi great video , I have the same lathe and there is a lot of hidden options. Its a great value for a starter lathe or something to make easy simple projects. My only beef is the chuck is a bit some may upgrade that in the near future.
The chuck on this one is awesome for accuracy. I will note the brand down for next time I need one and try and hunt it up. I have two little known Chinese lathe chucks and they are both excellent. Don't buy that horrible shitty Sanou stuff. It's crap and it's being sold everywhere. My understanding is it's another Fuerda line, a brand which used to be excellent until production left Europe and went to China. I bought one of their China offerings and it was terrible (the pinion gears jumped mesh with the main scroll gear) . Got my money back, but left a bad taste in my mouth. Cheers Rob
This is a reasonable alternative to a carriage lock though not a perfect one. I’ve used this method on my 7x12 as well as my 9x20 until I could fabricate a more solid way of locking the carriage. Although this method works for facing since the force is pushing the carriage towards the tail stock. It’s not ideal for facing since backlash in the half nut will cause the carriage to move slightly towards or away from the headstock and could result in problems like broken cutters. When machining rigidity is your friend and things need to be locked down as solid as possible. This is definitely a decent way to lock the carriage for facing cuts as you demonstrated. But a true carriage lock will eventually be needed. I will say I have used a parting tool with the carriage locked in this manner. It does work to a degree. But the results can be less than ideal.
good bit of advice Rob , my Optimum TU2004V has one but it was hidden under the top slide on the rear section of the cross-slide, it was just a socket head bolt that was flush with the cross slide ( I have since changed it to a normal hex bolt as the socket head was always getting swarf in it I also added a small bush to make it sit proud of the slide so a ring spanner could be used ) have a look and see if it is there , My lathe is very similar in the carriage and cross slide , the model below mine is pretty much identical to the Sumore lathe
That's genius! I was just looking at how to lock the carriage and came across your video. Nice one! The only downside I can think of is that there is still a little bit of play in the carriage, it's not entirely locked in that sense. But before I make any modification I'll try this and see how it works.
It actually works very well for facing cuts - no problem, same as dealing with play in the cross slide. I haven't tried parting with it, but can't see why it wouldn't be OK - just apply some handwheel pressure on one side. I know a lot of mini lathe owners have always done it this way. Cheers Rob
I got it from another mini lathe user. It's a simple trick that many use. It works fine. You can even part with it if you keep pressure on the carriage hand wheel.
I just subscribed ☺ to you. Good luck with your mini Lathe. I'm just getting started with my system. Haven't turned anything yet. I'm still getting my area, to put all of it together.
G'day Rob that was a great review and the lathe is really something else especially when you compare the crap that has been sent over for years. The first thing that I noticed was the castings the one that you always notice is the tail stock usually these are shocking and as you pointed out the chip tray at the back, if this is going to be the standard of the finish it will be great when they start selling larger lathes and with the added bonus their warehouse is here makes it even better. Well done about the carriage lock some people over complicate things, all the best John
I have a sieg lathe, 7x12, which is almost identical apart from some cosmetic differences. I imagine they all come from the same factory. Had mine about two years and still learning. Most recent addition was a 125mm chuck which gives me a wider range of material sizes. The biggest disappointment is that its hard to get a decent finish on mild steel. I use the carbide inserts available through aliexpress at a reasonable price, not too sure about the quality though. I have also ground my own hss tool bits which isn't too dfficult. All in all a reasonable little lathe for a beginner like me who farted about in engineering classes as high school, so in retirement I wanted to prove to myself that I wasn't too hopeless.
Hi Murray, to get a decent finish on mild steel try using a shear tool. As you can grind HSS it should be a walk in the park. I did a video on this way back: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Ta5F3WC-gPo.html I use mine regularly as nothing else will come close on crappy metal. If that doesn't work then I'm afraid you are beyond help ;) Cheers Rob
G’day Rob, you could have shown this a year ago before I made a carriage lock. No seriously I did know but found I still had chatter and mainly creep, chatter was mostly gib adjustment but creeping back when facing off a large part was always a problem, a lock fixed the problem. Cheers Peter
I recently sold the lathe to a young guy starting out in metal work. He got a good deal. The unit had been going perfectly at that point. It's very well made and amazing value for the money. All the larger lathes (and mills) have gone up substantially in price during the last 4 years and I'm seriously wondering if I can even do another "Best Bang For Buck" video for lathes under $2 K, due to the extremely limited selection available. The Paramount Browns FL-550 is still the winner at just a tad under the limit, but it remains to be seen how much longer they can keep that price. It's definitely the size and type of featured lathe I would buy. The main thing that annoyed me with the 7 x 12 was the small throat in the scroll chuck. It is definitely worth buying one with a 100 mm chuck to get around that restriction. Cheers Rob
Looks like they are sold out at that introductory price : www.ebay.com.au/itm/7x12-inch-180x300mm-Mini-Lathe-Machine-For-Metal-Sumore-SP2102-With-LED-Light/233746107544?hash=item366c5a8c98%3Ag%3AXYgAAOSw6rxfYd5X
yes it looks like a functioning carriage lock indeed I'm just wondering if it's rigid enough? would the t-plate underneath the ways lock the carriage better? I'm not an expert in any way, just thinking loud. I saw on many videos people struggle with parting tools because of the chatter / vibrations, which literally look scary and dangerous. when the guy put the proper carriage lock, the parting became seamless, even on a relatively small machine.
Yeah, there was some backlash and if that movement doesn't affect the overall result then it seems like a good workaround solution to me and I hesitate to offer any other solution, just window shopping this stage. Plus the Sumore people have been busy so won't be buying one any time soon. Anyway, cheers for the video 📼
I have been doing this for years mainly because I couldn’t be bothered to find the spanner to fit the carriage lock on my boxford and it save damage when forgetting to release the lock. However it isn’t anywhere near as effective as a real carriage lock due to play in the lead screw nut and deflection. Clamping the saddle to the bed is a much more rigid arrangement. So I am not really knocking your idea I use it myself but it’s not a carriage lock.
It's not locked if it wobbles back and forth lol when you "locked" it and you shook it, it obviously is loose a d will most definitely produce chatter. A tiny little wobble may not seem bad by eye but when it comes to precision lathes and mills, a tiny bit of movement by eye is alot... "locking" the lead screw does not lock the carriage completely
I've seen radius tools with a swivel to cut convex surfaces, but it would be tough to scale down and reverse for this lathe. Maybe a round end mill straight in, if the bearings are up to it. Lathes aren't usually built for a high axial load.
Disconnect leadscrew when you want to machine at 2AM and wife is sleeping. Also useful if you want to attach a variable speed motor to the leadscrew for infinite and reversible feed rates. I have the VS motor on mine even with a full QCGB just so I don't have to hear the gear train.
How heavy a cut could you take with that lathe in mild steel?....From what I can see it doesn't seem to struggle too hard making those cuts you are doing. I hear form a lot of people these lathes are only good for Aluminium and brass.
From what I've read in various user manuals it looks like 2 mm is the maximum recommended DOC. That seems a bit much to me. It turned mild steel fine. The tools supplied are pretty low rent, but work. Some better cutters would help it a lot. You need sharp tooling with any mini or micro lathe. Even my tiny Sherline lathe has no problem turning steel and even handles carbide OK. There's a lot of BS out there about these baby lathes really ;) Cheers Rob
Hey Rob. As I'm sure many people have already commented, you still have the half-nut backlash to deal with - indeed, when you engage the nuts at 2:34 and say "guess what, folks, the carriage is totally locked", you jiggle the handle and the slop is clearly visible. Somewhere around 1/8 of a turn of the lead handle, maybe? Now, sure, as long as you're cutting in a way that takes up the slop, you'll be OK, it's no worse than machining in a way that takes up the slop in the cross slide nuts. It does cut out any serious precision work, though, as well as anything that involves cutting in both directions, or, god forbid, milling. What's more worrying, though, is the amount of slop in the leadscrew / half nuts on a brand new lathe. That's not great fit and finish, on a lathe that otherwise looks to be OK. Any chance of quantifying the slop on all the axes? The OCD in me also wants to see the bearing surfaces printed on a surface plate, and a full set of alignment tests (after correctly bolting it down and levelling the bed, obvs) too.
Hi Michel, I loosened off the leadscrew end play a bit while playing around with the adjuster. I haven't set it back to where it originally was yet. The half nuts actually have very little slop, but like all half nuts and hand wheels, it has some. Cheers Rob
Actually your comment got me thinking Michel. My extremely hard working 10 x 18 has a lot more slop in the half nuts than when I last checked them 20 + years ago, so I guess it must be time to do it again ;) It's all fully adjustable, quite a good design. Like a lot of slop and wear in lathes, you tend to get so used to it you simply compensate for it over the years. Cheers Rob
The information from this video, in conjunction with how to take the slop out of the lead screw from another one of your videos (the one where you broke the gear), turns this into a very effective Carriage lock.
Well bugger me. All that effort to fit a ways lock and that is all I needed to do on my baby lathe...my proper lathe is a different story of course. Cheers Rob!
I don't know, dealing with backlash on by "locking" the half nut on the lead screw doesn't sound ideal. Nor is it as "precise" as you can't lock between threads.
Not quite "locked" is it? Prevented from accidentally moving it by the operator, yes. When I want a carriage lock, I want it locked to less than a 0.01mm, not to the total backlash of leadscrew bearings and halfnut clearance....
Seig use the same generic design which is shared across most machinery manufacturers in China. It's the same system for all other common lathe designs. Cheers Rob
mate i wish you where local to me ... i have a little brass machined part thats broken thats on my oxygen machines that fills my medical oxygen tanks and they want 600 bucks for a replacement for it LOL ... would be a great little piece as a test project
why does he have to be local? if you can take some pictures and measurements, he could make it for you (if he wants to do that kind of thing) and mail it to you
this doesn't do the same as locking down the ways, lockdown is to help rigidity, and a leadscrew (maybe unless a ballscrew) won't do that, it does not "work perfectly"
Seriously, dude? That carriage is not "totally locked", it wiggles all around the play of the half nut. Which is _completely_ useless. It will neither increase precision nor help in any way against chatter.
That doesn't work still has more than a little flex for facing cuts! Good try though most of us had already tried that 1 .. lol. . I feel like your getting paid to boost this product!?!? This lathe is obviously just like harbor freight 7x12 besides cam lock on tailstock
It's a good little lathe. I don't have to do any follow up videos on it. So butt out. Try doing some RU-vid yourself instead of whining on about my stuff. If you don't like it leave. Cheers Rob
@@Xynudu well, yes, you have to open the half nuts for manual. But you don’t want the lead screw revolving all the time, so you put it in neutral. I wouldn’t want a hand wheel on the lead screw either. Old British lathes had those, but they got rid of them.
I have one on the Sherline (that's all it has) and like it. Gives good control for fine feeding. I'm thinking of putting one on the Sumore as well. Do whatever floats your boat. Cheers Rob
@@Xynudu sure miniature lathes are simple, and can’t fit the gearing in. My Unimat 3 has a wheel mounted at the end of the lead screw too. But you don’t want to use the lead screw if you don’t have to because you wear it out, usually in the first third, near the spindle. That’s why most lathes either use a feed rod, or use a lead screw with a mechanism for auto feed, other than for threading. But you know this.
Hi Mel, that's why leadscew covers are so good. I have them on my 10 x 18 and after 20+ years hard use (including lots of grinding) there is no wear on the leadscrew or bleeding from the half nuts. Basically grease and forget, as it is 100% shielded. I use a special Loctite grease for low speed shafts on it. Cheers Rob
