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

“that carriage is totally locked!” i gotta say that the 1/8” visible slop when you move the handle doesn’t really make it seem like its totally locked

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.

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.

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

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 .

I love the detail that you cover this lathe Rob.

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.

Your channel is fantastic, thankyou very much.

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.

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.

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...

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

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.

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 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.

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

Hi Rob, That looks like it will work well... Well done for sharing... Cheers Paul,,

Great idea man!! I was thinking about making on for my new machine!

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

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

Genius - I’ll give this a go tonight. Thanks Rob. Watched both your Sumore videos today, can’t wait for the next one!

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

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.

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.

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.

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.

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.

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.

Good idea. Looks like there's still a bit of movement but good enough to keep the carriage in one place.

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.

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.

Another tip top video .!!!

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.

Been a year or more and I'm just checking to see if there have been any issues of concern

Hi, Not locked it will still move about 1mm (no good when parting off).

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

Where can I buy one of these

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!

Can you provide a link where I can buy one in Australia. I can't find any online at all.

Good tip. But that would drive me bonkers.

G'day Rob I see you are thinking outside of the box again. The carriage is locked.

Nice lathe how much do they sell for, what's the biggest diameter of stock you can do?

Did you discuss how large a part can be lathed ..limits ?

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.

Rob, Do they sell a 4 jaw chuck to suit?

How do you turn a concave surface on end of stock with this lathe?

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.

Nice one chief. Keep it simple. I noticed your mini lathe has a lead screw thread dial. Did it come with it?

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.

That’s not a rigid carriage lock, there’s too much slop in the carriage hand wheel to lead screw thread.

It looks awfully like my Sieg lathe purchased years ago..

Clearly thats not locked. A lock is suppose to add rigidity.

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

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....

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’s not a carriage lock…

It is not the best method of locking the carriage for parting off duties.

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

That’s a horrible, and really sloppy carriage lock. You have a neutral so that you can move the carriage manually, not for a carriage lock.