New 7x14 Mini Lathe Headstock Tear Down & Rebuild with Angular Contact Bearings 

I thank the universe for Aussies like you. Just took apart my headstock. Holy crap. It had enough metal debris to build a new lathe.

"De-burred with a brick." Love it :)

You've given me inspiration to upgrade my lathe. Good on ya mate!

Thanks again for documenting. I have one of these fine engineering marvels and the first thing I did was re cut the register. Dramatically improved run out. Fine work on everything. I have some tapered bearings for mine, but I think you have convinced me to go with the angular bearings.

you made my day.

I have been watching your series. Looks like they picked their best quality lathe to send to you. 🤣

I actually started laughing when that second lock nut went on.

I think you made the correct choice with the bearings. They can take higher rpm, they are sealed and they are direct fit vs the tapered rollers. The stiffness is not necessarily that important, even the shaft itself being that thin springs to a slight banana shape long before the preloaded bearings feel a thing. The machine is anyway only as rigid as the least rigid spot, which is far from the bearings in this case.

Thank you for this series, a ton of ideas for fixing the Chinese Mini Lathe.

Great series Trevor, with the angular contact bearings you should have explained which way they go in. As you said, they should be opposed, you need to point out hiw to identify which way. "THIN GOES IN" refers to the thickbess of the inner race.

"Deburred with a brick" lol. Great progress Trevor, keep it up!

I've been binge watching your series because i just got my mini lathe. Great videos! And thanks for the effort :D I just learned a lot. But i think i won't do everything you did, but i will try to get my lathe work more or less correctly.

Thanks for making this series, looking forward to the next ep. Some thoughts on the headstock: Replace that plastic spacer with a metal one ASAP, it (and the wobbly nut) is carrying the preload now, not just locating the gears. The plastic will creep losing the preload which is necessary to keep the balls from skidding. If you're ambitious, and since you don't have gears in the headstock you could even put spacers between the bearings, equal length, for both inner and outer races.

Nice assembly vid. What you need next is a #3 morse taper test bar to check the head stock alignment to the ways. Mine needed shims to get alignment correct. Thanks

Nice work

Actually, the run-out you measured is very good for a three-jaw chuck, especially a Chinese one. Don't mess with it...

Hi Dedicated watcher,keep em coming.

Hi nice to see how you rebuild a precision head stock spindle. Just here to see your approach. Lance & Patrick.

A really great Series, Thank You so much. I am afraid I don't have your patience and tenacity to go to those lengths for perfection, I have fixed many of the common problems and I get decent results from something that arrived as a piece of rubbish at £599. It is an 8 x 14 Chinese "Seconds" reject tarted up and sold on e-bay with no support etc. etc. But she makes the parts I want to make. A 4-jaw independent chuck replaced the 3-jaw rubbish it came with. Still struggling with cross-slide backlash and nuts that won't adjust decently. But we survive. :-D Thanks again for all the great videos mate!

That lock nut is something else....... Made for a pre-bent shaft maybe? Thanks for a great video.

Thank you for the video. Cld be a strange sequence but I have just finished CNCing this lathe. Concurrent with learning to turn a drawing into G-code Iwill follow your lead with the tuning/mods

Dude kick ass accent. Ausi I gather. Good vid bro.

much easier bearing install, put shaft in the freezer for an hour, doing field service we use dry ice

Don't know why, but RU-vid "unsubscribed" me from your channel! Removed all of my videos because of some of the changes RU-vid has been making, but did upload some new ones and a revised old one. Don't trust RU-vid anymore. As for your channel, can't thank you enough for recording, editing and sharing the knowledge. The lathe series is my favorite. Cheers m8

great job!

It would be harder to machine that wonky locknut than machine a true one LOL

Nice job 🤜🤛 Watching in Alabama

Hi Aussie, remember always to "preload" the dial gauge on the surface, so you are sure it doesn't read 0 for some measurements.. just a tip, thinking you already doing it

Pissed myself laughing when i saw your "wonky" locknut Trev, i thought you had knocked off mine till i realised you only had one buggered unit...........I got two. Great vids mate, keep em coming.

18:00 このロックナットの歪みは、小型旋盤の標準仕様のようですね This locknut distortion seems to be the standard specification for small lathes.

If you watch the removal of the second lock nut of the spindle it was cross threaded that’s why the threads were bugged

A dial test indicator is better than a drop gauge.

any practical ideas on sealing the head stock for oil lubrication?

Great video series. Without a hi/low it looks like actual seals could have replaced the plastic shields and allowed a taper bearing install. My King Canada lathe has the Hi/Low so its not an option and I'm starting the install of the same annular bearings.

"They just can't help themselves. Everything is just shit" - great summary of the SIEG mini-lathe. I'm also the sort of idiot to try and fix it up. :)

Your choice of bearing geometry is right. However, I would go with a nicer brand though. My favorite brand is Nachi but for this case, I've purchased NTNs which provide precision tolerances close to SKF high precision series at a budget price. Those Japanese are just like that you know... I do not think that your bearings will fail soon though.

Not sure if Im a glutton for punishment but I am enjoying this series. If only to see what issues you find and how you fix them. I was thinking about a chinese lathe but after watching you and quite a few others with these on youtube Im starting to feel as I did when I found out all the side effects of the cancer treatment I had (run screaming out the door rapidly). Perhaps in my case spend a few more shekels for a better quality unit. That said you have some great workarounds and fixs for the many short commings these units have. Any way you are hilarious and informative possibly a down under version of AVE. And with that its your shout. Cheers Bloody hell Im finally first...

Do you think that one day we'll say "aah, they don't make them like that anymore!" that's some real effing craftsmanship eh?

Congratulations you did an excellent job. I have a question: Before painting the headstock did you remove the old color first? Did you apply primer?

Would it be worth while making a new main shaft to fit a bigger 3 jaw and larger hole through the centre? Something I’ve been thinking about doing with my metal master

Greetings from Canada - I'm just trying to source the main shaft bearings and my local supplier says there is no such thing as a 30X62X16 double sealed Tapered Bearing. I checked our the eBay link provided and it shows what you used (the bearing with the blue seals) Can you confirm to me that the bearing you got was the one in the eBay link. Thanks for your assist. All you other techniques have worked like a hot-damn! I expecting the lathe to perform much better than the OEM delivered product - in fact, yours had more severe issues than mine did but I did have all the same issues, just a few less severs.

What is the spec’s on the replacement bearing you used?

hope you can tell me what belt that is and where u got it

Did you ever video the results cutting material after the bearings were replaced? Mine without any pressure on the chuck looks great on the dial indicator, but when I apply pressure to the tooling you can see the chatter. Have any video showing the improvement cutting?

Great video! I found this super useful to guide me in making my own lathe. (I cant do worse than the chinese)

My mind was already blown by the paint on the spindle... But holy crap, that crooked-ass locknut! 😂 Man, quality sure has gone downhill since I got my 7x10 back in 2010. It even had properly finished parts, like it was made by people who gave a damn! (Imagine that!)

How are the AC bearings holding up since you installed them?

Better with the motor on😀😀😀

Looks like that second lock nut you took off the back of the spindle was extremely out of square on the thread. (I see you pointed it out on the way back on ) :) I have noticed your chuck backing plate Is part of the spindle. What kind of weird arsed design is that? How can you mount a 4 jaw chuck for example unless it is exactly the same size on the register? Maybe you bore the back of the chuck out or make a backing plate for the backing plate. Interesting video, thanks for making it 🤠

Hi, I watched all the chineeese mini lathe video and you are brillant! Much more than me lol. I don’t know how to level the headstock ( same bad level at the back, exactly like yours) . Can you tell me How to fix this problem? Thanks in advance, Louise.

18:20 It's a feature!

Isn't that just the bore rather than taper?

Watching your series (great information). Got to ask (given the level of quality of casting and machining from the factory -) are you sure that the center bore of your lathe is parallel to the bed (ie , a dip or buildup of a 1/10000 on a corner[s] of the bottom of your headstock would easily account for run out over the length given after the bearing swap)? Should add I've already watched the whole series (just re-re-rewatching interesting ones)!

You could replace the black ring that is bent !!!

Since all the improvements, how well is the lathe working? Cheers

Nice work. I have 1 mini lathe also and following your instruction to improve it. Could you advise me about bearing number? Because I didn't see it clearly. Many thanks!

Is that blue loctite or some type of anti-seize? OMG that's paint...

Any improvement in rigidity with the new bearings?

Where can you find bearings if you want to buy them for your lathe? I have a china lathe a bit different than this. Can I just measure the axle and the races and order something? Where?

Mate! Are you sure that that bearing nut is not used as a cam for the oil pump?lol

Enjoying your videos was wondering if your head was out of alignment? Mine giving me a taper when tunring

What did you use to put the bearings? Press? Hammer?

I think they painted the shaft to bring the tolerances back to spec. because their lousy machinists took too much off. :)

My question to you and everyone else is just exactly how do you conduct a pre-load. There is no spec’s on these Chinese mini lathes. So theres no torque specs.

I don't buy nails from the Chinese anymore

paint n smash on parts ,,,ancestry suggests this started when the makers started not to give two shits ,exact date is locked in a safe in the ccp main headquarters ,i have a new lathe like yours still boxed ....glad i bought all the accessories the basic is not good ,,,bit miffed the cam lock was not on the tailstock the pic said it was there,ebay meh....

You are talking in German.... Scheisse , dis ding..... :-)

Sorry but the lathe you got was worse case junk. But at least you know how to fix it glad mine was not this bad. You can get better chucks from China.

Please use microns also........there are many hundred thousands of them on everywhere.....even in inches....?! Lol !