Thoughts on Mini-Lathes

[verbotenwhisky]

I'd add to your list:
Unless you have actual hands-on experience with a Chinese 7x 'mini-lathe', it's probably best not to comment extensively.
I often see people who have never been within miles of a 7x, pontificating online about how bad they are, suggesting inappropriate 'improvements' and alternatives.
My recommendation would be to direct questioners to one of the 'dedicated' 7x lathe sites - the FB 7x group or the groups.io 7x12 group if FB isn't palatable.

I've never owned a 7x lathe, but I slept at a Holiday Inn Express once.... I ruled one of these out after trying a friend's machine. You have to also understand that for a time I was using a drill press as a mill so I understood the work envelope issues well. To be honest I didn't find anything wrong or surprising about his, it was what I was expecting. I watched Quinn a BlondieHacks with the PM1022 and one or 2 others, listened to what they had to say both good and bad, and really didn't see any great issues with the machine and even debated buying the PM1030 which is a longer version of the PM1022. So I do not understand why others are so insulting to these, for me it was about wanting an AC motor and a large work envelope to match what I could handle on my mill. If one buys an economy car then complains because it cannot haul 1000 pound load I do not believe the economy car is the issue. Its much like buying a Chinese machine for half the price of an American machine then expecting the quality of the higher priced machine, without doing anything to it...... Its about expectations and they need to be realistic.

 

[SouthernChap]

i would not know what to classify it as if not a mini? to me anything < 400lb is a mini.
i would agree with the size (or rather the price) makes a difference with the QC, not that this is a high quality lathe, and out of the box a lot needs to be addressed to make good parts.
the construction is just a scaled up 7X with more power and not much more width in the carriage.
the QC is better than i expected but not in the same zip code as a PM or Grizzly.
I like the additional features like the 1100W Brushless motor, and the 1.5 spindle bore as well as the front mounted gearbox (it is much nicer to just flip a lever on the front to increase/decrease the feed rate as well as the feed direction)
IMO it is missing 2 things 1. rigidity and 2. a power cross feed, but I'm working on adding those.

I'd reckon it's probably got more basic rigidity (i.e. leaving aside that ridiculous aluminium compound ) than the 7x machine.

In my mind, a mini-lathe is a 7x machine marked by a notable lack of rigidity and significant limitations thst really have to be worked round.

9x, 10x and11x lathes are to me, benchtop machines that are normally a bit more rigid and often a bit better specified (8x being a weird hinterland of machines of very varying characteristics).

That said, the ML7 is a 7" swing machine (3.5" in English terms) but has a 20" between centres capacity and whilst not without limitations, can comfortably machine most types of steel, so eh...what do I know.

 

[SouthernChap]

I've never owned a 7x lathe, but I slept at a Holiday Inn Express once.... I ruled one of these out after trying a friend's machine. You have to also understand that for a time I was using a drill press as a mill so I understood the work envelope issues well. To be honest I didn't find anything wrong or surprising about his, it was what I was expecting. I watched Quinn a BlondieHacks with the PM1022 and one or 2 others, listened to what they had to say both good and bad, and really didn't see any great issues with the machine and even debated buying the PM1030 which is a longer version of the PM1022. So I do not understand why others are so insulting to these, for me it was about wanting an AC motor and a large work envelope to match what I could handle on my mill. If one buys an economy car then complains because it cannot haul 1000 pound load I do not believe the economy car is the issue. Its much like buying a Chinese machine for half the price of an American machine then expecting the quality of the higher priced machine, without doing anything to it...... Its about expectations and they need to be realistic.

I really think we do have to make a dividing line between the 7x lathes and the larger, but still benchtop, machines.

There seems to be a significant uptick in capability, once you go beyond a 7" swing in the Chinese machines.

 

[SouthernChap]

Those with a 7x know well enough both the limitations and potential of such "small" machines.

And that's why those people who have used the 7x Chinese mini-lathes and worked on them to get them to a useful level could be such a helpful resource to those thinking of buying such a lathe.

 

[Aaron_W]

I'd reckon it's probably got more basic rigidity (i.e. leaving aside that ridiculous aluminium compound ) than the 7x machine.

In my mind, a mini-lathe is a 7x machine marked by a notable lack of rigidity and significant limitations thst really have to be worked round.

9x, 10x and11x lathes are to me, benchtop machines that are normally a bit more rigid and often a bit better specified (8x being a weird hinterland of machines of very varying characteristics).

That said, the ML7 is a 7" swing machine (3.5" in English terms) but has a 20" between centres capacity and whilst not without limitations, can comfortably machine most types of steel, so eh...what do I know.

Yeah to me a mini is basically a table top lathe. Something the owner can store out of the way when not being used if desired, so weighing at most maybe 150lbs. Due to weight many of the 8" lathes don't really fit this, and although they have a similar swing the Atlas / Craftsman 6x18", Myford 7 etc don't really fit the mini title either due to their weight and arrangement (separate rear mounted motor) making them more practical for at least semi-permanent mounting on a bench.

Small lathes that don't fit my mini definition are just small bench top lathes.

 

[GrifterGuru]

And that's why those people who have used the 7x Chinese mini-lathes and worked on them to get them to a useful level could be such a helpful resource to those thinking of buying such a lathe.

True enough.

I have had some trials and fun with mine and know well the "weak" points of the thing quite well. One of them being the need to fit a "extended travel" cross slide. Something I looked at and came to a hybrid solution of my own that gives a greater travel than the offered E/T kit though that is on the lathe I am rebuilding, not my SC3.

At present, I have to pull the spindle to replace the bearings on my SC3 (tackling that tomorrow hopefully), but other than that, I have found it plenty capable of machining 6061 & 6082 aluminium, cast iron, varying types of mild steel as well as 316 stainless.

Adding the fourth headstock bolt on my SC3 improved things a fair bit too. Not sure if it was a factory oversight or not, but it was only affixed with three bolts.

 

[Aaron_W]

Adding the fourth headstock bolt improved things a fair bit too. Not sure if it was a factory oversight or not, but it was only affixed with three bolts.

So many of the small import lathe issues seem to be tied to being ultra cheap. A very common improvement to the 9x20" and 10x22" lathes is adding 2 more bolts to the compound. From the factory they only have 2 bolts holding them down which allows a lot of flex. Drilling and tapping two additional holes for a total of 4 hold down bolts adds a great deal of rigidity. Doesn't seem like a huge expense but I guess the cost of 50,000 additional bolts adds up to real money.

 

[GrifterGuru]

So many of the small import lathe issues seem to be tied to being ultra cheap. A very common improvement to the 9x20" and 10x22" lathes is adding 2 more bolts to the compound. From the factory they only have 2 bolts holding them down which allows a lot of flex. Drilling and tapping two additional holes for a total of 4 hold down bolts adds a great deal of rigidity. Doesn't seem like a huge expense but I guess the cost of 50,000 additional bolts adds up to real money.

Same is done on the 7x lathes. Two more gib screws on the compound, four more gib screws on the cross slide as well as adding pins at either end of the cross slide gibs, once the bananna gibs are swapped for brass gibs.

Throw in a new split / adjustable cross slide screw nut for better lash control whilst you are at it and an improvement can be felt.

Oh and don't forget the bearings mod for the cross & comp feed screws and the pocket mod for the coumpound rest and a few of the "issues" disappear. oh and probably best to fit those Angular contact bearings to the headstock whilst you are messing with bearings.

Then there are the "fine feed" gears to be added to the change-gear train. An extra pair of gears tro slow down the lead screw for slower carriage speed and better material finish.

Maybe you should swap the compound for a riser block for better ridigidity, but then maybe thats a step too far....

 

[Garage Dog]

I'll add my .02. I bought my 7 x 14 from LMS and I'm very pleased with it. It's my first lathe and I knew very well what to expect from watching all the Y/T videos. Yes, they need work to get them to perform better. I contemplated buying an old Craftsman or SB but the reason I went with the 7x14 was due to the availability of all sorts of parts and accessories available with just a click. I didn't want to spend time trying to find parts for a 50 year old lathe at a premium price. Also the mini Lathe fit my mini budget. I like to boat, fish, and kayak too and that eats up disposable income as well and I'm not about to give any of that up.

Anyway, I'm quite happy with my choice. It has taught me what is important to make a lathe work properly through a lot of trial and error. It has also taught me how to work around problems. Yeah, it doesn't like 1018 to much but it will turn it, just have to take shallow cuts but that's ok with me. It turns 6061 and brass beautifully.

Oh, LMS is great to deal with. I had an issue with the cross slide lead screw and I called them and I had a new one FREE of Charge in just a few days.

 

[455dan]

I bought a slightly damaged HF 7 x 10" and fixing a broken hand wheel used it quite a bit.
Then a 30 year old 12 x 24" Harbor Freight Taiwan lathe that needed some electrical work showed up on CL and I jumped on it.

A new HF 7" x 10" is only $300 less than the used gear head with quick change box was bought for.
Someday going to pull the gap piece out and actually try some of the 17" swing .

I barely ever use the 7 x 10" anymore, the difference in feel and rigidity is hard to overstate, but 87lb compared to ~900lb. makes the 1224 a much more enjoyable machine to operate. Even on small soft material parts I choose the larger machine. I will keep the 7x10 it is nice to have a back up that can still do some work.

ps. parting harder steels also makes clear why many prefer a 3K lb+ High end lathe.