Mini lathe buy, question on options

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arcwick08

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Oct 12, 2011
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Hey team,

I'm about to pull the trigger on a mini metal lathe, mostly for use making odd fittings for tractors, pen parts, etc. One of those big "etcs" would be making 1.24x8TPI threaded faceplates and the like for my big wood lathe.

First - I know all the LMS lathes can cut 8tpi, let's put them aside for a moment (mainly due to $200 shipping).

Looking at the Harbor Freight 7x12 (PN 93799 I think), and a few of Grizzly's smaller machines, none of them appear to be able to cut that thread (12TPI is the lowest)

The big question: Can the cheap 7x12 lathes (HF, grizzly 8688) be adapted to cut that larger thread in some way? Rather, I know they COULD be, but the question is really, could this be done easily? Are there folks selling after-market change gears to get down to that threading? Some other bit of gearing wizardry?

Thanks in advance!
 
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magpens

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I have the mini-lathe you are talking about, namely, the equivalent of the Grizzly or Harbor Freight.

It came with a set of change gears supplied.

Doing a quick calculation, I should be able to get 7.91 TPI out of it. Is that good enuf? That's out by 1.125 %

If you have a copy of the User Manual, I can tell you precisely which gears to use where.

Might be able to get closer to 8 TPI if I try harder.

If the LMS lathes can do 8 TPI, I am quite sure this one can, but might have to buy a gear or two from LMS.
 
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arcwick08

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Reading up, it appears that maybe these manufactured simply don't publish the full range of what their machines can thread? As magpens said, LMS claims that their mini lathe is virtually identical to the most other 7x12 mini lathes (the grizzly and HF), with parts being interchangeable, and their lathe can do 8TPI.

I'm going to pull the trigger on the HF 7x12... I know a local machine shop that could make me a specialty gear if need be. And if worst comes, I've got a local HF that I can return it to (rather than trying to return to Grizzly or other mail-order).
 

jalbert

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I fudged around with the gears on my grizzly 7x12 and got it to cut a little under an 8tpi thread. I'm having problems with the leadscrew getting thrown out of gear though, so I don't know if this is a great idea. Maybe it wasn't designed to cut any coarser than a 12tpi thread? When I bought my grizzly, I wasn't thinking about threading though because I assumed that I would just be sticking with taps and dies. In retrospect I wish I had just saved another $300 and bought a HiTorque since they can cut as coarse as 4tpi, however like you, the crazy high shipping charge from littlemachineshop would probably have prevented me from buying one anyway.
 

arcwick08

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Jalbert - the shipping cost from LMS is what put me onto the HF in the first place.

Update: I've got the HF 7x12! Hurrah! Had it a week or two now. Over all, it's fine for what it is. And it's just what it is. I used the 20% coupin, whole thing cost About $500. Another $100 in bits and parts on top too.

I've made a few things (couple rings, bushings) and it works pretty well for those items. However, I already have some buyers remorse. I wish I'd saved my pennies and gone for one of the larger 10x22 machines from Grizzly (or maybe the big hitourqe from lms).

Three complaints about the HF;

Power: I can stall it without trying, in even small drilling or truing operations.
Stability: It's just not a big machine. No matter how close I get the gibs, it's got enough vibration that (coupled with a lack of power) it just doesn't preform well.
Tailstock: Very disappointed here. When tightening it down, it must be manually aligned with the headstock using one hand, and tightened with the other. It will not self-square against the bed ways. This makes drilling an utter PITA.

I've done some machine work in the past (under the supervision of a pro), so I like to think that the above are not COMPLETELY due to my ineptitude. Still disappointed.

Let my story serve as a warning to others! I think that unless you ONLY want to turn VERY small items, these mini lathes may be slightly too mini.

I'll continue to use the HF for some tiny (tiny. tiny.) parts here and there, but I'm already starting to save my pennies for a larger mini/midi lathe. If anybody is interested in a HF 7x12 with some tooling, let me know and we'll make a deal :0/ (I'm in Western NC)
 

KBs Pensnmore

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I have 7 X 12 also, I didn't buy it, but had it given to me by my brother. I'm on my third motor, about 8 belts, 6 motor pulleys,4 driven pulleys.
It performs well, when it's running, and only taking a few thou cuts.
The headstock is not lined up with the V ways, the tailstock is out of line, the saddle dovetails are tapered by about 15 thou. Motor is almost impossible to get square, the belt drive is hard to keep tight, always moving out of alignment.
I also have the X2 Mini Mill, don't get me started on that one, but have spent as much in replacement parts as purchase costs. :mad:
Kryn
 

arcwick08

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I'm glad I'm not the only one with some issues on this machine. I think I'll be craigslisting this guy in the near future. Bummer :-(
 

jalbert

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Additionally, the variable speed potentiometer stopped working on my grizzly, so I am waiting on a replacement pot to arrive, which hopefully will get it working again. I can't say I'm terribly impressed with the grizzly after owning it for only 4 months.
 

mecompco

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Looks like it's almost better to look for an older used lathe than buy a cheap Chinese one. Granted, my late '40's/Early 50's era Craftsman 10x36 has some issues, but it does work pretty well. The half-horse motor (amazing how much bigger half-horse on this is compared to my HF wood lathe with a "half horse" motor) easily spins up the 20 lb. 4 jaw chuck and has never stalled, even when turning/drilling steel. I can get within a thou or two turning steel--some of which is due to lathe wear/tuning and some of which I'm sure is due to my skills (or lack thereof).

I'm sure a later model Craftsman or even better South Bend would be an even better choice--probably for around the same price as the new Chinese lathe.

Regards,
Michael
 
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