[mark c]

Hello all
Newbie here. I've been involved in CNC for many years, running set up and programming and now want to get one for a home shop. Was looking at the Harbor Freight 8 x 12. Would this be a good one to add cnc to? I have no designs that it will be like anything I have at work ( huge horsepower, 31" swing, live tooling, C and Y axis capabilities) but want something that has a little power and rigidity. Will be cutting alum, probably no bigger than 5" dia, using Fanuc style canned cycles.
Next, has anyone done this to this lathe? I'm new to this aspect and want it to turn out "right". I've seen posts about some aspects, but haven't seen a "Adding CNC to mini-lathe for dummies". I'm sure the info is here but need a push in the right direction.

Thank you all in advance

Mark
:cheers:

[mark c]

Anybody??????

[cbcnc]

Mark,

I guess lathes aren't as popular as mills and routers are. I would love to have one but don't.
The only thing I know of that comes close to a "how to" for mini lathes is on the DAK Engineering site. Otherwise the home of TurboCNC.
Here is Dave's address and the article on converting the lathe:
http://www.dakeng.com/lathe.html

Chris

[mark c]

Thank you
I'll check it out

Mark

[CNCPlastic]

I think industrialhobbies.com converted one recently, you might check with Aaron over there.

[mark c]

Cool
Thanks

Mark
:cheers:

[gdl357]

I found this, for ideas.

http://home.netcom.com/~madynmetal/U...20steppers.htm

[mineralman]

Just getting caught up on my reading. Mark, have you looked at the Lathemaster 8x14 to CNC (www.lathemaster.com)? You mention you want something solid and rigid, and this one is truely head and shoulders above the 7x12 or 8x12 lathes (no affiliation, blah, blah, blah. Just a very satisfied owner of one.) I used to own a 7x12 but recently sold it.

This is not totally altruistic, as I'm contemplating CNCing mine, and would surely like someone else in the same boat so to speak.

Larry
New Orleans

[RotarySMP]

My feeling (having converted a 7x12) is that you should get the biggest, least featured, cheapest, most rigid lathe you can.

Most of the discussion of the various flavours of 9x and 8x lathes centers around the half-norton gearbox, wobbly compound, cross slide feed slot burrs, change wheels etc.

When you do a CNC conversion, all this stuff ends up at the tip (actually collecting dust in a box under the bench

There are a few really stripped down models of 9x out there, and that would be what I would go for. Aim for one with a t slotted cross slide. From what hve gathered all the chinese 8x and 9x lathes are decendants of the Austrian Emco's which were 7x lathes. The 9X has quite a tall headstock and is thus less rigid.

Toss the single phase chinese motor and put on a treadmill motor and controller or three phase and VFD on the spindle.

Toss the leadscrew and mount a ball screw. Toss the apron and hang the ball nut on a plate.

Toss the compound, make up a ball screw drive for the cross slide. Mount a Phase II AXA to a plynthe. Build an enclosure. Add an spindle encoder. Run TurboCNC on an old Pentium or celeron, will be up and running.

It was just a shame I don't have space for a 9x lathe, as I end up torturing the 7x12.

[mark c]

Thanks for the ideas guys. I'm going to buy something, but not as soon as I'd thought. Probably not for a month or so. I'm still reworking my micro-mill. Lots more work than I'd thought it would be.
I'll probably go for the Lathemaster 8 x 12. I want something that's strong as well as "ready to go" as far as slop and squareness goes. I do plan on using TurboCNC, if only thats what I'm familiar with. Would like to run a different motor and encoder too. Just not sure how to do all this. Will be asking lots more questions in the future.
Larry, we'll collaborate for sure here. Nice to have parallel effort in a learning process. Let me know if you start anything.

Thanks again guys :cheers:
Mark
[email protected]

[RotarySMP]

For an encoder, turbocnc is only looking for a one pre rev pulse, so there are some really simple ways to get it. I used Dave K's circuit and an optical gate, but even easier are the optical gates with the driver and schmitt built into them. Then you just need to supply 5V, gnd and a signal out pin.

[balsaman]

Thanks for the ideas guys. I'm going to buy something, but not as soon as I'd thought. Probably not for a month or so. I'm still reworking my micro-mill. Lots more work than I'd thought it would be.
I'll probably go for the Lathemaster 8 x 12. I want something that's strong as well as "ready to go" as far as slop and squareness goes. I do plan on using TurboCNC, if only thats what I'm familiar with. Would like to run a different motor and encoder too. Just not sure how to do all this. Will be asking lots more questions in the future.
Larry, we'll collaborate for sure here. Nice to have parallel effort in a learning process. Let me know if you start anything.

Thanks again guys :cheers:
Mark
[email protected]

It's good to know that the Lathemaster 8x14 is the same as the Harbor freight 8x12. I own the HF version, and reviewed it here:http://www.cnczone.com/modules.php?n...rticle&artid=6

Up to today I thought the Lathemaster was 2" longer, but today I took my chuck off and installed the #3 morse taper dead center in the spindle, and it measured 14" center to center, so the HF version is also 8x14.

The lathemaster comes with more accessories. It's also $200 more. It's never in stock.

Eric

[mineralman]

You know, I think you're right. I downloaded the HF 8x12 manual, and in looking through it, many of the pictures and directions are identical to the Lathemaster 8x14 and its manual. The gearbox/banjo and gearing, motor, pulleys, etc. are identical.

This is great. Now we've got two sources of accessories, but having bought from both sources, the Lathemaster items are superior to HF stuff. I've been singing the praises of this machine since I first saw one at Lathemaster's two years ago. Now having owned both a 7x12 and a 8x14, I prefer the 8x14 as it is far more rigid, and should make a great CNC platform.

I contacted Industrial Hobbies regarding CNC of this machine. He wrote back he'd done a 9x20 recently, and wasn't familiar with the 8x14. Depending on the precision/accuracy needed, you could probably save some money and use the OEM leadscrew on the 8x12/14. Mine has no discernable play on it.

BTW, I occasionally visit three HF stores in the gulf coast area and have never seen an 8x12. There's always a 7x10, a 9x20 and a 13x36 on display. Your review said it was delivered. I don't think HF stocks these either.

Larry
New Orleans

[balsaman]

They don't stock the 8x12 at the FH stores. They stock it at the warehouse and it's delivered free. I bought mine on sale for $439.00. I see now they are $499.00 again.

Eric

[eferg]

I just posted this in another thread - looks like this is a better place for my post...

Hi,

I'm new to this forum. Some background: I have a Grizzly 7x12 mini-lathe and a Lathemaster 8x14 with 5C collet chuck (I'm in the process of converting the 8x14 to a treadmill motor and DC speed controller). I also have a 4 axis Taig CNC mill and homemade controller box based on Gecko drives.

I want a benchtop CNC lathe to make steel parts 1.5" max diameter, 1" max length. No drilling or threading - just face, turn, bore and profiling of the OD. So, I don't need a large lathe, but final finish of the part is somewhat important.

The Lathemaster 8x14 (same basic design as Harbor Freight 8x14) seems to be a good candidate for conversion. I'm impressed with its mass, smooth solid operation, and lack of slop in the moving surfaces. Its not that much more expensive than the 7x12 minilathes, but it works straight out of the box with no adjustments or modifications required.

I see two options to CNC this lathe ( I also want to retain manual control)

1. Remove the topslide (compound slide) entirely. Add a tooing plate. Mount a stepper in front of the crosslide dial. Add a leadscrew and nut below the carrage apron and drive it with a stepper bolted to the right end of the bed. Another possibility is to convert to ballscrews since the stock crosslide does have 0.004" backlash.

Advantages: Uses many existing lathe components. Should be an easy and low cost conversion.

Disadvantages: Backlash in stock crosslide screw/nut. Manual operation may be impractical due to motor location.

2. Second idea: Slide the carrage all the way to the right and don't use it for CNC - just for manual operation. Build a base for a pair of CNC slides using a spare tailstock mounting base. The 8x14 has a large base on the tailstock - mill it flat and you now have a rigid platform that can be bolted to the bed and easily removed. Bolt two steppermotor ballscrew slides to this base and add a tooling plate to the top.

Advantages: No alterations to the lathe. Easily switch back and forth from manual to CNC operation. Increased accuracy due to precision ballscrew slides.

Disadvantages: Limited axis travel compared to option #1 (OK for my application). More costly design. Available slides may be too tall to fit under spindle centerline.

Any comments, suggestions on either idea? Would Nema 23 steppers (say 210 oz) have enough force for my application? (0.010" cuts in steel). Would precision slides of the size required handle the forces needed to take light cuts in steel?

Stevie - where can I find details and photos of your lathe project?

Regards,
Ed

[mark c]

Check this out:
http://www.stirlingsteele.com/latheplans.html
I'm most of the way modifyiny my 7 X 12 using these plans. They're well thought out

Mark

[mineralman]

Keep us posted. I am very interested in how you do the cnc on the 8x14. I haven't gotten around to doing anything yet--- I'm making too many chips manually with my lathe and X3.

Larry