I currently have a HF12x36 (33274) and a Grizzly 9x20 (G4000). I am reluctant to CNC the HF because of all the gear drive mechanisms involved. I am thinking about some of the same issues with regard to the Grizzly 9x20 the half gearbox. Additionally, since I may have to begin downsizing my shop I am thinking about selling both of the lathes that I currently own and replacing them with a smaller CNC lathe or possibly two.

It seems silly to buy an expensive lathe with a lot of features (like a gearbox) to CNC. So I am thinking about one or possibly two of the following lathes:

(1) Grizzly 7x12 (G8688)
(2) Microlux 7x14 (82710)
(3) HarborFreight 8x12 (44859)
(4) LatheMaster 8x14 (CQ6120x320)
(5) LatheMaster 9x30 (HD250x750)

Questions:

Other than the obvious concerns of weight, mass and price, which of numbers 1,2,3 and 4 would you choose and why?
Has anyone had the opportunity to do a firsthand physical comparison of both the HF8x12 and the LM8x14? What are the differences between them other than accessories?
If I bought #5 I believe that it would probably be in addition to one of the first four, so, would you keep one lathe manual and CNC one or would you CNC both?

Thanks,
Alan

Given that space is not a premium concern to you, I would not (again) CNC a 7x lathe.

Since you already have the 9x20 and they are cheap, just CNC that. The gearbox which you will put ina box in the corner of the garage is probably only worth about 80 Rinimbi.

Why sell the 12X lathe? You can never have a big enough lathe!

Mark,

We are looking at retirement and moving into a smaller place where space will be at a premium. Also we are looking at moving to a different city and the cost and hassle of moving a 1000 pound lathe is not cheap.

Alan

I am currently gathering parts for a 9 x 20 conversion to CNC. Your right about the gear train on the 9 x 20's - the questions stands "Could it be made any worse?"

However, through the CNC conversion, just about everything will be gone from my machine. The bed, carriage, cross slide, headstock, and tail stock will be kept, the rest will be made into a boat anchor.

I already have mine converted to a DC spindle drive. I will be using Gecko 320s, Servos, and ball screws for motion. So, as you can see, not much left of the original machine.

Chris

What about a model similar to the Grizzly G0516? It is the model I have been thinking about as a first lathe.

Robert

Robert,

Positives:
I like some of the specs on it (9.75 swing, 21" between centers on the lathe). It comes with 5" 3-jaw and 4-jaw chucks).

Negatives:
I have not heard many positive things about 3 in 1 machines in general.
It seems to have the same poor design on the compound mount as the 9x20.
The mill at the back seems to make that addition of a DRO more difficult.
The fixed position of the mill head in relation to the lathe head makes it less useful as a 4-axis machine.
The size of the milling table attachment to the crossfeed is pretty small even in relation to the minimill.

Plus I already have a RF30 Mill-Drill and a HF Minimill (both R8).

Alan

What about a model similar to the Grizzly G0516? It is the model I have been thinking about as a first lathe.

Robert

Robert,

Positives:
I like some of the specs on it (9.75 swing, 21" between centers on the lathe). It comes with 5" 3-jaw and 4-jaw chucks).

Negatives:
I have not heard many positive things about 3 in 1 machines in general.
It seems to have the same poor design on the compound mount as the 9x20.
The mill at the back seems to make that addition of a DRO more difficult.
The fixed position of the mill head in relation to the lathe head makes it less useful as a 4-axis machine.
The size of the milling table attachment to the crossfeed is pretty small even in relation to the minimill.

Plus I already have a RF30 Mill-Drill and a HF Minimill (both R8).

Alan

Thanks for the response... A couple additional comments.

The mill head does not need to be attached and LMS sells a matching base/table to turn it into a X2 mill ($200).

LMS also has a replacement spindle if one would rather have R8 tooling ($50).

There are a few other places (PennTool) that offer a similar lathe without the mill head but the price is close to the same. Being you have a mill I see your point.

The larger swing and the extra chucks are a nice feature though.

I have been looking at that G0516 also. The leadscrew cover is one less thing to make that you really need on a CNC. Can you get a T-slotted cross slide for it? Get a three phase motor and a VFD and it would be sweet. Still not worth trading in the machines you have though.

Chris,

I have never been totally happy with the 9x20 in terms of quality of cut. (But until recently I hadn't been happy with my 12x36 or my mill. I spent some time tuning both of them and am now getting great finish cuts.)

So, maybe I need to spend some time tuning the 9x20 and see if I can improve the quality of its cuts and get rid of the chatter.

Alan

I am currently gathering parts for a 9 x 20 conversion to CNC. Your right about the gear train on the 9 x 20's - the questions stands "Could it be made any worse?"

However, through the CNC conversion, just about everything will be gone from my machine. The bed, carriage, cross slide, headstock, and tail stock will be kept, the rest will be made into a boat anchor.

I already have mine converted to a DC spindle drive. I will be using Gecko 320s, Servos, and ball screws for motion. So, as you can see, not much left of the original machine.

Chris

Mark,

I would not (again) CNC a 7x lathe.

I know that space was a big consideration for you in deciding upon a 7x lathe. However, within its size limitations, how do you feel about the performance of the cnc'd 7x lathe?

If the 7x lathe had a more powerful motor, would that solve a number of the issues? If so, would it be feasible to increase the power of a 7x lathe with a treadmill motor to increase its cutting power?

Would the 8x14 be enough larger to satisfy 90% of the reasons behind your statement about not CNC'ing a 7x again?

I know the feeling that "one can never have a big enough lathe", but I have done jobs that were actually less scary on a smaller lathe (turning very small parts up next to a big chuck).

Thanks,
Alan

I would keep the 9x20.
but for the record, the 7x12 I have is a great little lathe. I have been able to keep my work within .0005" if I pay attention to accuracy. Most of the stuff i do is not critical with measurements, so i dont bother with that. The motor on my Homier is labeled as 400w and 4/5HP. I can stop it with my hand at the lowest possible speed which i think is 30-40RPM. After 50 or so torque jumps up

Phantomcow2,

Two of the three people suggesting that I keep the 9x20 don't have one. I think the idea of the 9x20 may actually be more appealing than the fact of the machine.

I had basically considered and rejected the 9x20 as the CNC option for a variety of reasons. Most of the things I do are up close to the chuck; the 4-jaw that came with the G4000 is not something that I want to deal with for a CNC machine; the crossfeed support needs to be modified to even think about CNC; and I can probably sell the 9x20 configured as it is for almost enough to buy one of the smaller machines.

If I need a machine longer than 14", I may well need the 9x30. Most of the things that I have turned, that would have been too long for an 8x14, were too long for a 9x20 (hence the 12x36). There is no way that I can justify having both a 9x20 and a 9x30.

I have only seen one 9x20 configured for CNC and that in and of itself may say something (I am not sure what?).

I may reconsider keeping the 9x20, but what I want to find out if any of the other smaller options that I listed present a better option than the 9x20.

Alan

I would keep the 9x20.
but for the record, the 7x12 I have is a great little lathe. I have been able to keep my work within .0005" if I pay attention to accuracy. Most of the stuff i do is not critical with measurements, so i dont bother with that. The motor on my Homier is labeled as 400w and 4/5HP. I can stop it with my hand at the lowest possible speed which i think is 30-40RPM. After 50 or so torque jumps up

If you do small things, then i can highly recommend the mini lathe.
Overall its a good system, thick gib strips, functioning power feed with threading ability left and right hand. I dont think Sherlines or Taig lathes can thread without add ons.
The 7x12 I have has been sufficient most of the time for my needs. Only once have I neded one more inch, so you might be better off going with the 7x14. I plan to convert to CNC at some point.
Its understandable not wanting to turn small things on a large lathe, i do the same. At my school we have got a 13x48, i rarely use it and prefer my mini. So i think that will do if thats the route you want to take

Phantomcow2,

Thanks for that input, that is the kind of information that I am looking for.

Now if I could get Mark (RotarySMP) to tell a little about how he feels he has tortured his 7x CNC machine and the end results (good or bad), Balsaman to give some feedback on his HF 8x12 (14?) and CNCadmin to give some more feedback on his Lathemaster 8x14 this might become a useful thread for people, like me, thinking about which machine to CNC.

Has anyone cnc'd a MicroMark MicroLux 7x14? It supposedly has a slightly more powerful motor and the headstock is 1" longer than the other 7x10's and 7x12's, not to mention that it comes with a cam release tailstock. I wonder if that motor makes a significant difference in its cutting ability?

I would even appreciate "Chris D" commenting on his 9x20 CNC conversion when it's done.

Thanks to all who have contributed so far.

Alan

Phantomcow2,

Thanks for that input, that is the kind of information that I am looking for.

Now if I could get Mark (RotarySMP) to tell a little about how he feels he has tortured his 7x CNC machine and the end results (good or bad), Balsaman to give some feedback on his HF 8x12 (14?) and CNCadmin to give some more feedback on his Lathemaster 8x14 this might become a useful thread for people, like me, thinking about which machine to CNC.

Has anyone cnc'd a MicroMark MicroLux 7x14? It supposedly has a slightly more powerful motor and the headstock is 1" longer than the other 7x10's and 7x12's, not to mention that it comes with a cam release tailstock. I wonder if that motor makes a significant difference in its cutting ability?

I would even appreciate "Chris D" commenting on his 9x20 CNC conversion when it's done.

Thanks to all who have contributed so far.

Alan


Somtimes you just have to slap yourself on the forehead and say "wake up!". I completely forgot about this version of the 9 x 20 lathes that were converted to CNC. Emco Maier company of Austria, who were the original designers of the 9 x 20 lathes sells CNC versions!

I was consulting as a CNC instructor at a local company for about 6 years, we had 3 of them in the classroom - they are called PC Turn 50 machines.

It has been about 6 years since I have been there, but this much I remember....


It had a 6 station turret on it - very weak design - too heavy of a cut and the "Shot pin" would release and allow the turret to rotate.

The cut quality was pretty good in aluminum - keep in mind, these are Austrian built machines.

The control they used was a psuedo Fanuc control (you could also get a psuedo Siemens control with them). The control was okay, far from good.

The maximum traverse speed was 29 or 30 IPM.

It used small ball screws - don't know the size of the X axis screw, but seem to think the Z axis screw was about 1/2" diameter. It was mounted on the front of the machine as opposed to the back like one of the retrofitters has done.

It used small stepper motors - I believe they would have been size 23 motors.

They would not cut steel at all unless the cut depth was .020" or so. My 9 x 20 cuts steel MUCH better. It did a pretty decent job of cutting aluminum.

The accuracy of those machines were a bit questionable. When I gave the students an assignement, I expected to get a part back within tolerance (+- .003") Seldom was the case of a student blaming the machine for out of tolerance work, however, anything closer would have been very tough.

I don't recall the machines (steppers) missing steps ever - that is the strange thing.

As far as I know, those machines are still running fine though.

Chris

Chris,

You are right about Emco-Maier producing a small lathe that was the predecessor of the 9x20. Chris Bannister (member of the 9x20 group) from Melbourne, Australia had one (an 8x18 IIRC). I think the Austrian machine was probably better designed and surely better executed than the 9x20. I looked at one years ago. Chris B. used to argue that the Chinese copied all of its flaws and few of its good features (I'm paraphrasing but you get the idea).

I knew that Emco had done a little 5x12 CNC machine but I didn't remember the 8x18 being available CNC (that doesn't mean it wasn't).

Having used a D-3 chuck mount on my larger lathe I am less enamored with the threaded chuck mount on the 9x20. I understand that the Emco-Maier had a sort of modified DIN taper for its chuck mount rather than the sort of straight register of the 7x10, 7x12, 7x14, 8x14 lineage use for chuck mounting. The taper mount would seem to provide more consistent centering alignment when removing and replacing a chuck. Though, it is probably easier for a beginner to turn the straight register than to get a taper set properly.

Alan

It looks like the Lathemaster and the 8x12 do not have a variable speed motor, so your limited greatly to what your spindle speeds can be. THat is something that sets the mini lathe apart, a variable DC motor. The lack of htis does not seem to bother some people, but it drives me nuts if i odnt have it.

Phantomcow2,

You are right, they don't come with variable speed motors and neither does the 9x20. I have already purchased a KBIC-125 DC controller and am looking to decide what motor I want to buy (and what lathe I want to put it on).

Several people have replaced the standard AC motor on the 9x20 with a variable speed DC setup. Alan Trest (stickman4) says on his website that he is planning to do that to his 8x14. Has anyone done that to any of the minilathes to get more power out of them? Are they strong enough to be able to use more power?

Alan

It looks like the Lathemaster and the 8x12 do not have a variable speed motor, so your limited greatly to what your spindle speeds can be. THat is something that sets the mini lathe apart, a variable DC motor. The lack of htis does not seem to bother some people, but it drives me nuts if i odnt have it.

I would not hesitate to put a more powerful motor on for the mini lathe.
Others may feel different, but i have never found the motor power to be a limiting factor. On mini-lathe.com though, the author says he starts to approach the limits when he uses the 5 jaw chuck with large stock.

Phantomcow2,

Did you mean 5" chuck?

Alan

On mini-lathe.com though, the author says he starts to approach the limits when he uses the 5 jaw chuck with large stock.

Phantomcow2,

Did you mean 5" chuck?

Alan
Yea thats it, 5" chuck. Thanks for catching that

Sorry I didn't reply earlier.

I wouldn't do a 7x lathe again because it is just too low powered to do the sort I things I like making. A good example was turning the bell mouths I made for a friend. The largest diameter was only about 72mm, but I needed endless cuts, as the machine is so underpowered. One should note that the motor on my 7x is rated at 250W although the same motor is rated at 4/5 HP when sold to the US market. I am not sure how much more power this lathe could cope with.

The tail stock delivered with the 7x is not even worthy of use as an anchor (too much bog in it).

If you only want to do small stuff, it is a great machine, but realise that even making a part out of one inch steel, turning down a feature to say 1/2 inch is an exercise in patience.

I am with Mark, the mini lathe is great for small things and the fact that it has the variable speed control. Otherwise it just takes too long to do some serious turning. You can grow a beard waiting to finish that job. I have the MM 7X14 and I like the extra bed length. Still it is not very powerful. I am looking at the 9X20 and the only thing holding me back is that I need the variable speed. So when I get the dc motor and controller, I will make a stop by HF (locally) and get one.
Jose.

i was just in a shop and they had the new Haas CNC lath .. it is not a production machine as it has no guarding or chip containment ...small but has all the bells and whistles .. im not a sales man .. just havent seen one quite so small in a nice machine like a Haas ... the price i heard sounded pretty good too ... your call ..

Pacosoide,

I appreciate the comment about it being under powered because I thought that maybe the more powerful motor would make a real difference. Do you think that adding a treadmill motor to the 7x14 would solve the power problems? Is it strong enough to handle the extral power?

Thanks,
Alan

I am with Mark, the mini lathe is great for small things and the fact that it has the variable speed control. Otherwise it just takes too long to do some serious turning. You can grow a beard waiting to finish that job. I have the MM 7X14 and I like the extra bed length. Still it is not very powerful. I am looking at the 9X20 and the only thing holding me back is that I need the variable speed. So when I get the dc motor and controller, I will make a stop by HF (locally) and get one.
Jose.

How much more extra power are you talking about? I agree that steel can be difficult to turn. But i just made a leadscrew thats 10 inches long. A slow powerfeed with good coolant and .020 cuts worked alright and left a brilliant finish. I have considered putting a nice variable speed DC motor on there with a little more power, but i think that would mean replacing the motor controller which would be expensive. Also i would have to figure out what my RPM is. So i probably wont, and since i do 90% aluminum, 5% delrin, and 5% steel, im happy

I have KBIC-125 DC variable speed controller which currently has the resistor for 10amp at 90VDC. With a heatsink and the correct resistor it can go 15amp at 90VDC. So I am looking for a 2HP 130VDC motor 3000 to 5000 max RPM. I have been told that the 90VDC and 10amp setting will work but result in a lower max rpm and more like 1HP.

Alan

How much more extra power are you talking about? I agree that steel can be difficult to turn. But i just made a leadscrew thats 10 inches long. A slow powerfeed with good coolant and .020 cuts worked alright and left a brilliant finish. I have considered putting a nice variable speed DC motor on there with a little more power, but i think that would mean replacing the motor controller which would be expensive. Also i would have to figure out what my RPM is. So i probably wont, and since i do 90% aluminum, 5% delrin, and 5% steel, im happy

I would be comfortable switching to a 1HP motor for my mini lathe. The machines mostly cast iron, if bolted down to a bench it is plenty ridgid. It must be bolted down though.
2HP im not sure, i will leave that to you to figure out :). If you are indeed ordering a mini lathe, try the stock motor for a bit before you attack it

The jump from 250W to 1Hp is a huge jump. My little 250W motor broke the lip off the round cast iron compound clamp (Okay that was a crap design using a thin feature in cast iron in shear). I would expect a 1HP motor to be capable of stripping the hi-lo ratio gears, so you would probably be better off putting a timing pulley directly on the spindle.

I wouldn't agree with Phantomcows statement "the machine is mostly cast iron, If bolted down to the bench it is plenty rigid". A 9" southbend is probably 4 times heavier, and has only 3/4 HP (but real Watts, not the little midget ones in my lathes motor), and that is still only considered a light lathe.

Yes a south bend is 9 times heavier, I use a 9x36 often and no doubt its a very nice lathe. But my mini lathe is bolted down to a bench, a very sturdy bench at that. I can hacksaw stuff on it, take decent cuts for its size, since then it has never moved or vibrated itself off the table. A little more iron would be nice, i cant argue that. However this will make it less portable if that is a concern to the owner
My homiers motor is labeled 400W. I managed to take a small chip off the compound myself due to not paying attention.

Having only a 9x20 at the moment, that is not CNC'ed, I have to call on some of my other experiences. The first thing to realize is that none of the lathes are optimal or even close to good for CNC conversions.

Given that you will likely need a large lathe than you would for manual machining. If you think that one of the 7" lathes is all you need for your manual work then I'd look seriously at the 9x20. There are a number of reasons but one is simply that you need more room unless you expect to manually change your tooling everytime it is needed. On the other hand if a 7" lathe can easily handle everything you expect to do it does have advantages one of which is rotation of the spindle. You simply won't be running the 9x20 in reverse with a chuck mounted and cutting anything.

From a size stand point the 9x20 is a good choice. From a mechanical standpoint it is questionable due to the spindle issue described above. Being able to cut in either direction is extremely usefull on a CNC lathe. Further a lot of mechanical work is required to tuern the 9x20 into a good manual lathe, which is also required for a CNC conversion. The remaining issue is that I don't believe that the conversion can be done well without loosing some of the manual functions.

Dave

Hi all,

Money definitely matters to me, that is why I am trying to gather as much information as possible before making a decision.

There have been a lot of suggestions regarding the 9x20 and I really appreciate the support for conversion of the 9x20 and it could be that I will ultimately decide to do that. However, I am still very interested in the 8x14, based on the good things that I have heard about its rigidity, but, I still haven't received any feedback regarding the HF8x12 or the LM8x14 and whether it might be a better choice for CNC conversion than the 9x20.

In the following thread (post 15) "eferg" talked about possibly CNC'ing his LM 8x14 and Mineralman expressed interest in finding out about the results but I haven't seen anything more.
<http://www.cnczone.com/forums/showthread.php?p=68092#post68092>
Paul (CNCAdmin) wrote a review of the LM 8x14 in <http://www.cnczone.com/reviews/showproduct.php?product=24> but no info on suitability for CNC conversion and Balsaman wrote a review of the HF8x12 in <http://www.cnczone.com/modules.php?name=Sections&op=viewarticle&id=6> but again no info on suitability for CNC conversion. Also, Alan Trest (Stickman4) has started on the CNC conversion of an LM8x14 at <http://stickman4.homestead.com/8x14cnclathe.html> but hasn't finished it.

I really want to get some more info on the 8x14, its manual capabilities and its suitability for CNC conversion.

Alan

have you seen this review?
http://home.earthlink.net/~hf8x12

If you do end up getting it, make sure to report on how you like it. Someday i may end up selling my 7x12 for it. The reviewer there says it is the exact same as the lathe master stuff.
Most reviewers wont say if its suitable for a CNC conversion or not. It looks similar to the SIeg machines, so i would say its fine for a conversion.

Phantomcow2,

No, I had not seen that one before. But the more I see of the HF8x12 and LM8x14 the more intrigued I am by them.

Thanks,
Alan

Your not the only one intrigued. The only setback I see about it is that there are only 6 speeds. It goes 125, 210, 450, 620, 1000, 2000 rpm. 1000 to 2000, thats a jump.
According to that review, the HF 8x12 is the same as the lathe matser 8x14. Maybe sometime i will sell my 7x12 with tools and look at that.
Im still happy iwth my 7x12, so down the road perhaps

Phantomcow2,

I was thinking of replacing the motor on the 8x14 with a variable speed DC motor. That would overcome the 6 speed limitation. Whether I bought a 8x14 or CNC'd my 9x20 I was planning on the variable speed DC motor conversion, that's why I already have the DC controller and I am getting ready to buy the DC motor.

Alan

Here is a comparison of the 8x and 9x lathe features that seem to be different in ways that might affect their suitability for CNC conversion.

I tried to get it to show here but I got nothing but grief. When I tried to put the table in here is stripped out all of the spaces so nothing lined up. I may edit this later if I can figure out how to show the table here.

When I look at this comparison, I think that it speaks in favor of the 8x14. I guess it really depends on what you think is most important though.

Alan

I have a Lathemaster 9x30 and would think it a good choice for CNC. It is a very solid, very rigid machine, and (as the 8x14 reviewer says) does not require all of the modifications most of the Asian lathes do for rigidity.

Some of the things it lacks (tumbler reverse, quickchange gearbox) are not disadvantages for CNC. In fact, it is a simple matter to remove the leadscrew gearing and clear the way for your CNC drive there.

I find this lathe is nicely proportioned for benchtop work and there are a number of excellent accessories available for it from Lathemaster. You can also readily adapt your eBay purchases to it. I just mounted a 5" Buck Set-Tru 6-jaw chuck to mine, for example.

Last, and very much not least, the service and support provided by Lathemaster are just excellent.

Best Regards,

BW

Bob,

I guess I may wait to make a decision until after I sell my 12x36. I like the looks of the 9x30 and if I sell both my 12x36 and my 9x20 I might be able to find enough room for the 9x30 in a smaller shop. I like not losing so much length between centers but it may come down to what I have room for when we sell this house.

Alan

why not start a poll on the subject?
might be intresting to see where people are putting there monies at a glance
just my 2 cents

wow, I thought I have made up my mind on getting a rong fu (HF version)mill and the 9x20 hf lathe since there is a retail store intown. I really dont need the 20" length on the 9x20 so the 8x12/14 is really looking nice plus it sounds like its better built. I have to give them a call, I wonder if they will special order stuff into the store that they dont normally carry in the store?

Darren

Edit: well they dont even have access to it in the store so they cant special order it. so now it either pay the shipping or go with the 9X20. Great more decisions. :idea:

CNC Darren,

I asked the local HF store and they claimed that company policy and something to do with the way interstate sales were taxed prevented them from ordering in items that show "internet and catalog only".

Alan

CNC Darren, if you plan to get that 9x30, you might want to sign up with HF and get their 10-20% off coupons (email every week or something). That'll at least cover the tax and some toolings.

I am subscribed to it, there is also a Yahoo group called cheaptools that the members post good coupons they get in the files section. I already used the 20% coupon twice on little stuff, if i was ready to get the lathe i would use it for sure!

Thanks for the tip tho!

Darren

What type of moter is your KBIC controller hooked up to? is it the stock motor?

cncuser1,

I haven't hooked it up yet. I have a 1.5 hp Pac Sci 110v DC motor to install when I get some time. I am trying to finish up my router before I really start to CNC my lathe.

I just fitted a 5" 4-jaw chuck to my lathe so that I could turn the Nema 34 plates for my router steppers.

Alan

Has anyone converted the 8x14 into a CNC unit? I have a high interest in the lathe after realizing it would work well where my 7x12 falls short. I do want to convert to CNC and want to make sure it can be done before purchasing one. (chair)

Check this website. Very interesting. This gentleman has converted an 8 X 14 mini lathe.
Great job and excellent description of his process.
Here it is: http://www.sover.net/~snowleop/cnclathe/

He has other very interesting projects.
Jose.

Thanks for the link, it looks like that is a 7 x 14 however. I'm having a hard time finding any info about the 8 x 14 mod. Will the 8 easily convert also ?