[griffithbuilt]

Hi all, first post, new to the forum.

I'm currently a student at a local community college studying CADD/CAM and Machine Technology.

Anyway, I have this Harbor Freight/Central Machinery lathe/mill combo that is basically a metal lathe with a drill press above it. It runs 2 motors, one for the "mill" spindle and the other to run the main spindle/chuck on the lathe. X&Y for both machines are lead screw driven with handwheels.

I was curious if I may be able to manufacture some parts that would allow me to attach either stepper or servo motors to this machine to in effect have a full cnc lathe and mill in one. Additionally I am interested in adding a VERY SMALL rotary table w/ stepper in order to facilitate the potential for simple 4th axis work.

Ideas, comments, etc? I'm just at the formative phase of this project so any comments are appreciated. I can take photos of the machine if necessary also. Also curious if it is vital to run ballscrews or not. Seems from my research that the sherline lathes and mills run a leadscrew. As a note though, the backlash on this particular harbor freight machine is pretty sloppy.


Jason

[carbidecraters]

I really dont think it is stout enough to handle hard feeds

[balsaman]

It can be done. Have a look at hobycnc.com for some hardware to drive the axes.

You may want to change the screws. Most folks who have tried to use the existing screws have not had the best results. It can be done tho.

Eric

[Torsten]

Cnc and backlash free ballscrews.
Two different things, just adding computer controllable motors
to your handwheels will not alter the capabilitys of the machine
you will be able to do the same machining as before but don't
have to crank the handles any more the computer will do it for you.
Backlash free Ballscrews on all slides will improve the machines
capabilitys but under manual use wont be able to get the fully
benefit from this.
Having both is where Cnc really leaves the manual machines far behind
in capabilitys.
Good Luck

[griffithbuilt]

yeah that whole idea is basically out the window after further discussion. i think i'll simply keep my tooling and set it up for one specific operation (say, turning delron bushings or something else with a generous tolerance) and call it a day.

i am however quite interested in now performing the ballscrew conversion on an old '53 leblonde regal that i've got at the other shop. where would be the best sub-forum to discuss that topic?

thanks again,

jason

[mrbaseball]

How accurate are these lathes from Harbour freight?? http://www.harborfreight.com/cpi/cta...emnumber=46199 I'm looking into bying a lathe/mill combo, but have heard that these are all mad ein China and are not very accurate. Filks say that there is way to much play when everythign is locked down.

Any comments? Opinions?? what would be another choice for this price range??

[Redline]

I have one and it is very sloppy!

[wjfiles]

I have one of these machines HQ500.
When I first puchased the machine I stipped it down and reassembled it.
The main reason I bought was for the capacity. I can face a 14 inch cast iron disc flat within less than 001" TIR.
I can turn a 1" diam shaft and hold 0005" over 12 inches.
These tolerances are not possible without frequent adjustment and are the product of the ways. A skilled operator is paramount.
The lead screws and nuts are another story. The X axis only has a half nut ( and I mean HALF) The material is not a good wearing brass.
The craoss feed nut is a little better because it is a full nut but there is no adjustment for wear..
I plan too modify both nuts in the near future.

[boghog54]

so i bought one ofthese chinese machines from HFT, simply because the price was too good to pass up. on sale for $499 and i had a 20% off coupon, so with my gratuity to the governor, i got it for $425. anyway, i don't know much and i'm hoping some kind soul here will tell me what basic tooling i need for this machine and where i might purchase it. i plan on using the machine to make small parts for motorcyles and hot rods, etc, nothing that will require a great deal of accuracy so i don't need a lot of complicated stuff. please be specific and remember, you're dealing with a rookie! thanx in advance

[widgits]

Doesn't a ball screw have to have some backlash?
Otherwise it would be a direct metal on metal fit
causing galling of the screw shaft and the reciprocating balls
I have changed many ball screws over the years, one thing I
found is they all have backlash of some variety
and even pitch error (nothing is perfect)

I wouldn't waste my time trying to figure out how to CNC control
one of these small chinese imported lathes

But I will give some advice on what to look for in a machine
Buy a bigger machine, but not too big
An old tooling guy I know has a 17" Sheldon and I was at his
place running it one day
I asked why he didn't get the 21" machine for just a few dollars more
His answer was that he doesn't want to work on any parts that big
"Pain in the Butt"
He also pointed out how he mostly uses his old 9" South Bend more than
any other machine in his shop
Because it's simple and fast and accurate enough for 95% of his work
(He bought his South Bend in 1947 for $281 with tooling!!!)
These are great little machines that they made 10's of 1000's of
Parts are redily available pretty cheap thru E-bay and the like
I wouldn't buy a machine off E-Bay But some tooling like steadies
and collet closers most definetly

I keep and eye out on Craigs list for lathes and sometimes you can find
an old South Bend for about $500-1000
Usually some old machinist is no longer with us and the kids don't know
what to do with it
Or someone found a "Good Deal" and finally realized how much work
is involved with cleaning up an old machine like this
But it is worth it, A true labor of love and respect for machine equipment

(Don't buy the "C" model South Bend!!! different carriage without feed clutch knob, Everyone want's the A or B or heavy model and converts these)

Nice little machines for the money, Clean it up, oil and grease it,
Probably last another 60 years, and tooling is everywhere
And they don't weigh that much, and some models are benchtop

If you want to step it up a notch maybe look at Leblond or American,
Lodge and Shipley, Monarch, or Hardinge
The Leblond's and Americans are mid $ range machines and parts are
harder to find
The Monarchs are very nice machines and are very high $
(Watch out for the 10" EE, The variable spindle speed control craps out,
and is very expensive to fix) But a nice solid machine

Hardinge make a little toolroom lathe that is very well made and are
cherished by all machinists with any knowledge,
But these get pricey, very pricey

Harrison (English) makes a very nice machine with an awesome reputation
Sometimes these can be found for about $3-4000K
But parts are expensive

Cazeneuve is probably the finest lathe made
I say this because I ran one for many years and love it
Shear joy to work on!!!
And options not found on any other machine
Do a google search for a Cazeneuve HB360 (Smaller size machine)
And check out the features of the 3 speed tailstock
Multi trip stops for the cross slide with built on .0001" dial
Widest carriage in the world for a machine this size
Note the carriage handle is on the right side
They do this to keep you out of the way from flying chips
14" machine 10 HP Enough said!!!

Take your time, keep an eye out and sooner or later one will
show up
I bought my Leblond 15" for $500, made in 1948
Sweet old gearhead lathe that I can take apart with a cherry picker
load into a truck and move it myself in about 2 hours work
I will make it run another 60 years

A friend of mine bought one of the Chinese lathes only he stepped it up
a bit and got the 14" x 40"
He found that when it was put together they didn't clean all the casting
sand out of the headstock before it was assembled
And now it is busy eating itself for breakfast, out of warranty, nothing he
can do about it

Chances are if it's an older american made machine with flame hardened
bedways it was built pretty darn well

That's my 2 cents
Hope it keeps some of you from harms way

Widgits