[FPV_GTp]

hi guys

OK , i see one familiar name in this forum and some Aussie like me.

but the true run down is im a motor mechanic and have some free time on my hands

I love drag racing and have a few fast cars and i want to go faster , presently building a 1200Bhp plus turbo 6 cylinder 4 litre falcon E series motor. will find out if i make the horse power once i get it on the heenan and froude engine dyno i run at work.

I'm in the process of contemplating ( have started converting , stripped the old lathe and just fixing her now so it looks good at least ) this old copy lathe to a CNC_lathe . I know it will not be good and fast as some of the CNC_machines out there in the market place like the Okuna's , Mazak' , Puma's , Hitachi Seiki's , Mori Seiki's and Pinnacle's and the list is endless.

But if i had the cash i wouldn't hesitate to buy a MIlling center and a lathe in cnc setup. Maybe in a few years time

It's more a hobby at this stage for me , i want to be able to make my own parts at a slow pace .

i see a great deal of knowledgeable people in here and cnczone.com and many other good websites.

so here it goes i have this lathe and have attached several pictures of it , it is a very robust unit so rigidity is not a issue.

Will have to make all the brackets and adapter to couple the stepper motors to the lathe. This is not a issue as i have other lathes and mills at work. But the problem is im new to electronics and CNC is not my strong point. Some sort of guidance would be appreciated as to the approach i take on doing this conversion .

Yes some may say its a big machine but i thought why do a bench top lathe when i can start on the big lathe and be done with it .

Its just a larger version of the small bench top unit and i want to be able to turn some bigger parts than what the limits of the bench top lathe will permit.

I plan to convert a pacific U2 universal milling machine also to a 4-axis cnc setup also which is sitting in a section of my workshop probably tackle them both at the same time

I'm one that does things BIG , now the stepper motors i had planned to use are http://www.kelinginc.net/SMotorstock.html ( NEMA 34 HIGH TORQUE STEPPER MOTOR 1812 oz-in, ½” Single shaft with flat, 180
KL34H160-62-8B ½” Dual shaft with flat: Price: $189 ( in stock)

this crowd has drivers and power supply also am waiting on a email back from them as we speak.

these stepper motors are probably over kill for the lathe and mill setup but for the price there selling them i figure just spend a little more and get some decent horse power steppers.

again im open to criticism and suggestions here guys , what are your thoughts i need all the help i can get am a fast learner , did bachelor of applied science , all math, science and computer studies at university back 20 years ago and kick my self in the head i didn't finish schooling . Did FORTRAN77 , basic , Pascal program writing back in 1984 now i am showing my age


1. stepper motors or servos ? size ? brands ?
2. stepper motor controllers ? servo controllers ?
3. power supply ?
4. spindle speed controller ?
5. Ball screws and nuts/flanges ? size and specifications ? what brands ?
6. what software ? sorry im not being biased here , i am looking into " Mach " ?

any help will be great here guys

and i'm extremely sorry if some of you think i shouldn't have posted this thread in this section , looked all over and thought this would be the best section for this post

there is no chronological order that i have written this post so correct me

cheers

[HuFlungDung]

Off the cuff, I would say to avoid using stepper motors on large machinery, unless you can find a closed loop controller system that will detect and correct for lost steps. I do not think Mach will do this yet.

Ajax cnc or Camsoft cnc, that is a couple of the more often mentioned names around here.

The level of precision required for a useful lathe X axis is very high. This requires lots of steps, and to obtain decent rapid rates, you need a controller that can crunch lots of numbers, fast. Camsoft, and the Galil card that it often uses, can count as many as 12 million encoder counts per second.

Ajax can likely give you some advice over the phone about what you've got already that may work, or a complete system.

Camsoft, well there you'd be able to use a bit more of your programming smarts to write some logic. It takes lots of time, but, it is a versatile system. If you are going to do a mill and a lathe, you might get double use out of a Camsoft system and the time required to get it running. As a bit of a tinkerer hobbyist, you might enjoy the battles to make the system work as you envision.

Sorry, but I know of no really cheap way to do a professional quality retro, and on a larger lathe, you don't want any whoopsies coming out of the woodwork that did not originate in your g code.

[FPV_GTp]

hi

We in Melbourne Australia have a newspaper called the " Melbourne trading post " , this newspaper has categories of different things for sale from cars to house hold goods to tools and machinery. Yes they are listed on the net and i was reading it and come across some guy selling ball screws.

I telephone him and with a few minutes i was on the road to his place.

He lives about a 1 hour drive from me on the freeway so i zoooooooooooooooommmm down to Geelong, to my surprises 3 of the 4 ball screws were NEW never been used or taken out of there wrappers.

The ball screws are German made by Steinmeyer and the purchase order papers come with the ball screws .

The ball screws are 40mm units , this one i have taken pictures of is 600mm long. the others are roughly 2000mm long . Does anyone read German all the documentation is in German ?

One of the longer ball screws and nut/flange was seized due to the fact there was a lot of grit on the shaft and i imagine inside the nut also.
again this size ball screw and nut is over kill for my lathe but they cost me for all four $150 so i couldn't not complain nor resist buying them.
Now that i'm on this forum , not be harsh on me when i ask this question , i'm new to CNC machinery and computer drawing software and software that controls the CNC machinery .

are there any threads a guy designed a tool change for a lathe has anyone got any other ideas of there own , would love to hear if you do and any pictures or information on a CNC_tool changer for a Center lathe.

what is the best softawre to run a CNC_lathe in 2 axis ? and why ?

Is there a demo version of the software on here that i can have a play with ?

cheers

[FPV_GTp]

hi HuFlungDung

I/m confused now mmmmmmmmmmm

why is there any difference between a small ( desk top lathe) to a 2 tonne monster and bigger ?

other than driving 100 ozin to 2000 ozin stepper or srevo motors

i had a look at theses two websites Ajax cnc or Camsoft cnc thanks for that HuFlungDung , i will weigh the pro's and con's of all the systems out there

cheers

[FPV_GTp]

hi

anyone used this card

http://cnc4pc.com/Multifunction_CNC_Board.htm

what other cnc drivers are there , guys any help would be fine


cheers

[balsaman]

I would go gecko's and Servos. Forget the steppers.

Eric

[arturod]

FPT,

Hi, I make the multifunction board that you posted earlier. That board comes with many bundled features that will make your life easier when retrofitting a lathe. I have other goodies like relays and index pulse index that you will find very useful.

There are a large number of options depending on what you need and want. If you are going to need high speed, and budget is not a problem, you should go to centroid, camsoft, galil, or others.

When doing lathe work, you might need speed on your axis is you run a fully automatic machine that needs to travel to each tool position. Geckos and servos should work ok, if you are not very high speeds. Consider steppers only if you are not going to do lots of traveling.

Arturo Duncan
http://cnc4pc.com

[keithorr]

The bit about closed loop back to the software as opposed to just closed loop to the card or driver doesn't fly for me. If the machine delivers the product, and an error signal shuts things down when the servos can't keep up, then all is good.

There are options to take a pulse signal to a servo. I have camsoft, but I could have achieved the same results for less money. One thing camsoft has going for it is I/O and logic, but if I was turning bar stock and just needed to turn on a couple of devices, I wouldn't worry.

I think Mach with Gecko servo can keep up.

[BobWarfield]

RE toolchanger, that's getting to be out there in the realm of lots of extra credit. Consider gang tooling first. You can mount a rear tool and get to 2 tools easily. After that you could envision 4 tools. After you've gotten proficient with that, you will have figured out how to do the toolchanger or more likely bought a lathe with one.

I will say that I have heard it is very hard to retrofit a new control to an old CNC lathe. Your project is not that, and I have never heard the details of why it is challenging, but I have heard it more than once.

The last thing I will mention is that lathes are a bit of a stepchild for Mach. I wish it wasn't so, because I am also working on a CNC conversion, but the lathe functionality always significantly lags the mill functionality, and I mean by a lot. I am hopeful that Art will find more time to work on the lathe piece if more people get interested.

Best,

BW

[balsaman]

Get the tool changer right outta your head. No need to concern yourself with changing tools automatically until you got the lathe working under cnc control. One challenge at a time man.

E

[FPV_GTp]

hi

need some form of a tool change to drill , bore and internal threads and tapers

I saw on a small bench top lathe that i nearly purchased but realized i was going to pay way to much for what i was getting after i did my homework

The bench top lathe is a training lathe a company in Adelaide Australia makes them for tech schools , way over priced i could purchase a second CNC old mazak or okuma for the price they wanted for theres.

But of the topic now the little lathe had arranged on the X- axis cross slide 4 tools in there holders , the way they where orientated mad it possible to machine large objects in the 3 jaw chuck

will try and find there website and upload a picture so you people can see what im am talking about. nifty little setup

At this stage i do have a budget to meet on this project and it seems everyone has divide differences on what software to use and hardware ?

Seems everyone is saying stay away from stepper motors and use servo motors ??

What is a servo motor like on the insides and one have a picture of one pulled apart ?

I have pulled apart small stepper motors so know what there construction is like but can not find anything on the web to see inside a servo motor cause everyone is raving on about servo motors , there the best thing introduced to cnc machinery since the invention of sliced bread


cheers

[FPV_GTp]

FPT,

Hi, I make the multifunction board that you posted earlier. That board comes with many bundled features that will make your life easier when retrofitting a lathe. I have other goodies like relays and index pulse index that you will find very useful.

There are a large number of options depending on what you need and want. If you are going to need high speed, and budget is not a problem, you should go to centroid, camsoft, galil, or others.

When doing lathe work, you might need speed on your axis is you run a fully automatic machine that needs to travel to each tool position. Geckos and servos should work ok, if you are not very high speeds. Consider steppers only if you are not going to do lots of traveling.

Arturo Duncan
http://cnc4pc.com

"I retrofitted a Hardinge HC CNC lathe that had an old bandit control. The machine was working OK with the bandit control, but I had the same problem as you have. Dealing with old electronics and an awkward control (compared with what Mach3 can do.) This lathe runs fully automatic with 10 feet power bar feed and an 8 post tool turret.

Here is a brief description of what I did and how much it coasted:

I used a PC with two parallel ports. I used two cnc4pc bidirectional boards (that I make and sell). The second one was set to use pins 2-9 for input, so I had a total of (5+13) 18 pins for input, and (12+4) 16 pins for output. The cost of these cards is $26 each. I also used an A4 Power supply (that I also sell) for providing 5 and 12vdc that is used to power all the circuits. These power supply costs around $29.

I used the original power supply and motors, but, replaced the tach and resolves with E2 2000CPR encoders for x axis and 1000 CPR for y axis. These encoders are about $32 each. I also replaced the old drivers with G302 from Geckodrive, this cost $114 each. I also replaced the stepper driver that runs the motor for the tool turret with a G201, also costs $114.

I replaced the nice 500CPR encoder that was mounted on the spindle with a C3 - Index pulse card (that I also sell). This card costs $16. With this index pulse I am able to thread and run a closed loop cycle on my spindle. I replaced the awkward speed control with a Hitachi VFD that costs $330, and also used the C6 – Variable Speed control board (that I sell). This board costs $27. With this board you configure your spindle just as you would a step and direction driver, and with the index pulse feedback you have 100% control of your spindle’s speed.

I also replaced the mechanical home switches with the same Index pulse card that I used on the spindle. That way I get a very accurate homing. For the turret home I still used the original mechanical relay that came with the machine. There is no need for precision here, since the turret has a turret lock that holds the turret in place.

I also used the C5 – Solid State Relay Board (that I sell for about $46) to control; turret lock, coolant pump, collect closer and power bar feed, and the cut-off tool.

I also use a C4 – Safety Charge Pump (that I sell for $17) to control the system along with the e-stop switch.

I also installed a 150CPR encoder from us digital (about $32) that acts as a manual pulse generator.

The only thing that I miss from the old control was the speed of the servos. In terms of control I lost nothing and gained lots of features. I currently plan on installing proximity switches to program tool checks o other things. The total investment was extremely low compared to the benefits that I achieved.

Arturo Duncan
http://cnc4pc.com "

Hi Arturo Duncan

now i read this quote you posted in this thread link http://www.cnczone.com/forums/showth...ight=big+lathe page 2 of the thread u posted what i have highlighted in bold blue and visited your website and you have all the goods i need to convert this manual lathe to CNC_lathe , i want to use either a laptop or a PC which there are heaps around the place . I want to be able to basic turning , boring , taper_turning internal and external, thread cutting internal and external .

Arturo Duncan i'm new to all this and ask you would you be interested in giving me guidance in a complete conversion on my old_copy_lathe to a cnc_lathe , I will purchase what is need from you and assemble it at work my end.

I ask the same question like NC Cams
Master Machinist , it is just a lathe with a X and a Y axis a 2-axis , even on OLD CNC machines why cant you just bypass the old fanuc controller and just use the stepper motors/servos/ballscrews and yes some of the hydraulics to operate the chuck(s) , tailstock . coolant pump and any other things that need to be switched on or off , lights , door safety open etc ????

I have spoken to a few people my end of the world in Australia and some of the responses i get is how big is your bank balance , and i look at them and say none of ur F@#Ken business. Everyone wants to get rich quick.

And some of the sales pitchers i get when i tell them what i want to do with my manual lathe they all say its impossible to do ??? and when i say why can people convert small desktop lathes and mills with succes they just ramble on all this bulls@#t to me . I PMSFL

lets see what happens here

cheers

[FPV_GTp]

hi

Bought another center lathe with gap bed and a 3 meter bed , come with some bits , a 3 jaw chuck , 4 jaw chuck , 3 jaw soft chuck , 5MT live center , a between center bung , 4 chuck keys , tool post spanner, travel steady and fix steady. Missing a face plate

i need to adapt the chucks to the head as it had some camlock chuck arrangement on it , will be easy job and just go over the machine and a coat of paint and she's is ready for work

I have some big rollers i need to machine up , i want to make a sheet metal roller and a few other machines that i need.

and no i don't want to convert her to CNC LOL

I saved her from the metal scrap heap and i have a few jobs i need to do on her , she looks good and I will get her running right

cheers

[FPV_GTp]

woooooooooo

had a look a MAZAK, MULTIPLEX 6200, LATHE, MULTIPLEX, OPPOSING SPINDLE beautiful piece of machinery

if ii had the money would not wait one minute more would buy one straight away

tomorrow is saturday here in Australia and the big tattslotto draw is on first prize is $20,000,000 will buy one ticket for that draw

just in case i win and forget about the red ferrari

cheers

[FPV_GTp]

hi

has anyone had a look at doing something like what this guy did ??? Converting an Ordinary DC Motor to a Servomotor ??? have a look at his website http://truetex.com/servomod.htm

cheers

[balsaman]

When I say use gecko's and servos, that is what I mean. Gecko 320 drives www.geckodrive.com and ordinary DC motors with encoders attached.

BTW I am not blowing wind. I have converted a milling machine using Geckos and servos (DC motors with encoders attached) and Mach 3 for software. Here are just a few parts the mill has made. I don't sell any of these products.

Beware of taking advice from those who are trying to sell you something....

E

[FPV_GTp]

When I say use gecko's and servos, that is what I mean. Gecko 320 drives www.geckodrive.com and ordinary DC motors with encoders attached.

BTW I am not blowing wind. I have converted a milling machine using Geckos and servos (DC motors with encoders attached) and Mach 3 for software. Here are just a few parts the mill has made. I don't sell any of these products.

Beware of taking advice from those who are trying to sell you something....

E

Hi balsaman

had a look at the gecko drivers and many other drivers and stepper and servo motors. Seems the way to go but there are many other options out there.

Balsaman what software are you using ?

what are the advantages of servo motors as opposed to stepper motors ?

I want to make fuel injected parts , trumpets , fuel rails , fuel bungs , fuel injected manifolds , throttle bodies , webber style throttle bodies , holley carburetor style throttle bodies with a square bore base 4 venture in different sizes .

Also for a particular vehicle want to make and modify front stub axles for larger brake conversions.

finally found the link to the australian guys in Adelaide that make small cnc lathes and mills for training tech schools , not cheap link is http://www.axmell.com.au/Hercus/CNC%...Index_Page.htm

they make some sort of four position TOOLPOST changer "A choice of Tool post and holders are available. The NOVIM is fitted with a four position manually operated toolpost. An eight position Automatic turret is an option. The turret is activated by a PC command and is bi-directional. A quick change style toolpost is also an option. "

i spotted a different setup on a lathe some guy was selling out my way where on the X cross slide there was 4 different tools holders positioned on the table where the software of the lathe selected which tool to use

The lathe that i want to convert to CNC-Lathe i will be mainly doing turning around the chuck area but at times will be turning ford 9 inch axles to the specs that i need as i do a lot of 9 inch differential modifications for different Australian cars have even done one for a 240 Volvo and some other weird cars.

So i have to machine the back of the flange and flange diameter bearing and seal diameter and the axle shaft length where i cut the spline , so also machine the spline diameter.

Had 5 differentials to do in the last week , manually machining theses axles is very boring work , this way if i had a cnc_lathe i could program the different axle lengths for all the different cars

cheers

[HuFlungDung]

Servo motors don't have resonance issues like steppers might/can/do.

Closed loop feedback to the control helps assure that your machine is in correct position, and is not slowly getting closer and closer to the chuck with each part, until you start to wonder "what is that ticking sound?"

Steppers are good to run stuff that doesn't have highly variable loads, or are non-critical in nature. A cnc lathe under control is still a dangerous piece of machinery, and the bigger they get, the more damage can be done. You want the most reliable control you can get, not something that may or may not move exactly where you told it.

[arturod]

FPV,

What I did was a bit simpler because I started with a lathe that had all the mechanical stuff for cnc already in. What I did was to replace the old control with a PC and a box with all the electronics that I make. This lathe is where I test all my stuff. I know I should post some pics of it. It is 100% functional. The only thing I miss is the very fast servos it had (the servos it currently has are the same, but I changed the drivers to G320s). The high speed was nice, but I really do not need it. You explain it very good with the Ferrari example. In my opinion the axes speed really hurts while tool changes. These are my opinions on the most relevant aspects of the lathe conversion:

1. Axes motion control. You want to use steppers. Check out some of the videos for CNC machines using stepper, if you can live with that, go ahead. For a couple of bucks more you could probably go with servos and probably do 50% faster. Geckos are great, but if you’re in Australia, you might consider rutex. I have no experience with them.

2. Tool Turret. Some people just gang up the tools on the table. The good thing is that it is simple, the bad thing is that you need a long x axis to be able to fit all the tools, you are also limited in space; you probably always take the risk of crashing a tool. It probably also has to do with how you do your programming. Another option is to use a 4th axes cnc indexer, John Stevenson did http://machsupport.com/forum/index.php?topic=970.0 . Keep in mind you MUST lock the turret while cutting. You MUST use some kind of index sensor to make sure the control does not loose control of the turret. My machine has a pneumatic lock and I use the index pulse card for homing the tool turret. Works fine for me.

3. Power Bar Feeder, Pneumatic Chuck, Cut-Off Tool. I have no mechanical experience with this, they came with the machine I have. I have seen many plans on the internet that will help build your own. I just replaced the old relays with one of my 4 relay boards. I also control the coolant and turret tool lock with these relays. It is all very simple, you would connect the relay just as you would a regular switch.

4. Control Software. I use Mach3, so far it has everything I need; tool tables, etc. I have written simple visual basic macros to control the turret and tool changes automatically. I created M commands for controlling bar feed, cut-off tool, pneumatic chuck, etc... Most are pretty simple, just using activate and deactivate commands, and sensors (index pulse card, and switches that already built into the machine when I got it). For example, if I did a bar feed cycle, the machine would stop until the chuck was locked and the sensor activated.

5. Variable Speed Control. This is too easy; I just bought a $300 VFD and connected with one of my variable speed control boards. This comes built in the Multifunction board.

6. Safety Charge Pump. A lathe is an EXTREMLY DANGEROUS machine. I learned this when once my PC froze (you know, windows xp). The chuck opened automatically and the bar feed pushed the ½” x 3 feet rod at 2000 RPMs across the shop. I always tell this story to people that are attempting to retrofit a lathe so that they take appropriate persuasion. Now days all the relays, locking cylinders lock all the devices in case of a power or PC lose. A safety charge pump (this feature is also built in the multifunction board.)

7. Threading. I use one of my index pulse cards; Mach does the rest, too easy.

8. I/O Many people will tell you that you cannot get enough I/O from the parallel ports to convert one of these machines. Keep in mind that you can always use a modbus device for additional I/O. I have a modbus device, but it is just for testing purposes. The machine runs with it. I have a two parallel ports, the second port has pins 2- 9 for use for input. This is how my I/O looks like.
OUTPUT INPUT TOTAL
LPT1 12 5 17
LPT2 4 13 17
TOTAL 16 18 34

The features I have are:
a. I control 3 axes using G320 with US Digital encoders on the motors that came with the machine. I use a G210 to run the stepper motor that runs the tool turret.
b. The machine has homing switches for all axes, including the tool turret, so the machine homes all the axes automatically.
c. I have encoder feedback from the axes fed back into mach. I do nothing with this info at this time, but I write a simple program that could compare the axes position in the control software and compare it to the feedback position, and take some action. I am not sure if some people will call this true closed loop, but for all practical reasons I guess it could work as closed loop.
d. I have an MPG, which is a 250 cpr encoder that helps me position the axes. Works very nice.
e. I have an index pulse sensor for threading. It also reads the actual spindle position.
f. I have VFD with one of my Variable Speed Control Boards that control the spindle speed. I have it configured as a closed loop system with the index reading from the spindle, the spindle speed is very accurate.
g. I mentioned earlier, I control the bar feeder, pneumatic chuck, coolant pump, turret lock, and cut-off tool.
h. The E-Stop is just an NC switch connected to one of the input of the cards. My Cards have an external enable pin that gets disabled by the safety charge pump and lock everything in case of emergency.

I believe this covers most relevant aspects of my experience. Please do not hesitate to contact me if you need further advice.

Arturo Duncan
http://cnc4pc.com

[NC Cams]

Paragraph #6 in post 19 is EXACTLY why I will NOT use any form of Windoze to control a CNC. Any O/S that lets the processor take control of what's going on so it can do what it wants/needs to do is a dangerous entity.

I can not be convinced that you need a multitasking machine for a lathe or mill controller. If Bridgeport could get a 386, 486 or Pentium 133 to run a mill, lathe, VMC (4 axis plus spindle speed) and surface grinder with the same interface card and DOS software in 1996 or thereabouts, why do you need Redmond's latest experiment in incopletely developed O/S to try to reinvent the wheel today???

PC104 back planes abound out there - can't say there is no more support for ISA. Pricey, yes. Not available/supported??? Hardly.

The way I see it, steppers are low cost and efficient controllers. However, they're trying to use fancy digital electronics to simulate truly analog motion. Adding encoders to warn of errors is too much too little too late. Take the encoder and use it up front, not after the fact.

Besides, sooner or later, the speed factor you're trying to achieve will result in resonance with a stepper - resonance that can't necessarily be tuned out. See the circle cutting problem thread elsewheres on the site.

Servo's on the other hand are essentially analog devices. If you've ever "driven" an RC car with digital servos versus analog ones, you can literally "FEEL" the difference. The digital servo moves in steps and shudders, the analog one moves in linear proportion and smooth fashion.

Need instant proof??? Take your mouse and make a perfectly diagonal line across the screen - it can't be done because it is a step fuction device. You get closer to perfect as you add steps to make smaller and smaller errors occur but you're still dealing with a step function device.

Servos have their own problems but torque and speed are not usually part of those problems. For a hobby type lathe, you could deal with sterpper issues. For industrial iron like you're working with, you're going to need a BIG stepper. At what point will you be approaching the cost of a servo and will it perform when it has to MOVE the iron???

My Fanuc powered lathes have 90vdc motors, 12 amp continuous. Rated speed is around 3000rpm. Torque output is huge due to the pulsed DC drives they use. If you plan on moving the carriage quickly, you need OOMPH. An equivalent DC drive today would need comparable voltage but probably 20 amp continuous/50amp surge rating due to the current surge. At that point, the only stuff close to being able to drive it would be one of Advance Motion Control's DC servo gems. Don't think Gecko or Rutex make anything that robust

DON'T buy anything until you decide/figure out what you need to have to move what you're trying to move. Look at similar commercially made CNC lathes and see what they used for power/drives/etc. Perhaps it might be expensive but, in an industrial setting, properly engineered stuff simply runs.

As simple as you'd think a lathe would be to CNC retrofit, the separate lathe retrofit thread shows that the task is frought with peril and unfulfilled promises. The reason lathes don't get the attention is simple economics - far fewer lathe retros so why bother???.

Too bad Bridgeport never did a Ezpath lathe retrofit kit. At least it worked and was well devloped. More than what can be said for some of the other lathe retrofit systems out there.