I need some help here please.... I have a grizzly G0463 (X3) and I want to make it both manual and CNC. I keep hearing not to do it. my original post is at http://cnczone.com/forums/showthread.php?t=54261 I was just hoping that I might get some more hits if i was more specific. there has go to be a way to do this. This is my first conversion so I am pretty clueless. I know that it can be done because i run a bridgeport at work that is both manual and CNC, but I don't know how to do it with my Grizzly. is there anyone out there that can help? I need a lot of specifics since I am new to the conversions. Any help would be greatly appreciated. Thanks a lot
Nate

My question would be "Why?". I find that using the MDI and Jogging controls are more than adequate for simple jobs. No, I don't have an MPG, but that might be another option.
It also sounds like you don't have ballscrews on the the unit at work because they can be easily "back driven" and this could be a real pain if you were trying to do a manual job with them.

Just my .02 worth.

I get the why a lot..... I just love manual machining. I know that I will get some gasps from this but i prefer manual. :) I just want to have the ability to run some programs in CNC when manual would be too hard to make it. I don't need to have ballscrews if I can't have them. I would just like to be able to do both CNC and manual and I don't know how.

Depending on the machine you cnc, this may or may not be possible. When I first did my mill/drill, I used the original lead screws. Well to make a long story short, that lasted just a few weeks until I just plain wore the brass nuts out! Then I went to ball screws and haven't looked back. Like I said earlier, if you want "manual" operation, plan on an MPG to do it. I don't have any handles on my axis and don't miss them. For that quick job, I just use either the jogging functions or MDI. Works for me and sure beats counting turns:})

Think of it as power feeds!

That's true and it all makes sense, but for the sake of sounding stubborn, I would still like to see if it is possible. the mill that I have is http://grizzlyindustrial.com/products/Mill-Drill/G0463 is there anyone that knows if this will work? Thanks a lot,

You aren't the only one to want to do this, and there are a couple of strategies I've seen people use. I do not know if any would work well for your particular type of machine though, you'll have to decide that for yourself.
One nice strategy I've seen is to mount the motors at one end of the screw, leaving manual crank handles at the other. Obviously, this only works if you are messing with the screws and bearing blocks, or getting new ones entirely.
Second is to make it convertible with removable indexed mounts that essentially interchange with the handles.
Third is to have double-shaft steppers and mount the handles on the back where the encoders would normally go.
The first may or may not be possible, and the second two have some potential disadvantages. In any case the motors will need to be unplugged from the drives during manual operation to prevent damaging them with voltage generated by spinning the motors by hand.

Don't know of any of these that might work for you, just different ways I've seen it done successfully in the past on various machines.

StepperMonkey,
thanks, those are all good ideas. I had even considered the double shaft motors, but someone warned me of generating electricity by cranking the steppers, but of course i missed the obvious and never thought of unplugging them from the controller. 2 questions with that if you don't mind. Will cranking the stepper motors give me enough "drag" to make manual feasible? And will i damage the stepper motors at all? Thanks a lot

I'm planning to convert an X2, and I also want both manual and CNC available after the conversion. My plan is to use servo motors, driving the leadscrews via timing belts, and leaving the original handles basically where they are. The servo encoders will provide DRO in manual mode.

This is how the dual mode bridgeports I've seen have been set up.

I thought about this as well..... but like i said i am pretty clueless..... what kind of pulley ratio would i need? Where can i buy them? thanks

My plan is to use servo motors, driving the leadscrews via timing belts, and leaving the original handles basically where they are. The servo encoders will provide DRO in manual mode.
.

Where are you going to feedback the encoders to, to get DRO?
Al.

Ok i think that I am developing a plan, but since I have absolutely no idea what i am doing :) i thought I would run it by you all and ask some questions.

On roton.com i found some 5/8-10 acme lead screws that are .100 per rev and i think that I want to switch out my stock leads for these since I am used to the .100 per rev. Now a lot of people recommend anti back lash nuts.... i don't know what these are. (i know what they are meant to do) if i change the lead screws do the anti backlash nuts take place of the regular nuts? also where can i buy them? Does MSC or McMaster Carr offer them?

Now if i did a pulley system I am thinking that I would make a bracket off to the side and mount the stepper on it and leave the handle on the lead screw in front of the pulley. what kind of ratio is needed and where can I get these?

I have also head from Hoss that if I buy the Keling dual shaft steppers and put a handle on the second shaft as long as the steppers aren't connected to the driver board I can use it manually this way.......

I am not worried about positioning because I have a DRO kit that I can put on or I have 2 new Trav a Dials that if no one buys them on here I can use. So what do you think?

I know that these are probably questions that are simple to you or that you have heard before, but I know how knowledgable everyone is on here and I really don't want to screw this up. :)

Thanks for all the help.

You can make your own anti-backlash nut. One way is to take a nut, and split it partly in half (hard to explain, but if you cut all the way through, you would end up with 2 nuts). Then put a screw through one part so that its pushing against the other. The harder you tighten the screw, the less backlash you will have.. Be aware that there will be a lot more friction. You might also make your own nut out of delrin or something similar. Less friction, but it won't last as long as a brass nut.

Ratio? Depends on several things. What motors are you going to use? What power supply, and how tight are the gibs on your machine? With steppers, most people tend to go with a 1:1 ratio.

You can use a handle on a steping motor as long as it's not connected. The motor wont take damage.

Once you have learned how to machine works in CNC, my bet will be that you will hardly use the manual side. But it won't really hurt to implement the manual system as it probably won't cost a lot more.

Blight,
thanks for the info. I think that this is the way I want to go, but I know there is somewhere that you can buy the anti-backlash nuts. I will just have to find them. I know how to run a CNC, but I do it so much at work that I kinda want to get back to "the old school" way with manuals. Hopefully i can just figure out how to make it all work

Every person I have known who run any manual machine for any significant length of time has wanted power feed.

A CNC has power feed on every axis. :stickpoke

I know a lot of people prefer that. This is just what I prefer. CNC is cool and I do enjoy it, but nothing can beat a true "craftsman" that can do things on a manuat that most other people can only dream of doing. I like that and i respect that and by making a machine that I can use CNC and manual gives me the ability to play around with the CNC and expand my knowledge of manual. I can run both, but I haven't the slightest clue how to build both and that is why I am asking a lot of questions. :)

There is nothing mystical about twiddling those handles. If you have the skill to do it with gcode on a CNC machine you can do it with the handles on a manual.

Beginners to CNC/machining tend to have the impression you just strap a blank on the table press a button and 5 minutes later you have a finished part. It couldn’t be further from the truth. You need to know everything you need to know to do it manually, and then some. Whether it is CNC or manual you have to decide cutter type, feeds, speeds, DOC, work holding, machining strategies etc, etc. By the time the handle twiddling or activate stepper bit comes in the quality of the finished part is already decided. With hobby CNC you are not just the machine operator you are a manual machinist with some significant, additional skills.

Phil

Edit: When a skilled machinist has set everything up correctly the manual man hits the power feed lever and the CNC man hits the run button. No handles in either anyway.

I know a lot of people prefer that. This is just what I prefer. CNC is cool and I do enjoy it, but nothing can beat a true "craftsman" that can do things on a manuat that most other people can only dream of doing. I like that and i respect that and by making a machine that I can use CNC and manual gives me the ability to play around with the CNC and expand my knowledge of manual. I can run both, but I haven't the slightest clue how to build both and that is why I am asking a lot of questions. :)

I understand all of that. I have been running,setting up and programming CNC machines for the last 6 years. I am just trying to explaing to the people that keep asking me why I want to do this the reasoning behind this. I can sit down and program a contours, angles and such in mastercam apply all proper tools, surface footage and such and make the part probably a lot quicker than it can be done manually. I just happen to enjoy the manual side of machining more than CNC and would like to set up my machine to do both. If I were running a bridgeport here at work I would use the powerfeed a lot but when cutting pockets not so much.... with that being said I am still looking for someone that has done this type of conversion that can point me in the right direction (maybe with a thread they did) to where to get the items that I need such as the 5/8-10 anti-backlash nuts that I am having the worst time finding. Everyone seems to stop at 1/2". Thanks

Just found this video on an adjacent thread - post 6:

http://www.cnczone.com/forums/showthread.php?t=55153

Maybe you should contact the guy (bertmiller).

Phil

I am still looking for someone that has done this type of conversion that can point me in the right direction (maybe with a thread they did) to where to get the items that I need such as the 5/8-10 anti-backlash nuts that I am having the worst time finding. Everyone seems to stop at 1/2". Thanks

where to get the items that I need such as the 5/8-10 anti-backlash nuts that I am having the worst time finding. Everyone seems to stop at 1/2". Thanks

You can request a quote here.
http://www.antibacklashnut.com/
or from Nook (http://www.nookindustries.com/acme/AcmeTabNut.cfm).
also buy some at techno-isel.com (http://www.techno-isel.com/LMC/Products/AiNuts01.htm)
plus
nollinc.com (http://www.nollinc.com/index.php/contents/Products/Leadnuts/ABnuts.html)
Hoss

thank you both very much this is a big help. :)

Where are you going to feedback the encoders to, to get DRO?

In CNC mode, the encoders will feed into a Linux PC running EMC2 (http://www.linuxcnc.org), which does the PID control and outputs the servo motor PWM duty cycle. For manual mode I'll just turn off the motor amplifiers, or disable EMC2's PID controllers in software. I'll need to boot the PC if I want DRO, but I can live with that.

Ok now a stupid question.... :) I need two anti backlash nuts per axis right?

Nope, just 1 per axis.
you'd use 2 regular nuts per axis to make an anti backlash setup.
These anti-backlash nuts would be cheaper and take up less room.
Hoss

nsiters,
I've been down the exact same road you are going down. I converted a RF dovetail column mill to CNC and kept the "option" of manual machining by leaving one handwheel attached to the non-motor side of the x-axis and using double shaft stepper motors so that I could either attach a handle to the y-axis or add encoders if I found them needed.

I have been a manual machinist for ~10 years, and I used a Bridgeport EZ-trak with servos that was a fine manual mill and 2 axis CNC. The EZ-trak was not as easy to use as Mach3 for mostly manual on-the-fly machining. So that is why I really was convinced I needed to keep manual capability on my home (RF) machine.

I've honestly never missed being able to crank the handles. With mach3, the keyboard keys will jog the axes. You can machine just like you do manually, except instead of counting handle revolutions in your head, you can pay attention to the cut quality. Instead of trying to find arm positions that are less tiring, you can pay attention to the part more. There are times with a manual machine that your arms will just get too tired, your pinky finger on the jog key won't get tired.

I find that for a one-off part, I can often machine it faster by typing in g-code in the MDI mode than I could by cranking because I can type faster than the machine can complete the pass, so the machine doesn't stop moving, and I think about the next moves and type them in.

Keyboard jogging is just like manual machining with power feeds, you are touching the keyboard instead of moving the knobs, but the keyboard is more controllable.

My advice is to leave yourself the option of mounting handles if you are still unsure, but don't actually mount them until you've tried using just the MDI functions, and jogging to replace manual machining.

Check out fignoggle.com. He seems to have both Manual and CNC in one.

Thanks guys for the replies this has helped me out a lot on my way.

I've done the fignoggle conversion. If does maintain manual operation although the extra drag on the z-axis from the ballscrew and motor is noticeable and a little annoying. I suspect any method of a mechanical disconnect or clutch will add drag.

Ringram,
so on those plans does it use the Acme Screws or does it use ballscrews with some kind of built in drag? Thanks

It uses a ballscrew which in itself turns very freely. I guess it's the added weight of the stepper motor and the drag of the magnets in the motor which must be rotated when the z moves up and down manually. Someone else who has done the conversion please chime in on this. Could be just others do not see this issue.

Hmmmm... Sounds interesting. I will have to take a look at that...... I am getting ready to order my stepper motors and was wondering if these will work for me http://cgi.ebay.com/3-PCS-NEW-NEMA-23-Dual-Shaft-STEPPER-MOTOR-282-OZ-IN_W0QQitemZ380011877751QQihZ025QQcategoryZ78196QQssPageNameZWDVWQQrdZ1QQcmdZViewItem or should I go with the 450oz? I am swapping out the stock lead screws in the Grizzly (which are 5/8-10) with some precision 5/8-10 acme screws and some anti-backlash nuts from Nook Industries... will the 282oz hack it? I have heard that the 450oz are overkill. thanks

I have 330 on a 5tpi ballscrew that just barely makes it on the bench (no cutting forces involved yet) for my X axis. Factor in 10tpi and a less efficient screw and you're probably better to go with the 450. It could go either way, but I'd opt to go for the 450's personally. You're not going to get rapid feeds either way though I'd be willing to wager.

Just read this post and heard you have sucessfully converted a RF dovetail column mill to cnc. I have the Lathemaster Mill and am about to go down that road. Might I enquire about your components and sources? Any and all information would be greatly appreciated. If you can post a picture or two that would also be very nice.... Thanks man....peace..


Pete Matos
Matospeter@charter.net
865-363-9218

A lot of it has to do with the voltage used. As an example, I have the power/torque curves handy for the brand of steppers I like to use. Given the screw pitch you are talking about, it shows even the smallest available - a puny HALF stack 50/oz motor - at 72 volts will start out at about 50/oz at standstill and deliver about 34/oz at the IPM range we usually run.
It shows the double stack 253/oz motor at 24 volts starting at only about 180/oz at standstill and turning out only about 26/oz at the same speed.
Quick calculation shows an average 450/oz at 24 volts would turn out about 14/oz at that speed.
Which do you think works better? Bigger motors/lower voltage just don't help above 5 or 8 IPM. Above that they are worse than even the smallest available nema23 motor with higher voltage.
Smaller motors, higher voltage. The only way to go. There just isn't any other way around it I'm afraid. Bigger motors and higher voltage if you an afford the drivers. Voltage has to come first, period. Bigger motors come AFTER. Even 36 volts keeps the curve flatter, 48 or 72 even better.
24v just doesn't play on a big machine.

I just picked up some nema23 425oz motors for the x and y and a nema34 640oz for the Z some gecko 203 drives and a keling power source.... KL-350-48 48V/7.3A
110V/230V what do you think? i hear good things about the geckos.... if i have to i can always upgrade the power supply. thanks again everybody for all of the great info.

once again showing my ingnorance... what is a breakout board and do i need one for my setup? any suggestions? thanks

The breakout board is what connects your computer to the drivers. It's an I/O interface connected to the parallel port of your computer. So yes you need one. I myself has been using PMDX for all my machines. Good boards with well covered documentation. I'm using the PMDX-122.

@pete from TN
I am not happy with a lot of things I've done, so she's still a work in progress. I'll send you an email so we don't hijack nsiter's discussion thread.

e-mail sent!!