Possible Purchase of PM-25MV

[shooter123456]

I would bring sockets, wrenches, screwdrivers, allen wrenches, vice grips, pliers. I would assume all are metric?

Did you order the factory stand?

My machine has a nice mix of metric and imperial screws on it. Seems like the small ones are 10x32 or 8x32. Then there are a bunch of M6 and M8 screws, and then M12 screws holding the column to the base.

 

[codexmas]

Assuming our machines are identical (Safe bet that most things are the same, but designs change slightly over time) to disassemble you will need:

Separate head from Z axis slide:
-Socket wrench or standard wrench. I don't recall what size it was, but there are 3 nuts holding the head to the slide. It is a little bit tight under there so a large wrench or one of the adjustable ones may have trouble fitting. If I recall correctly, the tool kit that came with my machine had the right size wrench for those nuts.

Separate table from saddle:
-Allen wrench (hex wrench, L wrench, whatever you want to call them), standard wrench, flat head screwdriver, and pliers. You need to separate the leadscrew from the table. The end supports are held on with socket head cap screws and have pins for locating (Need to pull straight out). The handles are attached with a lock nut and have keys (thats what the pliers are for). Before sliding the table off, you need to loosen the gib using the flat head screw driver. Should slide right out once you do that.

If you need to take the column off the base, that is attached with 4 large cap screws. You will need a 10mm allen wrench to unscrew those. They are on tight, so you may also need a way to get more leverage.

That there should do it.

Awesome! Thanks for the detailed info and not having to lug way more tools with me than needed.

I was thinking I could top the crate on it's side to fit into my car, disassembly seems like the safer choice

 

[devils4ever]

Okay, I've been looking at shooter123456 CNC conversion with great interest and it got me thinking. I was planning on getting the DRO and possibly the X axis power feed which adds about $900 to the cost. For about that much more (I think), I could add CNC instead. I've been watching videos of CNC mills (the ELS one by Clough42 is great) and I have to say I'm very impressed. A lot complicated cuts done very easily. No more endless turning of the handwheels! I assume there's no need for a DRO on a CNC mill?

Since I'm an EE, I can handle the electronics/electrical part of the CNC conversion, but the mechanical part is more intimidating especially the ballscrews which seem to be the biggest issue on conversion. Milling all the needed parts would be tough since the mill would be disassembled.

So, this brings up a bunch of questions.

1. Has anyone used the ProCutCNC kit? It's a little pricey, but it would take out all/most of the mechanical issues. Are their ballscrews good?
2. Otherwise, where to get the ballscrews that require no modification?
3. Where to get a PC/motherboard that has a parallel port? Is just one port needed?
4. I'm assuming LinuxCNC to drive everything? I'm very familiar with Linux so this isn't an issue.
5. How much current needed for the power supplies? Unregulated power at ~48V?
6. Fusion 360 for CAD/CAM? Free for hobbyists? Hard to learn? I'm pretty good with Draftsight 2D.
7. Can the mill be used manually? I know there are no handwheels to turn, but can the X or Y axis be told to move 1.000" and stop? I assume it must since you need to find the edges of the work piece as reference.
8. Is speeding up the spindle really needed? I assume that's only to increase the feed rate? For slower feed rates, the spindle speed is okay?

Thanks.

 

[shooter123456]

I assume there's no need for a DRO on a CNC mill?

You can use one to map your ballscrews and improve accuracy, but your machine controller will keep track of position and give you a psuedo DRO (based on commanded position, not necessarily true position).

Milling all the needed parts would be tough since the mill would be disassembled.

You just need to make the conversion parts before you take it apart and put the ballscrews on

Has anyone used the ProCutCNC kit? It's a little pricey, but it would take out all/most of the mechanical issues. Are their ballscrews good?

I haven't used them so I can't comment on their quality, but I would say they are on the more expensive end. Hard to say if their ballscrews are good because they don't advertise where they get them. Assume inexpensive imported screws unless they show otherwise.

Otherwise, where to get the ballscrews that require no modification?

You will likely need to grind down the X nut for clearance under the table. Otherwise, nothing should need to be modified. I got some nice ground C5 screws last week and given the cost of the procut kit, if you decided to make it yourself, you could afford the same screws without spending more.

Where to get a PC/motherboard that has a parallel port? Is just one port needed?

Integrated parallel ports aren't common anymore. You can get a PCI-E to parallel port card though which will do the job just as well. 1 parallel port is needed, 2 may become necessary depending on how many other things you want the computer to control (ie limit switch inputs, pneumatic drawbar, 4th axis, spindle, encoders, etc). If you get a motherboard with multiple PCI-E slots, you can add on another card later.

I'm assuming LinuxCNC to drive everything? I'm very familiar with Linux so this isn't an issue

That is what I use and I am very happy with it. Issues are few and far between and it is relatively easy to customize if you are familiar with linux already.

How much current needed for the power supplies? Unregulated power at ~48V?

I used a 7.3 amp 48v supply for mine and it was sufficient.

Fusion 360 for CAD/CAM? Free for hobbyists? Hard to learn? I'm pretty good with Draftsight 2D.

Fusion360 is free for hobbyists and shops that make less than $100,000/year. I started with AutoCAD and found Fusion360 to be far more user friendly and relatively easy to use. It takes a little while to get familiar with it, but once you are, make complex models isn't particularly difficult.

Can the mill be used manually? I know there are no handwheels to turn, but can the X or Y axis be told to move 1.000" and stop? I assume it must since you need to find the edges of the work piece as reference.

Yes. With linuxcnc you can jog using a keyboard. The feedrate is adjustable and you can switch between incremental and continuous feeding. The increments are adjustable so you can have it move for example .1" with every button push, or crank that down to .0005" while you are touching off your work. You can also use MDI which is where you would type a single line of G code for it to run. Something like "G01 F50 X1". If you are using relative positioning, that will move the X axis 1" in the positive direction at a rate of 50 inches/minute. If you are in absolute positioning mode, that will move the X axis to the position 1" in the positive direction from the zero point. You can also get a manual pulse generator (Basically just a fancy handheld controller) that has a wheel on it that can be used the same as a handwheel would.

Is speeding up the spindle really needed? I assume that's only to increase the feed rate? For slower feed rates, the spindle speed is okay?

Absolutely necessary, no. Nice to have for a variety of reasons, yes. Higher spindle speeds can give you better surfaces finishes and let you run it faster. It also helps you get the spindle up into the SFM ranges that carbide really shines. The other reason for higher spindle speeds is to help it run smaller cutters better. For example, a .125" end mill running at the stock max speed of 2500 rpm is only moving at 82 SFM. One of the speeds and feeds tables out there lists a minimum speed of 200 SFM. It will still work below that range, but it isn't ideal. Even just doubling the speed makes a huge difference in cycle times and surface finishes. When I started, I was just really excited to see the mill cutting stuff all by itself, but shortly thereafter I started thinking "Ok this is really slow, lets get things cooking a little faster."

 

[macardoso]

I'm another G0704/PM-25 CNC guy. I've done a couple conversions and can offer another opinion. My system is:

• Mach 4
• Ethernet Smoothstepper
• Allen Bradley Ultra 3000 AC Servo drives and motors
• Industrial PC (no parallel port)
• Custom built Hoss-Machine-Style motor mounts
• Roton ballscrews

Has anyone used the ProCutCNC kit? It's a little pricey, but it would take out all/most of the mechanical issues. Are their ballscrews good?

Haven't used so cannot comment directly. If you want to save money and have extra time (plus access to machines), making your own conversion can be fun and cost friendly. On the other hand, if you have the cash to spend on it, buying a kit will save you weeks to months of work to build your own.

Otherwise, where to get the ballscrews that require no modification?

Several online sources (Chinese eBay) offer end machining services. Some even have the Hoss machine style screws premade. Just ask them to quote you for the extra machining if needed. I would suggest buying decent screws. I have Roton brand (USA) and they're not good. Just never meant for high accuracy motion, very sloppy.

Where to get a PC/motherboard that has a parallel port? Is just one port needed?

I would strongly suggest using a motion controller. Most use Ethernet, but you can also get USB ones. They offload a lot of the processing requirements from the PC and give you better quality motion control plus tons of IO.

I'm assuming LinuxCNC to drive everything? I'm very familiar with Linux so this isn't an issue.

I'm a long time Mach 3 / Mach 4 user. I paid the $200 for Mach 4 hobby and have absolutely loved it. It is good to use right out of the box, but offers a ton of structure to allow you to create your own functionality and screens. I used it to develop a serial interface to my servo drives. Learning curve is a bit steep if you aren't well versed in object oriented programming, but 90% of people don't need to write any code.

My Mach 4 is running on Windows 10.

How much current needed for the power supplies? Unregulated power at ~48V?

Pick your motors first, then select the drive which will match the motor. Finally add up all the drives and that will size the PSU. Get close to the max voltage of the stepper drive.

Can the mill be used manually? I know there are no handwheels to turn, but can the X or Y axis be told to move 1.000" and stop? I assume it must since you need to find the edges of the work piece as reference.

Yes, you can use the keyboard to drive it around, manually execute code line by line (MDI), or install a Manual Pulse Generator (MPG) - basically an electronic handwheel.

Is speeding up the spindle really needed? I assume that's only to increase the feed rate? For slower feed rates, the spindle speed is okay?

What Shooter said. Mine runs at 5000 rpm max. Mostly useful for tools 1/4" and smaller, especially in soft materials (aluminum)

 

[macardoso]

If you want, there may be some content in my build log that could be useful. This is very centric on Mach 4 so if you like the LinuxCNC route then this will be less applicable.

G0704 CNC AC Servo Rebuild (Picture Heavy)

Hi All, About 5 years ago I completed a CNC conversion of a Grizzly G0704 milling machine. Like everyone at that time I chose to go with the Hoss Machine style conversion as there were not many options on the market. I was not comfortable designing my own system at the time since I was just...

www.hobby-machinist.com

The one downside of CNC over manual is that you cannot "feel" how the machine is cutting. This will require you to learn to calculate your cutting speeds ahead of time and listen to how the machine runs. This really only applies if you plan on doing really basic work on the machine that has no reason to be CNC'd

EDIT: I should say that the link above is definitely on the far end of the spectrum for complicated conversions. You can get away with 3 stepper drives and a power supply (which is how I started)

 

[devils4ever]

Well, a quick search of ProCutCNC has inconclusive results. Some positive, some very negative. I see that arizonavideo is selling conversion kits for the PM-25MV that seem highly regarded. This might be a path. I'm not sure I can handle modifying the ballscrews on my mini-lathe. Does anyone have the drawings needed to order from eBay? However, I think I prefer buying a kit with all (most) machining is done.

I assume LinuxCNC only works with parallel ports? Does it support Ethernet Smoothstepper?

Is the motion controller supported by LinuxCNC?

Is your 48V supply linear? Is it regulated? Is there one for each stepper?

Thanks for the info on the Manual Pulse Generator. How/where does this connect to?

I would like to start slow and build up if necessary. Spindle speed up might be in the future.

Thanks to all!

 

[shooter123456]

Does anyone have the drawings needed to order from eBay?

I just ordered 2 1605 double nut screws with BK12 end machining, one 750mm long, the other 350mm long. Then a 2005 double nut screw, 600mm long and BK15 end machining.

I'm not sure I can handle modifying the ballscrews on my mini-lathe.

You don't need to modify them with the lathe. The only thing that would be needed is grinding down the X axis nut with a bench grinder to clear the table. When you order them, you specify the machining done on the ends and they will arrive pretty close to ready to go.

I assume LinuxCNC only works with parallel ports? Does it support Ethernet Smoothstepper?

LinuxCNC can be used with ethernet, but not the smoothstepper. LinuxCNC turns your computer into the motion controller so you don't need a second motion controller.

Is your 48V supply linear? Is it regulated? Is there one for each stepper?

I don't know for the first 2 questions, but the third, 1 power supply for the whole system.

Thanks for the info on the Manual Pulse Generator. How/where does this connect to?

Typically it will be a USB and connect directly to your control PC.

 

[macardoso]

Not an expert on LinuxCNC so You'll need to defer to Shooter for better info.

Does anyone have the drawings needed to order from eBay? However, I think I prefer buying a kit with all (most) machining is done.

I used the CNC conversion kit plans from Hoss machine (www.migration.G0704.com/G0704_dvdrom_download.html). Looks like his price is $65 nowadays. Truth be told, there is nothing special about his plans and I have redesigned all of the hardware over the years except for the ballscrews. The ballscrews can be purchased pre-machined here. I think those are just standard import quality screws, but better than Roton . I've heard rumors that many of the conversion kits can arrive much later than expect since people are making them at home, but maybe that situation has improved.

I assume LinuxCNC only works with parallel ports? Does it support Ethernet Smoothstepper?

...

Is the motion controller supported by LinuxCNC?

After a short bit of research, the ESS is not supported by LinuxCNC, but many other I/O and motion control boards are (see here). Mach 4 has pushed for everything to be run by externals boards (which I am a fan of) and there are many options on the market. For stepper based systems, you don't need high pulse rates, so most motion controllers are fine. As you need higher step rates, then your selection of motion controllers dwindles.

Is your 48V supply linear? Is it regulated? Is there one for each stepper?

I have always used one Switch Mode Power Supply shared between all my axes. There are calculators online to figure it out, but if you have three 4A motors, you do not need a full 12A PSU.

Thanks for the info on the Manual Pulse Generator. How/where does this connect to?

Some MPG's connect over USB or wireless. There are handy, but have a lag associated with the connection and drivers. I opted to buy a hardwired unit which I connect to 15 or so I/O points in my machine cabinet. These I/O are on my motion control board.

I would like to start slow and build up if necessary. Spindle speed up might be in the future.

Good choice. If you do go the CNC route, you'll get 80% of the benefit by doing 20% of the effort that others have done. From there it is up to you how far down the rabbit hole you want to go.

Don't forget to have fun!

Mike

 

[erikmannie]

The 90 degree turn on my stairs probably rules out using the method Darry used. I'll have to break it down into manageable pieces.

It's good to hear that the spindle bearings aren't a big issue.

Has anyone used the factory stand? Recommended?

I have the factory stand, and I am very happy with it. I like to keep my mill goodies in the cabinet under the mill.