[J S Machine]

Ok, I decided to start a build thread to document my steps on what needs to be done with this mill to get it to CNC. I have posted a few threads asking questions about this, so I guess this would be the best way to go about this and get as much help as possible. I have done some reading and have a lot more to do. I would like to go ahead and get a few parts ordered, but I guess I will have to decide what to order first.

I considered going the cnc fusion route, but I guess I can build the end pieces and whatever else I need. I am a cnc programmer for a living.

I buikd knives a s a hobby, and I would really like to start doing better parts and repeatable parts. Having cnc capability in my shop will completely change what I am able to produce and how much of it. I considered other machines such as a Tormach or other nice small CNC, but I just can't afford the cost. Maybe if I can build this thing up to where it will hold really good tolerances, I will be able to use it to produce a little bit and make some money to move into a nice machine like a Tormach. Money is the issue here. I'm trying to save as much money as possible. I have two small children at home and they are first priority.

Another reason to do this project is to learn how everything works. At the moment, I don't really have a clue, and I am looking forward to learning about it. In the mean time, here is my mill. I made the way covers for it when I got it a few years ago, and also did a lot of work.



Out of the box it was not in usable shape. I went to tram it in and found the nod out by about 1/16th of an inch. I took everything completely apart, deburred all the edges and holes on the mating surfaces, shimmed it, and put it back together. The side to side movement will allow you to tram the X in relation to the table, but the Y has to be approached in the rebuilding and shimming way.

I ended up putting about .003 worth of shims under my column/base flange. This brought the nod to within .0005". When I mounted the head, I made sure it was straight up and down too, perpendicular with the table. I drilled a small hole down low with a center drill, and then chucked up to a long shaft where I could raise the head all the way up and check the location of the point on the end with the small hole I drilled. I ended up loosening the four bolts behind the saddle to adjust it. I also removed paint from a bunch of mating surfaces to get better results.

Finally, I shimmed the rack gear out too. I ended up putting .027" of shims there to fix the dreaded sudden drop in Z.

Anyway, I know much of this will be eliminated when I tear it down to add all the parts, but I have to build them first.


I'd appreciate any info on this. I will be reading similar build threads in the mean time.

Thanks

[hoss2006]

Just ask us questions and we'll help as best we can.
Hoss

[gcofieldd]

Here is a good build thread:

http://www.cnczone.com/forums/bencht...ersion-21.html

And another:

http://www.cnczone.com/forums/bencht..._maybe-86.html

And another one

http://www.cnczone.com/forums/bencht...ersion-10.html

Also, I can't find it but someone had a really cool solution for the z-axis ball screw. They mounted behind the column by mounting flat plates on both sides of the head and joining them behind the column with a block of aluminum with a hole in the center which the ball nut mounted to and the ball screw ran through.

[The Blight]

Also, I can't find it but someone had a really cool solution for the z-axis ball screw. They mounted behind the column by mounting flat plates on both sides of the head and joining them behind the column with a block of aluminum with a hole in the center which the ball nut mounted to and the ball screw ran through.

It sounds like it could be this one:
Attachment 217008
Its from this thread. I haven't posted any updates for years and I had no idea someone actually replied to it.

[J S Machine]

I have been doing some serious reading here. I have been focused in DJbird3's thread for a while. I will start reading the others as soon as I get to them.

I think I will run into a major problem with this. I'm sure I'm not the only one to encounter this, but my SX2 is the only thing I have at home to do any machine work, other than a mini lathe. I need the mill assembled in order to make some of these parts. What have you guys done that had this problem? I mean I can't possibly mill my table parts without using another mill. I have mills at work, but getting to them is a pain in the butt and I usually have to do any .gov work off the clock. This is doable, but I'd rather avoid it if at all possible. I would like to be able to do as much of the work as I can before I tear the mill down. I know that all the mounts and coupler pieces can be made before hand. At least I hope they can...

[Fastest1]

I have been doing some serious reading here. I have been focused in DJbird3's thread for a while. I will start reading the others as soon as I get to them.

I think I will run into a major problem with this. I'm sure I'm not the only one to encounter this, but my SX2 is the only thing I have at home to do any machine work, other than a mini lathe. I need the mill assembled in order to make some of these parts. What have you guys done that had this problem? I mean I can't possibly mill my table parts without using another mill. I have mills at work, but getting to them is a pain in the butt and I usually have to do any .gov work off the clock. This is doable, but I'd rather avoid it if at all possible. I would like to be able to do as much of the work as I can before I tear the mill down. I know that all the mounts and coupler pieces can be made before hand. At least I hope they can...

You have access to some other machines at work and you dont want to use them? Come on, some people here drill, scrape, lap, sand and or file their parts down because they have no other choice. Take advantage of it til you dont have to.

[109jb]

I have been doing some serious reading here. I have been focused in DJbird3's thread for a while. I will start reading the others as soon as I get to them.

I think I will run into a major problem with this. I'm sure I'm not the only one to encounter this, but my SX2 is the only thing I have at home to do any machine work, other than a mini lathe. I need the mill assembled in order to make some of these parts. What have you guys done that had this problem? I mean I can't possibly mill my table parts without using another mill. I have mills at work, but getting to them is a pain in the butt and I usually have to do any .gov work off the clock. This is doable, but I'd rather avoid it if at all possible. I would like to be able to do as much of the work as I can before I tear the mill down. I know that all the mounts and coupler pieces can be made before hand. At least I hope they can...

On my first conversion I completely disassembled my mill, measured, planned the conversion, then reassembled the mill to stock condition and made the conversion parts manually. Then disassemble, hope I measured everything right and put the conversion together. It worked, but if you have access to another mill it is easier.

[J S Machine]

I was looking on the homeshopcnc site earlier, and I noticed that they also offer servos in addition to the steppers I have been seeing. I noticed they are more expensive. Is there any advantage to using these vs steppers? Will the same type of driver work for a servo like it will for a stepper? Thanks.

[hoss2006]

No advantage on a machine like this, steppers are more than adequate if you use a good matched package like this.
G540 3-Axis NEMA23 381oz in PSU48V/7.3A | Automation Technology Inc
Servos require servo drivers like the G320x for DC servos, AC servos need AC servo drivers.
Hoss

[J S Machine]

I understand. I guess I will use stepper motors. One thing I've learned about this is from what I can tell, most any combination of components will work, but everybody seems to set them up a tad differently. I am drawn to DJBird's thread because the plans he provided in PDF are very nice. Would it hurt anything to build it the way that he did? I think it looks like a pretty solid design, and his attention to detail is second to none.

As far as the other machines go and doing work to the SX2, I did not mean to come off like I was complaining about it. It's just that when you do this stuff for a living, and work a lot of hours, the last thing I want to do is spend even more time at work...lol. If it comes to that, I will do it. I can already see that it probably will, because to do it right I will have to use another machine.

I would like to start ordering parts, but I am not sure what to order. I was looking a the materials list on DJBird's plans, and see he gets the ball screws from homeshopcnc. That's the reason I was looking a that site yesterday. I noticed that in his plans he has one piece of ball screw stock listed at 4'. I assume he just cuts the length he needs to work with from this. This is fine, I can do this. I cut ball screws at work pretty often and turn the ends for different stuff. Most of it that I have seen is case hardened. I also see that he uses three of the square zero backlash nuts. I guess these are all the same for each axis? Regarding this stuff, I assume that it is pretty much all the same. I did not in his thread where he had problems with the first nuts and ended up swapping them for more because of tolerances. I guess I will just have to order the same and hope mine turn out ok as well. Are there any other reputable manufacturers that would be better?

As far as motors, I see that he is using all Keling stuff. For the X and Y axes, he has either a 282 oz./in. or a 355 oz./in. For the Z he has either a 425 oz./in. or a 495 oz./in. I assume that the larger oz./in. motors would be stronger? I want to build this thing as strong as possible so that I don't have to worry about it being underpowered. I know that there will come a point where it is really just overkill, because the machine won't have enough azz anyway to support the cut that I am trying to tell it to do. I have already noticed this with use in its manual state. It is stronger than I thought it would be, but it does have it's limitations. It is no Bridgeport.

Hoss, Regarding the Keling motors and drivers, How do they compare to a system like the one you linked to? Are their six of one and half a dozen of another, or are there significant advantages to one or the other? Whatever I get, I would like for my control or driver to have the option for the fourth axis, so I can use a rotary table or chuck. I'm not sure what to look for in the parts when buying this stuff.

I've got stock for most of the parts, but I'll have to get some stuff. I'm debating on whether or not to just buy the couplings or make them like he did. Some of this stuff turns out to be more trouble than it's worth to make.

Pleases excuse the ignorance in my questions. I have been reading and I am learning little by little, but I am still confused about much of it.

[hoss2006]

It may seem like any combo works together since there are so many but not every combo works well.
Motors have amp and voltage ratings that need to be matched to a driver and power supply to get the best performance.
Many combos do work well with different components that still are in the ballpark.
Gecko has a formula for a motors max voltage that many of us use when choosing pieces, square root of the motors inductance times 32 = max recommended voltage for that motor.
I have a page dedicated to this though more for the 0704. G0704 Electronics
I use the keling (automation tech now) parts on my machines and have no complaints, the benefit of the g540 package I linked is that it is a good match for the sx2 in terms of performance for the buck.
The g540 has the 4 drivers and bob built together for simpler wiring and runs at 48 volts which I'd say is a good voltage for many machines and a great match for the 381 oz/in motors (53.5 max using the formula)
Hoss

[J S Machine]

Looking a the specs to the kit you linked earlier-

G540 3-Axis kit (115V /230VAC):

1 pcs G540 4 axis driver with 4pcs DB9 connectors (I assume that this means I can add a fourth motor later on to get that fourth axis, for like a rotary table or whatever?) (Also, how is this driver different from the ones that DBird talks about in his thread - KL-5056D digital?)

3 pcs NEMA23 KL23H2100-35-4B(1/4” Dual shaft with a flat) 381 oz-in (Does this mean I will be running 381 oz./in. on each axis?, I assume these are plenty adequate.)

1 pcs KL-350-48 48V/7.3A 115V /230VAC power supply

[hoss2006]

Yes you can add a 4th motor for a 4th axis.
the kl-5056D is a digital driver, I use on my g0704, it can run the bigger 570 0z/in 5 amp motors, it is way overkill for the sx2 imo.
381 oz/in is plenty powerful for the sx2, they are even used on some g0704's and 10x22 lathe conversions.
If you read other x2 conversions the 381's are popular choices.
Hoss

[J S Machine]

Ok, thank you for your help so far. I will focus on the kit you linked to. I assume these motors all mount pretty much the same..in other words if I build the mounts like they are detailed in the drawings DJBird has, pretty much any motor in that range should fit?

Also, I see on the homeshopcnc site that they have the square ball nuts like DJBird lists in his bill of materials. I assume these will work okay. What is the difference between the ones he is using and the others which are basically a smaller cylinder with a flat on the bottom for a mounting point?

I am going to buy the screw and ball nuts first. I will go ahead and get all the brackets and parts made that I can, including the screw work. On the homeshopcnc site, they list several options for screw stock with the part number 1605. What is the difference between free end machining and fixed end machining? -or should I not worry about this because I will be cutting to length and turning my own ends anyway..?

[hoss2006]

Yes all nema 23 motors should fit. Get what ballnuts he used or you could have problems getting it to fit all together, the flanged ones need ground down to fit the confined space under the table.
If you are turning your own ballscrew ends no need to pay them to do it.
Hoss

[J S Machine]

Ok, I will go with what he has listed for the ball nuts. I called my local motion Industries, and they can't cross reference the part number, so I guess that is a OEM number from REX industries.

DJBird3 (Don from here on out) has the end machining detailed nicely in his prints, so I will just buy the stock and cut to size / machine it.

For now, I will go ahead and get an order up in the next week or two to get that. This will get me started.

[J S Machine]

Another quick question. I guess I will be running Mach 3 software. How does the machine tell the control where it is? In other words, on the XYZ(and 4th axis) readout on the main control screen, does the control get it's location by the motors themselves, or will scales have to be installed?

[hoss2006]

you'll set your origin on the part, zero the dro's in mach 3 and run your code, it will move the axis based on the origin in your code, no need for physical dro's.
Hoss

[J S Machine]

So it basically keeps up with where it is by knowing how many revolutions of the motor, etc.?

[hoss2006]

It's more about how many steps it moves.
There are tutorial videos here.
ArtSoft USA - Video Tutorials
Hoss