CNC Mill Conversion Questions.

[TomS]

Regarding Chai's ballscrews.

Got them yesterday (Tuesday), screws machined to my specs, nut ground as per drawing, ground section finished as per the rest of the nut, looks like an off the shelf item.

Cost was US $120.00 for parts and $49.00 shipping,great value for a hobby machine I reckon. Doubt very much if I could get just one screw for that amount locally. Just prepping the machine for installation, as I figure it'd be a good Father\Son thing.

I'll report back after the weekend regarding operation.

I had the same experience. Bought the ball screw/nut package (X, Y, Z screws and nuts, 2 BK12 housings, 1 BF12 housing, and 1 FK15 housing) for $196.00 including shipping. I made a mistake on the X axis screw length and ordered another for $59.00 including shipping. I have no affiliation with Linear Motion Bearings but when I get exceptional service at a reasonable price I like to share this with others. Chai is the guy!

Tom S

 

[JimDawson]

Re: more cnc Q.

Hi Karl,
I am also shopping for a pc to run my CNC mill project, this is one being considered:
http://www.ebay.com/itm/321497867225?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT
I'm attracted to its very small size, It doesn't have a parallel port but I don't think I'll need one as I'm going to use a Galil 2240 motion controller that uses RS232 or ethernet. Am I on the right track or do you see any pitfalls I am not aware of?

Thanks

Ed

I'm not so sure of this one. These types on minis have a tendency to bottleneck, especially running windows. If your streaming to a caching controller, (do the Ethernet controllers cache?), this would probably not be a problem, though for modest increase in size, I would think this one mentioned before would be a better machine for the task and leave the option for parallel port intact.

Mark

That mini should work fine with a Galil controller. The Galil controller has 256 line cache. This should be in it's own thread, we're kind of hijacking MCRIPPPer's thread. Eddyde, if you want more information on this subject both Karl and I can help you out.

 

[Eddyde]

Re: more cnc Q.

I'm not so sure of this one. These types on minis have a tendency to bottleneck, especially running windows. If your streaming to a caching controller, (do the Ethernet controllers cache?), this would probably not be a problem, though for modest increase in size, I would think this one mentioned before would be a better machine for the task and leave the option for parallel port intact.

Mark

Thanks Mark, I'll verify the "caching controller". I would think it does, as the Galil is a fairly sophisticated industrial controller. The mini PC says it has been tested with various versions of Windows, including XP which is what I would be running. If I can get it to work, it is the one I would like to use. If not this one looks good as well: Dell Optiplex 745 SFF Pentium D DC 2.8GHz 4GB 160GB.

 

[Eddyde]

Re: more cnc Q.

That mini should work fine with a Galil controller. The Galil controller has 256 line cache. This should be in it's own thread, we're kind of hijacking MCRIPPPer's thread. Eddyde, if you want more information on this subject both Karl and I can help you out.

Thanks Jim, I'll move the discussion Here.

 

[Eddyde]

Originally Posted by Eddyde
Hi Karl,
I am also shopping for a pc to run my CNC mill project, this is one being considered:
http://www.ebay.com/itm/321497867225...%3AMEBIDX%3AIT
I'm attracted to its very small size, It doesn't have a parallel port but I don't think I'll need one as I'm going to use a Galil 2240 motion controller that uses RS232 or ethernet. Am I on the right track or do you see any pitfalls I am not aware of?

Thanks

Ed

That mini should work fine with a Galil controller. The Galil controller has 256 line cache. This should be in it's own thread, we're kind of hijacking

MCRIPPPer's thread. Eddyde, if you want more information on this subject both Karl and I can help you out.

Jim Thanks for all your help. So far, I purchased a Galil 2240 motion controller and 2900 interconnect module with cable. Now, I'll I'll buy the mini PC as it sounds like it would work. I also am trying to finalize the motor decision... I'll post some questions on that a little later.

 

[Karl_T]

Re: more cnc Q.

Hi Karl,
I am also shopping for a pc to run my CNC mill project, this is one being considered:
http://www.ebay.com/itm/321497867225?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT
I'm attracted to its very small size, It doesn't have a parallel port but I don't think I'll need one as I'm going to use a Galil 2240 motion controller that uses RS232 or ethernet. Am I on the right track or do you see any pitfalls I am not aware of?

Thanks

Ed

I'll only speak for Galil cards with my control, Camsoft. The Ethernet connection does not work as well as having the card right on the computer's PCI bus. I go with the HP/Compac because its plenty big enough to take the oversize Galil cards.

Ethernet may be fine for other uses with Galil.

Karl

EDIT, my bad, i just answered without reading above. sorry to mess up this thread.

Mods can you move it?

 

[JimDawson]

Good call on the Galil motion controller. Did you get the 100 pin cable with the system? What controller software are you planning on using?

I have done 3 CNC conversions using Galil, with one in process right now.

 

[Eddyde]

Good call on the Galil motion controller. Did you get the 100 pin cable with the system? What controller software are you planning on using?

I have done 3 CNC conversions using Galil, with one in process right now.

Yes, Thanks for suggesting Galil, once I researched their products I felt they were the best choice for the project. I do have the 100 pin cable however its 4m long and I'm planning on mounting the interconnect module right next to the motion controller. I am looking for a shorter cable on eBay, if I find one, I'll sell the long one. I'll also need a 2908 module and cable for the aux encoders, they seem a little scarce, at least for a reasonable price.
I was thinking Mach 3 but now they released Mach 4 so I'll see if that's compatible with the DMC2240.

 

[Eddyde]

Re: more cnc Q.

I'll only speak for Galil cards with my control, Camsoft. The Ethernet connection does not work as well as having the card right on the computer's PCI bus. I go with the HP/Compac because its plenty big enough to take the oversize Galil cards.

Ethernet may be fine for other uses with Galil.

Karl

The Galil DMC-2240 that have is a stand alone controller not a PCI Bus card so I have to go with RS232, Ethernet.

 

[JimDawson]

Regarding Mach3 and Galil

Here is an excerpt from my website: ( http://www.dawsoncontrols.com/millupgrade.html )

''I recently did a retrofit on a 4-axis (basically has 2 independent Z-axes) CNC router for a customer using Mach3 CNC software and stepper motors and a couple of cheap parallel interface boards (this was not my system of choice, it was dictated by the customers’ budget). It worked pretty well except it would tend to lose pulses on turns and on the Z-axis. I could never get it exactly right no matter what adjustments I made. I finally tried installing a Galil Motion Control DMC-1846, 4-axis motion controller, and tried to run it on Mach3 with the Galil third party plug-in. That was a complete disaster. Mach3 was trying to micro-manage the very intelligent Galil card and Galil didn't like it one bit. Disclaimer: This is not to say that Mach3 or the Galil plugin is a bad program, I have used Mach3 successfully in other, lower speed applications with out the plugin. It seems to work fine at slower speeds, but when the speed requirement goes up it seems to come up a bit short.''

Mach4 may solve the problems I had with Mach3. What Mach3 did along with the Galil plugin is to try to operate the Galil card like a parallel breakout board, and that just overloaded the Galil buffer with hundreds of commands / second, rather than letting the Galil card actually control the motion. All of the motion control was being done in Mach3. The way it should work is to send a translated G-code line out to the Galil and let Galil figure out how to best execute the move, that is what is does for a living. IMHO whoever wrote the Galil plugin for Mach3 made a tactical error in the way they approached the task.

The above problems are what prompted me to write my own controller software, which I'll give away for free to anyone that can use it. It will only work with Galil products.

The best deal I could find on a 2908 module is $208.50, the 36 pin cable may be available from Galil, I can't find it anywhere else. If you use closed loop steppers, you won't need the 2908 module unless you want to use the AUX encoder inputs for another purpose.

Another option is to operate the steppers in velocity mode rather than step and direction. Then you would use the Main Encoder inputs for encoder feedback, and use the +/- 10 volt analog command signal to drive the steppers amps. In this mode, the steppers act just like servo motors. You do have to use stepper drives that will accept the analog input signal, normally +/- 5 volt or 0-5 volt input. It's no problem to program everything to do this. In a few days, I should have a couple of stepper velocity controllers that I bought for a project, I'm going to see if it's possible to run them from a Galil command signal.