Messages

1181

General Mach Discussion / Re: Stepper motor as spindle

« on: May 09, 2009, 09:51:48 AM »

The problem with swap axis . .  as has also been said before . . . is that once you go into 'spindle mode' you loose all reference to azimuth.

If there is some way to get that back, within code or simple macro, no one has yet posted it that I have seen.


The comment on motor speed is simply inaccurate.

1182

General Mach Discussion / Re: Homing Again (Newbie needs help!)

« on: May 09, 2009, 08:06:24 AM »

I really can't think of a reason so separate the pins since you tell mach in the setup which way to go to find the 'home' switch and mach has the very nice 'soft limit' feature for the other side.

Unless I'm missing something, that just leaves e-stop service, in which case it really doesn't matter which switch was hit, so they could certainly all be on one pin for that purpose.

It is unclear to me how many physical switches the OP has. A slick setup I read about is to have a 'home' switch near the center of travel and then separate limts at each end to cut down on homing time. Would Mach then need a separate pin for the 'home' vs limits, or can it keep track via a 'last position' type of process?

 

1183

General Mach Discussion / Re: Homing Again (Newbie needs help!)

« on: May 09, 2009, 07:48:01 AM »

If I remeber correctly, Mach treats a 'home' switch differently than a 'limit' switch. A 'home' switch can also be a 'limit' but not vice versa or something like that.

It's been a while since I messed with this aspect, but in my setup I have only a single switch on each axis and Mach treats this as both home and limit. It functions as you describe you want . . i.e. it moves till it hits the switch and then automatically backs off the switch.

It appears you have told Mach that you have three switches all on the same pin.  Unless you have three physical switches, you *may* need to use only 'home' on one end and 'limit' on the other as Mach is set up to 'back off' the home switch as you want.

You may also need to have the 'home' switches on one pin and the 'limit' on another, but I'm not sure about that. In my setup, Mach pays attention to the direction of travel and therefor knows which switch it is about to hit. I don't know exactly how the multiple switch per axis setup works.



 

1184

General Mach Discussion / Re: Can two 36v power supplies be used in series to get 72v?

« on: May 09, 2009, 07:28:55 AM »

Another update:

My repaired switching power supply put out two amps for a few minutes and the more fireworks. It is now in the trash and I just kept the nice aluminum case to put Geckos or a speed controller in someday perhaps.


Anyway, I found what will hopefully be a permanent solution to the delema. I found a fellow who will make up an unregulated power supply for me that can be switched back and forth from 38V to 76V. You have to contact him and ask for what you want as his listed PS do not automatically have this feature. He did not charge extra to custom build a PS the way I need it. Hopefully this will be the end of the drama.


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370197063676&ssPageName=ADME:X:AAQ:US:1123

1185

General Mach Discussion / Re: Stepper motor as spindle

« on: May 09, 2009, 07:18:21 AM »

You will be very limited in what you can do with a stepper as a spindle.

Consider using a servo. It is basically the same kind of motor as a typical DC spindle, just has an encoder so it knows where it is.

The caveat is that the only reason (that I can think of) to want a stepper for the spindle is to get positional accuracy and in Mach, there is no facility for that on the spindle, so you are really no better off thatn using a regular motor and an indexer.

You can set up the spindle as an axis, which gives you the positional accuracy, but then you cannot run the motor continuously without some tricks. For an example of this  see the recent post entitled 'Success - Mini machining center . . '. (sorry I don't know how to link to other posts here).

There is a development effort going on right now for threading that may change the landscape on this issue.

1186

General Mach Discussion / Re: spindle speed as a function of vectoral speed.

« on: May 09, 2009, 07:07:47 AM »

If I understand your question, you simply need to set your feed rate in travel per revolution.

G95 (as I recall) and then set the feedrate per rev of the spindle. For example F.005 will move .005" per spindle rev. If you change the spindle speed, the feedrate will then follow.

1187

General Mach Discussion / Re: Can two 36v power supplies be used in series to get 72v?

« on: May 06, 2009, 01:40:56 PM »

Just to finish up this story, I received the rest of the replacement chips yesterday and installed them in the fried 36V Keling Switching PS

No joy.

So, I sniffed around the area with an ohm meter where the power transisitors left their scorch marks and I found there was a resistor and a diode that got cooked along with the switching transistors. 
Replaced those and Viola! Up and running again.

Theoretically I have replaced the weak links with better quality componenets and now have a reliable PS.


I don't have the courage, frankly, to short the output as a final test 


NoSmoking; got the schematic, thanks.

1188

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: May 06, 2009, 08:18:41 AM »

Thanks for the compliments.

Vmax,

It's an el-cheapo indexer. So far I have machined the ends only for needle thrust bearings so that I can run with zero clearance. There is no internal cavity, as the spindle just rides in the cast iron bore with a few thou clearance. There really isn't enough meat to cut the ends for seals or for ball or tapered roller bearings. This iteration was just for development purposes . . . i.e. "get 'er done" and have something to work with.

I started with a 640oz-in stepper, went to a 900+ stepper, then to a NEMA23 Servo and now to the final NEMA34 Servo. The new 1,800 line encoder for it arrived yesterday (new model from US Digital)

So, now turning back to the mechanics of it, the only parts coming forward from what you see will be the motor mount and the big timing pulley. The next step in the project is to take a better quality 5C spindle from a Phase II brand indexer (sitting in my garage)

http://www.use-enco.com/CGI/INPDFF?PMPAGE=453&PMITEM=240-3226


. . . . and mount it on sealed ABC3 grade deep groove ball bearings in a new head made from a solid block of metal (I haven't decided on the material). For the level of this project, those bearings are a reasonable compromise. I used them on the original X2 spindle and they have done very well. SKF calls their version 'Precision Plus' . they run in the $50 per bearing range.


 




bearings

1189

General Mach Discussion / Re: Xbox 360 controller plugin won't load . error says defective also says Mach4.

« on: May 05, 2009, 04:46:20 PM »

I dug out my old laptop that I first used to run Mach when I was adding CNC to my mill. This laptop had the wireless Xbox controller working with it.

The version number on that .dll is 2.0.0.1 and it works fine with my new wired controller . . . on the laptop.

I copied the entire Mach subrectory from the laptop onto my office computer and it still does not load the plug in.

I went thru the registry and deleted everything with the word Mach in it and then erased the entire mach directory and reloaded from scratch. STILL says plugin is defective and (new info) if I try to create a profile, I get an error that the install is corrupted and there was no license found , again that is in a box that says Mach 4,

Is there Mach4 stuff included in the 043 version perhaps? Is there a plugin loader or somethign like that for Mach4 that's hiding somewhere?

The only difference (other than it being a laptop) is that the laptop has XP home and my other machines have XP Pro.

Quite the mystery

1190

Show"N"Tell ( Your Machines) / Success! Mini Machining Center under Mach3 control - Video link

« on: May 05, 2009, 04:24:11 PM »

Hi everyone,

After much study and work and help from this forum and other resources, I have my servo powered 4th axis up and running. It does everything I wanted it to do.

In the current arrangement, the mill spindle stays active and still functions as normal.

http://www.youtube.com/watch?v=2KNit__LJE4

For now, some interesting programming is needed along with a custom macro to do the thread passes, but in time, I think Mach3 will have features to make this much better.

I don't plan to make aluminum bolts from round stock. The part just demonstrates the various functions I wanted to get working.