Messages

1

Mach SDK plugin questions and answers. / Re: Mach iOS Pendant, finally

« on: January 17, 2016, 03:09:49 AM »

Apologies, my server host switched IP's on December 25 and I hadn't noticed. Should be live now
www.machpendant.com

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Mach SDK plugin questions and answers. / Re: Mach iOS Pendant, finally

« on: June 04, 2015, 02:20:40 PM »

Im almost ready to launch a new version of the app and server applet that has MUCH better support for webcams.

Basically, ive changed the mindset for webcams. All you need to do is plug the webcam into your mach machine, select the proper device in the server applet and go. Of all the support emails I get, 99% are about webcam compatibility. This should solve alot of those problems and make hooking up a webcam feed much, much, easier.

If any existing users are interested in being beta testers for the new version, shoot me an email at mmaat(at)ualberta.ca

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

« on: January 09, 2015, 05:19:42 PM »

I would have thought that a stepper can actually spin pretty fast if programmed correctly though perhaps im wrong there.

*Please anyone feel free to correct me if im wrong here*

I believe, that if you are running Mach at 35,000 mhz kernel speed, that implies that it can make 35,000 pulses per second, meaning 35,000 steps per second, which at a full step would be 175 rotations per second which is 10,500 RPM. Now, the caveat is, that is a 1:1 ratio which obviously wont work, and 10,000 is probably beyond the rated RPM for a stepper. If you throw an 8:1 ration on there, you're looking at 1312 RPM (at the 4th axis) with the stepper running 10,500 RPM. Also, as Simpson mentioned, the faster a stepper turns, the more torque/holding power it loses. So basically, you'd be at the point where it would be pointless not to do a Servo if you are planning to do high speed operations.

That all being said, I still went with a stepper because of cost, ease of setup, and I didnt need to do lathe work on my mill. Its all about what your intended use is for the machine.

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

« on: January 09, 2015, 03:41:56 PM »

6:1 or 8:1 with a stepper will have good holding power, but it may not have the resolution you are after.

With a 1:1 ratio, each step of the motor is 1.8 degrees. With a 6:1 ratio, each step will be 0.3 degreess. With an 8:1 ratio, each step will be 0.225 degrees. With half steps, those degree numbers half. With microstepping further the same occurs.

If you assume full steps, and a 3" diameter work piece, each step would be:

- 0.047 inches of circumference travel per step if 1:1
- 0.007 inches of circumference travel per step if 7:1
- 0.005 inches of circumference travel per step if 8:1

Again, those number shrink if you half/microstep, but you will also lose torque. I decided to go with a harmonic drive coupled with a pulley ratio to get 66:1 which should give me awesome resolution regardless of workpiece size. For reference, i believe HAAS' 4th axis is 88:1. Also keep in mind that with a stepper you probably wont be able to spin it anywhere near fast enough to do any spindle work like Simpson is doing with his Servo setup. Lastly, 8:1 may be difficult to accomplish within a specific given space. You will probably need to have a multiple pulley setup which can potentially introduce more backlash.


A servo will allow you to get much higher resolution with much lower of a pulley ratio, and will also allow you to spin it up fairly fast. The downside is servo's dont have much holding power, which is why Simpson introduced a brake when doing 4th axis work vs lathe work.

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

« on: December 08, 2014, 10:35:28 AM »

^ Agreed, thanks again for all the help!

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

« on: December 08, 2014, 03:44:27 AM »

Wow! From what you started with in the first page of this thread to what you are building now is SERIOUSLY impressive. My hat is off to you. I really appreciate your help with my questions.

I'm going to be building something similar to your first aluminum framed prototype. Ill be using a spin index spindle, SKF 6209 bearings, and probably this Servo (http://tinyurl.com/nh6j2bo). I'm planning on gearing it to 3:1 only, for simplicity. I'm thinking that should give me enough torque and hopefully get me around the 1400 RPM max speed range. I will be using it to machine mainly 6061/7075 and 1018/1020, nothing too crazy. Most parts will be a couple inches in diameter or less. Anything that is bigger will only be indexing.

- I'm unsure on the calculations needed to get the rotational accuracy I should expect.

- For small diameter (3 inches or less) work pieces, and 2550 oz in of torque (850 oz in peak * 3), will I absolutely need a brake?

- I really love the Gecko products, and all of my builds have Gecko drives. I know you said the G340 didn't meet your requirements, but based on what I'm building, do you think the new G320x will accomplish what I'm after (bearing in mind that my 4th axis will not be anywhere near the Mega and Ultra stuff you are building now, but more so inline with your first aluminum house prototype)

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

« on: December 06, 2014, 02:38:31 AM »

After doing a little bit more reading on another thread you participated in I see you are using 6000 series SKF Deep Grooves (on the first few prototypes anyway, the new ABEC 7 one sounds sweet btw!). I ordered up some 6209's just now. Was gonna go with the 6309's, but I wanted the higher RPM rating for some of the turning i do. One other question I had for you, in some of your pics it shows you line boring the bearing bores in the aluminum housing. It was my understanding that in order to preload these bearings, the outer races would have to be seated against something (horizontally). In other words, I would have assumed that you would have had to counter bore the bearing holes and leave a bit of a backing for the outer race to sit on rather than boring the hole straight through. Is the friction of the bearing fit enough to hold the outer races for the preload?

If my question doesn't make sense let me know and ill whip up a CAD model to show what im trying to explain.

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

« on: December 06, 2014, 01:24:01 AM »

I was directing it at you. I am going to build a somewhat similar setup for myself using a spin index spindle. In several of your pictures you show what appears to be a sealed angular contact bearings. Are these not angular contact then? Or maybe you are using two dual rows? If not, what are they, deep groove?

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

« on: December 03, 2014, 12:28:12 PM »

Do you have the part number for your sealed AC 45mm ID Bearings?  I read through the thread but didnt see it. All I can find is non-sealed versions.

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General Mach Discussion / Re: Tool Change w/ Height Offset

« on: October 24, 2014, 04:59:05 PM »

Okay, so moral of the story is that any time you perform an M6 T*, you should accompany it with a G43 H*

That's fine, and easy enough to change in my post processor, but that leads to a few lingering questions for me:

- What is the purpose of M6 T* if all it does is change the visual number showing on the screen. It doesn't change the tool offset used. Technically you could just call G43 H1, G43 H2, and never issue an M6. Is the purpose then, of an M6 T*, only useful for automatic tool changers?

- Secondly, if you HAVE to call a G43 H* in order for the tool offset to change, what is the purpose of this button? I assumed that for each tool you could turn on or off the tool offset. What exactly is the purpose of this button then if you have to call G43 anyway.