Messages

101

General Mach Discussion / Re: Hobby CNC Spindle Motor Choices

« on: July 26, 2010, 12:08:34 PM »

You might take a look at wood routers. Look for one with a collet type bit holder.

I have a Dewalt- the spindle is almost 3/4 inch in diameter and has a very nice collet just like a milling machine. AND it releases without having to tap on the spindle like some collets I have used.

The price might be a bit over $200 but it is rated 2HP and I have abused it for close to 10 years now and it is still solid.

Has a variable speed pot on the router (nice for working in plastics) and a soft start. I got mine as a factory reconditioned unit.

There are a number of manufacturers who produce similar units.

102

General Mach Discussion / Re: Mach3 for embroidery machine

« on: July 26, 2010, 11:57:23 AM »

I am familiar with embroidery amchine as my wife has 2...

I have also thought of using a program like mach for a quilting machine - similar process, just differnces in the amount of detail.

My thought is that the easiest way to do the operation would be to have a sensor in the sewing machine main shaft and use it to inhibit motion when the needle is moving down. I don't know how quickly Mach would respond to that signal. The other way would be to stop at the end of every move and cycle teh needle. That might be more like the way the original embroidery software worked.

It would be more work... But seeing as you have already created teh software to convert from DST to G-code - you might look at some existing sourcecode for a CNC control (there are a couple out there for DOS) and modify it so that the needle finction doesn't have to be explicitly programmed - it is a added function at the end of every move.

I have worked a little trying to decode the Janome format and there are 2 types of moves - a stitch or a position. A position move leaves a thread that needs to be cut. Kind of like G00. All the other moves would be G01 with a stitch at the end.

103

General Mach Discussion / Re: z axis driven pump: pressure regulation /logic input question

« on: July 26, 2010, 09:38:15 AM »

Sounds like you just need an output on/off. 

If i understand correctly - you are extrududing some material - you need to extrude at some pressure. It sounds like you need to have a signal for extrude on/off and then let the pressure control be part of the extruder and don't worry about it being an axis. Axis's are for motin in the X Y & Z planes. Is the extrusion amount in any way deopendent upon what Z & Y are doing, or are they supposed to be programmed so that they are moving at the proper speed so you get the correct deposition?

Otherwise you are going to have to always be moving Z in large enough moves so that it can provide enough volume to exceed the pressure which would be better done with just on/off control.

104

G-Code, CAD, and CAM discussions / Re: Creating GCode to cut a solar dish mold.

« on: July 23, 2010, 04:17:52 PM »

Actually it isn't that hard - you would basically cut a bumch of circles with the z calculated off the radius to give you the right focal length. Don't have to be too picky witht he roughing cuts, but you would need to keep the radius changed small for th finish cuts. A ball nosed endmill (the larger the better for finishing)

105

General Mach Discussion / Re: What speed computer are you running with Mach?

« on: July 22, 2010, 11:36:40 AM »

1.8 Ghz Dell Optiplex GX260 with 256 Mbytes (8 used by the video) not connected to the network. Have CAD and other software on the machine but I don't use anything else when a CNC program is running. Would like more memory but that is what I could get out of a free computer here at the school. Use a USB stick to transfer programs.

106

Sieg Machines / Re: Seig X3 configured in INCHES.

« on: July 20, 2010, 11:08:09 AM »

As with most things in the machine would there is the ideal and then there is what you really end up with.

I started out with 12700 as my step count and was coming up a gnat's eyelash short so I played with the calcualtor and some more movements and came up with 12776 and am able to get parts to the size I expect.

Sorry - it is Adam Stevenson over on the Seig site got rather upset when I suggested that the KX3 could be configured in Native Inch. The way I see Mach3 is that it is able to configure the machine however you want it to be configured and however works out easiest for you. I have worked with a coiuple systems that did enforce a set of units (generally the one's I didn't care for in the application...) and seeing as how we do have a conversion factor from millimeters to inches (and there are many more counts per inch than millimeter) it is a rather painless thing to have 2 configurations - 1 inch and 1 millimeters.

I am comfortable in either units, but seeing as how I have worked most of my life in inches it is just easier for me to visualize what i am doing in inches. Having my machine default to inches is just easier. (and I am probably a bit lazy...) I figure there are a few others out there who don't really want to be bothered in having to deal with those silly little millimeters and would just rather think in inches. Mach doesn't really care and as long as teh numbers are correct the result are correct. I see it more as a customer service thing. It used to be that the customer was always right, and you tried to deliver what teh customer wanted, even if you had other preferences. This customer wanted a machine that was native inch. And you never tell a customer it can't be done just because you see no need for it. He has different needs than you do.

107

General Mach Discussion / Re: Can I convert to Mach 3

« on: July 19, 2010, 03:39:45 PM »

Do you have any electrical diagrams? What would be important is the pinouts and description for the parallel cable. Also - can you look at any of the existing configuration information - especially port and pin info and steps per inch or millimeter. As long as it uses stepper motors and step/direction type control all it should require is a computer that will run Mach3 and a parallel port.

If you can document the signals at the parallel port mach 3 should be no problem.

108

Sieg Machines / Seig X3 configured in INCHES.

« on: July 19, 2010, 03:33:13 PM »

While this is frowned on by those in the Seig Support forum -
I am more comfortable working with a machine that is configured for INCH and so I re-configured my KX3 so that it was default INCH. I kept the original XML files so that I can run it in "factory" mode, but I have had no occasion to run it that way since I created my new configuration.

I made a new config that I call KX3 Inch and under Motor Tuning I made the following changes -

Select Native units = Inch

Steps Per = 12,700 ( I played with this and came up with 12776.66 when comparing to an indicator, 12700 should work)
Velocity = 100 (will work with my setup at 120)
Acceleration = 20
Step Pulse = 6

Mr Stephenson gave me a bunch of grief about making this change and how the machine wouldn't work, but all that I did was scale the numbers they were using for steps per MM and changed it to Steps per inch.

109

General Mach Discussion / Re: 3D acceleration problems and choppy cuts

« on: June 21, 2010, 01:29:59 PM »

You may be seeing some effects from the number of parts between the signal and the cutter. you might ought to look into some servos that can be driven directly from MACH witout the need for intermediate hardware.

I have used steppers and servos with one ot the rutex boards and the servo did not perform to my expectations. On the other hand I have used Yaskakwa servos in pulse/direction mode and Omron SmartStep (pulse/direction only) from 30 watts through 800 watts and found them to be very relaible. Aren't cheap, but they are very relaible.

You might also look at you drive tuning and deadband. If the drive needs to see a few steps before it responds you are going to get poor results. Is the drive system as tight as possible? Is there any lost motion in any axis that might be causing you some grief?

110

General Mach Discussion / Re: ORIENTAL MOTORS-ALPHASTEP

« on: June 17, 2010, 04:23:59 PM »

What's the problem?