Messages

161

General Mach Discussion / Re: Lazy cam problems

« on: September 13, 2008, 06:18:57 PM »

Here's the CorelDraw plugin to convert curves correcly http://www.candcnc.com/DXFTOOLDetails.htm

Steve

162

General Mach Discussion / Re: Lazy cam problems

« on: September 13, 2008, 06:14:55 PM »

You can get a program to add to CorelDraw that exports the curves properly, doesn't cost very much and works very well.
I'll remember the programs name and post back here with it.

For 3D cam I use Meshcam, I'll not claim it's perfect but it works well once you've got the hang of it.
That and Sheetcam are all I use, I too can't afford to use expensive programs but I'm willing to spend a little more to get a program that'll work reliably with relatively little messing.

Steve

163

General Mach Discussion / Re: Lazy cam problems

« on: September 10, 2008, 05:31:50 AM »

I use Sheetcam for my 21/2D work, it was $150 but I think it's gone up a little now, Les is working on a new version that is worth trying called TNG, it's free to try at the moment and there is no restrictions on the output.

For 3D work I use Meshcam

Steve

164

General Mach Discussion / Re: After using the “Steps Per Unit” in “Axis Calibration” my CNC wont run properly

« on: September 03, 2008, 11:06:00 AM »

On a direct drive 10tpi lead screw with 200 step per rev steppers set to 1/8 microstepping 16000 steps per inch is the correct setting, no idea how you got 32000 to work.
I set my steps per by calculating it and then tested at low acceleration and speed, then did the top speed and acceleration to suit, my mill is set way below what it's able to run but I'd rather have it cutting right and take a little longer about rapids than loose steps.
Mine is a mill though and doesn't have the travel your router has, however I bet it weighs a bit more

Steve

165

General Mach Discussion / Re: "Generally" Speaking, Quoting CNC work.

« on: September 03, 2008, 10:40:52 AM »

As has been said charge what you need to charge to make a living.
But don't undersell yourself, it's easier to come down slightly in price than having to hike it up.
I presume from what you've said your already established so you'll already have a good idea of what you need to make, I'd be tempted to keep the price similar though as you've invested in the equipment and time learning how to use it.
I'm self employed as well in sign making (CNC is a hobby as I used to be an engineer) and I hate that how much should I charge question, I work it out and then start to convince myself it's too much and before I know it I'm wishing I hadn't got the job because it's not paying enough
The only paying job I've done on my CNC was some small parts for a friend and I just said pay me what it's worth to you, for once I was pleasantly surprised.

Steve

166

General Mach Discussion / Re: Problem with cutting

« on: August 21, 2008, 11:56:29 AM »

Try copying the miil.xml file from the computer with the fast smooth circle too the other computer.
This will copy the good machines setting to the slower and avoid missed check boxes etc.

Don't forget to back up the other one first though.

Steve

167

General Mach Discussion / Re: Very basic question about tool diameter compensation

« on: August 17, 2008, 01:52:23 PM »

Not used lazycam but if it works like most other cam programs then it doesn't use cutter compensation.

You tell the cam program the process needed (inside, outside, left, right) and the tool size and the program works out the rest and outputs code for the centre line of the cutter so you have to use that size cutter to cut the job.
Sheetcam can add or remove an amount set in the process dialog so you can leave a small amount for a finishing cut etc, non of this uses G41/42 but seems to off set the original lines.

Years ago when I was using CNC for work we used to have to hand code so we always wrote the code for the centre line of the job and then applied tool compensation.
Now I don't use it, I just send the job through my cam program with a different cutter if I have to change it.

Steve

168

General Mach Discussion / Re: Contouring

« on: August 09, 2008, 02:25:50 PM »

If you on about 3D then I use Meshcam, $150.
It's quite a simple program and seems to do a good job.
2 1/2D I use Sheetcam, again around $150.

Steve

169

General Mach Discussion / Re: Very basic question about tool diameter compensation

« on: August 09, 2008, 02:21:11 PM »

As Gerry has said one is for going down the left of the line (tool path) as you look in the direction of travel (g41) the other is for going down the right of the line as you look in the direction of travel (g42)
You can can also lie to it to alter the offset in relation to the size of the cutter to get a larger or smaller part (or hole)
G41 also climb cuts while G42 is conventional cutting.
So if your machine has a significant amount of backlash then always use G42 and go Anti clockwise to cut on the outside and clockwise to cut on the inside.

I tend to use a CAM program though as it sorts it all out for you and it always says in the code what size cutter was used.

Steve

170

General Mach Discussion / Re: Very basic question about tool diameter compensation

« on: August 07, 2008, 02:45:29 PM »

As I remember from the little I've used tool diameter compensation you have to enter the tool diameters into mach's tool table, i.e T1 = 1mm etc.
you then call T1 in your code move to position then call the appropriate compensation G41 or G42, you then cancel the compensation after the tool is out of the job at the safe height.

Do a search on google for G40, 41 and 42

I also seem to remember there being a problem Mach at some point with calling compensation before the first move.

Steve