Messages

1

General Mach Discussion / 3d probing/digitizing - getting started

« on: September 21, 2012, 09:17:32 AM »

Hi everyone.
Anyone got any recommendations for getting started in 3d probing. Software, hardware etc.

I have been doing a little research but so far still at the slightly confused stage.

I have seen plenty reference to Mach Cloud but there does not seem to be a down load any more?

I want to be able to probe a 3d curved shapes and scale them up or down for creating G-code (or maybe I can use the scale facility in mach3 next to the DRO's?)

Any suggestions, experience and help very much appreciated.

Thanks
Nigel

2

General Mach Discussion / Re: Sync mill spindle with rotary axis possible?

« on: August 30, 2012, 06:46:40 AM »

Hi Hood
Ah, now I understand better what you were explaining. That's an interesting option, I could easily set the mill spindle up with a stepper motor. Thanks for that.

Hi Tweakie, yes I have the gearotic software, still playing around with it but it's great, I am definitely a fan of Art and Bob. These particular gears will be very small, probably 0.5 module so I thought hobbing would be best approach this time. I have plans for larger helical gears on another project for which I will use Gearotic to get g code and mill them with the rotary axis.

So much to learn

Thanks again

Nigel

3

General Mach Discussion / Re: Sync mill spindle with rotary axis possible?

« on: August 29, 2012, 08:55:41 PM »

Hi Hood
Thanks for your reply.
To hob a gear using a helical hob (as used by commercial gear cutters) the Z axis will be fixed, the Y axis will provide depth of cut and the x axis feed, all independent of the rotation of the rotary or A axis.
Correct me if I am wrong, but I gather that Mach 3 will only accept 1 pulse per spindle rev when thread cutting.
So thinking about it a bit more, if you were to hob say a 10 tooth gear, for each rev of the spindle the rotary axis has to rotate 36 deg and in true sync with each fractional turn of the spindle.
I am beginning to think that the pulse rate per rev of the spindle has to be high for this to work reasonably accurately, which I don't think Mach can do.

So, I think your rely has helped me answer my own question and as you say, it won't give true accurate sync between the spindle speed and rotary axis. So no, mach would not be suitable.

The compucut system does actually have a very high pulse rate per spindle rev., so compucut it will have to be then.

Thanks again

Nigel

4

General Mach Discussion / Sync mill spindle with rotary axis possible?

« on: August 29, 2012, 03:48:23 PM »

Hi everyone
I am thinking of buying compucut gear hobbing sync hardware/software to allow me to cut helical gears on my mill.

However, I was wondering if it's possible to syc the mill spindle with a rotary axis using Mach for turning.

Anyone tried this?

I am a newbie and have used mach 3 for milling very successfully over the last year but I have no experience yet of cnc turning, that's another project.

Your guidance appreciated.

Nigel

5

General Mach Discussion / Re: Noise - Aluminium foil screen? - Faraday Cage?

« on: July 03, 2012, 11:48:34 AM »

Hi Everyone
Thanks for your help and advise.
It ran 4 hours continuous at the weekend without a hitch but this evening I had continuous false e-stops, sometimes several within as many minutes.
So re-wiring with sheilded cable is now my urgent priority.

Thanks again
Nigel

6

General Mach Discussion / Noise - Aluminium foil screen? - Faraday Cage?

« on: July 01, 2012, 04:15:00 AM »

Hi
I am running my Sherline mill with a G540 driver and apart from occassional false e-stops everything is great.
False E-stops are becoming more frequent though. This is my only frustration with this set up.
Limit stop wires are in the same cable as the stepper motor wires and no screening so this is an area for immeadiate improvement.

I ran a 3 hour g-code without the spindle running and no problems, the same g-code with the spindle running gave several false e-stops, (strangely occasionally at the same g code lline!).

Not being knowledgable about such things it would seem the motor and/or it's controller are causing noise problems. (It's a DC motor with brushes)

I was wondering if I wramp the cables in alumimium foil or tape and earth this is it suitable screening? (I will re-route the limit switch wires separate from the motor wires)

Also I was wondering, if I were to put the controller in a Faraday cage, would it help? Anyone done anything like this? or is it just silly?
I would think a Faraday cage could be made from steel mesh and earthed. I know Faraday cages are used in high voltage areas to protect equipment, not sure if it's applicable here.

Additional info if applicable:
Power supply and G540 are in an enclosure together with an e-stop switch and cableing- there is no other E stop switch.
Enclosure with controller is within 2 to 3 ft of the mill.

Any comments appreciated.

Cheers
Nigel

7

G-Code, CAD, and CAM discussions / Re: g-code from a spread sheet ?

« on: November 03, 2011, 11:11:12 AM »

Hi Guys
Thanks for your replies, VBA is beyond me at the moment but I wold like to learn more about this not just for cnc.

Anyway, I found some info in this forum which pointed me in the right direction for what I am thinking, it's simple really, just build up a text string in column A, make column B your calc for X, C your calc for Y etc.

Make column A ="G01X"&B1&"Y"&C1&"Z"&D1&"F50", and so on, drag it all down, then you can paste column A into Note pad and finish of the rest. I guess you could build quite sophisticated spreadsheet if you wanted.

Cheers
Nigel

8

G-Code, CAD, and CAM discussions / g-code from a spread sheet ?

« on: November 02, 2011, 06:47:39 PM »

Hi
My recent entry into CNC had a troublesome start with hardware issues but now all is working I am having great success using Vectric 2d and meshcam software. I have several CNC components complete and enjoying the experience.

Now I am getting interested in how to write gcode, I can see some future projects with geometry that can be calculated from formulae, one such being roughing out a multi throw crankshaft on the mill for example.

Now, I don't know if this is a silly question but is it possible to generate gcode from a spread sheet and copy straight into notebook then into Mach 3? Or is it a case of painstakingly copying the calculation results into notebook line by line?

Or are there better ways? What methods are used when formulae are needed to calculate xyz and 4th axis moves?

Cheers
Nigel

9

General Mach Discussion / Re: Computer problem after running mach3

« on: October 09, 2011, 01:33:49 PM »

Hi Hood/Tweakie and everyone
I am back in Singapore so can continue with my cnc.

All systems go now

Just to recap, I was having problems with my PCI card as I could not configure it to EPP mode and windows was not doing so presumably because windows does not recognise the G540 driver. I had everything working with the charge pump disabled.

While in the USA I bought a PMDX-2PARPCI  card and have installed this, this worked immediately with the charge pump enabled. Works perfect.

I had also discovered that although my PC did not have a printer port there is a printerport connection on the mother board but my attempts to use it via a ribbon cable had failed. Well I bought a new ribbon cable and this now also works perfect, I set it to EPP mode via the bios.

So now I have more operational printer ports than I need! but I have learnt alot for my next cnc conversion/build.

It's been a saga and expensive learning curve.
1. If your pc does not have a printer port check your mother board before going down the PCI card route.
2. If you have to use a PCI card don't just buy a cheap EPP/ECP compatible PCI card unless you know you can configure it as appropriate, go to a speciallist cnc supplier for these types of products.


I also bought a Lava EPP only card as backup but have not tried this yet.

Thanks for your help guys, it's been a frustrating journey but you kept me going

Nigel

10

General Mach Discussion / Re: Computer problem after running mach3

« on: August 23, 2011, 11:30:59 AM »

Hi Hood
After contacting they gave me a delivery charge of 19USD so I am going to order PMDX parallel port.

Apparently the 60USD is a default PayPal thing and you have to contact them for an accurate delivery charge.

As this PCI board is properly spec'ed for the G540 am confident this will resolve outstanding issues.

Have recently read other threads concerning parallel ports I can appreciate why I have had some problems.

Cheres
Nigel