Messages

301

General Mach Discussion / Re: Why not G54 instead of G52 for multiple parts?

« on: January 06, 2010, 04:23:09 PM »

I created a Work Offset Program that reads in your G code and creates as many Work Offsets as you select while limiting the number of tools changes for each offset.

http://www.machsupport.com/forum/index.php/topic,6129.msg89737.html#msg89737

Hope this helps,
JH

302

General Mach Discussion / Re: Work Offset Code Generator

« on: January 06, 2010, 04:16:57 PM »

Update to the workoffset program.  Its now supports more Work Offsets



Thanks,
JH

303

General Mach Discussion / Re: Bridgeport Discovery 308 retrofit

« on: January 06, 2010, 04:05:34 PM »

Any progress on the 308?

I started on my 412
http://www.machsupport.com/forum/index.php/topic,13365.0.html

Thanks,
JH

304

Show"N"Tell ( Your Machines) / Re: My new project

« on: December 31, 2009, 12:17:51 PM »

Post some video when you can, its looks great !

JH

305

Show"N"Tell ( Your Machines) / Positioning Accuracy

« on: December 23, 2009, 04:08:41 PM »

Hey John,

The CPR/PPR does not correlate 1:1 to machine Accuracy or Repeatability.  Yes, if the CPR/PPR is low you will decrease machine Accuracy but the Repeatability would remain the same. 

I have not checked the specs in a while on the BP412, but I think the stock Accuracy was rated 0.0003in (0.008mm), with the 100CPR/400PPR we should get 0.00025in (0.006mm), just a little better than stock and very close to your 0.005mm.   I do not think the Accuracy can be increased much more than stock, due to the belt drive, thrust bearing and ball screw Accuracy stack-ups.

After a quick check on new Harding/Bridgeport XR760, I found it’s rated at 0.00024in Positioning Accuracy.  I think we are on track with this, please correct me if we are off.

Link to XR760 Specs
http://www.hardingeus.com/productView.asp?prodID=50

Thanks,
JH

306

Show"N"Tell ( Your Machines) / Mounting the New Encoders

« on: December 23, 2009, 12:22:50 PM »

With the stock Heidenhain Encoders removed, we needed to mount the new digital 100CPR Encoders.  I had some shaft couplers that would almost work with the new encoders.  So a quick adaptor and mounting block was turned to mount them.  Testing this setup is next on the list…

307

Show"N"Tell ( Your Machines) / Heidenhain Encoder Study

« on: December 23, 2009, 11:43:52 AM »

Each of the 3 Axis use the same Servo Motor(SEM) and Encoder(Heidenhain).  These encoders are analog and use a ‘flash light’ like lamp and light blocking set screws to calibrate/align the Encoder.  I am sure these were rock solid in their day, but they have been removed and will be replaced.  The analog phase shift technology is not combatable with the new servo drivers that we have been testing(Gecko, Viper and CNCDrive).

The stock BP412 machine had a resolution of 0.0003 and maximum speed of 300IPM (I need to double check this fact…)

To maximize the performance of the machine after the Mach3 conversion, the new encoder CPR/PPR is most important.  The resolution of the machine should be as good or better than before and the maximum IPM speed should be as close to 300 as possible without going faster(NOTE: The trust bearings have an RPM limit of 2600, ie 260IPM, I guess the machine designers assumed you would not be running at 300IPM for long periods of time).  Based on my calculations, an encoder with 100 Counts Per Revolution (CPR) or 400 Pulses Per Revolution (PPR) should equate to a machine resolution of 0.00025 and 300IPM with a Mach3 Kernel Speed of only 20000Hz.

Below are some pictures of a stock Heidenhain Encoder and an Excel Spread Sheet I used to help with the Encoder Calculations:

308

Show"N"Tell ( Your Machines) / Re: My CNC pressbrake build

« on: December 22, 2009, 09:17:00 PM »

Thats a BIG project.  How did you get that unloaded ?  My back hurts....

JH

309

General Mach Discussion / Re: help...cutting text (letter) on plasma cutter

« on: December 22, 2009, 10:26:17 AM »

Is it the plazma cutter or Mach3/Machine ? 

It might be something as simple as the feed rate, are you seeing lots of dross ?

JH

310

General Mach Discussion / Re: Mach3 running on Networked PCs

« on: December 17, 2009, 03:09:33 PM »

Cool, sounds like it is not a BIG deal. 

Been having some PC issues, the newly auto-rebooting feature while running a toolpath is undesired, so a new PC is in the works.  Time to step back and evaluate, come up with a better workflow solution, including networking.  No plans to connect them the internet, just a shop net.

Thanks,
JH