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Messages - chrisjh

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*****VIDEOS***** / Re: Mach3 Turn CSS Mythbuster
« on: November 08, 2013, 05:11:37 PM »
Hi Hood,

You raise some points I hadn’t considered.  I have not tried CSS with a parallel port connection, as my lathe is controlled via USB Smoothstepper.  So I can’t say for sure if a PP connection would work.  However I can’t see why not, as my understanding of Mach3 (which is not great; my understanding not Mach3, that is) is that the Mach3 PWM Spindle Control stream is simply passed through the Smoothstepper and not manipulated.

I cannot say categorically that the feed per rev remains constant but it appears to do so, both for diameter changes along the X Axis and linear cuts along the Z Axis.  I guess I could measure it but I am very happy with the way it behaves for me. In early days of development of my gang tooling setup, I found out that very large diameters slowed the spindle RPM to below the lower limit I set in Mach3, triggering the lower limit function of Mach3.  The upper limit is set to 1500RPM, well above the 1200RPM limit set in my Danfoss VFD, so I never reach the upper limit.

FYI, I use Mach3 Version R3.043.056 exclusively for both my lathe and mill.  The mill is PP controlled.
For the USB Smoothstepper, I use Plugin BETA Ver 0.015meg.  I tried later versions of the Plugin, but reverted to BETA Ver 0.015meg when I found that they would not report the spindle speed to Mach3.

In summary, given that G95 and G96  is not documented in the Mach3 manual, I have always believed that I have been lucky to strike something that works, and that it was more luck than good management.  I can’t recall why I even started down the CSS route, but I have vague recollections that I read somewhere that others had used it with success.

PS I searched the forum and found this:



Show"N"Tell ( Your Machines) / Re: Chrisjh Home Built CNC Lathe
« on: October 18, 2013, 12:43:35 AM »

Today I pieced together a video, mainly consisting of photos stitched together, interspersed with some old videos I recorded during the building of my CNC lathe.

This is my attempt to show the build process.

I hope it will benefit others.



Chris Humphris

*****VIDEOS***** / Re: Mach3 Turn CSS Mythbuster
« on: October 11, 2013, 05:46:26 PM »

I've had a few inquiries regarding the chromate conversion process. 

Attached is a procedure I have written which includes where to get Alodine 1200S in Queensland.  Basically it is available from Henkel Chemicals worldwide.


Chris Humphris

*****VIDEOS***** / Mach3 Turn CSS Mythbuster
« on: October 09, 2013, 06:15:18 PM »
I thought I’d share my experience with Mach3 Turn using Constant Surface Speed (CSS). 

Attached is a short dissertation that could be used to bridge the missing information in the Mach3 Turn Manual.

I cover the use of G96 (CSS On) and G97 (Cancel CSS and return to RPM mode), as well as some tips on using G52 Offsets for gang tooling equipped CNC lathes.

Below is a video clearly demonstrating that CSS works well with Mach3 Turn, if you follow the rules outlined in my attachment.
The video also shows how I use Alodine 1200S to chromate convert aluminium parts.  Please note that Alodine 1200S is not ROHS compliant as it is a hexavalent chrome.  However, if you do not drink the stuff you will be OK.



Chris Humphris

Show"N"Tell ( Your Machines) / Re: Chrisjh Home Built CNC Lathe
« on: September 04, 2013, 06:43:34 AM »

I purchased my spindle as a spare part from Hare and Forbes in Australia.  Part Number is LF1036.





The most complex part I have milled to date. 

A model train enthusiast approached me with his Autocad Sketch of a 1/16 Scale model of a Queensland Rail Steam Locomotive Type BB 18¼ . (The pistons were 18¼” Diameter).  As I understand it, this loco was the last steam loco produced for Queensland Rail before the era of diesel locos. A couple of YouTube videos here:



I had to create a 3D model of his drawings so I could program the part using HSMXpress. All 4 sides had to be machined with many processes.  I ended up creating 4 datums, one for each side so I could use the same reference point the LH side of the fixed jaw on my milling vice as I rotated the material.

I proved out my programming with a first off in Aluminium before switching to the final brass material.

The attached pics show the Solidworks 3D Model, then a couple of views of the completed chassis as it came off my X3 Mill.

I miss the age of steam!!  Enjoy


I use Mach3 Version 043.056 on my lathe and mill, as recommended by that great sage, Hood. All versions past 043.030 have worked for me.  Version 043.030 is the point at which my problem with M3 Spindle speed commands were corrected.

I use a USB Smoothstepper on the lathe, but parallel port control on the mill.  The Smoothstepper Plugin that works satisfactorily for me is "BETA2_v015meg".  I tried some later versions of the Plugin but had problems with Spindle RPM readout on Mach3 Turn (it would always read zero RPM).  So I went back to the version that worked for me.

CSS has always worked for me.  I use PWM output for the spindle fed through a PWM to DC Voltage Converter described in my dissertation on my CNC lathe.  The DC voltage is then used to control the VFD driving the 3 Phase 1HP spindle motor.  I have limited the spindle speed to a maximum of 1100RPM with VFD settings and this is the maximum speed you see in the videos.  I set this limit is mainly because spindle bearings start to get hot if I push it too hard.  Also, the VFD also starts to complain and issues warnings if I go past 1100 RPM (approx 3300 RPM motor speed).




I have been using this flywheel mechanical damping system successfully for a couple of years now.  It is interesting to place your hand lightly on the revolving flywheel when feeding at 0.25mm/rev, to feel a very distinct "pulsing".  It actually feels quite violent.  But the end results (finish) speak for themselves.

Obviously (hindsight is a wonderful thing), my resonance was purely mechanical and, probably the result of length and elasticity of ballscrew shaft combined with other moving masses at one particular frequency.




Below are links to a couple of videos of more parts made using Mach3 controlled CNC Lathe and Mill.

I am learning new techniques all the time and would like to share them with other users.





Hi All,

I thought I show you how I make part of a Semirigid Coaxial Cable Bender.  The bender is used to bend RG402 Cable in the RF Microwave industry.

I published a video on YouTube last week explaining to customers how to use the bender.  Have a look here if you are interested.


Here is my Syil X3 cutting the profile of the cross shaped part.




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