Fastest1,
Wrapping feature… Hmmm..  I don’t know anything about it. Time to start reading. I was trying to avoid manual code writing as much as possible hoping that ArtCam will take care of code generating for all 4 axis, but I never thought it is going to be easy to setup and run. Getting table two days from today and will start experimenting.

Glad.

Fastest1,
Wrapping feature… Hmmm..  I don’t know anything about it. Time to start reading. I was trying to avoid manual code writing as much as possible hoping that ArtCam will take care of code generating for all 4 axis, but I never thought it is going to be easy to setup and run. Getting table two days from today and will start experimenting.

Glad.

Glad,

The choice of wrapping software vs. manual code etc. all depends on what you are intending to do with the rotary. If for example you intend to engrave on a cylinder then you definitely need ‘wrapping’ software. However if you are just indexing, for say cutting a gear, then manually entering the code is very straight forward and hardly worth the fuss of a dedicated app.  Since you intend to use axes Y, Z and A then that would seem to eliminate engraving on a cylinder, (since that would only cut a single varying depth groove) so I assume the latter. (Engraving on a cylinder is normally axes X, Z and A, i.e. Y is converted to A.)

Just to make sure we are on the same page, the RT A axis is parallel with X, B is parallel with Y and C is parallel with Z.

And as others have suggested, do make a separate profile for each setup. I have for instance ‘Sherline-A’ and ‘Sherline-C’.

Regardless, not to worry, once you get your hands on the hardware it will all come together. This group will get you over any rough spots.

As a fellow Sherline (and Horological) hobbyist I predict that you will find this to be the most bang for the buck of any Sherline accessory.  Also I give you less than six months before you miss the fun of using all four axes and invest in a fourth driver. For example, by using the RT in the C-axis you can use an ordinary end mill to cut a gear! Lotsa fun!

Al

Hi Al,
Coming from you it is all sounds easy and very optimistic. I started believing that 4th axis is not a big deal .

My first challenge will be to rewire Sherline stepper from 6 wires to 4 (Xylotex board).
Second, is to properly setup table in Mach3.
Last but not list, to produce a G-code to engrave patterns on a flat surface using Y, Z and A axis.
The idea is to install RT flat on an X/Y table perpendicular to Z. Attach lathe type of tool bit on Z axis pointing down perpendicular to X/Y.  Z axis will go up and down driving tool bit into the engraved part installed in RT regulating engraving depth. Spindle will not rotate. Y axis will move in longitudinal direction fore. and aft. from outside toward center of the engraved part. So, when all three axis moving simultaneously: A rotates clockwise holding eng. part, Z drives non rotating tool in and out of the eng. part, and Y moving RT (eng. part) fore or aft.
I hope my explanation makes some sense.

Glad. 

Glad, I’ll try to help as best I can.

>Coming from you it is all sounds easy and very optimistic. I started believing that 4th axis is not a big deal  .
No big deal getting it installed and set up but depending on what you want to do with it, the sky is the limit so far as complexity goes.

> My first challenge will be to rewire Sherline stepper from 6 wires to 4 (Xylotex board).
Sounds like you have good input and a handle on that part.

> Second, is to properly setup table in Mach3.
The Sherline stepper is 1.8 deg/step or 200 steps/rev (360/1. and the rotary table has a 72:1 gear ratio or 5 deg/step (360/72). So for single stepping that would be 200/5 = 40 steps/deg. Multiply the 40 times the micro stepping jumper setting on the Xylotex board, e.g. if it’s set to 8 then 40 X 8 = 320 steps per deg for the Mach3 entry. The velocity and accel numerical values will likely be drastically different from your X, Y and Z due to the deg/min units.  Presumably your linear axes are already set-up so here is what I would do. Open the spreadsheet at this link:
http://www.machsupport.com/forum/index.php/topic,16315.0.html
Enter the input data for both linear and rotary axes. Enter your known reliable max rapid velocity for a linear axis and read the corresponding stepper RPM. Then enter that RPM in the rotary column and read the result steps per degree for the Mach3 velocity entry. That way you are comparing apples to apples (RPM). The accel will need to be changed in the same proportion as the velocity.

>Last but not list, to produce a G-code to engrave patterns on a flat surface using Y, Z and A axis.
>The idea is to install RT flat on an X/Y table perpendicular to Z. Attach lathe type of tool bit on Z axis pointing >down perpendicular to X/Y.  Z axis will go up and down driving tool bit into the engraved part installed in RT >regulating engraving depth. Spindle will not rotate. Y axis will move in longitudinal direction fore. and aft. from >outside toward center of the engraved part. So, when all three axis moving simultaneously: A rotates clockwise >holding eng. part, Z drives non rotating tool in and out of the eng. part, and Y moving RT (eng. part) fore or aft.
>I hope my explanation makes some sense.
You may have lost me here. Sounds like your rotary table is going to be mounted flat on the X-Y table with it’s rotational axis vertical, i.e. parallel with the mill Z-axis. If so, then the rotary is now the C-axis (following accepted convention; A-axis is parallel with the mill X-axis).  On the other hand if this is so, i.e., you are engraving a flat pattern on a flat surface, then why use the rotary? Wouldn’t the X, Y and Z do the same thing? And BTW converting Gcode X values to equivalent C values is not a trivial exercise. Been there, but sometimes it’s worth it. I would suggest that you invest in a 90 deg mount for the rotary and mount it on the X-Y table with it’s axis parallel with the mill X-axis and practice some cylindrical engraving first. Configure as X, Z, A. Lots of free wrapping software to convert Y values to A and I think you will find it quicker to get a feel for the rotary.
Hope this helps
Al

Hi Al,
Thank you for a very informative reply.

You are correct; in my setup it should be a C axis. I wasn't familiar with the right hand rule. I hope that setup you described in your post is still good moving from wrong A axis to correct C. I can use XY and Z axis for engraving on a flat surface if I could use rotating engraving bit or diamond drag. In my case I can't. I have to use lathe type tool bit with a single cutting edge producing circular patterns.

Think about my setup as a Rose Engine machine in vertical position. I don't know if you are familiar with the RE but here is a link to visualize what I'm trying to do. http://www.rgmwatches.com/about_rgm/engine_turning.php and click on video on that page. If you have an idea or suggestion how to achieve same effect without RT I'll appreciate it very much.

Thank you.

Glad

Glad, does your tool swivel? If not it seems like it would dig in at changes in direction. Never mind, I just watched the whole video. Incredible. Beautiful work. As if my eyes arent already getting bad, having to work via a loupe would be difficult.

That link shows some highly detailed engraving that is for sure. It is easy to miss all of the uses for these machines. When you say mount a lathe tool stationary to the Z axis, this is what I think of and cant wait to try
http://www.youtube.com/watch?v=B8l6lH4ydd4
This guy constantly amazes me with ideas I have never seen or heard of. Not that nobody else knows them, just not that my experiences have placed me around solutions like them. Good luck regardless of how you want to use it.

Hi guys…
Major screw up… I revered RT from 6 to 4 wires, and I don’t think I have made a mistake in that, but… After I fired up machine and tried to move RT something loudly popped on the board and I smelled smoke. Machine is dead, I’m 0confused and mad at myself. Dumb mistake – expensive smoke.  The worst part I have no idea what went wrong…

Though it will be a small setback, there are a few of us who have done this or similar. I did fry my speed control board while interfacing it with a Homanns board for control via Mach 3.