Joes machine ,rotary axis..

[mike hide]

I have a hobbycnc 4 axis electrics for my joe's 2006 machine .Curently I am only using three axes X,Y,and Z.

I would like to mount a rotary axis on the router table and use it to position a turned item automatically and let the machine detail the selected area . I am using mach 3 in the mill configuration would I need to use the mach in the turn mode to do this operation ?

An additional thought the ramaining stepper would have to drive the rotary axis does anyone have any idea what kind of hardware would be required to drive the axis. regards mike hide

[jalessi]

Mike,

You would leave Mach in mill mode and add a 4th axis.

The 4th would be your A axis.

The Sherline 3700 is a very good rotary, it will work perfectly with your Hobby CNC drive. You must use a eight wire stepper motor as you know.

See the attached link.

http://www.sherline.com/3700cncpg.htm

Are you thinking about doing inlay work on pool cues?

Hope this helps.

Jeff Alessi

[mike hide]

Thanks for the response Jeff, talking about pool cues I play with my nephew in law every Thursday night and I have yet to win two out of three games, and we have been playing for a couple of years . The cues are not the problem talent is I am afraid.

OK I have the spare channel, as I mentioned and I will keep the machine in mill mode .Currently I am using mach3 in conjunction with Sheetcam for the code generation. Using the forth axis does that mean I have to use another software package or can I still use sheetcam? regards mike hide

[jalessi]

Mike,

It would be a little easier to help you if we had a little information about the end result you want to accomplish.

You should be able to still use your existing software by faking the axis, "sending the output to the rotary instead of your Y axis"

It might be a lot simpler to get where you want to go if your software has a "wrap" rotary function.

Maybe a Sheetcam user that has a rotary will chime in.

You might want direct this question directly to the Sheetcam area of the Forum for a more exacting answer since I am not a Sheetcam user or expert.

Hope this helps out a little.

Jeff...

[Glidergider]

Jeff,
Thanks for the link of the Sherline. I'm concerned about the backlash. Does this product have a brake to compensate and to prevent vibration? I assume that Mach3 is used to accomodate the backlash, but the vibration is my other concern.

When I get into this area, I'll probably use a Wrapper Program to create the 4th axis code.
Dave

[cuemaker1]

I have a sherline rotary table (indexer) and use it for cuemaking on my Techno isel 19 x 14 servo machine. I have the table mounted in the standup position and have added a handle for manual movement if needed. I move the y axis servo cables to the indexer for engraving, but move it manually for inlays because I want them to have flat bottoms. One turn of the handle is 5 degrees.. Works great...

[jalessi]

Dave,

Backlash will not be a issue with the 3700, it is really that well built.

It is equipped with a backlash adjustment that is preset from the factory.

99.9% of all high end bench top mill manufactures
(Modelmaster, Mini-Tech, Revo 540 etc...) use the Sherline rotary exclusively.

You will not need a brake, there are several reasons.

1: When power is applied to the stepper drive the stepper motor is locked when at idle.

2: The rotary has 72 to 1 gear reduction, its not moving unless the Gcode tells it to.

Stepper motors are available with a brake, however the most common use is to prevent creep on a heavy z axis and to maintain zero when the CNC is powered off.


Jeff...

[Clockwork]

I designed a Lathe Router a while back using a Taig lathe for the rotary axis. It was built as a stand alone machine. The rotary axis could be used by itself as a rotary accessory on other machines.

Employed a 50:1 gear reducer on the stepper output. With 10X microstepping it specs out at 100K steps/revolution of the workpiece. It may give you an idea on how to accomplish what you're looking for.

A picture is here.

http://www.flickr.com/photos/11132086@N02/2111286068/

[Glidergider]

Mr. Clockwork,
Nice little factory you have there. Clocks look awesome.
Dave

[Clockwork]

Dave

Thanks for the kudos.

All of my machines were designed to perform specific tasks allowing me to quickly translate ideas into finished works. Only takes about 25% of the time that it did in the past.

[mike hide]

Originally Posted by Glidergider Jeff, Thanks for the link of the Sherline. I'm concerned about the backlash. Does this product have a brake to compensate and to prevent vibration? I assume that Mach3 is used to accomodate the backlash, but the vibration is my other concern. When I get into this area, I'll probably use a Wrapper Program to create the 4th axis code. Dave

Totally out of my depth here but what is a "wrapper program" mike hide

[jalessi]

"Wrap"

To wrap any shape or text around a cylindrical part via rotary axis interpolation.