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View Full Version : Joes machine ,rotary axis..



mike hide
05-11-2008, 02:24 AM
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
05-11-2008, 05:11 AM
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
05-11-2008, 05:59 PM
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
05-11-2008, 06:29 PM
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
05-12-2008, 07:52 AM
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
05-12-2008, 08:10 AM
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
05-12-2008, 08:18 AM
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
05-12-2008, 09:44 AM
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
05-12-2008, 01:24 PM
Mr. Clockwork,
Nice little factory you have there. Clocks look awesome.
Dave

Clockwork
05-12-2008, 01:52 PM
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
05-12-2008, 11:58 PM
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
05-13-2008, 12:20 AM
"Wrap"

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

mike hide
05-13-2008, 01:12 AM
here are a picture of what I want to make and a picture of my machine I built last winter.also apicture of a curley maple desk my first foray into cnc .The pilasters either side of the gallery door [no burn marks at all.....regards mike hide

mike hide
05-13-2008, 01:45 AM
I will try again with the pictures.hope they come out this time....mike

jalessi
05-13-2008, 02:25 AM
Mike,

Very nice work.


A candelabra like the one you posted may have to be made in several peices.

Your candelabra is extremely complex, it will not be a easy task to design.

What makes it really difficult are the complex organic parts such as the flower petals.

Your software is not up to a task such as this.

For sure you will have your hands full with a project of this complexity.

You might want to post a picture in jpg format so the majority of the forum members can view it.

That way you will generate more feedback.

Jeff...

blackbeard52
05-13-2008, 07:32 AM
Clockwork

Very nice clocks..... I built one but never got it to run :(

mike hide
05-14-2008, 12:22 AM
Mike,

Very nice work.


A candelabra like the one you posted may have to be made in several peices.

Your candelabra is extremely complex, it will not be a easy task to design.

What makes it really difficult are the complex organic parts such as the flower petals.

Your software is not up to a task such as this.

For sure you will have your hands full with a project of this complexity.

to tread" regards mike hide

You might want to post a picture in jpg format so the majority of the forum members can view it.

That way you will generate more feedback.

Jeff...
I agree the arms obviously will be done separately, they will need to be halved to accomodate the wireing and then reglued. As far as the "organic" parts are concerned I have done enough hand carving that does not pose a problem ,I would liketo guild and antique the whole piece ,that might pose problems.

As you mentioned the spindle could be done in parts ,in fact some parts will have to be done that way to allow for rewireing at some time in the future .One thing to mention is the carved detail looks complex but seldom noticed is the groundwork and that in many cases eats up time in trying to get it perfect. As far as that goes this machine could do most of the tedious groundwork . Of course in my case it might well be "fools rush in where angels fear to tread" regards mike hide

mike hide
05-14-2008, 02:05 AM
as requested here is a jpeg copy of the candelabra .sorry about the quality my scanner insists on the bars....mjh

mike hide
05-27-2008, 03:20 PM
as requested here is a jpeg copy of the candelabra .sorry about the quality my scanner insists on the bars....mjh

I have been on the board and designed several of the main parts .The arms have to be halved a 1/4" maleable copper pipe inserted and then reglued [to facilitate rewiring in the future]. The main column lower section I would like to hollow out so I could make the wiring connections from the arms to the main trunk line . In addition I would like to thread these two sections [one internal the other external.

Any how the resultant drawings have many curves mainly eyeballed, all in all some of the basic shapes are fairly cmplex . My question is how do i convert these pen and pencil drawings into some kind of CAD drawings that I can convert to code for CNC use . I had thought of photographing the hand drawings and introducing them into turbocad as jpegs or bitmaps, if that is feasible. I know some of the curves are splines which I believe sheetcam abhores that will have to be converted to polylines somehow .Any suggestions welcome ,I am afraid the learning curve is getting steeper and steeper at this point....regards mike hide.