Messages

841

General Mach Discussion / Re: Aluminium Cutting

« on: April 23, 2010, 12:19:41 PM »

You can get router bits for cutting aluminum dry from www.onsrud.com. They won't be cheap, though.

I'll second this. These bits can run at 'ludicrous speed' and the geometry won't try to pick up the sheet like a typical spiral end mill will. I'm pretty sure they come in down cut as well, which would help keep the sheet from singing you a tune.

I have had some success using a stick form of 'grinders paste' and a new one that I like is made by Boeing (yes, the jet company). In practice often I will trace out the path with a pen in the mill first, then go back and smear the stick lube on the cut line sort of like it was a crayon. Your compressed air stream will keep the tool cooled down (very important) but won't pick up the waxy stick lube. The lube does a very good job keeping the cutter surface 'slick' so it won't collect aluminum, and does not saturate everything around it like liquid coolant.

842

General Mach Discussion / Re: speed control of stepper used as spindle motor

« on: April 23, 2010, 12:07:33 PM »

Fascinating, as Spock would say,

If I understand the issue correctly you have a stepper motor driven pump that pumps paint in sync with movement of the X axis, and you have a controller in the mix that won't allow step dir spindle.

You might investigate the potential to set up the pump stepper as your 'A" axis.  In this way you can have independent control of the paint application, for example to start the X movement before the paint to avoid a puddle  . .  I'm speculating only here.

Mach will coordinate the movements of both axis so you could for example program:

G1 X25A7200

This would move the X axis 25 units and simultaneously rotate the pump 20 revolutions (or however much you have it set up to do). Actually this may be more intuitive than mentally converting linear motion into pump volumes, but in any case, be aware that Mach seems to have some 'interesting' ideas about how to mix rotary and linear speeds.  I'm still working on that one myself.

843

General Mach Discussion / Re: how to import vector artwork from graphics applications for cutting

« on: April 23, 2010, 11:46:23 AM »

I am no expert on this, but I did spend some time just recently working with an outfit that sells vector graphics in order to get the stuff into Mach correctly. Result shown here . . just hang in past the belt demo and you'll see the pretty fairy being 'engraved'. The artwork is specifically double lined for vinyl cutting so it is not ideal for engraving, but should be right up your alley:

http://www.youtube.com/watch?v=sC2urdg_bqg

The DXF format that is provided will not read into LazyCam correctly. I believe the problem is that LazyCAM does not support splines. It is my recollection that D2NC also does not support splines, but I would not swear to that. I used AutoCAD to import the DXF, exported a WMF and then read that into LazyCam fine.

The artwork vendor was seeking a less expensive alternative to AutoCAD and after a bit or research I discovered that a vectri program called Cut2D reads in DXF files that contain splines and then can output any format you need. It works great and it is $150. There are a number of other nice features worth considering if you are interested in engraving and blade cutting from vector data. A functional demo is available and it is a LOT of fun to mess with.

Both D2NC and another utility program from http://www.cncwrapper.com/ work very nicely to wrap the image around a cylinder, if you have a need for that. The wrapper program is only $20 and is worth it just for the nice G-code editor in my opinion.
 

844

SmoothStepper USB / Re: Whats the current developement state of the SS?

« on: April 23, 2010, 11:31:33 AM »

Bob,

You mentioned that you have 'been thru' a G100 and a smoothstepper. I took that to mean you were not using either, but on second thought . . . .

Are you currently using the smoothstepper in a working machine? If so, would you say that known issues can be avoided and the product used with success, or is it still something of a crap shoot?

845

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 22, 2010, 12:41:35 PM »

My hat's off to Hood also as well as Himmy and many others for the generous time they spend helping others. My 4th axis project would have died without the 'swapaxis' tip which came from Hood. Instead, the project is slowly maturing into an actual useable product with several, possibly many people following along and duplicating it for themselves . . not to mention a spill over into servo driven lathe spindles which are borrowing the techniques.

I think this is quite a success and the kudos go to a lot of people, not just myself.

Latest neat addition is an indicator light to show when the 4th axis (or lathe spindle) is in 'indexer' mode. An indicator monitoring the lock status has been added and is shown in the latest video.

Speaking of which, I posted another video to answer some requests to demonstrate more shaving operations, particularly splines (gear teeth, pulley teeth, keyways, etc are also made the same way):

http://www.youtube.com/watch?v=B8l6lH4ydd4


I think that's going to be about it for a while. I am seeking suggestions on motion controllers/pulse generators equivalent to smoothstepper.

846

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 21, 2010, 05:38:58 PM »

Here is a fun accessory for anyone using a 4th axis:

http://www.cncwrapper.com/

Works great so far!

847

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 21, 2010, 01:13:37 PM »

News:

SwapAxis board has been tested with the smoothstepper and it works fine! 

848

SmoothStepper USB / Re: Whats the current developement state of the SS?

« on: April 21, 2010, 01:10:19 PM »

Wow, amazing site, you have there, Bob. I shall make a pont to peruse when I have more time.


Note to Smoothstepper owners: The SwapAxis board has been tested and works with the Smoothstepper.

849

SmoothStepper USB / Re: Whats the current developement state of the SS?

« on: April 21, 2010, 04:56:39 AM »

Yep, I understand about the shipping.  Just be aware there may be no malice aforethought.  Having worked with a number of small businesses, they will more often think in terms of wanting to cover costs than outsmarting their customers with clever marketing.

Perhaps, but I also e-mailed them about the shipping cost and got no response. There is a saying; "Don't expect to be treated better after the wedding than you were during the courtship".  Whatever hardware and software that I end up using might well be provided as part of the 4th axis package, so the vendor's attitude towards customers is particularly important. The shipping is just indicative, there are other red flags there. Having worked with small business, I'm sure you have seen the result of getting in bed with the wrong vendor.

Did you make that gizmo in your avatar? Amazing piece . . . sort of like metal scripshaw.

850

SmoothStepper USB / Re: Whats the current developement state of the SS?

« on: April 20, 2010, 02:41:28 PM »

Simpson, I could live with the shipping charge.  It's not crazy out of line when you consider they're probably trying to recoup whatever it costs them to pack a box, label it, and so forth.  There's usually more than just a UPS charge there is what I'm getting at.

After having been through a GRex and a Smoothstepper, I think the best answer on these boards is for Mach3 to publish a standard API for step generators.  The problem always seems to be with software.  If it could be written once, and reused across all the hardware, and if it didn't require custom plug-ins, then I think there would be more hope. 

I have to believe the Mach developers are tired of writing new interfaces anyway.  By now, there have been enough I would think they understand what's needed and could publish such an API.  Then it would be up to the board members to follow the API.  Maybe we could finally get one finished and well supported then.

It's not the $20, it is the ethics it represents to me. If they really need to make that extra $10, it should be added 'in broad daylight' to the price of the product and not 'slipped in', especially since they don't reveal the method of shipping, and give no options, only the price . . . .  I don;t like sneaky . . .  the entire pre-sale process, including greasing the bottom line by overcharging for shipping says something to me about a company.  Just a pet peeve of mine, perhaps, but I get that 'bad taste' in my mouth when I see stuff like that. I routinely ship world wide and I know what the costs are.

I agree about the API. I can't get comfy with smoothstepper for obvious reasons, but I read that there are 'several' motion controllers out there that work with Mach. Now that I have the swapaxis problem solved, I have started to snoop around a bit for a fast pulse generator so that I can get rid of the step multipliers, which cause a variety of ills.  It would be my preference to get something that will outlive Mach3.  Kflop is only one example, and at that it carries a price which may be fair considering it's capabilities . .  if it actually works . .  but I would not be using most of those capabilities, so it is not a particularly good value. Still, I was about to buy it to get on with my projects . . .  except for that taste.