Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Rikk on July 16, 2011, 06:01:09 AM
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Appologies for another newbie question but my heads exploding reading the various manuals and not getting to far.
I have a file to cut out the Z mount bracket, looks fine in Cambam and lines up perfectly with the material, same with cutviewer. But when I load it into mach3 the cuts are offset from the material.
You can beat me with a stick for not finding the answer with search or in the manuals, just tell me what it is first ;)
Below is what I see in mach3, and attached is the nc file
(http://rikk.smugmug.com/Scale-4x4/Machining/CNC-Conversion/i-j3q7sv8/0/S/zero-S.jpg)
Thanks in advance Hood ;)
...............Rikk
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What you will need to do is jog to where the code expects the X and Y zero position to be then press the zero at the side of each axis.
For example if you set the X and Y zero in your CAM as over the lower left corner of your material you jog there and set the DROs zero.
Hood
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That deals with X and Y but note that according to your code the top of material (TOM) is at 9.5 and you're cutting with +ve values in Z. Therefore you need to set TOM to 9.5. Normally you'd set TOM to zero and cut negetive.
Ian
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Stirling, the Z is a little of a red herring as I'm doing that manually at the moment to cut this mount which is for the Z axis.
Cheers Hood, I was doing exactly that, but on my main machine (no mill attached) and expecting everything to line up, tried it on the mill itself and it still looks offset but yep the cut is in the right place 8)
So is it actually meant to line up material/cut on screen?
Thought I'd use pen and paper while I work things out, much cheaper and safer ;) showed a friend a video of it doing this and got the reply back "oooh, you've invented etcha sketch"....git
Someone should make a tool with a spring laoded pen at the bottom, then you can use it exactly as you would normally testing auto zeroing etc as it's metallic but it would draw rather than cut 8)
(http://rikk.smugmug.com/Scale-4x4/Machining/CNC-Conversion/i-wJSGPV7/0/S/IMG1020-S.jpg)
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Stirling, aha read you post again. Right so in Cambam the material should be below the Z line NOT above it? Got ya..
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Hopefully not to confuse matters here is another way to do things that I often use.
Load the code then jog to a feature in the toolpath view, for example centre of the circle. Take a note of the X and Y DRO positions then jog to where you want the centre of the circle to be on your material, you can then type the numbers you noted into the DROs and regenerate the toolpath and the cursor should be exactly over the centre of the circle in the toolpath view.
For Z, some people like to have Z Zero as table surface and all material to be cut will be positive but the norm is material top zero and cuts negative. Its an individual choice but I personally prefer the material top as zero and cutting moves negative Z and the majority of machining world I would think the same, possibly router guys may be different.
I think a few people have made sprung pen holders, do a search and you may find something, certainly sticks in my mind I have seen it here.
Hood
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Hi Rikk,
Check out Sam's idea with the pen here http://www.machsupport.com/forum/index.php/topic,16012.msg108100.html#msg108100 ;D
Tweakie.
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Rikk,
Someone should make a tool with a spring laoded pen at the bottom
Here is mine:
http://www.machsupport.com/forum/index.php/topic,16012.msg108047.html#msg108047
RICH
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Cheers gents, i think the only thing with those pens (like mine) is no metal barrel so you can't use the auto centreing/edgfinding, I understand those are meant for doing drawings and not emulating a machined cut so for a different thing, oh well something to put on my to do list :)
I'll change my CAM file so the material goes below the zero, if I start off the same as everyone else now rather than change later thats better ;)
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no metal barrel so you can't use the auto centreing/edgfinding
An edge finder could be mounted along with the pen and an offset used after center finding or know the distance between them
meant for doing drawings and not emulating
somewhat limited but it does show the pathing and depending on the pen travel you can do pocketing to some extent, the
pen will track accuractely say around .005"
There is software for emulating code or you can just use Mach,
RICH
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Someone should make a tool with a spring laoded pen at the bottom,
http://www.widgetworksunlimited.com/CNC_Plotter_Pen_Bit_Thin_Line_p/cnc-pltr_pen_thin.htm
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Rich, I do have cutviewer and have been using it LOADS to see what is actually happening.....BUT, call me Mr cautious at the moment where I'm flailing in the dark (well perhaps there's a small light) it's nice to run this on the mill as well to see what comes out the other end 8)
Ger21, knew there had to be something out there (still going to make my own just to awkward ;) ), BTW just started using your screenset, VERY nice indeed :)
Just like to thank you gents again for being understanding and very helpful, it's a scary world out there getting started in CNC and you make it a much better place.
Thanks
..............Rikk
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BTW just started using your screenset, VERY nice indeed :)
Thanks.
Just a note. If you read page 9 of my Screenset Manual, you'll see a note in bold letters. If using the autozero functions, "The -Z Direction MUST be down"
This is so I can try to prevent you from crashing the Z axis into the top of the travel.
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Well, cut my first part today so well happy. Still need to cut the rebates in the other sides but after doing this I'm feeling much better about the whole thing. Most amazing thing is it fits 8)
It's only a test piece done in cutting board, but hey, have to start somewhere ;)
(http://rikk.smugmug.com/Scale-4x4/Machining/CNC-Conversion/i-TmxRSQ2/0/S/IMG1022-S.jpg)
(http://rikk.smugmug.com/Scale-4x4/Machining/CNC-Conversion/i-TfsZRMQ/0/S/IMG1021-S.jpg)
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Looking good :)
I can still remember my first parts cut on the clapped out manual Bridgeport that I converted and it too was Z Axis bracketry :)
Hood
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YEP Today it was spooky to press the Cycle start button standing in front of the machine, but next week you will be starting the machine from your cell phone while eating breakfast 5 miles away.
Good Job, (;-) TP