Machsupport Forum
Mach Discussion => Mach4 General Discussion => Topic started by: gme on November 29, 2016, 04:06:54 PM
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I already have Mach3, but am thinking about changing over to MACH4. The decision is dependent upon some of Mach4's functionality. In Mach3, I can use "Formula Axis Correction" to insert a simple linear formula to adjust for X (or Y) being out of square in relation to Y (or X). For example, if X is out-of-square by .050 inches over 48 inches of travel, a correcting formula could be written: f(x)=X+Y*.00104. (.050/48=.00104). "Formula Axis Correction" is located under "Function Cfg's" > "Formulas" in Mach3. I've searched around in Mach4, but can't find anything that appears to provide the same ability to correct for out-of-square conditions.
Can anyone tell me where in Mach4 to find this functionality, or confirm that it doesn't exist?
Thank you,
Gary
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I have the answer from the folks at ArtSoft.. The Formula Axis Correction is not in Mach4, and may never be. :(
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Hi Gary,
Not to put to fine a point on it but what they are saying is to build your machine square and not depend on the software to do it for you????
Next thing they will be saying is that you need to remove the backlash as well!!!!!
Shame on them!!!!!
ROFLMAO
(Pardon my sense of humor)
Mike
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Hi Mike,
No offense taken. I've seen similar comments in about every post on this and other sites where someone is trying to workaround a poorly adjusted machine, rather than just fixing the problem. Just so you know, I would never let my machine remain out of square for any significant amount of time. I mention it, because I tend towards perfectionism. When I built my machine, I spent days getting everything dialed in to within .000 to .001" - a point of pride. ;D
However, there's more to the story. Consider this: I have a job that can't wait. As luck would have it, the gantry gets bumped, and sure enough, it's now out of square. Unfortunately, I don't have a day or two to fix it. So, in comes handy axis correction formula. It will allow me to temporarily correct the problem to get the job done, and then fix the misalignment when I have more time.
Gary
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Hi Gary,
Well said, but for every person tat needs this formulas, there are bout 1k that don't.IMHO Mach 4 is concentrating on things that have more mass appeal like threading, rigid tapping, engraving, etc.etc. They are also raising the bar slightly over Mach3 in my opinion. One of the problems with Mach3 was that it did "everything" which led to its "problems". Mach4 is being written to prevent the "problems" and it may not ever have all the functionality that Mach3 had.
Strengthen the machine so that bumping it won't knock it out of square, unless you mean bumping it with a fork lift or other massive object.
Mike
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I have a similar problem only with the table of the CNC. It is made of 1.5" MDF supported by 4" steel beams. When the humidity changes the edges of the table swell just a little causing the piece to not be flat. This is especially a problem when I use a v-bit instead of a standard mill. While I could plain he table every day, it is not realistic. A way of surveying and adapting for the table would be very nice to have. I know most 3d printers have this functionality built into the software. It automatically touches at several places on the table and adapts accordingly.
I know this is a little off topic but I thought it was related enough to post here.
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Bumped the gantry and now it is out of square? Need a formula to correct for that? Never in my 20+ years of working with CNC routers mostly Fanuc controllers have I ever heard of that. New one to me. I would say that rather than try to correct it with software the construction should be changed.
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Pedio
Our standard practice is to flycut the spoilboard every shift, this would be your 1.5 MDF table in your case, and then touch off the tools in the changer. this way the operator knows where the machine is at. It takes us about 2.5 maybe 3 minutes to flycut .015 off the spoilboard and another 4 or 5 to touch off the tools. This is on a 63x145 inch table. If flycutting is not possible then I would recommend scrapping the MDF and laminating 2 pieces of .75 Baltic Birch and finishing the bottom and edges.
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Fwiw, Formula Correction in Mach3 is rather buggy and not all that useful. There are situations when the formulas are not applied, which results in lost steps when it tries to jump back into position.
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Pedio
Our standard practice is to flycut the spoilboard every shift, this would be your 1.5 MDF table in your case, and then touch off the tools in the changer. this way the operator knows where the machine is at. It takes us about 2.5 maybe 3 minutes to flycut .015 off the spoilboard and another 4 or 5 to touch off the tools. This is on a 63x145 inch table. If flycutting is not possible then I would recommend scrapping the MDF and laminating 2 pieces of .75 Baltic Birch and finishing the bottom and edges.
Brian - Are you saying to use Baltic Birch plywood? I have thought of putting plywood under the MDF to keep it from sagging in between the ribs.
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Hi,
while not 'formula axis correction' there is a very useful software utility I use for making circuit boards called Autoleveller.
The blank PCBs are not exactly flat no matter how hard you try by skimming the table, vacuum hold down, you name it.
Autoleveller, theres a freeware and subscriber version, probe the PCB blank on a mesh pattern and then applies corections
to the Z axis of your etching/engraving Gcode from you circuit board program.
With Autoleveller I can successfully isolate route a circuit board with 0.035mm copper layer (standard 1oz board) by taking only
a 0.05mm cut. Never been able to achieve precision depth cuts like that. Now making SMT boards with 0.2mm traces 0.2mm apart.
Probing a big area of MDF would present a few challenges and you would have to pre-process your G code before running the job
but otherwise its indentical to making a circuit board.
Craig