Feed Rate

[Trepole]

Hello, I have had my CNC for a few years but I still consider my self new at it. I am using Vcarve Pro 11 with Mach 3. Most of my projects have worked out well. My question is how do I control the feed rate, or the movement speed of the router. Mach 3 has three settings on the panel. I have tried all three, all seem to be the same. Have I missed something?
Thanks Tom

[Leo]

I have been using Mach 3 since 2007. I am not aware of 3 settings for feedrate.

Feedrate is controlled via Vectric Tool Database settings and output via the post processor.

The G-Code used by Mach3 that was posted out from Vectric will have a G-CODE line something like this:

G01X14.5F125
(this is just an example)

G01 tells the machine to move at a specified feedrate to the destination point
X14.5 is the destination point
F125 is the feedrate in inches per minute

Mach3 can override the feedrate anywhere from around 1% to about 250%

[martin54]

Why do you want to alter the feed rate ? if it is because you feel that generally your tool bits could be moving faster than they are at present then change the feedrate in the tool database but be aware that you may have to alter the spindle speed as well to maintain the correct chip load.
If it's for something more specific like the first pass on a pocket toolpath & you want to slow the machine down for that first full tool width pass then I do that sort of thing within the control software like Leo has mentioned you can over ride the feedrate from within Mach3, I don't use mach3 anymore but when I did I use to use the reedrate override & set the feedrate to about 60% of the programed feedrate for the first pass & then speed it back up to 100% once the full width cut was complete

[AboveCreations]

Hello, I have had my CNC for a few years but I still consider my self new at it. I am using Vcarve Pro 11 with Mach 3. Most of my projects have worked out well. My question is how do I control the feed rate, or the movement speed of the router. Mach 3 has three settings on the panel. I have tried all three, all seem to be the same. Have I missed something?
Thanks Tom

If this is what you are referring to, there isn't 3 different adjustments. There is only one.

I am not really sure why you would want to change the feed rate speed, so a little more explanation would help. Before ver 11 I did manually enter a bit of a faster feedrate when I was carving the roughing and the area that was carving was sometimes going over an area that was already carved. So if my feedrate was set from Vcarve at 40 and I was at an area that was carving very little, I manually entered something like 60 in the second box up from the bottom. It sometimes took a little coaxing to get it to 60, but eventually it would, but on the next G-Code speedrate change, it would go back to what the G-Code has. This was only to help a little with the rough cut of a 3D model. But I no longer do that since version 11 now has that option in the 3D roughing toolpath settings, which was my main reason I upgraded from 10.5 so quickly. I just love that feature!

But be aware, as martin pointed out... if it is cutting into the material and if you change your speed, you should be aware that the spindle speed needs to be adjusted with it. It may be better to just make separate toolpaths so your chipload is maintained on each carve.

[Trepole]

Thanks for all the help, I did check the tool data base and found the feed rate. My mistake was with the "jog rate" with the 3 settings. My Mach 3 screen is a little different. My concern was moving to a hard wood, oak, walnut compared to pine and foam board. Attached is a shot of my screen. I've had the CNC for about 5-6 years and have recently started to use it more. The machine was pre owned and in excellent condition and now discontinued. Legacy will still answer some questions. It works great though. I think the machine was originally set up for turning. That may explain the screen difference. Thanks again.

[martin54]

The screenshot for mach3 that AboveCreations has shown is the default screenset, there are various other screensets available, I used the 2010 screenset that ger21 on here sold for mach3 which also has some extra features not available in the standard mach3 set up.
If you want to set up your tools for cutting a different material then your best bet would be to use a new material type in the tool database. I believe the latest version has both hardwood & softwood as material types but not got software on this machine to check

[Leo]

I just use the default screen. Works well for me.

You should have the default screen still loaded.
Its not too hard to find it.
BUT - work with what you are comfortable with.

The JOG feedrate can be set to anything you want. I change that and cut manually quite a lot actually. Mach 3 is pretty versatile but you need to dig into it a bit. It is an older software and does have limitations but those limitations are pretty hard to find unless you really push the software.

[AboveCreations]

Same with me... I use the default screen and it works fine. I have tried some other screens, but as Leo said, stick with what you are comfortable. And I always reverted back to the original. I am not a mach3 expert and I wish the original coders would do updates, but I am not sure they care about it since mach4 is their go to product. One of my major gripes is whenever I power up my CNC computer and start mach3, I have to [Load] any file before I do anything. Otherwise, mach3 changes the XYZ coordinates whenever I load a new file. Very strange. I've ran into the machine carving into space if I don't do that. It is only when I first start mach3. If I have my machine zero'd to the XYZ and ready to carve, if I didn't load a file, (not always, but most times) when I load a file, the program scrambles the coordinates and throws my carving out of whack. Not sure if this is just my machine or it is a flaw in mach3. So to be safe, I simply load any file, set my XYZ and close it. Then I am good until I power up again.

[Leo]

When you close Mach3 it ask if you want to save fixture offsets.

You should click --- YES

[AboveCreations]

When you close Mach3 it ask if you want to save fixture offsets.

You should click --- YES

Yessir... I do that every time. But after I power back up and open mach3, when I open any new file, the XYZ scrambles or has random numbers already in the coordinates. Sometimes big numbers. As I said, I am not a mach3 pro. I've been using it for years, but this little quark can be costly if I don't open and close a file before I start the real project. Perhaps it is a settings that I am unaware of in mach3. Not sure.

[scotttarnor]

When you close Mach3 it ask if you want to save fixture offsets.

You should click --- YES

Yessir... I do that every time. But after I power back up and open mach3, when I open any new file, the XYZ scrambles or has random numbers already in the coordinates. Sometimes big numbers. As I said, I am not a mach3 pro. I've been using it for years, but this little quark can be costly if I don't open and close a file before I start the real project. Perhaps it is a settings that I am unaware of in mach3. Not sure.

AboveCreations, Is this what you are experiencing ? https://www.cnczone.com/forums/mach-sof ... 0-0-a.html

[AboveCreations]

When you close Mach3 it ask if you want to save fixture offsets.

You should click --- YES

Yessir... I do that every time. But after I power back up and open mach3, when I open any new file, the XYZ scrambles or has random numbers already in the coordinates. Sometimes big numbers. As I said, I am not a mach3 pro. I've been using it for years, but this little quark can be costly if I don't open and close a file before I start the real project. Perhaps it is a settings that I am unaware of in mach3. Not sure.

AboveCreations, Is this what you are experiencing ? https://www.cnczone.com/forums/mach-sof ... 0-0-a.html

I read through that and tried to understand the OP's issue. It doesn't appear to be the same issue as mine. My issue is simply that when I shut down mach3, I do select to save fixtures because it is at 0,0 for X and Y. The Z is usually raised to what VCarve is set for on the last toolpath. But now when I reboot (or shutdown) and when I restart mach3, it doesn't have 0,0 in the X and Y sometimes. And then sometimes it does... BUT! always, when I load a new file for the very time after first starting mach3, the mach3 program randomly put in x,y coordinates. Many times it is BIG numbers. I have to hit the zero in the X and Y to zero them. Then I can close out the g-code file and proceed with my work.

It's almost like the mach3 will not work properly until I load a file, zero out the coordinates before I do anything else.

[Leo]

I don't understand that.
My personal machine always starts up with the last fixture coordinate loaded.
Maybe I just have not noticed it, but to my memory I don't have that issue.
Something in the setting maybe? I don't know.
I will start my machine when I get out to the shop without loading a file to see what I see.

[AboveCreations]

Thanks for looking Leo. It is strange. And I've been meaning to ask the folks over on the mach3 forum, but each time I go there, I get stuff reading other things and lose my concentration because it is so huge... lol. Plus, I am not sure how to ask the question. I struggled to post it here, although it is quite simple. The mach3 program randomly changes the X Y coordinates whenever a new file is opened upon first starting up. It's not a big deal if I plan to re-setup my X Y after I load a file. But if I already have the X Y set at my zero, and if I forget that mach3 changes the X Y, it could be disaster. And it has happened a couple of times when I was in a hurry. Luckily I smacked the red shut off on the controller before it broke anything. lol. But I would sure like to know how to fix it because I don't think it is normal and never heard/read anyone else with this issue.

Everything else in mach3 works great on my projects.

[martin54]

Like Leo I never had any problems when running mach3 & I haven't had any problems with UCCNC which works very much like mach3, is it both sets of co-ordinates that jump about? or just the one?
Did mach3 come with your CNC machine fully set up or did you purchase it separately & set it up yourself?

First thing I always do on start up is home my machine so although I have never seen the DRO's jump about I could easily have missed it