Feed Rate

Discussions around the CAM Add-On of QCAD.

Moderator: andrew

Forum rules

Always indicate your operating system and QCAD version.

Indicate the post processor used.

Attach drawing files and screenshots.

Post one question per topic.

Post Reply
KHE
Active Member
Posts: 35
Joined: Sat Oct 09, 2021 9:54 pm

Feed Rate

Post by KHE » Thu Mar 17, 2022 11:20 pm

Version 3.27.1.0 Windows 11

I have just used the cam portion of qcad a couple of times on my imported cnc. Simple doors and a simple plastic part for a packaging machine. I started noticing the machine didn't seem to follow my speed a feed input from qcam. Today I did a simple toolpath. 24" diametre circle.
Profile 1:
24,000 rpm @ 800 ipm
Profile 2:
12,000 rpm @ 400 ipm.

I am not cutting. Just listening and observing. Both toolpath preform identical. Is there a possibility that I have entered something wrong in qcad of I have an incorrect setup? I don't see a speed command in the command line.

User avatar
Husky
Moderator/Drawing Help/Testing
Posts: 4935
Joined: Wed May 11, 2011 9:25 am
Location: USA

Re: Feed Rate input on post

Post by Husky » Fri Mar 18, 2022 12:45 am

KHE wrote:
Thu Mar 17, 2022 11:20 pm
Just listening and observing. Both toolpath preform identical.
What is the maximum speed (ipm) of your CNC?
Work smart, not hard: QCad Pro
Win10/64, QcadPro, QcadCam version: Current.
If a thread is considered as "solved" please change the title of the first post to "[solved] Title..."

User avatar
andrew
Site Admin
Posts: 9037
Joined: Fri Mar 30, 2007 6:07 am

Re: Feed Rate

Post by andrew » Fri Mar 18, 2022 10:24 am

Please indicate the post processor used.
Please attach your drawing file and G-Code output.

KHE
Active Member
Posts: 35
Joined: Sat Oct 09, 2021 9:54 pm

Re: Feed Rate

Post by KHE » Fri Mar 18, 2022 12:38 pm

Good morning Andrew

Thanks for your prompt response. I also sent an email to the manufacturer last night (Blue Elephant CNC). As it turns out the machine is set by default to ignore 'S' (speed) and 'F' (feed). My NK105 G3 controller had a parameter to change. I now have the machine following my g-code. I also see in the list of parameters the max. velocity of the machine is 10,000 mm/min (about 400 ipm) so I may have not seen the change as writen anyway. The machine only reads mm. I need to change my template file so G-Code (G41/G42) (mm) is default. Please confirm by saving the template with this g-code active it will default to it. I have attached the files as requested. I know I am solved but I have a question pertaining to the g-code. I am trying to learn how to read the g-code. I don't know what to open it with. I can read the basics in the command line of Qcad but it does not mean much to me at this point. I don't see anything to do with speed. It must be there as the machine is now following speed and feed as set in qcad.
speed and feed test.nc
(628 Bytes) Downloaded 294 times
speed and feed test.nc
(628 Bytes) Downloaded 294 times
One of the reasons I am asking this has to do with multiple tools. As it is I know how to create the tool paths in Qcad reasonably well. Some doors I make use several different tools. I can't save individual tool paths (or don't know how to). This means I need several files to make the doors. The machine stops at the end of each profile depending on tool use. It would be brilliant if I could somehow write a pause in the g-code so the machine would wait for me to make a tool change and then press start to restart the cutting. Even saving individual toolpaths within the file would be nice.
Attachments
Circle.dxf
(188.81 KiB) Downloaded 275 times

User avatar
andrew
Site Admin
Posts: 9037
Joined: Fri Mar 30, 2007 6:07 am

Re: Feed Rate

Post by andrew » Mon Mar 21, 2022 10:52 am

KHE wrote:
Fri Mar 18, 2022 12:38 pm
Please confirm by saving the template with this g-code active it will default to it.
If you use a drawing template for new files, yes.

If you don't use a template, you can also set the default configuration under:
Edit > Application Preferences > CAM > CAM Export > Configuration used for new drawings
KHE wrote:
Fri Mar 18, 2022 12:38 pm
I don't know what to open it with.
You would usually open the G-Code with the software that came with your machine and talks to the controller of the machine.
KHE wrote:
Fri Mar 18, 2022 12:38 pm
It must be there as the machine is now following speed and feed as set in qcad. speed and feed test.ncspeed and feed test.nc
The S codes in lines N40 and N120 set the spindle speed. The F codes set the feedrate (F5000, F10000, etc.).
It would be brilliant if I could somehow write a pause in the g-code so the machine would wait for me to make a tool change and then press start to restart the cutting.
Some controllers have a code to wait for some kind of user input (pressing a button, confirming in the controller software, etc.). You'd have to refer to the user manual of your machine or controller for that. Once you know it, you can create a post processor that incorporates that code before a tool change. Feel free to post back to the forum for help.
Even saving individual toolpaths within the file would be nice.
You can use the eye-symbol in the toolpath list to hide individual toolpaths. Hidden toolpaths are not exported.

CVH
Premier Member
Posts: 3416
Joined: Wed Sep 27, 2017 4:17 pm

Re: Feed Rate

Post by CVH » Mon Mar 21, 2022 11:22 am

KHE,

Remark that the feed for an arc or a circle is also limited by the machine maximum linear acceleration allowed.
It seems that this is usually over estimated and may be the source of positioning losses.

There may also be a arc Feed reduction factor.
That serves to keep the chip load steady ... optimal at the outer side of the cutted area.

Regards,
CVH.

Post Reply

Return to “QCAD/CAM”