help with commissioning a machine

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john brooks
Registered Member
Posts: 2
Joined: Tue Jan 31, 2023 4:25 pm

help with commissioning a machine

Post by john brooks » Wed Feb 01, 2023 1:29 pm

hello all, i have been recommended, by a friend to try your software to run a cnc plasma machine. i am only commission this machine and getting it set up ready for production.
my background is precision machining on convectional machining and cnc over 40 years and now i run my own company doing mainly proto type work and anything once, i use ONECNC for all my drawings and tool parts but my Experience in running cnc plasma is very limited and the cliant i am commissioning tis machine has zero Experience.


I have converted and upgraded many cnc machines over the years but this one has presented me with many problems, from badly copied Chinese controllers and no documentation to being badly put together. after fixing the problems i can fix the machine is still not cutting acceptably. leading me to asking a friend that knows cnc plasma for advice, when he stopped laughing at me for even trying to use the software that came with the machine (fastcam) he pointed me to QCAD.

spec
cnc controler - f2300a
torch hight controler - avc168
plasma - lgk 2001gbt
table size 5foot * 12foot

Questions-
1 is your software compatible with the above components?
2 do u have a dnc editor for the above components?
3 is there any advice you can give on the competence of this set up, including any upgrade.
4 do you do mutable licenses as my client and i would both want our own copy of your software, because im doing this commission for cost and in return i get use of the machine.

best regards
john brooks

sorry for the poor litercy, very dislexic engineer.

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andrew
Site Admin
Posts: 9019
Joined: Fri Mar 30, 2007 6:07 am

Re: help with commissioning a machine

Post by andrew » Wed Feb 01, 2023 1:37 pm

First, please note that QCAD/CAM just creates G-Code from drawing files. It does not in any way directly connect or interact with a machine or its controller.
john brooks wrote:
Wed Feb 01, 2023 1:29 pm
1 is your software compatible with the above components?
QCAD/CAM ships with a number of post processors, some of which produce plain G-Code with or without G41/G42 for tool radius compensation. This might work out of the box or with small adjustments with your controller.
john brooks wrote:
Wed Feb 01, 2023 1:29 pm
2 do u have a dnc editor for the above components?
No. G-Code is text and can be edited using any plain text editor such as Notepad or TextEdit, etc.
john brooks wrote:
Wed Feb 01, 2023 1:29 pm
3 is there any advice you can give on the competence of this set up, including any upgrade.
Unfortunately not, we're a software company with limited knowledge about particular hardware except for the one we have on site.
john brooks wrote:
Wed Feb 01, 2023 1:29 pm
4 do you do mutable licenses as my client and i would both want our own copy of your software, because im doing this commission for cost and in return i get use of the machine.
No, licenses are strictly per user.

A single user license for QCAD/CAM is EUR 103 / GBP 92.00 (excl. VAT).

john brooks
Registered Member
Posts: 2
Joined: Tue Jan 31, 2023 4:25 pm

Re: help with commissioning a machine

Post by john brooks » Thu Feb 02, 2023 8:43 am

thank you for your reply andrew. i understand that your software creates the g code from the drawing but when i have retro fitted a cnc nill, it takes me a long time to just the post proseeser to get the g code to come out right depending on the controller. some times there is a pts file but mostly it is trial and error.
my question was not direct to the problems im haveing.. fastcan dose ont slow down the cutting speed as it goes into a corner and has no way of doing this in the set up apart from manual add g code after posting., dose QCAD have this as a option in pre post? is qcad optimized for plasma cutting and all is veruashions.
as i said plasma cnc is fairly new to me so i am have a learning curve on its problems,, my fav retro refit is the old interacs brig port and can set up the post proseeing file in my sleep, no matter what controler is used.. the FASTCAM software that cam with this m/c is clunky and seams to be not optimized for anything,, doing drawing on it, reminds me of useing a old copy of bob cad, picking cutting parth is unclear and the code it spits out is child like and seam to have no way of changing it pst , post prosessing...



many thanks john

CVH
Premier Member
Posts: 3364
Joined: Wed Sep 27, 2017 4:17 pm

Re: help with commissioning a machine

Post by CVH » Thu Feb 02, 2023 10:01 am

john brooks wrote:
Thu Feb 02, 2023 8:43 am
fastcan dose ont slow down the cutting speed as it goes into a corner and has no way of doing this in the set up apart from manual add g code after posting., dose QCAD have this as a option in pre post?
Sorry to say but path trajectory control should be handled in the CNC controller board and its software.
Besides maximum FEED speeds there should be settings for maximum accelerations.
Just like a car, a CNC setup can not take hard corners at maximum speed (FEED).
Then you could also compare a heavy CNC machine with a Truck and that needs wider bends than a car.

A basic example:
A large arc with G2/3 will not be an issue but radius=1mm might not be achievable at the given FEED there the required acceleration in X & Y exceeds what is possible.

Most good controllers have something that is called 'Look ahead Feed' (LAF).
When the next motion is not tangentially connected with the current motion the FEED must go down at the end of this motion to take the corner.
For the CAM output this are merely 2 G-codes ... Go from A to B and go from B to C.
QCAM does not do anything else but exporting these two G-code instructions.
It is up to the driver board to handle these instructions the best way possible.

A certain amount of play could be calculated in.
With G64 we can usually set the amount that the trajectory may fail the exact path ... Or 'cutting corners' to keep up the FEED.
G61 will set exact path meaning that a dead stop is required at a hard corner.
G61 and G61.1 is not a good idea with Laser or Plasma as it may scorch the material with the low average FEED in the corner.

Another solution is to cut corners in the design phase instead of the arbitrary motions with G64.
One could add a rounding at every corner so that the path is tangentially connected and the FEED can be locally maximized.
The controller will still have to decrease FEED at the rounded corner to comply with maximum accelerations.

Regards,
CVH

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