Cut Rifling Machine Help

Hi All

Looking for some help and advice with linuxcnc and basically to confirm what we're trying to do can be done with this software.

Bit of back ground, I work for a British company that makes rifled barrel blanks for precision firearms, mainly using the single point cutter method. We are currently using very old Pratt&Whitney sine bar machines, which are great and still produce very accurate barrels but we're struggling to keep up with demand and decided we need more cut rifling machines. To find more Pratt&Whitney machines is unlikely in the UK so we went down the route of looking into making our own CNC version of one. (There are some commercially available ones on the market but the're expensive and have little support for them in the UK if it went down and needed repair.) 

We have got to the point now where we have finished all the hardware tasks; such as building a bench top prototype machine, sorted the control box, wired it all in, installed linuxcnc and made some stepper motors move. To be honest these were our strong points so we took the easy route first and are now trying to sort the software side of it out. Looking back we really should of sorted this part out first before we committed the resources to the physical side of it.

 Basically really need help with a few points about linuxcnc that we've naively assumed can be done but actually might not be possible. These's are probably really stupid questions to people more experienced but we are complete novices.    

1) Can you make a complete custom GUI with ini and hal files to suit for a machine that doesn't behave anything like a mill or lathe in linuxCNC. (No current template like axis or Gmoccappy would really suit a rifling machine). Is it a task that realistically needs a very experienced user to do and is not feasible for novices to achieve in a reasonable time frame.

I know linuxcnc is installed with Glade to help develop GUI's but is it capable of developing something from the ground up?  

We need to have 3 set up screens and one job monitoring/status screens. The machine has 3 axis's of sorts, hence the need for 3 set up screens. First screen is for setting linear movements along the barrel. Second screen is for tool rotation as the linear axis moves it along the barrel. This will set the rifling twist and no of grooves to be cut. And the last one is to raise the rifling cutter hook in the tool after a set of grooves has been cut.

And all of this will need connecting up to the hardware side of things through, i'm guessing, the .hal and .ini files. 

2) If part one is possible with linuxcnc, can anyone recommend any reading/learning material to help us. Or any videos of similar projects to point us in the right direction.   Any help or advice much appreciated.

James  
 

Thanks for the pointers and links. Got some reading and understanding to do but it does look like we can achieve what we want with Linuxcnc. This is all a bit alien to us but will give it a try and hope we get somewhere. Otherwise its probably going to be outsourced to someone who does know what there doing.   

Yes....the movements between the linear and rotational axis's are critical, they must be co-ordinated and repeatable otherwise very bad things happen. We have used closed loop steppers for those axis's to help with this.

Once again thanks for replying  

James

   



 

Yes it seems a friendly community on here with lots of help. The problem I've got is the steep learning curve with this software and my lack of technical knowledge on the subject. I was brought up on manual machines and have had some experience on 2 axis CNC lathes for profiling the blanks but building a machine from scratch is a different game.       

That's interesting you used to target shoot. Might of used one of our barrels maybe? We come under Sassen Engineering now but used to be called Border Barrels based in Scotland. If your ever in the area of Birmingham and fancy seeing how we make our rifle blanks drop us a message.

Progressive rifling was one of the reasons why we wanted to build this machine. Its impossible to do on our Pratt&Whitneys sine bars and we've heard good things about it across the pond. Apparently slight gain, for example, 1in8 at chamber to 1in7.8 at muzzle really helps accuracy in certain calibers. CNC will also help with us switching over the number of grooves to be cut, every time we go from 4 to 5 to 6 its a 1 hour job needing two people really. Hopefully on a CNC machine it will be as simple as typing a number into a box.

James  
  

Yes, we have designed what we want the screen to look like and even the process of setting the job on paper. We did decide on four tabs/screens as mentioned before. It made sure you'd go in a set order and not miss anything that would crash it when starting the job. The rifling cutter heads are difficult to make so we try and protect them as much as possible. But looking at it now you could just fit it all on one screen.

I have done some basic configs to make sure the wiring, E stops and motors work and get to explore how the Hal and ini files work. Just did basic moves with some G Code. Still just reading and watching videos on customizing the GUI and how to connect pins to buttons etc.

Not to sure on starting from 0 to required twist. Im sure its been tried but ive never seen it done in person. I suspect its asking to much of the bullets jacket to go from 0 to 8 and may strip or disintegrate it upon leaving the muzzle. 

    

My preferred one was an immensely heavy Martini-action '22. Nobody else liked it, but I found the stability helpful. It didn't occur to me at the time, but it could have been very old.

It was. They went into service in 1871 and were used for 47 years. I think quite a few were converted to target rifles.
I have fond memories of a .310 calibre Martini Cadet which I restored and carried in a saddle scabbard down the front shock of a motor bike when mustering in the late 70s. Together we dispatched quite a few wild pigs. The projectile weighed 120 grains and lumbered along at about the same velocity as your .22.

Taking very small steps tbh. I cant stress enough how new I am to this again. Just started learning how to make buttons in Glade and connecting them up through Hal Config. 

Spent last night trying to install the touch screen drivers which hit a dead end quite quickly but think ive worked out how to do it now. 

I will post some picture of the machine at some point to show how its looking and for anyone interested