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johnB wrote:

I wonder, is there a Raspberry HAT that can direct interface with a stepper driver ?

Thanks
Jonh.

www.instructables.com/LinuxCNC-on-Raspbe...i-With-GPIO-Control/

You are absolutely right about most of that, and it’s certainly many months in the future.
But one nitpick: what I want is not a perfectly synced machine/CAM system. It’s more a system where we don’t have to care about the sync. But let’s leave that aside for now. I can revisit it in due time and see whether it works the way I think it will or not.

Martin

The sort of thing you are imagining is a bit of a fantasy for our kind of lathe and use case. A perfectly synced tool table in CAM and LinuxCNC is unlikely to work, as you will never have enough tool holders to never have to edit them. Think drills. I can say from experience that the next size drill you need is never the one loaded.

Maybe on those big machining centers with chain type 60 tool magazines, but it is not going to happen on our set ups. 

In practice, there are two scenarios.
- You are making one off home shop/ tool shop parts. You have enough tool holders for  the most common tools, and you have assigned them pockets where they are most often used. For these jobs, you will often not program full multi tool programs, but use a mix of simple programs for more complex bits using a single tool and Lathe macros for simpler paths where you also manually swap in tools. 
- You tool up the machine for a production run. In this case you will go through and set up each tool, assign a pocket and if needed set manual break points for manual tool changes with our lathe. Tool set up is a fact of life in CNC machining. LinuxCNC can't know which tool holder you are planning to swap in manually.

There are many many more things to work through getting your lathe running under LinuxCNC before you even need to consider this issue.

 

It should work now.

I don't seem to have that handy. I will be back to the machine in a week or 2. I will make a backup and upload my configuration. What issues are you having?

Hi,
could you finally solve the following error problem with your delta Servos?

I am really interested to learn more about the problem and the final solution.

best wishes,
Gogonfa

That's a great condensed source of network latency reducing tips

Only quibble I would have is that:

setp hm2_7i76e.0.read.timeout 100000  

Is not correct as the hm2 read timeout is scaled in percent of the servo period

EDIT: actually that is correct as values larger than 100 are interpreted as ns

But a 100 usec margin is very small on most systems and will likely result in many
unnecessarily dropped packets .

Default is 80% of servo period and this is fine normally




 

How did you realise the integration loop? Is it possible to share your cia402.conf?

just checking if I can read my submitted post. I submitted one previously but do not seem to find it even in my recent post tab.

Rod share your tips please or add them to my guide ... I really like to learn something new about this topic!

Thanks

My ears have their own ring, so I get used to things like that easily. I would however love to dump the 30+ year old DC servos and Amps in favour of something more modern. Looking at the complexity of my electrical cabinet in comparison to modern systems makes me think there is room for improvement too. If I can get it up and running first, at least it can make some money to pay for its own upgrades.

Hello, I wanted to add my configuration files to help some of you.  I know many of you have been like me scowering around for answers looking up every possible key word to get your system up and running.  Now I don't have a spindle hooked up yet this is just to get X Y Y2 Z up and running.  There was some configuration in the Leadshine Parameters as well that had to be made. 1 of those is Parameter 6092 (0x01) had to change to 10000, not sure why, but it just worked.  Also make sure all the slaves correspond as well with the PDO's. Just remember this is very basic in what I had to do to get the servos moving and running with one home/limit switch per AXIS.
 
 
 

 

The next time I see that error, I will try those things.

I am working on an Ursviken press brake retrofit to LinuxCNC and decided to document my progress etc here, and probably ask questions along the way. If you have any hints or advice for me, feel free to say so.

This press brake came with a Compaq pc booting some form of MSDOS and a Mitsubishi FX-64M PLC. The press brake had been forgotten in a warehouse for who knows how long until the current owner ended up buying it. After installation in the shop, upon first power-up, it complained of a depleted PLC battery. Sadly, the new battery didn't recover the lost memory. After multiple unsuccessful attempts to get Ursviken to get the thing working again, they showed me this project. I said I think I can make it run on LinuxCNC.

I pulled the PC and the PLC and installed a "Fanless industrial mini-pc" with 4 ethernet ports. For i/o I am using Mesa 7i80HDT + 7i36 + 7i54 and Beckhoff ethercat EL1409 16-inputs and EL2409 16-outputs.

Original 10 axis configuration was:
Y1 and Y2 = left and right ram (top die height)
X = backgage forward/backward motion
R = backgage up/down motion
Z1 and Z2 = independent left/right motion of the two backgage fingers.
Crowning: This feature currently has a mechanical malfunction so the customer asked me if I could leave crowning as an option for later if he decides he wants it. I said yes.
VDT = variable width bottom die, appears to have been present on the machine at some point but was apparently deleted.
PSB and PSA = automatic sheet lifter with a height axis and an angular axis. My customer requested to remove that because it will be in his way more than he uses it.

Target configuration:
Y1, Y2, X, R, Z1, Z2, and optional crowning. Y2 is slave of Y1. Z1 and Z2 are independent, except they run on the same rail and must not collide.

I see this machine has tonnage control, but I do not find any electronic pressure feedback sensor on the hydraulic system. It does have two servo valves, one for each side, plus an electronic proportional valve for the entire hydraulics. The servo valves appear to pertain to motion speed for each side. I wonder if the proportional valve sets the tonnage? It might get interesting driving that proportional valve with a DC servo motor output. I plan to limit it to one polarity only and try to modulate it to about 50hz PWM. I think it might work to use a software pwmgen running at 50HZ in hal to set the hardware pwmgen to either 0% or whatever pwm % is the max mA rating of the valve coil.

X and R axis each have a Baldor 90VDC servo with tachometer feedback to the Cybelec servo amps and encoder feedback to the PC controller. The Cybelecs' drive power is set with +/-10VDC from the 7i36 card.

I will try to power the servo valves and the proportional valve using the DC servo outputs from the 7i54 card.

Z1 and Z2 axis are DC worm drive motors powered by fwd/rev contactors and basic encoder feedback to the PC.

Crowning is a common AC 3 phase induction motor on a worm gear box driving an ACME lead screw protruding from the left side of the bottom bed. It is powered by a fwd/rev contactor.

I’m heavily dyslexic, so I write it myself but let ChatGPT make it readable, even though it changes the grammar more than I’d like — it’s still better.

Regarding the question of manual tool changes, what I mean is this:

Consider that you have a toolholder with two tools in tool-changer position 1. Because you’re making a very complicated part, you need more toolholders than you have positions in the changer. In this situation, you will eventually have to exchange the holders manually.

What I want is for the machine to ask me only when my input is actually needed. I’m not too concerned about a few unnecessary moves.

What I do want to minimise is the number of times I have to intervene, and the number of points where I can mess up. That’s why I want a single point of truth for the pocket number on a ganged toolholder.

Edit:
Examples of when it should not do a manual tool change:
Changing to a different pocket that already has the correct toolholder in it.
Changing to the same toolholder but to a different tool mounted on that holder.

And if it does need me to exchange a holder, it should have already rotated the turret so the pocket to be used is positioned in front