Retrofitting Thor

[Chaz]

So, what the heck is Thor ...

Let me introduce you to my 2.x ton concrete mill I build some years ago in my double garage.

This is the full build thread, its a fairly long read - https://www.mycncuk.com/threads/9616-Th ... light=thor

Fundamentally, its a 3 axis milling machine, designed and built by yours truly, with zero / little knowledge but a ton of ambition (and cost).

It uses Panasonic Servos in Velocity Mode, coupled with CS Labs IP-A and their MPG module. It currently has a 6.8KW (nearly 10HP) 24K HSD spindle on it.

Here's some vids of first movements etc back in the day.









And then its first bit of machining, note the 'spectacular' and not so rigid plywood table for testing ...



and making some plates for itself (control panel) ...




Its not been the most reliable. We all know that Mach 3 sucks and upgrading to 4 didnt really help. We then moved and then Thor had no love for a number of years. I've recently got it up and running since. Mach 4 was still rubbish, currently using CS Lab's own SimCNC which looks decent. Its been stable however still get odd issues from time to time and simply dont trust the controls, not when I have rapids of 15m/min etc. It also one more system to learn, remember and be confident with. There isnt a lot of support and Ive needed to use some custom Python for simple probing and tool change routines.

I've made the decision to cut my losses and migrate over to Centroid Acorn. I'm hoping to do a custom rack of sorts which, if I can make it fit, will allow me some use of the tool changer functionality of the spindle etc.

And of course I need to change from velocity to position mode but Ive used these Panasonics extensively, so know that its possible.

[Chaz]

And some pics from when it was still nicely painted and finished.

[richardb15]

Crikey, a CNC 3 axis oil rig anchor, looking forward to seeing this up and running with Acorn! 15m/min with that amount of weight/momentum, frightening! I thought the nearly 1 tonne table on my Bridgeport was a hefty lump to be hauling around on rubber 8M belts

[Chaz]

Crikey, a CNC 3 axis oil rig anchor, looking forward to seeing this up and running with Acorn! 15m/min with that amount of weight/momentum, frightening! I thought the nearly 1 tonne table on my Bridgeport was a hefty lump to be hauling around on rubber 8M belts

Yep, the Spindle and associated bits are too heavy and it does rock the machine when it changes direction.

Got Centroid installed, Y is moving but only in 1 direction on both + and -. I've had this before, normally its related to parameter 4.2 where you tell it what type of Input Mode to run but cycling through all the options hasnt fixed it, so need to see how I've sorted it before.

I'm running 24V to the common point of the Step / Direction and then Step / Dir is each via a 2.2K Ohm resistor (Manual says 2K but I dont have any at hand). I might lower this and see if its the issue.

[Chaz]

I've managed to get the Y Axis working by removing the 2.2K resistors and that's fine.

The X and Z are Minas 5 drives, Y is Minas 4, they have slight differences. Both X and Z are only vibrating, moving very slowly, wont respond to a command. Ive programmed them Identically and both are doing it so a bit perplexed. Ive turned down the ridgidty setting, still doing the same. More fault finding ....

[Chaz]

Bit stuck. I cant get the A5 Minas Panasonics working. Its odd, they just hum and move slowly and dont respond. Must be a setting somewhere. The single A4 one is working well.

Ive got some other drives which I know will work but then I need to make new mounting hardware. Not keen on that ...

[Chaz]

I'm back to this after some time out of action. I cannot get the A4 drives to work. Noticed that if I go to the display parameter that shows what mode the drive is in, it says SPD control despite being set to Position via the menu. You can use something called C-Mode which offers a primary and secondary mode but I'm not using this and Ive not enabled / set this.

Any ideas?

Panasonic Minas A4 drives. The A5 drive is working perfectly fine.

Thanks

[Chaz]

OK, I assumed these were A4 drives, different menu to the other but they are also A5. I finally managed to get it in Position mode, helps if you chose the correct parameter.

I'm current stuck that I can only get it to go in 1 direction and it doesnt matter which config I use, I cant improve that. Going to mess with slightly smaller resistors and then if that doesnt work, Ill see if I can wire in one of there differential boards Ive got from Amazon.

[cnckeith]

direction signal might need inverted if you are sure you have it wired correctly

[Chaz]

Thanks. Thing is, I'm not sure.

On the Panasonics you have 3 different ways to wire these and also then have software options. I'm trying all permutations. The best Ive got thus far is movement which is stuck in one direction when I ask for X+ and X-. I've got some small boards that should be able to generate differential signals, trying to get them going.

Ironically the Y drive is working. Its the same series of driver but does look a bit different as its 1.5KW, not 0.75KW and there are some differences in the front panel / menu.

I even crossed over the Y connector and it does the same on the X axis, IE, one direction. So something with the drive. Ill have more time later and this weekend to experiment further.

I've got cheaper servos which Ive used plenty in the past on Acorn. The motor mounts look similar. If the shaft size is the same, I wont carry on with this struggle for much longer and just swap them all over.