Denford Software & Machines

Hi,
My spare novamill control box is now fully functional and I've decided to put it to good use, I have a set of compatible steppers and have them running perfectly on a prototype loom.

I'm hoping to make a 4 axis hot wire foam cutter, obviously I need to control a 4th axis. Having dug around in the machine setup it looks like the software supports a 4th axis but my understanding is that the denstep card is short a 4th stepper drive, can I connect one of my existing stepper drives into the denstep controller to provide an integrated control solution?

Fallback is a larger 3 axis foam miller and a garage full of blue snow every time i cut a wing!

I already have two types of stepper controllers, one type via RS232 8bit word (sync, dirver address, step count, speed) and one type with discrete pins for direction step, and microstep. These were bought to build the hot wire cutter and drive my telescope mount but I never figured out how to co-ordinate the cut for CNC with either type. the scope mount works great tho.

Any thoughts?

As always any help will be much appreciated.

Cheers
Barry

You may be able to tap into the 4th axis step+direction pins from the top board.
I'm not sure about earlier Densteps, but 4th axis step and direction signals go through the big 96 way connector from the top control board, down to the bottom I/O and stepper board.
In the past we have made a PCB to sandwich between the two in order to tap into the 4th axis signals. However, I'm sure we had some issue with the signal common (+ve or gnd - I can't remember what but seem to think we had to disconnect/connect something for the 4th step+direction pins to switch properly)
This post has the 96 way connector info in it:
viewtopic.php?f=54&t=2264

So, have you managed to create and run your own MINT files on the old box then ?

So it sounds like there is hope...

Small steps for me, currently I have the steppers running in a harness as a pseudo novamill via vrmilling. They all move via jog control and the DC motor drive output runs up to over 100v.

in my naivety i'd assumed that i could duplicate the settings in the vr milling novamill machine setup into a bespoke machine which would allow me to change travel limits step per mm and activate the 4th axis in the control box... does that mean I'm creating a new mnt file?

Always learning...
Cheers
BPM

Yes you could create a new machine.
The files to look at are:
\Config\Novamill.ini (copy and rename this XXXX - also edit the mint file entry to be XXXX.mnt)
\vrmilling\machine list.ini (edit this and add the new machine name and folder XXXX)
Novamill.mnt - copy and rename this XXXX.mnt - you will have to try and enable the 4th axis in here. I'm not 100% sure the older boards are capable of configuring a 4th axis, so I'd have a good look at the mint 1st, changing things like these and downloading it from MintMan:
CONFIG = 2, 2, 2 becomes CONFIG = 2, 2, 2, 2
SCALE = 1, 1, 1 becomes SCALE = 1, 1, 1, 1
etc...

VR Milling may not support the 4th axis stuff on the older boards either, in that case you'd need to concentrate on writing a .mnt file to do what you wanted - without using a PC you could have the axes jogging from inputs, or have fixed cycles which started when you pressed a button etc..

So which are the pins which would work the 4th axis if it all goes to plan?
only X, Y and Z are discussed in your linked thread.

Or would I set that in the mnt file?

I'm software litterate so there may be hope...

Barry

Have a look at the Eurocard schematic - all the pins are shown in there and are the same as the Baldor top board connector
viewtopic.php?f=15&t=2119

OK page 5 of the doc from your linked post only lists stepper 0 to 2, so where is stepper 3 IO for step, direction and microstep for the 4th axis? Or is that the option IO?

I prob need to look at a 4 axis mnt file, are there any 4 axis machines already listed in vrmilling that have mnt files with a 4th axis enabled?

Ta
BPM

Thanks for the reply on the eurocard page I must have posted there in error, wondered where it was. So am I out of luck making a 4 axis machine with a stock board? Or do your boards have a 4th axis?

The later Nextmove ST boards with a green or orange 7-seg LED have a connector which taps off the step+direction for 4 axes.

I've added a post with the step and direction header info on it:
viewtopic.php?f=54&t=3576

It may be that Denford have some older RS232 Nextmove ST boards available, or you can maybe find a similar way to connect the 4th axis on the Denstep top board

OK thanks youve been very helpfull so far,
Taking the next logical step, do you have any information on the denford top board re if the option pins are used as direction step and boost, and if the 4th option pin is used for home? I've found documentation that sugests the option pins are used for stepper drive but I dont have any details as to the pinout. If you have the information, which option pin is used for which function?

If i can confirm the pin allocations then I'll just solder a fly lead on the back of the 96 pin header option pin connections on the board and create a new connector for a driver card. Or do you have a scematic to confirm if the option pins are routed directly to the 50 pin ontion card connetor on the bottom board, again if so which pins are they connected to in the option card connetor.

Otherwise I'm going to have to enable the 4th axis in the mnt file and try to identify the individual pins with a multimeter, but this still wont help me to idetify if there is a dedicated home pin without blindly applying a voltage to the remaining option pin without knowing if it may damage the card.

Any help much appreciated
Ta
BPM

I've just had a look at the Denstep mint manual and it would seem that it was only capable of 3 axes anyway...
email technical denford co uk to see if they can supply an older Nextstep (RS232 only) top card (as these are often replaced in USB upgrades)

OK thanks for all your help.
At least I know that my current kit wont cover the job. I'm going to look into using my rs232 stepper drivers to controll a lightweight 4 axis machine but if that doesnt work out I'll drop technical a line and find out costs of a nextstep card.

Thansk again youve been very helpfull.

Cheers
BPM