My experiences with a Dongda built CNC 3020-T, and th Controller Interface Schematics
Hi,
I'm new to the forum, and have recently purchased a small Chinese mill for use in PCB routing.
It's a CNC 3020-T.
The controller is a blue and white case, and uses a 36 way Centronics cable to connect to the mill.
This one is made by Dongda, and I purchased on Ebay from a seller in Germany, instead of direct from China.
The price was similar, and as I live in the UK the unit arrived within 4 days. Possibly much quicker than would have been from the source.
Anyway, it came in a large cardboard box, inside was a wooden crate with plenty of packing and wooden supports inside.
So, after unpacking, connecting up and loading/configuring Mach3 software it was time to try the first run.
No real drama, except the information in the documentation on configuring Mach3 ports and pins had errors and was translated in a rather confusing way.
The motor outputs settings as per documentation is fine except for the spindle, as even though it implies spindle control, the circuits (once I had investigated), are not wired up inside the controller.
Also, and more importantly the E-Stop circuit did not work.
This was due to incorrect defaults in Mach3, and no mention of the Input settings in the documentation.
The ones that work are as follows: Inputs
EStop: Enabled, Port 1, Pin 10, Active Low.
Now everything works fine, and the machine works ok for PCB milling, maybe not good for anything more serious such as aluminium, but for the price £330, I am very happy.
Now, I have already decided to fit some upgrades that seem to be a shortfall on all versions of these machine variants.
The usual limit switches, and spindle control are first on the list.
The circuit boards as fitted appear to allow for these features, with missing components indicated on the interface board overlay. So as a start I mapped out the board tracks and produced a circuit diagram as best I could (attached). One thing became clear very soon, there is a fault on the board layout that has a track linking +5V to pin 1 of the Input header connector. This would have messed up the feed from a potential limit switch signal, but I intend to correct this issue over the coming days/weeks.
Maybe this is why the feature was never installed in the first place! But it is easily fixable.
As the mods are completed I will update the thread, hopefully for others to use/adapt for their own machines.
Re: My experiences with a Dongda built CNC 3020-T, and th Controller Interface Schema
Hi Bob,
I'm new also and discover that I just receive exactly the same interface board like you.
I'm very interesting about your research. I have the same issue with the switch limit and On/Off spindle.
Could it be possible to send me the schematic with a best resolution in PM ?
Thanks.