Novamill will not connect - limit switch error

Information and questions about Denford CNC Control electronics, general electrical issues, cables, diagrams, stepper motors, drives etc...

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Posts: 2
Joined: Mon 12 Dec , 2016 11:12 am
Hardware/Software: Microrouter v3

Re: Novamill will not connect - limit switch error

Post by tryagain10 » Mon 12 Dec , 2016 12:17 pm

Hi Giles

Was it a new board from Denford or did you find a recon board?

How much did it cost?

Posts: 23
Joined: Sun 26 Feb , 2012 19:47 pm

Re: Novamill will not connect - limit switch error

Post by Giles » Mon 12 Dec , 2016 16:53 pm

I got the top board and driver biard second hand for £100

Someone had a mach3 conversion for sale on ebay so i asked if they still had the old boards.

Posts: 27
Joined: Tue 13 Dec , 2016 23:36 pm
Hardware/Software: Novamill
- in process of upgrading controller to Mesa I/O and LinuxCNC
- retrofitting head with power drawbar
- and next year, raise column by 70mm

Microrouter V3

Micromill 2000

Re: Novamill will not connect - limit switch error

Post by madebymccoy » Tue 04 Apr , 2017 9:13 am


I've had a similar issue, but found it much harder to diagnose.

When I first got the Novamill, it was showing a limit switch issue. I was replacing the original top card with a Mesa IO card, so thought it would be an easy job.

After temporarily rewiring the limits, e-stop and guard inputs to the Mesa, I found the X axis seemed to be at fault. At one stage I had every cover and junction open, testing continuity and resistance. No faults whatsoever.

I left it on the to do list, and went through the process of finalising my wiring, with DIN rail terminal blocks and a cable loom for the steppers (to the Baldor lower board).

The X was proving a real pain. Under power ended up tracing the limit and testing, plus replaced most of the in panel wiring, or detached and reattached them. Nothing. Last check I found one of the ferrules on the new wires I'd added an hour or two before was at fault. And then it just starts working.

Okay so my fault? Nope. I'd been testing the X axis for over a week and the new wiring was between the original limit terminal and the Mesa. I'd been testing using croc-clips, loop outs and probes. The only assumption I can draw at this stage, is that in diagnosing the problem I'd inadvertently caused and reattaching every terminal along its length, I must have fixed the original issue (but was masked by my own cock up).

I'm using the lower Baldor for the stepper drivers and the 12vdc supply for the Mesa and IO. Not using it for anything else, as the Mesa is PNP, so I have had to swap the limits/e-stop/guard from common ground to common 12vdc. The Mesa is not that worried about the line voltage, so I can afford voltage drops on the 12vdc.

With my error it appeared to be a terminal clamping a ferule or a wire not housed properly causing the flake out. Meh.

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