Denford Software & Machines

Am using Compact 1000, have been having this problem on and off for some time (months). But seems to be happening more frequently. No apparent reason as to why and can be any one of the three axis not just refusing to home but actively moving in the opposite direction - usually very very slowly. Can run the machine for several hours and produce a number of products with no hassels. Then it starts this homing nonsense. Or it can refuse to home and have an axis drive in the opposite direction right from booting up in the morning. Have tried numerous reboots, clicking homing micro switches, checking there is no dust build up around the switch etc. Then just as suddenly it starts to behave itself. And today something NEW! When tried to home the machine after a tool change, none of the axis moved, but according to the machine control display, the Z axis had traveled over 600mm and was still going! Gave up in disgust at that point, shut it all down and walked away. Any ideas?

Hi,
Usually if any of the axes start to HOME in the wrong direction (i.e. Moving slowly away from the datum switch) then usually as you have sussed out, it is dust / debris on the datum switches. First when the VR Milling boots up,don't home any of the axes, open the Compact door and press each of the datum switches and hold them in, if everything is OK, i.e. the switch, wiring and Input, then you should get a GREEN axis letter appearing in the Control Panel Window.

Regarding "The Z axis had traveled over 600mm and was still going!" problem, Check the fuse is OK on the Nextmove control board. Locate the Nextmove control board in the electrical panel on the Right hand side of the Compact, it will have a 7 segment display on it, the fuse is located to the lower Right hand side of the 7 segment display, check also that the clips that hold the fuse in position are tight around the fuse when it is replaced

bradders wrote:then you should get a GREEN axis letter appearing in the Control Panel Window.

You need to be running VRMilling version 5.22 or above.

Am usually fair concious of the dust build up issue around the switches and make a point of vacuuming them off. Is it possible for dust to get INTO the switch housing? Currently running V5.14.0.364 of VR Milling

Hi there,

Sometimes its best ro get a stiff bristled brush to give the datum switches a good clean out, if you do this and then put that latest Version of VR Milling on your PC you will be able to perform the tests as described above


Get VR Milling Ver 5.29 from here

http://www.website.denford.ltd.uk/suppo ... -downloads

You have then got the lastest version

Yes the dust does get inside the switches. I normally put the vac nozle next to the switch & press it say ten times. This normally seems to get the dust out from the contacts.

Sorry guys for not getting back earlier, have been very busy with getting my F1 Team ready for the International Comp.

Have looked at the pc boards in the machine, the board with the 7-segment display DOES NOT have a fuse on it - of any description. Unless there is a different fuse shape or body that I've not come across before. The board to the right of the 7-segement board, with lots of diodes, a large capacitor and what appear to be power transistors bolted to a heat sink, does have a fuse. This tested OK. The board directly beneath these two, has three fuses, all of which tested OK.

Any other suggestions?

Can you download the lattest version of VR Milling 5 and run that.

Next time you have the homing problem abort the procedure with the Esc key.

Then with the software still in the Home mode press each home switch in turn. The axis is displayed in green at the bottom of the positional display window when the switch is actuated if the switch is functioning.

If the switch contacts are jammed open with dust the axis letter will be displayed constantly (and the axis will move away from the switch slowley when you send it home).

The best way to clean the switch is to put a vacuum nozel up to the switch then manually operate the switch.

If you just use an air line or vacuum without operating the switch you will not clear the dust as it is trapped between the contacts.

Are you going to London for the World Champs?

What team are you with. We could meet and go through this.

Steve Oddy
Technical Director
Denford Ltd.

If the read outs are incrementing when you try to hame then it may be that the the fuse that on the Nextstep bottom board has blown, it is shown to the Left of the "Z AXIS MOTOR" inset.

Our agent dealing with this states "The catalyst for the latest issue seems to be a student pushing the E-Stop during a job."

Our Technical Director Replies

It sounds to me like there is a problem with the power to the axis drives.

The first thing to check is that the E-Stop circuit is working.

When you press the E-Stop there is a safety relay on the distribution PCB that drops out. As you release the E-Stop you should hear it pull in.

Better still take the cover off as you can see the contacts changing over.

The Relay is labeled RL1 and is about 60mm x 15mm x 15mm in size with 5 change over contacts.

I have seen machines where the E-Stop button has filled with dust and the relay is not energizing as the E-Stop is released and hence there is no power getting to the steppers.

Is this an older machine?

We changed the E-Stop button several years ago (it used to stick out much further than the current one).

There are 2 contacts on the E-Stop Button one is connected to the control card and reports the E Stop status the other drives the E-Stop relay.

If they press and release the E-stop a few times you will probably hear the relay pull in eventually and the machine will work.

May be worth vacuuming the contacts on the back of the switch while someone presses and releases it.

Hi Steve, am with Team Bio-Hazard, Menai High, Australia. I'm Ian one of the supervising teachers, Mike is the other, and is currently off doing the itinerate marking for the Industrial Tech. HSC practical work. It's getting on towards 10pm as I write this, will try to have a look at things again tomorrow (Saturday), pretty busy though, 5 days before we leave. Thanks for the photos, gives me a better idea of what's what on the boards. Talked to Daniel Bryan-Curnow of REA who gave some suggestions. Have found that while the computer thinks the axis is moving, can trip the home switch manually and the display will indicate that it has homed. All this started just after using the E-stop to halt a spigot clash. Haven't thought to listen for the relay drop out but have noted that the E-stop is displayed on the control panel and it does disappear after the E-stop switch is re-set. Used the E-stop to halt the apparent homing routine after the distance traveled on the Z-axis exceeded 600mm. If I get the chance tomorrow will try to check it out. Home to catch up with at the comp. All the best.

Because there are 2 contact block on the back of the e.stop button, it sounds very much like one is working - ie the one that tells the software when estop is pressed, but the other is not - the one that shuts off power to the axis drives.
Thats why the software/control think the axes are moving, but there is no power to them.

Of course it could still be a fuse to the axis drives which has blown (as mentioned before)

Morning all, 8am Sydney time here. Re-read what I wrote last night, especially that last sentence, wouldn't have thought that a glass of wine would have hit me that badly.

Will be in at school later today, I'm assuming the axis fuse you refered to is the single fuse on the board with the three connections to the axis motors. Did test this (continuity tester on multimeter), proved to be OK. Will try to have a look at the e-stop switch.

Incidently, if I install the latest version of VR-Milling, will our existing license file still be useable?

I'll get back to you later.

Yes the drive fuse is the one pictured. It should be a 6.3amp semi delay 20mm fuse.
The licence key is still the same. You should be able to install the latest version straight over the top of the earlier version.
You may also be best installing EasyUpgrader & checking that the NextStep csrd is up to date. It's the second option on the VRMilling install scren. Make sure you run it from the new version of VRMilling.

Sorry guys, it's been a day of stress outs, stuff ups, angst and dummy spits. Consequently I haven't manage to get anywhere near looking at the CNC mill. Don't know if tomorrow is going to be any better.

I am sure the problem is the E-stop relay not pulling in when you release the E-stop button.

If this is the case you will probably find pressing and releasing it a few times will make it work again.

If this is the problem post a photo of the E-stop button here and I will bring one down to the F1 finals with me next week.

Greetings all,
just on a week now that we're back from London, think I'm over the jet lag. Got to the CNC machine yesterday, removed each switch in turn and blasted them out using a can of "Dust Off". Re-intsalled and powered up and every thing seemed to work. Ran a job through this morning, SUCCESS!!! all is sweet. Fingers crossed that it continues to behave. Will keep you posted. Many thanks for all your help and suggestions.

regards
Ian

Glad its all up and running