Thread: Another chinese CNC router

Yep, I was just fixing the maths part of it.

Always did need my maths correcting

It was a simple problem that I should have found as soon as I installed the G540.xml file.
Thanks to rodm's earlier assistance when I was first setting up with the supplied controller, I did have the steps per set to 400. I should have noticed the change to 20000.

The X axis bearings weren't too bad as far as fit goes - no idea on the quality. It just needed a bit of loctite to fix them in place. Z axis seems OK. The Y axis will need a bit of thought. The hole for the bearing on the motor end of the ball screw has about 10 - 15 thou play, too much for loctite. The proper way would be to bore out the hole and fit a bearing with a lager outer diameter but that requires I get the mill assembled and aligned so the quick (temporary, honest!) is still to be found.

Hi Geoff,
For a quick fix use a shim around the bearing. Coke can cut up?

Thanks Rod,
I've got a pack of brass shim material I bought for tramming the X2 mill. Thinnest is .05mm which should do the trick.

With a bit of Loctite bearing mount as well

I've been somewhat slack with this project but now the big desk is out of the way, the CNC router is back on top of the To Do list.

Doing a regular browse at the tip shop, for $5, I scored a large electrical cabinet in which I'm going to mount all of the electrical components.
It measures 600mm x 400mm by (about) 200mm deep so there should be more than enough room for current needs and expansion.

The two catches that hold the door shut are broken so I need to fix them as I can't find any mention of the manufacturer (Hime) to ask about spares.

The cabinet fits nicely under the old printer stand/trolley I also got from the tip shop.

First job, clean out all the MDF dust in the shed (perhaps I should finish off that Dust Deputy project first )

EDIT: Added a (poor) picture of the catch.

Originally Posted by snowyskiesau

The two catches that hold the door shut are broken so I need to fix them as I can't find any mention of the manufacturer (Hime) to ask about spares.

G'day Geoff,
It looks like a standard industrial switchboard, so you should be able to order new catches through your local wholesaler (AWM, Middys... etc) and they'll supply you with some from Rittal or NHP. You wouldn't need original spares..
They probably won't be too cheap though... the cabinet you have would be around $500 worth, so you got a good buy on that

Thanks Malibu,
I shall check out the electrical wholesalers (after Christmas). I've also found a source of wing locks (as they are called) that may do the job for a lot cheaper.

Next job is to decide what needs to go in here and where it should sit. I have a NVR power switch that I'll mount on one side along with the emergency button. On the ohter side, there will be some 240V outlets for the computer. It would be more convenient to mount at least the switches on the door but I don't think that's safe or even a good idea. As long as the emergency button is easy to get at, having to reach down for the mains switch is not an issue.

Not a lot going into the enclosure so I wont be squeezed for space:

G540
VFD
48V power supply
12/24V power supply in case I need lower voltages for relays or similar.

This will leave plenty of room for future expansion (relays, ???)
I'd appreciate any links to similar power cabinets as used in DIY CNC. I'll head on over to cnczone.com for a browse,

most mechmates are set up using off shelf boxes like these or the guys custom make them out of sheet steel its common that the stuff is mounted on a sheet of allum that acts as a heat sink

I've just been looking at the mechmate forum, some nice layouts there.

The major issue is that in most of the wiring diagrams I've seen, the emergency stop is at mains voltage. For this reason, remote mounting of it is not a good idea.
Ideally, I'd like a low voltage control for the emergency stop switch(es) so I can mount them safely where ever I need to. These low voltages switches would drop mains voltage to the controller/VFD.

If you want to control the emergency switches through low voltage use a solid state relay. Alternatively look at Homann site as he has 24/240 volt relays for the G540.

You might want to consider putting the VFD outside the enclosure as the VFD is plastic cased and might cause some EMI problems. Don't forget some computer fans to circulate air through the enclosure.

Thanks Rod,
I've a few 12V fans I'm planning to use, hence the inclusion of the 12V power supply. I've a large heatsink that will go on the G540.

I remember a previous post of yours regarding interference from the VFD and that it was best to keep it separate. For the sake of keeping things tidy and dust free, I'll go with the VFD in the main enclosure but in a separate, perforated metal enclosure of its own. I can always move the VFD is this doesn't work.

Just trying to find some suitable plugs/sockets to use through the enclosure for steppers, limit switches etc. If I can get the extra bits I need ordered by 6:00PM, I'll have them tomorrow for something to do over Christmas.

After all this time, I've finally cut something with the 6040! No one could accuse me of rushing a project.
I think I was shamed into it by the Hobart Hackerspace who had theirs up and running in a day or so.

I had been putting it off until I had the new controller finished but decided to do a simple job as a test. At least I've joined the ranks of the CNC users, albeit briefly.

Now I feel enthused to get this finished. I've got an aquarium pump to replace the pump supplied (which lasted all of 10 minutes before expiring quietly)

The new controller is taking shape. It's like a jigsaw puzzle to try and decide the best layout..
Next job, build the table for it.

Originally Posted by snowyskiesau

I've got an aquarium pump to replace the pump supplied (which lasted all of 10 minutes before expiring quietly)
.

Be careful with an aquarium pump, they pump air not water, you need a pond pump