Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

[JOGARA]

Not sure where I am going wrong here.

Putting my 2 parts together and finding that one looks like it is a rhombus though it is meant to be oblong.
The long sides are parallel and flat to the touch. But on both ends, the opposite corners are not parallel.

[jamesgates1000]

Looks like one of your axes isn't square

[JOGARA]

Hmm

Built a new enclosure for the machine. This meant I disconnected the PC and moved it for a sort time while I built everything.
Put it all back together and now the CNC stutters.


[edit]

It looks like turning the backlash toggle off stops this...

The machine earlier did lose a load of steps though and fked up my part -_-

[edit 2]
Now getting that "Is the Xpod inserted OK? it has ceased to respond..." error again god dam it

[njhussey]

The problem with "kits" of parts, especially electronics is that they are not well matched. The stepper motors will probably be high inductance ones, the switch mode PSU will be underated and so it wont run as well as it should. You'd be far better off getting your motors from Zapp or somewhere like that where they'll be good ones.

As. You're electrically minded building a custom P S U should be a breeze...

Sent from my HUAWEI VNS-L31 using Tapatalk

[JOGARA]

The problem with "kits" of parts, especially electronics is that they are not well matched. The stepper motors will probably be high inductance ones, the switch mode PSU will be underated and so it wont run as well as it should. You'd be far better off getting your motors from Zapp or somewhere like that where they'll be good ones.

As. You're electrically minded building a custom P S U should be a breeze...

Sent from my HUAWEI VNS-L31 using Tapatalk

Ill take a look at the Zapp stuff, thanks.

As for the power supply, if I get my motors from Zapp I can get an OP supply.
Those Chinese switch modes are pretty good though. I have a 12v one powering a lot of stuff in my workshop 24/7 as well as my 3D printer and CCTV system.

[njhussey]

The switch mode ones don't take back EMF from the drivers when the machine is decelerating. If you make a linear PSU with some nice big caps then this is best, and you can make it to the ideal voltage. You really want some nice 80V drivers and a 72V PSU...then it'll fly which is what you need to cut plastic. I cut UHMWPE at 8000mm/min, your matched set wont get near that.

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[JOGARA]

The switch mode ones don't take back EMF from the drivers when the machine is decelerating. If you make a linear PSU with some nice big caps then this is best, and you can make it to the ideal voltage. You really want some nice 80V drivers and a 72V PSU...then it'll fly which is what you need to cut plastic. I cut UHMWPE at 8000mm/min, your matched set wont get near that.

Sent from my HUAWEI VNS-L31 using Tapatalk

Hmm good point.
I am not too good with power supplies. As in making them. I typically just get off the shelf.

Have you made your own?

[Clive S]

Hmm good point.
I am not too good with power supplies. As in making them. I typically just get off the shelf.

Have you made your own?

There are only 3 main components (toroidal transformer, rectifier & a couple of caps) or you could buy one from Zapp

[JOGARA]

Isn't there a way to dump excess power coming back from steppers?

Like resistors or something.

[Neale]

Isn't there a way to dump excess power coming back from steppers?

Like resistors or something.

Unfortunately not. There are two main problems with the switch-mode PSUs in this application, although they are great and very cost-effective elsewhere. One is the back emf issue as mentioned, while linear power supplies dump excess power into the smoothing caps (one way to look at it, anyway). The other is that linear supplies are much more tolerant of peak overload. A switch-mode supply tends to hard-limit, maybe even shut down temporarily, if you try to draw more than rated current where a linear supply output will tend to just sag a bit which is not usually a problem. If you are now looking at Mach3, you might also consider something like a UC100 or UC300 with UCCNC which is looking like an attractive option these days. Still need a break-out board but it's a better option than using Mach3 and parallel port.