My Cheapo Chineese 3020t mini CNC Build (more like improvements) leanring all the way

Managed to find a quick hour to do a bit on the machine with not the best results :-(.

Anyway I have wired up the limit switches and installed a second cable track on the opposite side to the motor cables to try and keep them separate. I have also drilled and tapped some holes to help clip the cables nice and neat

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I labelled each of the limit switch cables only to find I did the wrong lol, only need one cable per axis (2 switches)

Plugged it all in but its still not working correctly, motors seem to stop intermittently and something up with the y limit plug socket in the box.

I have not done anything to the settings apart from set the units per step which seem to be working now (when the motors don't stop)

I have sent an email to planet cnc and will do some more investigating tonight. Very frustrating as its starting to look really neat, just got to make sure the hardware has been assembled correctly

All a learning curve , be it a VERY frustrating one lol

Cheers

Right chaps, had a bit more time to play with the machine and iron out some faults, it appears my motors seem to stop working off their own accord, if you jog it one way then it move fine until it meets a slight bit of resistance, then it just stop's, but makes a horrible noise and tries to move each way slightly. My motors are anchuan 57hd0401-15sb. Im hoping that this is due to the severe lack of torque? My theory was to buy a new set of motors anyway with my installing the larger spindle, so I may purchase just one new motor to clarify that the low torque is the problem. Anyone had any experince with this type of problem?

https://www.youtube.com/watch?v=aJUiAyduROk

You would have thought even craptastically weak motors could move an unloaded x axis back and forth.

Seems likely to me that you may have some binding going on. Does it happen on all axis?

Morning Zee,
yes it does mate. I took the motor off the axes and it spins freely, but if you apply your finger to the output shaft it causes it to go mental

I spotted on another site about the motors something about these being 110v?

will try and find out

That's a bit disappointingly poor! even a little cheap nema 17 on my 3d printer driven from an onboard driver won't do that.

you may need to look at upgrading drivers as well/instead of motors... seems like they aren't giving the motor much juice if they stall that easily.

do you know what drivers you have in there at the mo?

Quote:

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Originally Posted by ravihotwok

I spotted on another site about the motors something about these being 110v?

will try and find out

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the motors won't be 110v, if anything they'll be talking about the psu input. most switching psu i've seen these days are 110/220v but some do require you to move a jumper.

one assumes if yours was set to 110v it would have gone pop already on 220v.

this is what I have mate

https://planet-cnc.com/product/mk34-...e-accessories/

looks like these are the drivers https://planet-cnc.com/product/motordriver-2-5a-32/


says current selectable.... i would say there is a good chance the current is set too low.

hmm, sounds interesting mate. Is this a variable that is changed via the software or manually on the control board?

Cheers

i would guess a jumper or pot on the board.

looking at the pics, you have a little dip switch to choose the micro stepping setting, so chances are the red jumper is your amperage setting.

edit - infact I think i can make out "Imax" next to the jumper in one pic, so thats almost certainly the puppy. Check what it is set to.

I will go and have a look at my pics now matey

Looks like your motors are 2.0A from a quick google (you may want to verify that yourself) so thats the setting you'd want on the drivers

right I understand exactly what you mean, the 4 little boards are the drivers, and there is a jumper on the 2 pins the other side to the 2 pins labelled imax

I have looked at the pics of my install and the jumper is on the same 2 pins as in the advert on the site ie opposite to imax. Should I put the jumper onto the imax pins?

yeah those are your drivers, what you referred to in an earlier post as your new driver board is actually your motion control board.

Again, only working from educated guesses given the blurry pics on their website an no instructions, but you have two variables you can set on those drivers. micro stepping and amps. the micro stepping looks like it is set by the small dip switch, which leaves the red jumper for amps. one assumes the different jumper positions correspond to 0.5, 1.0, 1.5, 2.0 and 2.5 amps... if that is a correct assumption then you'd want the second from last pins if your motors are indeed 2.0A

You have explained a hell of a lot this morning mate, in very easy terms. I really appreciate that mate, hopefully this will solve the problem but even if it doesnt I have just gained a lot of useful knowledge in regards to my box. In other news I have been in constant contact with planet regarding my issues, I have now begun to learn how to add shortcuts into the planet software, the jogging buttons on the front of the box itself now work which is a nice little touch, managed to get one limit switch working on the z axis but the others are wired wrong. Bit worried about the y axis though as when I plugged the z axis into it nothing at all happens, there is a i/o tab on the software which shows when a input is activated, put the z limit switch cable into the x axis and it registers a input but with the y axis nothing at all happens. Need to check my soldering but im pretty sure that is ok now.

your limit switch plugs are 4 pin... I assume that is to allow two switches per axis? sorry to state the obvious but have you definitely wired up to the correct pins in the plug for the Y-axis if that's the only one not working? You could have got the two switches crossed over such that the circuit is never closed and thus you would see no change on the IO.

yes mate pretty sure, the x and y axis have 2 switches wired in series (but I had the wires the wrong way around so I know they wont work. But on the z axis I only had 1 switch at the top of the z axis. When you press the switch the input on the software screen lights up. If you un plug it and place it in the x axis the input for the x axis lights up on the screen so I know the plug is working on the box. When I try it in the y axis nothing happens on the software screen which is making me think something is a miss with the box if that makes any sense mate

ah I get you...

I would double check your soldering on the Y-axis input then and also double check however that inputs/outputs board connects to the motion controller is plugged in fully and all required wires are present and correct.

If you have a multimeter you can check for any shorts on the input side, continuity between any of the pins would show that you have a short in there which would present a permanently closed circuit, thus any opening of the circuit by the switch wouldn't have an effect, giving the result you are getting there. Worth a check. You can also check that you have continuity between the board and the motion controller on that line.

As an aside, while nice to have, limit switches certainly aren't a necessity on a machine this small with weak motors like that - it won't have the power to damage itself and you can just start it up in one corner and set soft limits if you like. My first machine never had any limit switches at all, my second machine only had one set for "home" and soft limits for the end stops. Nothing to stop you from using it "as is" while you figure out your limit switch issues.

Cheers mate, I was aware of this, but I am also more aware of my lack of experience with these machines so wanted some safety precautions lol I still have a cork on a fork when I eat to prevent accidents lol

Yeah but my point is you are eating with a rubber fork anyway with this machine - it's not going to be powerful or fast enough to cause itself any damage from hitting the stops. The safety is built in by it's lack of guts :thumsup:

Just something to consider if the y-axis proves more difficult to track down than some chasing with a multimeter.

yeah totally understand, we have tested it with a multimeter and all seems to be ok I think (but it was my mate who tested it)

I spent a lot on this box so if there is a fault with this box or a internal board I would like to get to the bottom of it, but it is nice to know that it wont self destruct the machine if I do make a mistake when operating it,,,,,,,,,,,,which is inevitable :-)

While it's certainly always possible theres a fault in the hardware, I find 9 times out of 10 it's operator error and I've just done something silly or overlooked something. Do some investigating with a multimeter and you may well find it's shorted or not making it all the way to the motion board input.


I've found a schematic for your driver board - my assumption was correct... you will want to set the jumper to the second from last set of pins to allow it to use 2.0 Amps (has 2A next to the pins). That would explain your motors being so pathetic as they were only getting half an amp. You can also see the dip switch settings to set microstepping which will give you smoother motion. You will need to then adjust steps per unit to match however.

Attachment 22661

awesome detective work there, I was too busy trying to find a schematic for the whole box. didnt think to look for a schematic for the individual driver (actually forgot they existed)

here is a pic of the soldering I did, the limit switch plugs are on the bottom.
Attachment 22662
I cant see anything obviously wrong from the picture, to check the back of it would mean removing all the soldering to allow it to separate. Am I correct in understanding that I could program the end socket to act as the y axis input if it works?

Just an idea

Really the easiest way to check for shorts or a break in continuity between points is using a multimeter... anything else is just guessing. If you don't have one, they are fairly cheap and extremely useful when doing anything remotely involving electronics.

Yes it is probably possible in your software to assign whatever switch input to whatever axis, but I have no experience with the planet-cnc stuff I'm afraid.

The other thing to watch out for when soldering boards like this is the tiny whisker of solder that bridges two connections. Can be difficult to see. Can't tell from the photo, but a scratch between adjacent soldereed pads with a small sharp implement may detect something, if there is anything there.

right then massive update, followed your advice and the motorrs are running sweet. Back to the y axis limit switch I have also followed your advice and found there is a problem with the board, the pins are connected fine, but there is a break in the signal somewhere. Not sure where though. Think im going to gave to remove all the solders and remove it from the metal plate to have a nose ffs

many thanks neale, after all the grief I got about my soldering skills (or lack of) that was my first port of call but they all look fine. I think I have found the problem. I have tested all the pins against each other and found an inconsistency with limit plug no2. All the other tests on the other plugs behave the same but when I do the same test on the no 2 plug nothing happens. There doesnt seem to be a visible circuitry on the pcb so i am guessing this is enclosed within the pcb somehow? uploading a vid now

here you go chaps, excuse the crappy diagram but just wanted to show the test

https://youtu.be/ZIXuiPqgiY0

will be sending this info back to planet and hopefully get a new one sent out. This will give me a chance to finalise my wiring and get the earthing sorted. Just really motivated now thanks to you guys, getting the motors to work properly has really cheered me up.

possible when you were removing the solder you pulled up or otherwise damaged the copper trace around the hole... If so you should be able to see the trace in question, just scratch off the surface next to your solder blob and run solder to the trace. Alternatively you could run a small jumper wire or use a pcb repair pen.

Well bit of an update. I sent rhe pcd back to planet nd they emailed me back the day they received it saying there was a faulty bit of soldering on rhe board which they have rectified and tested. It is now back with me and I have re fitted it. This all took 3 days fir play to them foe sorting it quickly. Anyway I have been stripping the old control box to now house the stuff for the spindle motor

Here is the old box, I stripped it and sprayed it the same as the new control box as I want to mount the 2 together.
Attachment 22767

Now I mounted the power supply thing and bolted it now, I spaced it about 5mm up off the deck to help air flow, not sure if it is needed but though as there are vents on the underside it would make sense.
Attachment 22768

Now I have to find a place to fit the small pcb which has the speed control dial plugged into it
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Is it ok to mount this box directly ontop of my new box so it is nice and neat? I think the power will go from one box to another so it would be much neater if the cables were kept internal hence linking the boxes?

Well another update,

I have rewired the limit switches correctly as I did it wrong the first time, I have also added ground wires to the shielding on the motor wires to connect to the star on the box I made. With the new diy motor power box I have made that is not fitted to the top of the planet box and I have begun wiring it into the planet cnc controller, just waiting on some confirmation off Planet CNC that I have wired it in correctly. I have soldered and heatshrunk the wires. Also installed a e-stopAttachment 22934Attachment 22935Attachment 22936Attachment 22937Attachment 22938Attachment 22939Attachment 22940Attachment 22941Attachment 22942Attachment 22943Attachment 22944Attachment 22945Attachment 22946Attachment 22947Attachment 22948Attachment 22949 button but need to work out how the hell that gets wired in lol. One job at a time