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

[ravihotwok]

Thanks very much Andy, very very helpful, Ive got the limit switches to try and sort tonight as well, im trying to run them as far away from the power cables as poss, but in some areas they will be very close especially the limit and power cables on the z-axis. Will have to see how I get on. Buying some MDF this weekend to make a sturdy table top and enclosure with a blow/extraction system, once thats done i can route the cables properly, when the cables come in close contact with each other I will try and think of some sort of extra shielding to help reduce interference (if thats the correct word).
Cheers for the positive comments :-) Helps keep my chin up with the build.

[Neale]

It's not a recommendation, but this works for me:

From the top, spindle power (screened CY) runs in the same cable guide as the Z limit proximity switch (unscreened 3-core) and Z stepper power (screened CY). Next level down they are joined by Y motor power and Y limit/home switches. These run together in about 2m of cable guide before splitting to go to various places (junction boxes, sockets on control box). Where screened cable is used, screens eventually go to star point in control box but screens are only connected at one end. Each cable guide also contains an earth wire which connects to the metalwork at each end of the cable guide to make sure that there is a reliable earth connection right from the spindle to the control box so I never rely on electrical connections via the linear bearings. As much as anything, this is to make sure that the touchplate connection is reliable.

I have had a couple of problems with the proximity switches but these are switch issues which I have been able to fix (and possibly due to using some of the cheapest switches available on eBay) and I have had absolutely no noise issues whatsoever from day one. Maybe it's luck although apart from ignoring advice to run power and switch cables separately, I have generally followed good wiring practice. I do also use 24V for the proximity switches (which my motion controller is happy to accept) and that also helps noise issues.

[A_Camera]

Well I managed to have a good session on the control box tonight and my first ever stab at soldering, its a lot harder than it looks.
First job was to solder the pins to the board for the motor connections and other plugs which in not sure of lol
Attachment 22075Attachment 22076

Sorry, but all the soldering joints you made looks like really bad work. I would redo this. Get a solder sucker like this...



...remove every large clump, make sure your soldering iron is not too large but is designed for the purpose and that the solder wire is thin enough, quickly melting and floating well on the surface. The surface must be clean and the tip of the soldering iron must be kept clean using the wet sponge. I clean it after each and every soldering point.

Here are a few do:s and don't:s:



You need to practice on something which is not going to be used, not something which you need later on for reliable operations. Get a magnifier and check/fix every point. You will get a lot of headache later on if you box this and start using. Even if it works now, it may fail at any time.

[ravihotwok]

Thanks mate, why are they bad? in the link you sent me it stated when the older balls at the top of the connection and doesnt make contact with the metal ring on the board it is bad, but the ones I have done which are balls but they are making perfect contact with the board rings? I will revist this though just want it clarifying so I fully understand mate

[ravihotwok]

solder sucker bought and arriving monday

[A_Camera]

Thanks mate, why are they bad? in the link you sent me it stated when the older balls at the top of the connection and doesnt make contact with the metal ring on the board it is bad, but the ones I have done which are balls but they are making perfect contact with the board rings? I will revist this though just want it clarifying so I fully understand mate

I can't spend time marking every point, but like I said, get a good magnifying glass and have a look at each one of them. Unless they are not looking like the one marked A in that picture I posted above, you have to redo it. Most of the ones I have seen in your pictures (not only in the one I linked to) are bad. If you have a ball it means the solder wire did not melt and floated out, or there was dirt on the surface or the iron or you did not heat up the wire you solder AND the surface you solder it to and so on... Just google "how to solder" and you will find millions of answers regarding soldering with pictures and Youtube video, so I will not go into more details.

[A_Camera]

solder sucker bought and arriving monday

Very good. Make good use of it, buy a few spare tip and filters also.

[Lee Roberts]

Ravi,

Just a couple of notes:

1. There is to much solder on each one
2. Get yourself some soldering flux, liquid preferable

The flux and soldering go hand in hand, when the solder "flows" better (you'll see the diffrence) because of the flux, it just works and you'll see what I mean about there being to much on each joint.

Flux isn't cheap depending on what you get, however if you get liquid flux you simply apply a very small amount, so it last's a long time.

If you keep application to a minimum you wont need to do a lot of clean up, in fact look for no-clean flux, I like to use isopropanol alcohol to clean any soldering/pcb jobs I do.

Links below for what I use, just dip your tip in the Kalafonia tin before each pass.

ALCOHOL BASED SOLDERING LIQUID FLUX SMD/RMA REWORK, REFLOW, REBALL, NO CLEAN

COLOPHONY/KALAFONIA Limited offer 40g for the price 20g tin Solid soldering flux

IPA 100% | 1 LITRE | Lab/Pharma. Grade | Isopropyl Alcohol/Isopropanol (99%) 1L

Look forward to seeing the rework :)

[ravihotwok]

sakes lads ive just bought some flux but its hard stuff, will up load a pic in a mo. Im going to spend sat afternoon redoing these solders, thanks for explaining it in detail, I thought it balled due to me putting enough into the area and the solder had no where else to go so created the ball. Now I know this isnt the case and can revisit it with the knowledge of what im trying to achieve.

On another note, I want to buy new steppers a mine appear to be proper crap. Any recommendations for 3 motors that will fit my machine? budget of £120 for all 3?

[Lee Roberts]

sakes lads ive just bought some flux but its hard stuff, will up load a pic in a mo.

Ok, well the better value option to what I linked would be to buy some solid Rosin like this eBay - Rosin Resin and mix it with the Isopropyl I linked to above, brake the rosin up and add to the Iso untill your happy with the viscosity.

Here is a video on that:



Don't know what flux you've got but i'm sure you can change its viscosity, again the Isopropyl is what you want but nail varnish remover is made from Acetone and Isopropyl is what you get from the Hydrogenation of Acetone, if you've got some nail varnish remover you could try mixing some with the flux you have already, keep in mind though that they put perfumes and other softeners in nail varnish remover so it wouldn't be the purest of fluxes.

I would just order some Isopropyl, its so handy for other things, Hexa the company I linked don't mess about so it should be with you sharpish.

On another note, I want to buy new steppers a mine appear to be proper crap. Any recommendations for 3 motors that will fit my machine? budget of £120 for all 3?

CNC4YOU is still the best place both on price and service, the motors are of the lowest inductance we can find vs other things, link below.

Link: https://www.cnc4you.co.uk/Stepper-Mo...YGH301B-Nema23