Hi Ryan
A million apologies about my frustrations. Electronics is not my strongest point and so takes my feeble brain some understanding. Please don’t think I was in anyway accusing, I was just super frustrated after spending so many hours of work, making it as neat as possible
regards
Understood, we are all just trying to help you get cutting.
I really apologize for all the angst and confusion but, as we’ve all seen, it would not work for MPCNC, as originally shown. Ryan is entirely correct about there being no color standardization, so trying to instruct other builders to connect wires according to color is useless. While the difference between right and wrong in this case is just a couple of connections, it is confusing enough that I second Ryan’s suggestion to purchase the wiring harness and be done with it. Though a retired electrical engineer and knowledgeable of what needed to be done, I found it confusing enough in my “elder condition” to simply buy the wiring harness for my Texas rebuild… and it worked perfectly, first time.
Thanks everyone.
wired x and y steppers in series and tested.
It works fine…
Evening Gentlemen
I now have an X, Y & Z axis moving as should. All have been tested YAY!
if only Postie had delivered the 5mm - 8mm coupler and stepper 16T gears, I would have finished. Anyway, This hopefully short delay will give me time to learn how to do some test cuts.
I already have my first DXF file which I will be cutting, but to begin with I’ll do something simples…
Regards and Respect Gents
Hey Sauntson, Glad you got your wiring sorted. I’m going to go the route of auto squaring and use cat 5e/6 wiring so I’m going to have fun and games too but different fun and different games when I get started.
Anyway I got jealous of the quality of your prints and my old blue PLA prints cracked as they were printed two fast and two jerky. My corners cracked when I tightened them and my z mounts broke as I had the wrong coupler which was causing the threaded rod to be spun eccentrically like an egg beater, which massively stressed the whole gantry when turning the motor.
Anyway I got frustrated with the quality of my prints this weekend as they have been getting worse and worse. I thought it was because I switched to PETG for a friend project but when I switched back to PLA I was still having issues. Then I refocused on the spool dry box £5 from Asda. I realised it is quite a big source of friction on the spool so I cut up an old chopping board and drill some 8mm holes in the right places to attach bolts and bearings I had spare from the MPCNC build. I now have one of the spool rollers that you can print but I didn’t have a working printer so I made it quicker and dirtier by hand. I also turned my Cura slicing settings down to fine. 0.1mm layer height.
all this seems to be paying off. last night I set off a print for the z top motor mount and I found it this morning perfectly formed on the build plate. I always check the print starts well and then I leave it in a detached building to complete over night (no one put at risk)
Anyway thanks to this thread I’m back on my game in the 3d printing world. soon ill be cutting too at this rate.
looking forward to seeing your first cuts.
Hi Andy
Thank you for the comments about my printing. I’m sorry I seem to have caused you some frustration by my print quality.
From my experience of all things 3D Printing, my only comment would be 0.1mm resolution is not always the best result, I did many tests and the quality of 0.2mm was better and naturally quicker than 0.1. I used to print everything in 0.1 thinking the parts would look better…
I shall wait with interest re: auto squaring. I read about that but thought slow and steady. I may upgrade later if I need such an action.
I also have my "working spools inside a box with some silica gel beads and reduced all friction by carefully lining up the Filement mid height on the spool and also using a guide tube made of PTFE to the printer. This reduced friction to almost zero. Inside my dry box I have a fool mount which rotates very freely. In the beginning I read so much about filament absorbing moisture etc.
If you’d like to all over 3D printing let me have your contact details
regards
Afternoon Gentlemen
Today postie delivered my penultimate item for my MPCNC, these being the 16t gears
[attachment file=65182]
I now have one more item to receive. That’s the coupler. I guess I could print one but having these delays seems to help as I get time without rushing.
Today I plan on installing those tears, checking / adjusting the stepper driver voltage and again researching how to actually run the software for a CNC… I see many attach a pen first time and Draw Ryan’s Crown…
I have downloaded his file and think this could be a good start. Saves me having a massive mistake and routering gouges into the build board.
any advice greatfully received
regard
Hi Gents
Just checking. My stepper drivers DVR8825 are set @ 1.67v, Is a little excessive.
These are my motors details
12v x 2Amps =24watts
24watts / 12volts = 2A
Therefore
Vref = I_TripMax * 8 * Rs
Vref = 2 * 8 * 0.1 = 1.6V
Am I correct in thinking I should set it to 1.6v on a 12v system or lower, much lower?
0.7V is good. 1V is really pushing it and needs lots of cooling.
Excellent,
Thank you Ryan…
Evening Gentlemen
Well Interesting day. I attached all belts and tightened according to the instructions.The X axis moves to its full extent without issue. While testing the Y axis it is very temperamental. moves to its full extent and then moving the other way stops and judders. No reason to when or where it stops.
anyway, thinking it was stalling, I increased the Voltage for that stepper driver from 0.7v - 0.8 and then 0.85v. This didn’t change anything and it still “stalled”
So I decided to swap X - Y and vice versa. This is where it got interesting. both axis then responded without issue…
mmmmmmmmmm Interesting. so I swapped them again and did some more testing.
Eventually I found the issue. After much head scratching and testing.
The stepper motor wires are terminated with these connections
[attachment file=65218]
The Control Board connectors are for these,
[attachment file=65219]
Replacing the black connector for a white one cured the problem and so it must have been making and intermittent connection.
They say these things are sent to try us…
Regards
The black connector in and of itself isn’t a problem, those DuPont style connectors are correct for 0.100" spacing headers. Likely the crimps were bad…
Evening Gentlemen
Thank you Bill, you could very well be correct as I changed one today for new connector and crimps and it does full movements without issue. I’m sure once ive changed the other two, it will LIVE!..
Still waiting for the coupler.
Having a test print at a drag chain but most probably will just buy two or three 1 meter lengths.
regards
I’ve had bad luck mixing the dupont and jst-whatever connectors. I have a feeling it’s actually the size of the pins that is different. Or maybe the length. I’ve especially had trouble with a jst pin on a board and dupont socket ona cable. I had enough trouble that I bought a whole JST setup. YMMV.
getting there faster than me then. I’ve just started re inspecting all my pla parts. All the blue parts originally printed on my Anet A8 before auto leveling or an E3D clone hot end and bowden style extruder setup, well they are weak as shit and are all cracking. So i am slowly reprinting them all in white PLA. My printer is set to fine and is doing a great job day and night. should be ready to get to where you are at for this weekend and the wife has promised me a project day by taking our kids to my folks house for a few hours. 
anyway i hope to avoid your wire issues with direct solder to cat5 breakout boards but that might introduce its own funnies. Keep going pal you are definitely getting somewhere, probably there.
jeffeb3
Totally agree with you, i also feel the mix of connectors is causing my issue. As stated before, having changed one connector the issue as gone on the Z-axis.
Andy
Im so sorry you have hit this frustrating problem. I have hit a roadblock as postie did not deliver anything today, so I’m waiting, waiting, waiting.
hopefully the last part and replacement connector will arrive tomorrow and then I short push to having it completed
regards
Specs are 0.65mm pins with 2.54mm spacing on the DuPoint, 0.64mm pins with 2.50mm spacing on the JST-XH (rated at 3A). There are smaller JST sizes with 2.0mm or less spacing on them. I don’t know about the Rambo models, but the RAMPS models all seem to use the DuPont style headers.
Evening Gentlemen
Thank you for your Advice, these are the connectors in my Controller Board
[attachment file=65414]
I think they are a compatible with JST-XH connectors like these pictured below
[attachment file=65479]
Regards
Afternoon Gentlemen
Today the replacement terminals and housings arrived. First I removed the useless Dupont Terminal
[attachment file=65500]
Not a very difficult task, Then a task I quite enjoy. Attaching the new terminals with the correct tool
[attachment file=65501]
Finally after installing the housings and attaching them to the control board
[attachment file=“65502”]
I connected the USB, powered up the 12v Power box and gave the X,Y & Z axis’s a full movement test. Very happy to report that all axis now moved to their extremities without the previous issue as described above.
I am getting so close to a first cut.
