Help with wiring and other questions

I’ve finished assembling the frame and gantry, and I’m now starting on the wiring. anyone have any pictures of their wiring layout ? I’ve never wired up something like this and need some guidance on wire management.

I’m using cat 5 stranded with the pairs twisted together and crimped into Dupont pins. The steppers have single shell males and my connecting cables will have 4 pin shells with female pins. I currently have the frame sitting on a 30 1/2" square table, with 2 sides slid back 6" on their tubes.

Before I get too far, what is the orientation of the gantry? Tool mount plate facing left front or right front, or does it matter?

And, finally, I’m using ramps 1.4 and 12vdc .4a NEMA 17’s. Which stepper config is best Series or parallel?

Series is better. Less heat in the drivers.

If you have a choice in Ethernet cable, try to find stranded. The solid stuff is hard to crimp. If you have to use solid, consider adding solder after you crimp. You don’t want them coming loose.

Put some hot glue on the connectors when you’ve got them wired correctly. Using individual pins on the motors seems like your going to have loose wires sometimes and that makes a real mess. Hot glue isn’t permanent, but won’t vibrate lose. When you’re done, give a tug on each wire and make sure they hold. Doesn’t have to be strong enough for rock climbing, but you don’t want a minor snag to cause a failed job or worse.

The orientation of the tool doesn’t matter, just consider your ability to change tools and bits. The extra space is not symmetrical either, which some people don’t notice if they make the perfect sized spoil board.

Mostly though, there aren’t many mistakes you can make that can’t be unmade. It’s a pretty flexible machine.


Thanks for all the help.

All the ethernet cables I have cut up so far are stranded. I retired from IT in the local school systems and saved several short lengths of cat 5.

I built a interface board from some perf board and header pins. Got it configured for connecting the steppers in series.

Got a couple more cables to build. Should be moving soon…

Hmmm, are there any dupont 4 pint to ethernet adapters out here, perhaps with a board to allow easy series wiring? What is the max capacity of the connections 12v 1A per wire?

Hmmmmmm might be a less expensive way than using my custom wiring kits, a breakout board. Super clean…

Someone on this site posted an adapter. Can’t remember who though.

I purchased a Dupont connector kit with male and female pins and an assortment of connectors, and a crimper, so I’m building my own. Also have a lot of purchased jumpers with Dupont connectors.

After solving a couple wiring problems and getting Ryan’s help finding a bad A4988 driver, I’m happy to say my MPCNC is responding to manual input from the display and Repetier.

I am having a difficult time figuring out how to send gcode to the Ramps. Also getting an extruder temp error using marlin.

What size is the resistor used to sub for the thermistor? Can’t seem to find that. I have downloaded the crown test file. Is their a step by step tutorial for sending it to the MPCNC?

Sux getting old…


There is a guide. I believe it is the same page that has the crown file. But you can either load it with repetier and hit “print” or put it on the SD card and put the SD card in the LCD. There is an option on the LCD for “print from SD” when an SD card is present.

You’ll have to fix the temp problem though. The firmware Ryan has has a version without E0 and that won’t depend on a resistor. Did you flash the firmware yourself?

Ha, no way, us old farts ask for help learn a lil bit and keep going. The youngsters would give up go to another site and talk crap about how it wasn’t fully assembled and they couldn’t get it to work. Joking youngsters, just joking.

Heffe is right my firmware should have the temp work around built in. Make sure you haven’t tried to change the temp in repetier or anything. The board should show 170C at all times.