New corner tops and bottoms are on the way.
Steppers, 2560 and drivers will be ordered this week but given I’m into the 3rd week of waiting for a transmission mount from QLD I don’t imagine they will arrive before xmas.
We finally got a break in the rain this week so the CNC table has been pulled down and will be prepped for some nice gloss red paint. Good old SCA special.
Exactly how big are your steppers? 
Remember the old expression “on a slow boat from China?” it’s sad isn’t it when things arrive from the other side of the planet well before locally bought stuff does.
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NEMA 17 stepper is 42mm (W) x 42mm (H) x 44 (D). Depth can vary based on the motor torque and windings connector.
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Sorry Tim - thanks for that - I was making an oblique reference to needing a gearbox! (which in turn is a reference to an earlier mentioned car project!
All is not lost however - I’ve filed away that “variable depth” measurement for future reference.
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Missed that, too early in the morning and not enough coffee.
Have thought about 1:5 or 1:9 gearboxes though 
.
Like the idea of mounting my LR1 like a Maslow so it doesn’t eat so much space.
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Steppers have arrived and so has the Rambo kit.
Looks like I’ll be having fun this weekend doing a bench test.
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Question for anyone that has used a PC ATX PSU for powering the RAMPS board.
Checked the PSU with power supply tested and all is in good order.
Checked Molex cables for 12v and got 12.4v.
Rerun the check with molex connector again and got 15.6v.
Anyone gone the PC ATX route?
Thinking I should get rid of the cheap $10 multimeter and retest.
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I’ve used on on a RAMPS board in the past, but have switched over to a dedicated 12 V power supply since then because the i3 clone I build used the power supply as part of the framing.
All the how-to articles I read said the ATX rail voltages were likely to be inconsistent without a base load on the power supply because it expected the motherboard itself to consume a certain load, so they suggested you add a power resistor - one that could dissipate like 5 watts lot of heat. I had one in mine and didn’t have any issues. Have you added a resistor?
Thanks Tom.
Done some more reading last night and seen that suggested as well.
I’ll give that a try. Thank you for the assistance.
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Rightio brains trust need your assistance on this one.
Setup:
Without Stepper connected.
ATX PSU (Different PSU to the previous one used.) 12v to RAMPS 1.4 = verified stable 12v at RAMPS green connector.
A4988 drivers. Set to 0.45v and verified.
Stepper motors 17HS19-2004S1
Used the datasheet here https://www.omc-stepperonline.com/download/17HS19-2004S1.pdf
Swapped the Red/Blue wires So that it is A+ A- B- B+
As soon as I connect the stepper motor the voltage on the A4988 jumps to 1.7-2.5v
Heatsink is noticeably hot. Once the motor is removed the A4988 does not return to the lower voltage.
Marline firmware uplaoded successfully and Repetier host connects to the board.
Thanks for the help guys I’m a bit stumped on this one.
EDIT: Turns out I had the A4988’s around the wrong way.
Changed that around but still seeing issues with the voltage spiking to 1.6-1.8v when the stepper is connected and trying to issue commands with Repetier Host.
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Update:
Plugged in the LCD and tried movement from the Marlin menu without luck.
What voltage should I be betting on the motor pins 1A, 1B, 2A, 2B
Hoping I haven’t killed a motor but seeking advice before I plug another motor in and do the same thing.
Thank all.
It is really hard to kill a motor. Think of them as wires. Wires themselves rarely fail (the connectors do all the time, but not wires inside steel boxes).
I am surprised you rewired the motor. They are kind of standard. You can tell if two wires are on the same coil easily (to find a+,a-). Disconnect the motor, it should soon freely. Sorry two wires. If they are from the same coil (A or B), then the motor will have some very noticable resistance to spinning.
As long as you have two wires from one coil and two wires from the other coil, they will work. Every other permutation is just a different direction.
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Thanks Jeff. Tested if the wires are on the same coil by jumping them together and definitely noticeable resistance. I didn’t swap the wires until after I had tested them.
Well that’s good to know about killing a motor.
Will do some more testing today and see what I can find out.
The troubleshooting continues.
I have setup the below to test but still not getting any movement on the Stepper.
12V to RAMPS 1.4 on 5A connector is working.
VREF of A4988 set to 0.35
12v to A4988 tested.
Using Ryan’s V1CNC_Ramps-2.0.9.2.
Modified
#define X_DRIVER_TYPE A4988
#define Y_DRIVER_TYPE A4988
#define Z_DRIVER_TYPE A4988
#define X2_DRIVER_TYPE A4988
#define Y2_DRIVER_TYPE A4988
#define Z2_DRIVER_TYPE A4988
//#define Z3_DRIVER_TYPE DRV8825 // A4988
//#define Z4_DRIVER_TYPE A4988
//#define I_DRIVER_TYPE A4988
//#define J_DRIVER_TYPE A4988
//#define K_DRIVER_TYPE A4988
#define E0_DRIVER_TYPE A4988
#define E1_DRIVER_TYPE A4988
and
#define DEFAULT_AXIS_STEPS_PER_UNIT { 100, 100, 400, 100 } // { 80, 80, 400, 500 }
Steppers have resistance to turning when it’s powered on.
No noises or attempts to turn from what I can tell.
Endstops are registering as TRIGGERED but if I jumper Endstop X still no movement.
Using one of the spare A4988’s and Stepper (Non modified wiring) that haven’t been used so electronically they should be working.
Have also loaded the RAMPS Test Code and get the LED’s flashing but no motor movement.
Any help very much appreciated.
IT’S ALIVE!!!
So turns out the drivers were leading me on a wild goose chase.
2 drivers I knew were dead because one had that smoke escaped smell and VREF was reading at 0.01, the other was reading at 0.04. The 3rd one however was reading at 0.30 but when I tried to change it would not increase or decrease.
Also that one got mixed in with the 2 drivers still in the box and unused.
Lesson learnt here is double check the drivers.
And don’t keep failed components around, or at least be sure to have a separate “known bad” bucket to sequester them in.
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They have been added to the recycle bin now.
Grabbed a replacement driver so now I can get back to setting out the electronics in the case.
I use them for bb gun target practice.
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That’s a good use.
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Will hopefully have some more progress in the next few weeks.
Last of the parts have been ordered so just waiting on them to arrive.
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