New Ramps, Motors wont move

I recently purchased a new Ramps 1.4 with sprinter firmware but am having some trouble setting it up. None of my motors will move. I have the board successfully connected to pronterface, but all axis behave the same way. When I send the command the motor will make a little noise and appear like its trying to move but none of them will budge. It almost looks like when I send a command to move the motor instead works to stay in place. Like my old board constantly ran the motors in a hold position. That seems to be what they are doing.

I have checked all of the opto sensors, they are functioning properly. When I block one and send the command the motor does not make a sound. I have tried adjusting the pot on the motor driver and adjusting the firmware values for the opto sensors. I am using a 500w power supply with a few of the rails tied together. I know they are not mechanically blocked because my old board moved them fine. Do you have any suggestions? Maybe I can check for a certain volt/amp range going to each motor? Please help I have been stuck here for days.

Edited 1 time(s). Last edit at 11/03/2013 10:01AM by alecKarfonta.

Dunno what you had before but have you changed the motherboard setting in firmware to 33?

---

_______________________________________
Waitaki 3D Printer

Thanks for the reply.
I am using the sprinter firmware from [reprap.org]
I checked it has the board set to 33(ramps 1.3). Are there other values in the firmware I could tweak that may help?
I tried Marlin as an alternative but couldn't open it in arduino, it says it can only open .pdes.

Before this I had a Gen6. (I had to get new sensors since the Gen6 had part of the Optosensor 2.1 built into it's board)

What volt/amp should I get to a motor when it is moving?

Oh and I forgot to mention, I am using six optosensors. I know three is the default config, is there something I need to change in the firmware for that?
Sorry I am 3d printer noob.

Edited 2 time(s). Last edit at 11/03/2013 09:58AM by alecKarfonta.

Solved.

It was the maximum motor speed in pronterface. The default was 3000(in this weird version I have), I had changed it to 6000 just fiddling with random stuff. Turns out I had to reduce that to about 500 and they started moving. Makes sense, cant believe I didn't try this sooner. Hope this helps someone.

alec,
Thanks for posting this. I'm having the same problem with my motors making strange sounds as well. I'll try changing my settings in pronterface and see if that helps my problem.

The default setting is 3000 I believe - mine is set to that. Your problem might be the driver chip current needs adjusting.

---

_______________________________________
Waitaki 3D Printer

The settings in your firmware (max step speed and max acceleration) will override what Pronterface tells it if you give it a crazy fast speed. There is no error message when this happens. If your firmware is set up with rational maximums the motors should run fine with any nutty speed set in Pronterface. Because "stuff happens" it's a real good idea to have the limits in the firmware set to reasonable levels.

What would you say are reasonable values? Cause in my version of sprinter they came as: max_feedrate[] = {200000, 200000, 240, 500000}; which seems kinda high. and max_acceleration_units_per_sq_second[] = {100,100,50,10000}; which seem ok.

The problem I am having now is that the Z axis moves way too much on the 0.1mm manual move in pronterface. I am trying to level the bed but the minimum step it will take is like a whole mm. I am calculating the Z steps per unit to be (200*16)/1.25. Where motor steps = 200, microstepping = 1/16, and the threaded rods are M8(I verified with a digital caliper).

If I lower this value too much they just don't move. I tried fiddling with the driver current but that seems to be correct cause any changes to that make it not move under any software settings.

Edited 2 time(s). Last edit at 11/17/2013 11:51AM by alecKarfonta.

There is no one "right" answer to any question on these printers. It's always going to be a "that depends" sort of thing. That said:

1) For X and Y, I see little need for a speed over 300 mm / sec. I have mine set to 200
2) For the Z something in the 2 mm/sec range seems to be about right. You could argue for a 4 there.
3) For the extruder, a lot depends on which one it is. Numbers in the 20 to 60 range are common.

For a normal i3 direct drive, you z steps per mm should be 4000. With normal belts and pulleys you would be in the vicinity of 80 for X and Y.

If your acceleration is down around 100, you probably will never hit the max speeds. Prusa has a nice calculator on his site that shows this pretty well. He also has the gear and step / mm stuff on the same calculator.

If things are gucked up from storage, pull it apart and soak the bearings in motor oil for a week. Do the same thing for the rods. It's a pain, but it's cheaper than buying them all new. There's no guarantee the oil will do the job. If it doesn't, you already are torn down for the new rods and bearings. Bearings are cheaper than rods, I'd swap them first.

You might ask the guy what sort of rods you have. If you have real good rods and real cheap bearings, they may always have been tight. It's a tolerance thing ....

Thank you for your detailed response.

300mm/min works great for my XY speed, they stopped making this thudding sound when they move. And Z seems to like 2mm/min the best, but it still moves too much.

I will definitely try soaking these rods and bearings. I think everything is the cheapest possible. Oh and I have an i2.

I think it could be that I am wrong about my microstepping. I thought ramps(or is this set in sprinter) was 1/16 by default. But when I calculate with 1/8 it moves a lot better.

Edited 7 time(s). Last edit at 11/17/2013 12:58PM by alecKarfonta.

If you are running "right" with 1/8 step calculations, there likely is a jumper issue on your Ramps board (jumper missing, bum solder joint, short) or you have stepper drivers that are not what we commonly use.

Oh that must be it! Thank you Uncle Bob, I didn't know about those jumpers. I just checked instead of the default 1/16th configuration my board came with no jumpers on it. I will try to find enough jumpers and let you know if this solves my issue.

Yep that was the problem. It now steps perfectly, thanks again everybody for the help.

Edited 3 time(s). Last edit at 11/17/2013 05:13PM by alecKarfonta.