X-axis misses steps when moving

Both of my axis’s are weak but the X-axis wont even even move through air without missing a majority of the steps. I am using an arduino mega with this ramps kit (https://www.amazon.com/gp/product/B072B9PQDM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1) and the power supply and series stepper wires from your site. I checked the stepper driver voltages already and both are at .66v. I am using the marlin firmware from your site as well as an LCD full graphic controller. I have controlled it both through the LCD and repetier host and have the same problem. I have worked with 3D printers a lot and am aware what a reasonable torque for the steppers should be and these are way below. I have also used this same kit when developing my own 3D printer and had great results with it. I tested different belt tensions and checked square. At this point I am at a loss as to what it could be.

Pictures of your build?

Is a 50mm move exactly 50mm on every axis?

What firmware?

What steppers, my steppers want more power? What steppers, and I have no idea what voltage a A49 needs.


If it would move 50mm before skipping I could test that but it won't even make it 10mm. The slightest touch will cause it to skip steps. I am running the marlin that was linked from this site. I'll see if I can figure out what steppers. I bought this as a partially completed build. These are the only pictures I have and they are obviously before I bought the wiring and controller.

I talked to the person I purchased from and he said these were the steppers he got (https://www.ebay.com/i/332726774653?chn=ps&ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F711-117182-37290-0%2F2%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.com%252Fi%252F332726774653%253Fchn%253Dps%26itemid%3D332726774653%26targetid%3D313776934696%26device%3)

Those are really big and power hungry, make sure you set your drivers accordingly.

Is there a general equation to determine what to set the driver values given the stepper current/voltage/resistance?

Don’t shoot for full power they will get way too hot. but I would say .8 should be better, but the a49’s can’t handle much so you are going to need a fan on them. Don’t take this the wrong way but you kind of have a bad bundle, giant steppers and a49’s are not a good mix. We used drv8825 as they handle higher current better, and now the new board handle it even better, we don’t even use cooling fans anymore but we have 76 oz in not 90.

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That is a great article. from what i have read on other posts in this forum to reach the current these motors need i will likely need a cooling fan on my stepper drivers. I will give this a shot and update this thread with the results. thanks

It may not be relevant but for some reason my jst’s are very touchy, anytime I have step problems on one axis it always leads to a broken wire or connection issue.

Just to update this, I stepped the current up to 1A and ended up being much stronger. to the point where i was worried about damaging something if i tried to stop it. Looks like i will be upgrading the drivers. Thanks!