Geeetech

My default is 70? I haven't been able to commit the changes yet.

Also, to be able to change the Stepper setting I need to execute M2004 E "Number". Can you tell me the command to commit to memory?

Hi William,

Just a little background, I noticed the heat-sink wasn't attached properly on the A4988 (from factory), so I glued it back on with some Thermal Glue and wanted to confirm it wasn't a overheating issues when the vRef was at a higher voltage per your recommendations.

I wanted to check the formulated current before testing again at the higher 0.8v to 1.1v range especially as the stock vRef was 0.46v and your recommendations were 0.8v to 1.1v.

I've been looking at the formula for the A4988 (https://www.pololu.com/product/1182) and my resisters are 0.05 Ohm (SMD black R050). The motors are geeetech 42HS3418-20B18 and I cannot find the specification or more specifically max current for this motor.

Based on my calculations a vRef with a 0.05 Ohm resistor at 1A is 0.4 vRef (1 x 8 x 0.05 = 0.4), however your recommend vRef would mean 2A at 0.8v and one of your support guys suggested 1.1v, which is 2.75A. I'm expecting the motor to be something like 1.2A or 1.7A Max.

Can you please confirm my calculations are correct for the E180 and confirm your recommendations?

Additionally, can you please give me a spec sheet for these motors, or the Max Current?

Thanks,

The recommended voltages for the different colors of the A4988 are not consistent, depending on their resistance
RED(0.8-----1.2V)
purple(0.3------0.4v)

Can you let me know were the datasheets are? Did you also get that motor information?

all my A4988's are purple. With adjusting per the recommendations could this have damaged anything? When I adjust the Steps/mm I get skipping here and there when the vRef is stock 0.46v (I'm going to turn this down again and retest, but when I've done this before the skipping is worse). I still don't know the command to commit to memory when I change the Steps/mm?

Also if the recommendation is 0.3 to 0.4v, why are they factory set to 4.2 to 4.6? I'm seeing a lot of inconsistencies, which give me more and more questions.

I got your machine wrong, the correct purple voltage is 0.4-0.5V

William wrote: Mon Jan 22, 2018 4:24 pm I got your machine wrong, the correct purple voltage is 0.4-0.5V

It is all my fault!

Thanks for confirming, I'll be upping the vRef to 4.6 or higher.

I found out when M2006 is excutes (for feedrate) it commits the changes to memory.

If you can get me the other information is would be appreciated.