Problem with AM882 drivers !..... or it could just be me !

[Buba b]

So i got these drivers on the recomendation of the forum thinking they would solve the none existent problems i never had with my Gecko G540 . So if you want to avoid my rant skip to the last paragraph.

All i can say is these drivers have been a pain in the arse since i got them , they ran in analog mode from day one but with a high pitched scream so had to be run in digital mode . Well it took help and hints from Gary at Zap and Mario just to get them to start up in digital mode . I wrongly thought that digital mode would be easy , just plug in , tweek the settings and there you go but ..... oh no ! the dam drivers didnt even want to admit they were digital at the start !!! . The complete lack of any info on the net on how to setup and problem solve these drivers dont help. The manual is as simple as " if its not turning it isnt working " Chinese type answer.
So i walked away for 3 months , it was cold in the garage and standing there watching the dam £300 drivers make up there minds as to if they would like to turn a stepper just wasnt appealing. Now its a little bit warmer ( just joking! ) i thought i would have a look again and im nearing the point of putting the Gecko back in .

Ive got the drivers set up on 2 axis with direct drive , in Mach 3 with steps set at 200 , when i jog .100mm the machine moves .040mm can some one please tell me how the crap drivers can do that ???? . Ive checked the XML file so its not courrupt and just cant see the big error im making.
Im off for a sit down in a dark corner and dream of the Gecko,s i should have bought .... they would have worked first time ! had lots of info on the net and be able to count to 10 .
L8r all

[m_c]

Sounds like you just need to change the steps in Mach, or change the microstep setting in the drive.

[Buba b]

Thats what it sounds like ! if i change the steps in Mach3 using the settings page it comes up with 279.7999 steps ( a stupid number ! ) which i know is wrong, so its got to be how ive set the drive up. Im trying to find how to set the microsteps in the drive using the limited info manual. Back to my dark corner

[Jonathan]

Back to my dark corner

If you switch the light on you might be able to read the manual and see the switches or software to change the micro-step settings. Find what you've got it set to, then work out what the step/mm value should be.

[m_c]

Having had a quick check of the manual, the drive should come as default set by software (I can't see the exact value listsed anywhere), however you can quickly change it by using the DIP switches.

So you can either connect the drive up to a computer and configure it through the ProTuner software, or just flick the DIP switches to acheive what you want (page 7 of the manual at http://www.leadshine.com/UploadFile/Down/AM882m.pdf shows the settings).

[Shinobiwan]

Hi Buba

The drives don't have an analogue or digital mode, you can't switch between the two. Its a hybrid. The pulses enter the drive as an analogue signal, this is converted to digital using a ADC, the drive does its magic using a DSP and then its sent through a DAC to the amplifier and out to the steppers.

If your not getting the correct distance that's a Mach and user setup issue. The drives are set to 8x microstepping by default and I'd recommend leaving them at that. You can confirm by connecting the drives to the PC using an RS232 cable. What pitch are your screws? From there you can work out your steps per.

I'd recommend sticking with them, they're far superior to the gecko and any other analogue drive. They do things those drives can't do such as higher acceleration, smoother running and more speed. If you do sell them let me know and I'll have them off you for a mill conversion I'm looking at doing.

[Gary]

If you got them from us, you just need to contact us, and we will help you.

[Buba b]

Maybe one day il get to like these drives but the Gecko was tough to beat , it work faultlessly for over 2 years , was easy to setup and always cut parts smoothly and keeps tempting me as i havent sold it yet!.
There was a good resson for buying the Gecko G540 as it was just plug and play compared to plug and .....
Well theres something im just not getting " surprise .. surprise" . When i said analog i mean DIP mode and i understand that the drive will be setup in one mode only ie: using DIP switches ( which the mill ran fine apart from the squeeling ) or Digital ie: software and nothing runs correctly !.
So i turnned the light on and its very dim!.
The drives are set at 8x micro steps on direct drive 5 pitch metric screws , and with the steps set to 200 in Mach3 i get the measurment above.


So is this the calculation i need for the steps steps/unit = (steps per revolution) x (microsteps per step) / (displacement per revolution)

I just played with Mach3 and set Mach3 to 270 steps at which point i got the machine to move the correct distance , just got to work out why its this number .
Im the weak link for sure but theres still room for improved manuals on Chinese products.
Back to my corner !.

P.S Il never sell these drives because they have gave me sooo much grief , instead im more likely to post a snuff vid of me cutting them up with an angle grinder just for the hell of it ....... wheres that grinder....

[Ricardoco]

Ok this all sounds a bit familier to me. All my problems were due to the fact i hadnt correctly set the dip switches on my drivers.. Grrrr it drove me nuts. but I did it in the end with a little guidence from the guys on here.. one in particular .. Jonathan.. LOL

[Shinobiwan]

Maybe one day il get to like these drives but the Gecko was tough to beat , it work faultlessly for over 2 years , was easy to setup and always cut parts smoothly and keeps tempting me as i havent sold it yet!.
There was a good resson for buying the Gecko G540 as it was just plug and play compared to plug and .....
Well theres something im just not getting " surprise .. surprise" . When i said analog i mean DIP mode and i understand that the drive will be setup in one mode only ie: using DIP switches ( which the mill ran fine apart from the squeeling ) or Digital ie: software and nothing runs correctly !.
So i turnned the light on and its very dim!.
The drives are set at 8x micro steps on direct drive 5 pitch metric screws , and with the steps set to 200 in Mach3 i get the measurment above.


So is this the calculation i need for the steps steps/unit = (steps per revolution) x (microsteps per step) / (displacement per revolution)

I just played with Mach3 and set Mach3 to 270 steps at which point i got the machine to move the correct distance , just got to work out why its this number .
Im the weak link for sure but theres still room for improved manuals on Chinese products.
Back to my corner !.

P.S Il never sell these drives because they have gave me sooo much grief , instead im more likely to post a snuff vid of me cutting them up with an angle grinder just for the hell of it ....... wheres that grinder....

Why are you using 270? 5mm pitch with those setting should be 320.

If your using a standard 1.8 deg stepper then the calculation is

Step per = (360 deg / step angle) x microstepping) / screw pitch)

or

320 = ((360/1.8) x 8) / 5)

Since the AM882 only deals with integers then a x7 micro stepping would give 280 steps per.

Have you messed with the DIP switches from the factory settings? Put them all to the default. I never touched mine and set it all up in software.

As for the whistling, this is something you'll have to live with. Its harmless and is a byproduct of the drive constantly monitoring and refining the current running through the motor. You can lessen it using the motor tuning software included.