Hi there : )
Thought I'de show you our new creation! Based on the A3977 ic. There are a couple available right now if you go to the link here https://www.nordevx.com/content/bipolar-stepper-driver otherwise they will be available in a couple of weeks. Also there's a distribution board available soon to go with it. This would probably only be used for smaller cncs/diy types or 3d printing : ) However we will be making more industrial motion control which will be more pertinent to the cnc/machining community. If you have any questions or comments let me know.
$32, that's about £20 plus shipping for a 35V 2.5A stepper driver. You can get 50V, 4.2A stepper drivers for about £25 including shipping, less if you buy a few at a time. I'd spend the extra £5.
Also, I find it worrying that the voltage and current ratings you specified are simply the 'absolute maximum' ratings taken from the datasheet. The absolute maximum ratings are just that, they're not the parameters you should be running the device at. In reality the voltage rating should be lowered to account for back emf from the stepper motors, and the current rating will be less then 2.5A since you don't appear to have any heatsinks on the driver ICs.
Can you give me a link to the 50V 4.2A stepper driver? The price is always difficult to set but I thought I set the price lower than any other A3977 based stepper driver I could find...in the U.S. at least. Also yes those are absolute maximum values straight from the datasheet, and that's a great idea I'll add recommended voltages and currents. The heatsinks I talk about on the front of NorDevX.com which I'm going to do some tests with. Without a heatsink you really shouldn't go over 1A at the moment.
One of these:
A943A TO REPLACE M542 CNC 1 Axis 4.2A DC24 50V Stepping Stepper Motor Drive-in Motor Driver from Industry & Business on Aliexpress.com
Or many of these:
Wholesale m542 stepper driver - Buy Low Price m542 stepper driver Lots on Aliexpress.com
Or if you're after a driver similar to yours:
57,42 stepper motor driver 3A DC12 32V, CNC stepper driver board,8 microstep,free shipping Wholesale price-in Motor Driver from Industry & Business on Aliexpress.com
Fair enough I didn't spot that you'd mentioned 1 amp without the heatsink. I take it you're planning on supplying heatsinks as an optional extra?
Ahhh yes of course the chinese ones you can get very cheap in fact if you go on ebay you can find them for even cheaper around 5-10 dollars. I've never looked inside them so I can't say anything about them. Another thing that seperates us is the smaller form factor as these are rather tiny. Also these will be opensource. And yes most likely heatsinks will have to be added...not sure if it should be extra or not I will probably just throw them in.
Not your fault but the biggest problem with buying your drives is that EVERYTHING from the US gets hit this end for VAT at 20% plus a handling charge put on by the post office so in your case the user will have to pay £10 to £12 extra per drive.
These drives, which BTW are very good, not blown one yet, come in at £25 for 3 post paid from China but always come in under the radar.
New TB6560 DC Stepper Motor Driver Board 3A Controller TB6560 Driver Board | eBay
Ower Gert just bought some small hinges from the States without asking me. cost £40 plus £14 postage and got hit for £16 duty.
I could have got the same items from China for £9 all in.
I can understand trying to buy home grown but both China and the US are imports so you buy accordingly.
Last edited by John S; 19-09-2013 at 10:35 PM.John S -
Forgot to add being smaller does nothing for me, it's not like we have to cram it in a tiny box.
On machines space isn't a problem and going tiny just means more heat in a smaller area.
Can't see what the obsession with tiny is. Seen more than enough blown Gecko drives with tiny power traces on the board supposedly rated for 7 amps when the Leadshine ones use the hard shoulder south of Milton Keynes and never blow a trace.
Last edited by John S; 19-09-2013 at 10:40 PM.John S -
One day maybey we'll be big enough to have a location up there so shipping isn't an issue : ) It's form is tiny because it's efficient, not everyone will need that and it's totally understandable. For instance DIYers might prefer larger components to hand solder...although I have to say one stereo microscope and you can have a lot of fun with smd components as a DIYer. It is not however so tiny that it can't perform at its maximum.
Last edited by NorDevX; 20-09-2013 at 12:52 AM.
I'd like to see your thermal calcs, test data and pcb layout. The 28degC/W junc-ambient rating is based on the JEDEC51-7 standard board of 114*76mm (with vias to JEDEC51-5). Yours is only 14% of that area so your thermal resistance is much much higher (its proportional to area), probably at least 170degC/W allowing for all the other components on the PCB. With a total Rds of 0.8ohm you risk random thermal shutdown at 1A especially on the inner units on that distribution board. I'd certainly not consider using this product.
Adding a heatsink to the package will have some but relatively minimal effect, the thermal path is to the PCB.
I recommend you move to the A3979 chip. Its pin compatible, has an Rds of 0.5ohm and gives a higher microstep setting. The 3977 is an old design and due to be deprecated soon anyway.
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