I thought if anyone wanted to convert a 3020 to use with ChilliPeppr and

I thought if anyone wanted to convert a 3020 to use with ChilliPeppr and a TinyG they might like this model I designed http://www.thingiverse.com/thing:971553 for 3D printing.

It adapts the existing screws pretty well so that there’s no need to drill new holes, and it’s just the right height so if you cut a square next to the parallel port, the USB plug fits nicely.

Hey, this is really cool. I’m guessing that this goes inside the enclosure that has the toroidal power supply in it? Is there heatsinking on this too? What does the final picture look like?

Thanks! :slight_smile: I added a pic in the Thing on Thingiverse:

But yes, it fits right in the enclosure. There’s no heatsink because I had read on the TinyG support forums that they found heatsinks weren’t as necessary for the V8 boards, which I had ordered, they said air cooling was more than enough:


“We used to ship TinyG with the little heatsinks (technically “heat spreaders”) that you probably recall. We removed the heatsinks because we discovered that using a fan to cool the bottom of the board was much more effective. The heat comes from the bottom of the chip, and the chip bottom is soldered via a “power pad” to the top copper and from there to the bottom copper through a bunch of thermal vias.”

And if you notice the fan actually blows in a direction that forces air from outside the enclosure to come in through the vents at the bottom and the side, which passes cool air from outside over the biggest parts like the toroidal power supply, and including the bottom of the TinyG. There’s quite a noticeable breeze from underneath on the bottom vent when you have the enclosure on and the fan on, so I left gaps on all the sides so the air could pass through and it seems to be working very well.

Also, with the stepper motors that came with my 3020T, I had to turn the pots down to 25% (they ship at 50% or in the middle according to the guide, so halway between min and the middle is what I mean by 25%) following the guide on tuning the stepper current. Before my steppers were getting extremely hot during long mill cycles, they were 140F or more sometimes, almost too hot to touch, but they didn’t have any thermal shutdown issues… now after following the current guide, they run at room temperature even on really long mill jobs, it’s great. So I don’t think there’s even a big load on the TinyG to begin with.

Oh, I got it. Yeah, that looks nice in that enclosure. I guess I overkilled it on my aluminum heatsinks then.

What voltage do you run your TinyG at? I heard the higher the voltage you run it at (within allowed voltages) the cooler your stepper drivers run.

I just ran the power cable that was going to the original board into the new board actually… I suppose I should have tested to see what it was running BEFORE I did that :slight_smile: But I just checked it now and it’s running at 28.5V, so pretty close to the max (there’s a 30V label near the TinyG power pins)