400w spindle upgrade problem

I received a defective 300w spindle. After figuring out the problem, Inventables agreed to provide me with a credit for the purchase of a new spindle.

I decided to upgrade the spindle to the 400w quiet cut spindle and was told by the customer service staff that I needed to also upgrade the power supply to the 400w one. I purchased both and received them yesterday.

When I installed them today, I found that the stepper motors were buzzing (corrected by lowering the current limiter pots). The z-axis needed current adjustment, presumable because the spindle is so much bigger than the 300w one.

Within 2-3 minutes, some smoke came out of the arduino / shield box. Investigating, I found that there is 48 volts on the power rail that supplies the spindle and the fan. The fan is only rated for 24v and the gshield appears only to be rated to 30v. This increase in voltage also explains why I had to adjust the current-limiting pots. The arduino rails are appropriately at 3.3v and 5v. I haven’t done much other testing as I’m worried about burning out the gshield and the power supply control board.

My old power supply was the S-400-24 and the new one is an S-400-48. It appears that I’ve been sent a power supply that is putting out too much voltage for the setup. I’ve sent a request to customer service for help, but am wondering if anyone on the forum has had the same problem.

The spindle and the new power supply were purchased from Inventables, after corresponding with them about this upgrade. They’ve been helpful thus far, so am very surprised that they seem to have sent mismatched parts and that I’ve got a non-functional machine for the second time.

Any help would be appreciated.

DC power supply must have pod for output adjustment, did you try to adjust.

No. In doing some research, it appears that I’m going to need to run the steppers off of the 24v supply and have a relay control the 400w spindle off of the 48v supply. I’ll be able to do it from parts that I’ve got at home, but very disappointed that this was not recommended by customer service and that I’m going to have to use both supplies.

Basically, it looks like the gshield can only handle 30v but the spindle will require 48v.

I’m hopeful that I’m wrong and that the Inventables staff have a better solution.

Hi @Bill,
I updated to the 48 volt spindle as well. The 48 power supply is only for the spindle. The 24 volt one powers the arduino , shield etc. The signal output from the shield triggers the speed control for the 48 volts spindle which also turns it on. Here is a link that shows more information http://blog.inventables.com/2014/06/shapeoko-upgrade-quite-cut-spindle-with.html
and a picture

Keep in mind that this post if from the old GRBL. You need to just use the spindle wires from your old shield to the speed controller.