Keeping things ontrack

After a short hiatus due to finals, Troy being gone, and a general state of busyness we started things back up. Oh and I think something or someone is starting to really spice up my life. I hope good things come of that...

CNC Power supply
All that aside, I've been keep things alive with my little airsoft business, Troy seems to have finished the basic shape of the new airsoft part that is under development. We are considering design enhancements, and the serious complications to actually fabricating the part. I just got the ball rolling on the powersupply for the control board thanks to Troy's help. We were able to clear up a few questions I had lingering. From his help I was able to determine:

-The powersupply must have a matching voltage to the control board. In our case we want it at full voltage of 36VDC.
-The current is variable, and will need to draw up to a max of 12 Amps, because each stepper is rated to 2 amps, but according to the information on the hobbycnc kit we need twice the amperage that the stepper motor is rated for. So with 3 steppers that adds up to 12 Amps in unipolar mode.

A quick look on ebay yielded a few subpar powersupply's, and a few way overkill powersupplies that cost 400$. With some searching we found Antek should be able to land us a quality Toroidal transformer for about 55$ + shipping. Troy already bought a bridge rectifier, and capictor. Although the calculations indicate that we will need to run another small capictor in parallel with the large 22,000 mF. This is because we need about 27,000 mF as dictated in http://www.geckodrive.com/upload/Step_motor_basics.pdf on page 11.

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Frame deliberations

After discussing 80-20 extrusion availability and cost we are considering getting some budget extrusions off of ebay. The only problem with this is that it will not be end machined or have any tapped ends. Going with the more expensive Bosch option will give us that, saving us some trouble. I think i'll need to get a price quote from bosch to ensure that ebay is indeed the better option.

The biggest issue I was encountering was mounting the Z-axis to the X-axis similar to 5-bears. After consulting Troy, he came up with a great idea to simply bolt the Z-axis to an intermediate base that serves no function other than to be a stationary mounting base.

The base most likely will be two 45-90 extrusions of full length attached to mic6 plate which will also mount the Z-axis. I'll need to calculate the deformation induced by the weight of the X-Y axis with a 45-45 section modulus to be sure they will be sufficient. If not I'll have to step it up to a stronger section modulus that can prevent the deformation.

Lastly, I still need to find out where to get the T-slot steel stock for mounting the fasteners for each axis.

The good news is after today, we have a real plan for all the major components of the CNC. Where to buy them, how we will integrate them. Now we are down to a few of the details, and the daunting task of coalescing it all together! But oh my, it is so much fun.