Rotary table - automation

[woodchucker]

bummer.

 

[rabler]

bummer.

I was expecting to need to redo the board. Some engineers are really good at meticulously reviewing every last detail. I tend more toward the approach of plowing ahead with a test board, and making a few iterations to get there. In a corporate world it would be a matter of iteration cost vs the cost of reviewing everything meticulously. In the hobby sense, its just a questions of what I want to do and spend on it. First time I've built a circuit board with surface mount parts. Those .060" x .030" diodes are a pain to see the cathode markings and get them oriented right when soldering.

Obviously this approach would not be appropriate if I was building bridges, dams, or avionics.

 

[WobblyHand]

Respinning a board isn't a big deal usually. It happens more when requirements change, either due to not understanding them in the beginning, or your goals have been refined. Getting boards done these days is really inexpensive. The most expensive part is 1) your design time and 2) the cost of shipping these days. My last spin cost $7 for 5 100mm x 100mm 4 layer boards. That was including shipping, so I had to wait a month to get the boards. For $75 -$100 I could have them in under a week. Still a bargain if you are in a hurry.

I probably should respin my ELS board to make it more robust, and easier to mount, but really don't have a compelling need to. It works good enough for the application.

 

[rabler]

Respinning a board isn't a big deal usually.

Yep.

I haven't populated the current iteration, and have already added a couple of features to the "wish list" *if* I do another spin. But at some point, perfection is the enemy of good enough.

 

[Boswell]

Those .060" x .030" diodes are a pain to see the cathode markings and get them oriented right when soldering.

My first surface mount design I used really small surface mount form factor going for maximum density. Like you it was very difficult to assemble the board by hand. Since then, I tend to use the largest form factor that is available for resistors and diodes. They are much easier to work with and are still very small compared to their thru-hole equivalents.

 

[rabler]

My first surface mount design I used really small surface mount form factor going for maximum density. Like you it was very difficult to assemble the board by hand. Since then, I tend to use the largest form factor that is available for resistors and diodes. They are much easier to work with and are still very small compared to their thru-hole equivalents.

I managed to dodge that pitfall. I set 0805s as an easy default for resistors and caps. There are bigger sizes but 0805 is pretty easy for non-polarized parts. And even pretty easy for LEDs. Lot of diodes in SMA or SMB size packages. But tvs diodes, which I wanted to include on external wiring, are difficult to find in larger packages, so I'm stuck with 0603's for those at the large end, many are 0402 or smaller. I find I need to use a microscope, not just a magnifier, to see the polarity markings on those. Most of my chips are SOIC or TSSOP if I have to, I don't use flat packs.

I find density still gets constrained more by trace routing for crosstalk minimization than by part count/space. (Using a 4 layer board)

 

[rabler]

I've been focusing on the 3 phase power monitoring implementation primarily. The code base was getting big enough that it made sense to split it into two projects and focus on one of them. But that project is reaching a point, probably not complete, but a point where it is usable. Guess it is a beta test deployment. I'm using the same printed circuit board for both of them, some unused circuitry depending on which application, but close enough.

I took the rotary table apart and cleaned it, painted it, and got it reassembled. Even got the toothed pulleys for the timing belt mounted. But it doesn't turn easily, so something is not quite right. The damn thing is heavy enough that I can give my back problems man-handling it. And my fingers if I'm not cautious. Which leads me to think I may want to go ahead and build out my bridge crane for my shop. Those who followed my shop build thread know I had plans for that.

 

[Reddinr]

Oh heck no. I avoid those like the plague. Anything small enough to inhale is just too small for this OG, even with a microscope.

many are 0402 or smaller

 

[dkemppai]

Which leads me to think I may want to go ahead and build out my bridge crane for my shop. Those who followed my shop build thread know I had plans for that.

Looked at the other thread quick, but didn't spot the details. What sort of design were you doing for the bridge crane for the shop? (Curious, as I'm slowly working on the one in mine...)

Dan

 

[rabler]

Looked at the other thread quick, but didn't spot the details. What sort of design were you doing for the bridge crane for the shop? (Curious, as I'm slowly working on the one in mine...)

Dan

Yeah, it's a fairly long thread. I dug through the whole thing and found the crane details for you. Look at the page before that one for a floorplan layout. Covering an area of roughly 38'x22' in a 12' ceiling. Probably end up with about 2500 lb capacity.