Specifications of what is required to complete machine?

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Mark Harris
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Location: Calgary, AB

Specifications of what is required to complete machine?

Post by Mark Harris »

I'm looking pretty seriously at getting a LitePlacer, but I'm trying to figure out what it's actually going to cost to get it setup. A lot of questions here sorry :) I just like to know what i'm getting myself into.

The website has:
The items not included in the kit are those that a typical kit builder is likely to have already or where adding them would not add value to the product:

Power supply
Cables and wires
Connectors, termination blocks, ferrules and other cabling accessories
Drag chains or other cable management
Enclosure for electronics
Reset/kill/safety switch and its mount (please don’t omit to have one in your build!)
Work table, screws to secure to machine to it
Computer
I can't find any specs on these, and having moved about as far around the world as is possible earlier this year, I gave away pretty much everything in my workshop/lab - so no stock of interesting bits and pieces.

* What is the powersupply for? What voltages/amperages required?
* What cables, lengths, conductor count, gauge, etc? Shielded/unshielded?
* Is there a list of connectors/blocks or a digikey/mouser/E14 bom/cart list?
* Drag chains are currently included, do I need any more than what is included?
* Any specs on the enclosure, suggested P/N?
* Is the kill switch just an E-Stop on the AC line, or something else?
* Any specs on the computer? I only bought my CAD computer with me but I wouldnt use that to run the PNP. If possible, I'd like to get a second hand machine or build something saving money wherever I can whilst not skimping on the things that actually matter.

In addition to this, a few other questions...
* I havent used the TinyG before, so:
-- * It looks like all the motor drivers are hard mounted on the board, how difficult would it be to bypass these and send the signals to "real" stepper motor drivers instead? TI make great parts.. but single chip stepper drivers have never impressed me much in regards to noise or precision. I'd prefer to run several Leadshine digital drivers instead. I saw an 8dB reduction in noise switching my CNC router to leadshine from analogue gecko drives, and oh so very smooth in comparison :)
-- * How hard would be to just replace it (ie, software wise) with a 32 bit processor like the SmoothieBoard?

* It doesn't look like it would be too difficult to replace the x/y motors with NEMA23 or 34's and a 3:1 belt reduction to improve accuracy and speed, I'd just have to machine a couple of new plates. Is the limit in the machine's accuracy the drive system or elsewhere?

* How open is the project to software refactoring? I've spent the past 4 years doing RF engineering but have a very strong background in enterprise C# dev (more than 10 years). I'd love to optimise the software and break it up into separate logical projects to make it easier to maintain/contribute to (as well as making it easier to switch out things like the motion controller ;)). I'd prefer to be able to contribute the effort back to the mainline.

* Is it possible to specify multiple tape strips for one value? For example, on Digikey i'll often order 100 2.2nF caps, and they will ship me a bag with 4x 25 prepack strips in it. Sometimes a panel will use more than 25 of the part, so can the system detect it has run out and move onto another row of them?

* Has anyone come up with a tool changer yet? An SRR1260 inductor weighs about 5000x as much as an 0402, and i'm not really a fan of manual work (even changing tool heads :P)

I'd be primarily using the machine for 5.5-6GHz RF prototypes, a panel or more a week. Some are pretty hard to hand place using tweesers (the way I've been doing it for years.. but i'm not getting any younger) because the parts are so dense and the pads are so small (Altium's high density option). I'm not so worried about speed, more about accuracy. Everything I do is 0402 except bulk capacitance, and most ICs are 0.5mm pitch or finer, many without leads (which is a huge pain for hand placement!). Some GPS filters are about the size of an 0603 but with 5 pads underneath. At $400 of machine setup per job to get some of the more tedious prototypes built by an assembler, the machine will pay for itself pretty rapidly I think. It also lets us quickly run off extra samples to send off to beta testers and retailers to try out.
JuKu
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Re: Specifications of what is required to complete machine?

Post by JuKu »

* What is the powersupply for? What voltages/amperages required?

24V, more than 5A

* What cables, lengths, conductor count, gauge, etc? Shielded/unshielded?

See http://www.liteplacer.com/wiring-the-motors/ and http://www.liteplacer.com/wiring-the-limit-switches/. Shielded CAT6 cables should work as well, two pairs have enough area (I haven't tried this, just passing forum experience).
Also two core cable for the lamps and solenoid valve. You need about 3m to reach the head and 1.5m to get to X motor + whatever extra to get to TinyG from machien corner.

* Is there a list of connectors/blocks or a digikey/mouser/E14 bom/cart list?

No. There is nothing special in the wiring, use whatever you are familiar with.

* Drag chains are currently included, do I need any more than what is included?

No.

* Any specs on the enclosure, suggested P/N?

No. It is optional anyway. Some people keep it on the table uncovered (like me), some have it under the table.

* Is the kill switch just an E-Stop on the AC line, or something else?

At minimum, a single pole switch on TinyG reset. I have that and haven't felt the need for anything more, but if you use the machine professionally (especially if there is more than one people in the company), do check local regulations.

* Any specs on the computer?

Windows, OS support for webcams, HD display recommended (need at least 1280 x 960), three USB ports (or a hub)

-- * It looks like all the motor drivers are hard mounted on the board, how difficult would it be to bypass these and send the signals to "real" stepper motor drivers instead?

The enable, dir, and step lines are on the connectors, so it should be just a hookup issue.

-- * How hard would be to just replace it (ie, software wise) with a 32 bit processor like the SmoothieBoard?

If the "another" board has good feedback from position and status (a message when movement stops, current position etc), not very. If not, about impossible.

* Is the limit in the machine's accuracy the drive system or elsewhere?

There is no single limiting factor. The vision algorithms, the drive system, shaky mechanics and the way it is calibrated all seem to come into play simultaneously at this level.

* How open is the project to software refactoring?

Nobody is going to stop you. :) there is already one rewrite of it. (I hoped that it would become the basis of next major revision, but that version is so much different and written by a better programmer, that I have a hard time getting into it.)

* Is it possible to specify multiple tape strips for one value?

No, but this should be added, along with capacity info and more gracious failure if there are not enough components. Contributions are welcome. ;)

* Has anyone come up with a tool changer yet?

No ETA, but I'm working on it. My fourth try leaked, tomorrow I try to build ver5.
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