DIY Shapeoko CNC Router $350

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04 Dec 2012 15:03 #27180 by Gensor
Sorry for the long dissertation, but felt I should share my efforts to date.

1st attempt: Delusions of grandeur… I wanted to build a monster CNC router/plasma cutter. Therefore purchased many of the components listed below including (4) Ebay Sanyo servos. Debug of the servo (15) cables was difficult (use of diodes) and felt I was able to move forward with a power supply where support on multiple forums was not as fruitful. To power these (4) servos would require an ISOLATED power supply with 220VAC input and 80+VDC 15AMP output which I did not feel comfortable sourcing parts without component specifics i.e. vendor, vendor p/n, and schematic. I share this so others can better understand some of the effort involved. Since I saw someone using LinuxCNC (formally known as EMC), mesa cards, and similar Sanyo servos on YouTube I figured I would have similar success. Given my effort I strongly recommend a newbie like myself designing a CNC machine around a smaller power supply and encourage stepper motor due to simpler requirements. That said, servos are superior due to encoder feedback.

2nd attempt: The goal for me and other future college kids in the family include learning LinuxCNC and Mesa card integration since they offer expandability more so than other cards. That said, I am now open to a stepper setup and see ShapeOko being an ideal learning tool for this effort.

Items acquired on first attempt:
Mesa 5i23
Mesa 7i44
Mesa 8i20
Mesa 50’ish pin ribbon cable 2ft long
Mesa insulated connectors for one of the cards
Mesa EMI shield ring 1/2inch inside diameter
Intel 510 flavor motherboard computer system, It was the motherboard of choice at the time

Items to be purchased:
80-90% of the bill of material for Shapeoko
www.shapeoko.com/wiki/index.php/Assembly_overview
www.shapeoko.com/wiki/index.php/Assembly_Step_by_Step
www.shapeoko.com/wiki/index.php/Main_Page
www.shapeoko.com/

This CNC router is designed for some cheap NEMA17 steppers

Now for the questions: Can someone reduce my learning curve and advise either an off the shelf servo setup NEMA17, or more likely an off the shelf stepper NEMA17 setup that will integrate with the Mesa cards already purchased. Again, the primary effort here is to learn LinuxCNC and Mesa expansion with “minimal” or “no” modification of the NEMA17 mounting plate. Thanks.

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04 Dec 2012 16:56 #27182 by cncbasher
you would be far better to just add steppers to this type of machine , the additional cost of using servo's is just over kill on such a small machine , and a drain on the Dollars !
add a 7I42TA to your 5I23 and some simple stepper drivers such as Gecko's or the kelling / leadshine types , and your just about there . use a power supply of say 24 - 36v @ 10A

as always keep it simple , it's easy to get carried away .

move on to servo's and encoders on a machine that realy needs it , i.e big and bulky ...

learn the basics and above all enjoy doing it , and have the satisfaction you did it , theirs plenty of very experienced people here who will guide you .

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04 Dec 2012 21:09 #27185 by andypugh

Now for the questions: Can someone reduce my learning curve and advise either an off the shelf servo setup NEMA17, or more likely an off the shelf stepper NEMA17 setup that will integrate with the Mesa cards already purchased. Again, the primary effort here is to learn LinuxCNC and Mesa expansion with “minimal” or “no” modification of the NEMA17 mounting plate. Thanks.


As mentioned, the 7i42TA will make for an easy connection between the Mesa card and any step/dir stepper drive. However, you can consider wiring directly. (My stepper lathe/mill has the Stepper drives wired directly to the 7i43 card).
I rather like the look of these drives:
en.uirobot.com/robot-archive-a-410.html
They are the same size as a NEMA17 motor, and bolt onto the end of the motor for a very neat installation.

I don't think I have ever seen a NEMA 17 servo motor. (Though a quick Google shows that they do exist)
Hmm, actually: www.ebay.com/itm/350586486139
Then a pair of Mesa 7i39 drivers would be a nice setup.
Though I can't tell if the motors on eBay have encoders. The very similar looking part here, with a different part number, does have.
( www.pittmanexpress.com/ecatalog/brushles...rsA0422052NC-NAXX-SP )

Steppers would be cheaper and less of a gamble.

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