Portable CNC - Leaving the workbench behind

Discussion in 'Workshop Tips and Secrets / Tools' started by ScaleBirdsScott, Oct 12, 2017.

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  1. Dec 8, 2018 #41

    ScaleBirdsScott

    ScaleBirdsScott

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    Armilite and cluttonfred like this.
  2. Dec 8, 2018 #42

    ScaleBirdsScott

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    To add some thoughts after looking it over, and also watching this video from them that does a much better (less kickstartery) job of explaining what is going on with this:

    [video=youtube_share;JfSBp8Q6FXU]https://youtu.be/JfSBp8Q6FXU[/video]

    And looking at the product page here:

    http://www.yetitool.com/SMARTBENCH

    I think it has some obvious issues that prevent it from being a workhorse production machine in the traditional sense: the gantry running off a single narrow beam down the middle would likely cause issues machining anything heavy out at the edges, the whole system runs on aluminum rails so its never going to be as good of a finish as a steel rail, the thing probably runs very slow cutting, the z-depth envelope is limited but it can do up to a 4" piece of stock which is not bad. the router it uses probably uses rather small collets and is probably 1/2 HP or so, the whole base probably isn't the most stable thing ever.

    But it has some obvious benefits for a hobbyist or pro-sumer: easy controller software the runs on a tablet, safety features built in, not a kit so no wiring or detailed assembly steps, portable and foldable for storage (bring it to a hanger, keep it in a loft or on a shelf in the garage, etc) looks like it runs on common 110 power, handles a variety of materials with simple hold-down (looks like vacuum hold-down), has a touch-off plate for tool height, it's apparently failry affordable (I'd say anything under $5k makes it to where somoene could conceivably bundle the cost of one of these into their aircraft building budget, especially if they consider the potential to sell it down the line when they are done) The slow cutting speed gives you time to react to errors before things go too pear-shaped, and the slow cutting isn't a huge problem when you are just making a one-off product from it.

    Time will tell what the actual precision and speed is, but more importantly what the edge finish and quality of cut is like. Their video claims some impressive numbers for tolerances, and if it can maintain that I'd be pretty impressed. The site says it's "£3495.00 Exc VAT and shipping" so who knows what that makes it landed to the US; but my guess is right around $5000, so it would be just the right price where I'd feel I'm getting a quality tool, without feeling like I'm bending over backwards to pay for some pseudo-industrial market prices. It's finding a sweet spot I like. Am I gonna buy one now? No. But if I diddn't have a router already and was looking at the options out there considering all the stuff I've got going on and what I've learned, this might be up on the list provided the reviews don't come back saying it's absolute trash with useless software.

    Does it meet all demands? Not exactly. It's not going to be good for someone wanting to 3D carve big foam parts. It's not going to machine plate aluminum very well i'm pretty sure (tho I'd let it have a go at maybe up to 1/8 with shallow passes and assuming I'd have to touch up the edges at the end of the day) It doesn't seem to be in any way optimized for someone looking to do smaller or more detailed parts, which is where a 2x2 foot router would be pretty well suited by comparison. It would be pretty loud, so that may be an issue. It does seem like it could handle cutting aircraft plywood, plastic sheet, and thin aluminum sheet as we use, as long as it's given proper speeds and feeds and no-one expects a dead perfect cut as if it came from a large professional router table. I would be curious if they would add an option for a misting tip or air-blast for chip evacuation, but by and large carbide bits can get along without any coolant just fine and the vacuum should do a fair bit for even alum chips.

    Overall I'm into it. It's not perfect but it could do well for those who really want that full-sheet cutting without that full-time dedication of space. Or for those who want something capable and turnkey without spending almost 10k or more.
     
    Last edited: Dec 8, 2018
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  3. Dec 8, 2018 #43

    proppastie

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    The movement accuracy vs the part accuracy is perhaps an indication of software resolution vs reality/rigidness of the machine.

    one might consider they were perhaps cutting wood for that part accuracy measurement. Which is lots better than I can cut by hand.

    Movement accuracy +/-0.005mm (0.000197'')

    Finished part accuracy +/-0.0125mm (0.0049'')
     
  4. Dec 11, 2018 #44

    Little Scrapper

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    I was just at a customers house who built his own CNC for his retirement side business. It cost him $3,000. I know nothing about CNC but remembered this thread so I asked him if I could take a few photos for you DIY guys. Is it ok if I post them? I don't want to detail your thread.
     
  5. Dec 11, 2018 #45

    cluttonfred

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    Sounds completely on topic to me, Little Scrapper.
     
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  6. Dec 11, 2018 #46

    Little Scrapper

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  7. Dec 11, 2018 #47

    Little Scrapper

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    Here's all I know, I could easily ask him more details if anyone needs.

    He said there's forums online that people get plans from. His is available plans built online. The base/legs were scratch built/welded and some of the aluminum machined brackets.

    He is retired and this is in his wood shop, about 40 x 40 and pretty cool. He makes signs, custom cribbage boards, calligraphy on wood, and makes restoration parts for vintage popcorn wagons for places like museums and zoos.

    I asked him about aluminum and he said absolutely it will he just doesn't because wood dust and aluminum dust is a big cleaning mess to switch so he sticks with wood stuff.
     
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  8. Dec 11, 2018 #48

    Tiger Tim

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    I would love to know where to get started on something like that. In about three weeks I'm getting a massive shop and will finally have the space to make all sorts of neat stuff.
     
  9. Dec 11, 2018 #49

    FritzW

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    This may not be the right thread for this comment but:

    There are a lot of HBA members interested in getting into CNC but can't get off BDC in the learning curve. There are also a lot of HBA members who have a pretty good handle on it. If anyone here wants to buy and/or build a CNC machine, the knowledge pool is already here.
     
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  10. Dec 11, 2018 #50

    Tiger Tim

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  11. Dec 11, 2018 #51

    FritzW

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    "Bottom Dead Center" (Opposite of "TDC")
     
  12. Dec 12, 2018 #52

    proppastie

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    I have seen used CNC routers on Craigslist and Ebay.......If you have the space might be a quick way to get your feet wet.
     
  13. Dec 12, 2018 #53

    Tiger Tim

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    Ahhh, I didn’t even think you were referring to the learning curve itself. I just assumed it was some CNC jargon for a some concept people have a hard time getting past. I used to be great with CNC software but never got my hands dirty with the hardware, which is one of the reasons I want to get my head back into this stuff.
     
  14. Dec 12, 2018 #54

    ScaleBirdsScott

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    The hardware and electronics are deceptive, it's very simple. Tons and tons of jargon and 'abstraction' over what is very simple in practice.

    There are many great primers out there, but for entertainment value you really can't beat ThisOldTony:

    [video=youtube_share;K0XfRPi_h2M]https://youtu.be/K0XfRPi_h2M[/video]
     
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  15. Dec 12, 2018 #55

    ScaleBirdsScott

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  16. Dec 12, 2018 #56

    ScaleBirdsScott

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  17. Dec 12, 2018 #57

    pictsidhe

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    Is anyone else looking at at the extruded aluminium frames and thinking "why not just weld up a nice, solid steel frame and carefully shim guide rails to it?"
    Is an arc welded steel outhouse just not in the spirit of a modern machine?
     
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  18. Dec 12, 2018 #58

    Little Scrapper

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    I can not answer any questions about it Scott, I would be happy to call the customer and ask. He is a wood worker not a metal worker so he had friends do the metal work.
     
  19. Dec 12, 2018 #59

    Hot Wings

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    8020 is fine for 2 1/2D wood machine. It's reasonably straight and doesn't warp too much when bolted together. Steel moves around a lot when welded but if you want a ridged full 3D machine for metal I don't see any other alternative. Maybe cast and machined aluminum if you have it in a constant temp shop?

    The trick is getting the ways/guides parallel and straight. The first side is reasonably easy. I like aluminum filled resin used as a bedding material for things like this, provided your ways/guides are straight to start with. The second side is easy enough to get parallel in the X/Y plane. Just use your X axis trucks to test the adjustment. It's parallel in the Z that gets tricky.* A piece of 4x8 ply will follow the warp of an out of alignment Z plane table and we don't care if the tool cuts 0.020 to deep or not. That is what the sacrificial surface is there for.

    Once you have the ways/guides planar (the X direction is now established) just bolt on some 8020 for the deck and use the machine to cut it flat.......after making sure the spindle is perpendicular, and the Y is parallel, to the X/Y plane.

    For a 2 1/2D wood machine welded steel would still be my choice. I think it's quicker and cheaper. If you have access to an automotive frame machine it can always be straightened if it warps more than expected. ;)

    *Haven't found a really good and easy way to do this. A water level and laser on the walls of the shop has it's limitations. Maybe a very large temporary Z axis spindle and a dial indicator?
     
  20. Dec 12, 2018 #60

    ScaleBirdsScott

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    Check out the playlist I linked above ( https://www.youtube.com/playlist?lis...rZYL6xBIjxsDzZ )if you wanna see the process of doing the Steel Craphouse method. I like the result and I would love to do one; certainly there are people who go this route. I personally could see upgrading my machine with a steel gantry and a set of liner rails vs extrusion. But shimming is a PITA... I'd probably have to build some temporary sidewalls on my main X and Y axis bases, and do the epoxy leveling compound method. And by the time I've done all that maybe I just need to start fresh. My table, for example, has an adjustable height bed. I've started to realize that the current way I've mounted it is pretty strong, with 8x 1/2" leveling bolts to brackets on the frame; but it could use some more gussets or something to really lock the table bed into the frame if I were to be doing heavier cuts.

    I don't have any particular questions, just complimenting it and offering up some resources for those curious about their own. But very cool.
     

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