Kickstarter: Cheapest CnC-mill yet?
Gadgetman
Posts: 2,436
https://www.kickstarter.com/projects/makesmithcnc/makesmith-cnc-the-most-affordable-desktop-cnc-rout
That's $195 + shipping for a kit.
Just add a Dremel or similar tool and you have a complete desktop CnC-mill.
There's still 15 days and 270 kits left.
(The designers have set a limit of 25 Early bird and 500 normal kits to avoid being overwhelmed)
They're using small servos and threaded rods, and claim a repeatability of 0.1 - 0.5mm depending on feed-rate and material.
Should be big enough to make small robot parts.
(In wood and plastic only. Its not strong enough for metals)
It should even be capable of making PCBs as long as you don't use anything smaller than 1205 SMT components.
That's $195 + shipping for a kit.
Just add a Dremel or similar tool and you have a complete desktop CnC-mill.
There's still 15 days and 270 kits left.
(The designers have set a limit of 25 Early bird and 500 normal kits to avoid being overwhelmed)
They're using small servos and threaded rods, and claim a repeatability of 0.1 - 0.5mm depending on feed-rate and material.
Should be big enough to make small robot parts.
(In wood and plastic only. Its not strong enough for metals)
It should even be capable of making PCBs as long as you don't use anything smaller than 1205 SMT components.
Comments
I'd be a little concerned about *dimensional stress* tolerance, caused by the lighter weight construction materials used in the frame. There is a surprising amount of deflection that happens when the cutter bears into even softish material. Accuracy specs are often just stated as the mechanical tolerances involved, rather than actual measured (didn't read the KS page; maybe they say). It's a pain to have to slow down the feed rate so much it's a chore to cut out even a small piece.
But this looks good. Wish they had it when I was in the market -- I spent $3,000 on mine!
I did read on their KS page one of the creators is finishing his degree at UC Santa Cruz. Go Banana Slugs!
This doesn't exactly make it the fastest machine on the market. but... The low speed should help alleviate some of the deflection...
(I believe the repeatability was a measured number. )
It shouldn't be too difficult to 'shore up' the frame a bit if it acts too wobbly, either.
I'm 'on the fence' about it, yet.
not to buy it for myself(I'm slowly, very slowly, putting together a ShapeOko for myself), but it might just do as a present for my nephew.
(I'm his godfather, it's my duty to spoil him, and besides, I gave his sister the 3Doodler last christmas. Got to top that somehow... )
9gram servos aren't tiny... 3.7grams on the other hand, those are tiny.
And 1.5gram servos has passed all the way into ridiculous.
$295 would be a 50% price increase.
Now they're keeping the initial outlay as low as possible to make it affordable by just about anyone.
OTOH, 9g servos couldn't generate enough force to flex the housing, so you needn't lose sleep over that issue.
Hopefully they'll offer an upgrade package. The servos are a turn-off enough for me to not even bother to look.
One of his earliest posts)
Perhaps that is completely true. Is it worth the price if it lasts six months? A year? These days people seem to be quite content purchasing cheap stuff, then not getting too upset when it fails. But the market has spoken, their campaign is successful. I must be wrong.
http://www.ebay.com/itm/Parker-Daedal-linear-bearing-ball-screw-slide-table-stage-CNC-X-Y-/261470670939?pt=LH_DefaultDomain_0&hash=item3ce0ddd05b
http://www.ebay.com/itm/Parker-404XR-XY-Stage-Linear-Ballscrew-Actuator-Renishaw-Encoder-Nema23-Motor-/221438627272?pt=LH_DefaultDomain_0&hash=item338ec54dc8
I might walk onto the street in heavy traffic and manage not to get hit. Doesn't mean it's a good idea.
That said, the video also shows a fair amount of imprecision in the mechanism, from whirling (bent) allthread rod to wobbling/misaligned gears. All the video is marked "sped up". Designing to a price point is very challenging, to say the least. They expect to take up some slop in software; as the servo gears wear that will get more challenging.
Per the old saying: "Pick two: cheap, fast, or accurate."
Project management triangle
It would be heresy if I suggested hacking up a vintage and vaunted Emco Unimat, so I won't bother. I have one of those somewhere in all my stuff.
Video shows one such modified: https://www.youtube.com/watch?v=48ic5yN8r4g
The problem is that too many products only choose one, the "cheap" criteria.
Yeah., but this is a milling CNC, and the KS project is for a computer-controlled router, which can be less robust. There's a line between robust and just plain bust, though.
These days successful Kickstarters gotta have a gimmick. This one went for cheap, and I think it's a bit too cheap. For (say) $100 or $150 more they might have built a better buggy, and then "sold" the uniqueness by making it a combo CNC router and 3D printer base, for example. Unhook the router and attach an auger (available separately) for feeding plastic.
Unless these 9g servos in the suspiciously familair blue plastic casings are actually high-end Maxon motors or something, no way will the units hold up after much use, regardless of the luck of the prototype. The blue-cased 9g motors from China are probably the cheapest servos on the planet. Not sure even you are that cheap, Erco!
There is no warranty. You have to wait for the product to sort out production. And if funding doesn't come through, your order is canceled.
On the other hand, EBay allows one to explore cheap as well.
My own preference for tool purchases is for something that is sturdy and will last a long time. I may not use it much in the beginning, but there may come a day when it will have to work hard to pay for itself many times over. Junk will just never pay for itself.... merely an educational device.