hamei wrote:That's a beautiful little piece.
And I wouldn't pay ten dollars for it. For actual use, it's shit.
I knew it!!!, heheh!!!
Thanks to god you said it, because one of my customers is selling these shit stuff here in my country to jewellers for medal engraving! So, I'm free of charges! I've not launched the stone!
hamei wrote:1) Made out of aluminum. Aluminum is one-third as stiff as cast iron. That means that for the exact same force, it will deflect three times as much as a part made of a more suitable material.
2) All bolted construction. Same problem. Bolted joints are nowhere near as rigid as weldments or castings.
3) The ways suck. It's very difficult to impossible to get the preload you want on round ways. If the female portion had seals and hydraulic oil pumped in under pressure they would be hydrodynamic ways, extremely stiff and very cool. But they aren't. If they are just a female bushing then you can't get the fit you need and can't ever adjust them for wear. If they use small balls for rolling elements then they concentrate all the loads on a very small area and wear very quickly plus have almost no damping effect.
4) The table : how the hell are you going to mount anything to that thing ? Every heard of t-slots, guys ?
5) The spindle : a three-jaw chuck ? Are those people nuts ? Any cutter except for a drill will have a sideways component of force. The very first thing they teach a person in shop class is to never I mean never put any kind of end mill or other cutter into a drill chuck. That means NEVER !
1) Sure! Anyway, better Aluminum and not MDF! Believe me, there are lots of commerical CNC routers here in Argentina being built over MDF frames!
2) Pretty sure too, yes... but you need to accept that in terms of assembly practicality the bolted construction is easier than weldments. To do it welded you need a good exoskeleton frame, already made with very tight tolerances, to help to hold the joins together in order to be sure that you'll not end with a useless structure once welded. Also, check out the very reduced workable area/volume. But I would go definitively for a casting structure, yes.
3) Do you really want to go all that far? Can be built some frame/structure with hydrodynamic ways for such a reduced workable volume? I mean... again, check out the travels! Look: "Travels: X-200mm * Y-150mm * Z-60mm" ...how would you manage to fit hydrodynamic ways into some desktop frame like this? Is it already possible at all with such a reduced target footprint? (It is not a retoric question, I'm honestly asking.)
4) Here I can not less than agree completely!
5) Ditto!, same as with the previous point (4), something like the Bosch GGS 27 L would be way better than that!
...and we should add...
6) The nuts and screws from the Sable machine are the same ones that you would use to assembly a very basic DIY machine, I mean, they seem to use common nuts and threaded rods from hardware-store! I mean, nothing with recirculating balls or at least some good Acme trapezoidal thread!
hamei wrote:We could continue but will refrain
Let's try with the next best thing for some extra dollars. What about something else from your country? Look:
Bodor CNC Router
hamei wrote:The point is, here's a very nice-looking device built with no consideration for its intended application. None whatsoever. I like hobbyists - I am a damn hobbyist ! but jeeze ... can we learn a little about the basics before we go making stuff ? Or writing web browsers ?
Give them a slap on the wrist!
hamei wrote:I don't see the price in this little guy
About U$D715.- at eBay U.S.A. for the whole thing, including everything, ready to hook up to your PC box... or if you prefer, you can buy the same thing in Argentina for U$D2599.- but that will buy you a parallel port cable and a cup of coffee too! Oh, well... ehrrr...
hamei wrote:but the sign machines are not nearly as pretty except they have the basics correct. I also have a hunch that the sign machines are a lot cheaper and they come with a working control right out of the box. It's in Chinese, of course, but still .... here's a (terrible) shot of a portion of a sign. Words are about 2 cm tall, workpiece was 14" by 22" (roughly 36 x 60 cm). Bigger letters in other areas, this just gives an idea of the accuracy of small cutters even with a small, cheap but properly designed machine.
You're right, the picture is terrible! ...but I understand the idea!
So, any chance to see a picture from the kind of routers that you make reference? I'm genuinely interested, even if I know that the chances to get them here to my country are pretty narrow, specially if one refuses to sell a kidney to pay to the customhouses... but I'm still interested.
hamei wrote:If CNC-Sable is the competition, maybe I should go into the biz of hobby NC machines ..... their stuff is crap. Beautiful crap to look at but still crap.
Never better said, and with your knowledge you should go... but I fear that with your (more polished and thorough) requirements, the overall cost would be from the very begin probably a lot higher than those U$D715.- from Sable... what do you think? Is it possible to put along something along the above mentioned lines for less than U$D999.- or something like that?
EDIT: Lots of typos...