phantom CNC

[Jim Becker]

I have the Stinger II and love it. You are not incorrect about the initial acquisition cost, but cost shouldn't be your only consideration. My initial purchase was somewhat business focused, so the industrial heft setup made a lot of sense and I'm happy to have it now. However, I will be frank and honest, it I didn't own the Camaster Stinger II, I'd likely have an AVID machine. The reason for that is because the company has rich experience, is also US based, and the machines are also expandable. That last piece directly applies to the "single" regret I have about my CNC machine decision not quite four years ago and that's not paying the relatively small cost difference for the additional four feet of length. I now have a shop space (err...will soon anyway) that can easily support a "full sheet" machine. Now I don't do a lot of sheet goods work, but that would certainly be helpful when I do. But the larger bed length would also enhance things like surfacings slabs, etc., that I also do with my CNC machine.

[Dan Richeson]

I have been checking out the Avids a bit more but it seems they really shake around while running. Is it because of the light duty leg kits they sell? If one welded a steel table and set a 4x4 pro on it would that stop the shaking? Just don't like the idea of spending 12 K on a avid and watch it bounce around the shop floor.
I did try to get ahold of camaster but they are busy with sema right now.

[Jim Becker]

Dan, while mass can certainly be a factor, especially if one is running at higher feed rates with a lot of direction changes, I also suspect that many folks don't take the time to meticulously adjust and level their machine while assembling it. It's absolutely critical with any bolt-together machine of any kind, not just a CNC, to spend a "yuge" amount of time with initial setup so that the machine, "in its spot" is fully supported by the floor. It's also true that these are not industrial machines and they shouldn't be expected to be as heavy and solid as an industrial machine. For their intended audience, however, they offer a lot of features and flexibility, including the ability to grow over time. I can't add another 4' to my welded frame machine like you can with an AVID, for example.

[David Buchhauser]

I have been checking out the Avids a bit more but it seems they really shake around while running. Is it because of the light duty leg kits they sell? If one welded a steel table and set a 4x4 pro on it would that stop the shaking? Just don't like the idea of spending 12 K on a avid and watch it bounce around the shop floor.
I did try to get ahold of camaster but they are busy with sema right now.

Dan - I've got two of the Avid Pro machines and they most certainly don't "bounce around the shop floor". I am using the Avid leg kits, and when properly assembled and leveled, work great. I initially thought about building heavier duty tables/stands of welded construction to mount my first Avid Pro to. But I thought I'd give the leg kit a try first, and I was very pleasantly surprised just how rigid the assembly is. Yes - I did spend the time to assemble and calibrate - and perhaps that makes a difference. If you are really worried about it, then you could always bolt the legs to the concrete floor for added rigidity.

David

[Wes Grass]

Newton's third law of motion ...

I ran a couple Avid's for a few years. Both had been extended to 4x16. Yeah, a rapid move on the gantry (X or Y axis depending on your POV) would shake the table. Looked like a potential problem, but I never saw any detrimental effects on the work. The only problem I saw with them was the gantry extrusions weren't perfectly straight. The first machine had a twist in it, and used the v rollers. We spent a fair bit of time shimming the mounts to straighten it out ... kind of. The second, with the linear guides, had a slight bow in it. Should have had it milled flat, but we didn't have the time and it never seemed to cause us any problems with parts fitting anyway.

Regarding the 'flimsy' legs, I was putting 700+ lb molds on one of them and had the gantry elevated A LOT for clearance. Bought extrusion and made our own uprights, and some smaller pieces to set the gantry on for level while swapping them out. Mold cavities were 15" deep, with about 3 inches thickness at the bottom. Cut with a 12" long carbide 1/2" ball endmill in the Avid spindle.

Dust collection was ... a 4" hose hand carried to suck up the chips every couple hours. After gaining confidence in the process I could start a roughing pass in the morning, and set it for another before I left. Shop was right off the freeway on the way to my shop on the weekend, so I'd stop in, clean it up, and set the next path. Same on my way home, 15-20 minutes work to save DAYS off getting the molds cut. Typical run time was about 7 hours. Pretty nice to start setting it up on Thursday, and pull a finished mold off on Monday to setup the other half ...yes, *HALF* ;-) Two quarters, actually.

That machine was built in a shipping container in the back parking lot. Double/double doors on the 'front' (long side), and doubles on one end. We didn't have room in the building for it, and were planning on moving soon anyway. The feet were screwed down to the wood floor. The other machine anchored to the concrete floor in the shop. I was skeptical it would hold, as the screws just went thru the plastic pads on the feet, but I never saw any indication they were moving, and the screws stayed tight. I don't think a 5ft wide machine would have been quite wide enough for a full mold, and the 4 ft'r was tight quarters in the container to begin with. Had to scoot sideways to get behind it, and had to be careful stepping backwards when you were in front ;-)

And a full mold would have been a bigger problem dealing with chips and dust anyway.

A lot of trash bags of MDF shavings went in the dumpster. And it would take a couple weeks to get rid of the scrap from cutting the laminations out. I think my record was 22 sheets of 3/4" Ultra-light in one day. I got pretty good at picking them up and getting them overhead to slide them in the end. And dodge the gantry pulling finished parts out while it ran the 2nd sheet. The vacuum table was worthless for this, so I had them programmed to plunge 1/4" holes for drywall screws before running the contours. I can't even estimate the hours on the spindle, and it just kept going like the bunny.

[David Buchhauser]

Wes - nice review! It sounds like these Avids were real work horses with great reliability. Thanks for posting.
David

[Wes Grass]

Wes - nice review! It sounds like these Avids were real work horses with great reliability. Thanks for posting.
David

I really didn't think we were gonna be able to pull this off with these machines, but even with a few hangups and hiccups, like one of the 'pucks' shedding a few balls, they got it done. The spindle was SOOOOOO much better than a router.

I'm sure I could have milled these from a solid block faster with a real 5 axis gantry mill, but the cost, delivery/installation time, and programming software would have killed us. We were using Catia for modeling, so that would have been an obvious choice. I think they went with it for a smallish foam model level 5x machine they got after I left for trimming parts.

I started out using my Surfcam seat for the 3d contours. But I think, it's been a few years, that I did the last set with V-Carve. The import of a 3d model 'underneath' the 2d profiles was of huge benefit. We had a number of 3d parts that needed cutouts in them, and it was quite simple to do that with short'ish 1/8" endmills following the part profile. Same with making hard vacuum fixtures to hold molded parts for machining. I think the cutouts would have been a lot more hassle with Surfcam. The nesting with V-Carve was pretty good, but I could typically save a sheet of material by tweaking things manually.

We had a couple fires with the indoor machine, running a router. The worst burned about 3/4th's of the dust collection hose back to the collector ;-) Cutters getting loaded up, or set too deep so the collet nut was rubbing on the work. A little more excitement and smoke than I wanted. Not good when the fire department shows up ... 'if you have a fire, call us, that's what we're here for. If that had got up through the suspended ceiling you would NOT have got it out'.

Good times ...