CNC Machine Suggestions for This Scenario?

[roger wiegand]

I volunteer at the Charles River Museum of Industry and Innovation (http://www.crmii.org) in Waltham, MA. We are located in the Francis Cabot Lowell mill, the first fully integrated manufacturing facility in the US, and quite arguably birthplace of the American industrial revolution. To complement our historically oriented exhibits related to Waltham and Boston based industries such as textiles, clocks and watches, bicycles, Polaroid, and early autos our director is interested in setting up some examples of small scale current manufacturing technology, with the notion that we might both make tchotchkes for sale in the museum gift shop and have related educational programming about the evolution of manufacturing methods. I have suggested that both CNC routers and laser cutting would fit the bill nicely. (we have various 3d printers, but so does every school and library, we'd like to go beyond that). We have a grant that would allow us to acquire a CNC machine in the (very) low 5 digits range (eg $10-15K).

We'd need a machine that could be turned on and run a pre-programmed routine task by docents with only a little training. Dust and noise would be a concern if excessive. Any programming would have to get done by a couple of volunteers (probably including me) who currently have no experience with such things-- though most of the other guys are engineers and machinists, I'm the woodworker in the crowd.

Would the kind of machine discussed in this thread be appropriate in this setting? I'd hate to recommend something that would become a boat anchor due to insufficient expertise to make it work. How loud are these machines? Is there reasonable dust control? I'm imagining that we could box it in plexiglas to keep inquisitive fingers out, is that correct?

If you think this notion is crazy please say so!

[Jim Becker]

Your situation can likely be handled reasonably well with some moderate "operational" training for the folks who will be doing the production work..with the right machine. Designs, etc, can be prepared by more skilled folks and the resultant files can then be used for the production. If you standardize certain positional things and material thicknesses for the files/jobs, that will make it easier. The bigger challenges will be training for tool changes and measurement unless you can fund a machine that has an automatic tool changer (ATC). With that, it will primarily be loading/clamping material and starting the desired job.

Duet and noise containment can be managed with an appropriate enclosure and may also help provide the necessary safeguards for safety should the work area be observable by the public.

I'm going to suggest you have a discussion with Gary Campbell about configuring a machine that has the higher level functions in a smaller machine appropriate for the kinds of things you want to produce. I don't believe that most off-the-shelf machines are going to fit "directly", but they might serve as the basis for a solution.

[bobby milam]

I think you might be best off with a cnc laser. I think that they'd be easier to learn on the software side, no need to buy and change out router bits, quieter, much less mess and just good ventilation to the outside. Routers are noisy and spindles are expensive both can be messy without using a dustshoe then it is hard for anyone to see what it is doing. Running a machine inside an enclosure without a dustshoe works to contain the dust but then there is a big mess to have to deal with at the end of the day.

Contact the major companies offering and see what kind of deals they have for education purposes.

[roger wiegand]

I certainly have been thinking about a laser, especially of we could design one of those kits to build, for example, one of the steam engines in the museum.

I have to admit to a conflict of interest in that if there were a CNC router I'm pretty sure I'd find some uses for it. The laser, beyond cutting sandpaper disks for turning, perhaps not so much.

[Jim Becker]

The conundrum with the laser is that if you want to go much beyond engraving and cutting really thin materials, the price tag shoots up considerably because of the power required to cut thicker stuff, like .25" hardwood stock. CNC and laser are complimentary in that respect.

[bobby milam]

It sounds like you might prefer a router over a laser. I assume you are wanting a small desk top machine? I would contact Shopbot and speak to them. If I am not mistaken they have a program that might work with you. I think they already have an enclosure available for their machine and they have a large user forum. Because of the noise I would recommend that you opt for a spindle on what ever your machine is. They are much quieter than routers. You really can't hear them run unless they are cutting wood but even then unless you are aggressively cutting, they are low enough that you can have a conversation next to the machine.

If you want something a little larger like a 4X4 machine PM me. I just was told of where you can get one easily below or at the lower end of your budget.

[Mark Bolton]

For that budget you could be in a 1/4" capable laser with a host load of cash to spare. Why not opt for a high speed 3d printer. Budget seems theme. Question would be what are they looking to have done out of the machine and how fast. If they don't want to deal with chips and dust collection and noise is an issue laser or 3d printer seem default. The cnc may be cool to energize people with tangible materials they are use to and be 3d. Laser ripping fast, many parts an hour but cutouts and engraving only. 3d printer kinda sucks cause your puking out more plastic the planet cant digest.

Museum level super cool would be a 3d printer with an integrated grinder and extruder where you drop in your used water bottle and get something out the other end. Like Wonka 2K.

[roger wiegand]

Museum level super cool would be a 3d printer with an integrated grinder and extruder where you drop in your used water bottle and get something out the other end. Like Wonka 2K.

That would really be cool, does such a thing exist?

[David Buchhauser]

That would really be cool, does such a thing exist?


I think only in the movies!
David

[Brian Backner]

Have you considered a CNC plasma cutter? One with a 4x4' bed capable of cutting 1/2" plate would fit well within your budget. The noise is not too bad and the shielding to prevent eye injury from the flash would serve double duty to contain/extract the fumes. You could cut a hundred widgets out of each sheet to sell in the gift shop!

[roger wiegand]

Have you considered a CNC plasma cutter? One with a 4x4' bed capable of cutting 1/2" plate would fit well within your budget. The noise is not too bad and the shielding to prevent eye injury from the flash would serve double duty to contain/extract the fumes. You could cut a hundred widgets out of each sheet to sell in the gift shop!

No I hadn't-- that would be for cutting metal only? I'll ask our machinists what they think. I imagine it's pretty spectacular to watch.

[Pete Taran]

Wouldn't the 4th of July like Sparkler Show worry the insurance minded types? Seems like a bridge too far for the setting described. Plasma cutters work by striking an arc to melt the metal and then blowing it out with compressed gas., All that hot metal flying around might cause issues. :)

[Brian Backner]

Wouldn't the 4th of July like Sparkler Show worry the insurance minded types? Seems like a bridge too far for the setting described. Plasma cutters work by striking an arc to melt the metal and then blowing it out with compressed gas., All that hot metal flying around might cause issues. :)


OSHA guidelines for setting these things up in industrial settings pretty much satisfy the insurance bean counter types. The bar grates upon which the work piece rests sits over a water reservoir to contain the blown-through sparks/slag and the entire thing would be contained within a plastic (I'm not sure which type - ? polycarbonate for impact resistance as well as an anti-UV applied film to block/diminish the arc) box with an air inlet and suction motor to draw the fumes - either through a filtration system to return the air inside the museum or to exhaust it outside via a vent stack on the roof.

[Mark Bolton]

There are tons of people out there re-claiming their prints and plastic

https://youtu.be/ITatWpY8vmA

[Brian Backner]

There are tons of people out there re-claiming their prints and plastic

https://youtu.be/ITatWpY8vmA


That's an interesting doohickey, but at $4k you'd need to have a LOT of printing mistakes/recycling to make it worthwhile!