CNC and hoist to Ceiling?

[Patrick Irish]

I want a CNC but don't have the space. It then hit me, what about building a CNC and then hoisting it to the ceiling when not in use?
I want to flatten odd shaped slabs and endgrain boards. Cut curved legs and templates etc.


Like this?

[Jim Becker]

The single concern I can think of is making sure it absolutely maintains, flat, level and square...so unlike in that photo, I'd want to have it mounted "permanently" on a solid and strong surface (torsion box perhaps) and raise THAT up with the hoist. No way would I want the stresses directly on the machine frame like is shown. The points that are being used are not in any way designed for that kind of lifting and it could wreak havoc with the machine's accuracy.

[Wes Grass]

The lifting load is on the main frame rails, so there's nothing out of place, load wise, in terms of the gantry. And the base is tied together by the table surface, so it should be stable in terms of remaining square. The base being rather flimsy to start with, it just needs to go back onto a stable surface to maintain flatness of the table.

The sling arrangement looks proper for evenly distributing the load.

Ideally, the base is much beefier and sits on 3 points. A torsion box would be a great addition.

[Jerome Stanek]

You could just add 2 pices of unistrut under the long rails and attach you pully system to them

[Jim Becker]

The lifting load is on the main frame rails, so there's nothing out of place, load wise, in terms of the gantry.

They were not designed for lifting. There's no way I would do things that way...it only takes a very minor distortion to completely whack the machine's accuracy. Lift the surface the machine is sitting on rather than the machine and that is much less of a risk.

[Brady Watson]

It's not a good idea...A machine light enough to hoist up will be flimsy and level & square are absolutely critical on light machines.

Camtech (now AXYZ) used to make a SpaceSaver CNC that sits on an angle - supposedly taking up no more room than a sofa.

If space is your concern, consider something like a ShopBot Buddy with moving and removable table. You can roll it around wherever you want & when you need it, slide in the 'PowerStick' with table and do what you need to do. When done, remove table and store.

[Malcolm McLeod]

I'll be a (devil's) advocate and so say it all depends on Mr. Irish's expectations of accuracy.

No clue what actual impact the crane will have, but if flattening slabs, will +/-0.030" in 3ft be close enough? If making a template, is +/-0.010" in 1" the proverbial good-enough-for-government-work?

I'd not expect to production cut piston fit joinery with such a rig, but Mr. Irish seemingly has more need of space than for 'pistons' and +/-0.0005" precision..??

(Some interesting alternatives have been proposed, and for the existing unit I would increase the section modulus of that bottom frame: maybe some 8020 profile at 4-6" height (to stiffen the frame's z-axis)? I'd also suspect that flex in the black plate couplings between the x- and y-axis induce more error than lifting it...? Some 8020 here might do wonders. But easy for me to say, it's not my shop or money.)

[Jim Becker]

Being even more "devilish", even a small deflection of the gantry and other mechanisms can make the machine run not just inaccurately, but also could cause premature failure. Stuff really has to be square and true because there are a lot of moving parts, as it were. That's why I remain of the opinion that it's best to have the machine mounted on a stable surface that can be lifted without "touching" the machine by whatever method is being used to lift.

[Keith Outten]

I agree with Jim. Most CNC owners don't even want to move their machine on the floor much less raise it up off of the floor. This goes double for machines that don't have a very strong welded frame.

[Maurice Mcmurry]

I do not have a CNC (yet) but I do have Unistrut on the ceiling. It is the gold colored heavy duty version. It is very helpful for lifting boats, small tractors, trailers, etc. When I get a CNC I hope I will have room for it on the ground.

[David Buchhauser]

This one has no welded frame, and it appears that the approx. 1" thick mdf base/table is the main structural element keeping it flat (or not). Who knows how flat the virtual x-y plane really is when in use, unless it is indicated in by sweeping the table with a dial indicator mounted to the spindle location and then the base/table shimmed and clamped to take any twist out of the assembly. I suppose a quick and dirty method would be to use a precision level across the rails and adjust until the rails are parallel the length of the machine. I seriously doubt that the "stresses" imposed by lifting as shown will put any immediate twist in the assembly, although changes in humidity may affect flatness irrespective of storage position (up in air or positioned on the workbench) unless the assembly is permanently mounted to a solid bench and then tuned by adjusting the side rails to parallel to both each other and the table the work will be mounted on.

If the slabs Patrick is "flattening" are for decorative use, then all of this may be purely academic. For any sort of precision work, then I agree that permanent mounting and subsequent "dialing in" would probably be the best approach.

David

[Bill George]

I would place a couple of heavy Unistrut pieces under the table and lift from those, not the machine rails.

[Brian Gouldman]

I’ve been eyeing the onefinity, partly because it supports wall mounting.