Cut the bed to mount big objects from underneath. Solution?

[tim]

3D File: a360.co/2OKLui1






my requirement is that i can bring big objects (bowls, balls) from underneath to my spindle.



i thought i can build this following setup:



i take a steelplate 24"x25" and will cut an 18" center circle.



i will weld the following construction, 24" wide, 24" deep and 27" high. i'm no expert but i thought i can use hollow steel bars, 1"x2" (and for the vertical connectors 2"x2").



my idea is to take the steelplate, bolt it down on all 4 corners with the cnc base and along the sides 2 times more. then also 4 times around the circle. the steel plate should be "one" with the cnc bed.

now i can cut the CNC bed and make the same circle into it with an anglegrinder.

finally i will weld the steelplate to the construction.



next thing i need to make myself a platform that i can lift. maybe i can take a car jack, so i can push things up from the bottom. basically make a platform with anchored hoseclamps so i can fix my workpiece on it. but i can figure that out later.



would my idea work? is it rigid enough?

[Hommer Woods]

That sounds mighty rigid to me. A car jack? Are you engraving bowling balls or something?

[Bruce]

Sound interesting to me. I'm guessing this would be good for dovetail joinery applications also. I'm not a mechanical engineer but if everything stays square and rigid it should be good.
If you could find some kind of clamping device that can be raised and lowered you will really expand your work space. Which machine is this for?

[tim]

Oct 24, 2018 13:38:52 GMT Bruce said:

Which machine is this for?

Carveking

[tim]

Oct 24, 2018 11:13:28 GMT Hommer Woods said:

A car jack? Are you engraving bowling balls or something?

i figured out already how to do, see my new post. yes bowling balls. actually not - it's for big bowls and vase.

[tim]

i will take the top steel plate, it’s 24x25, cut a 17" diameter circle in the middle. then i’ll bolt it down on 3 or 4 points per side with the carveking bed.



then ill make the same cut on the carveking, through the bed and the mountrails of the bed.



then i just need to weld the steelplate onto my table construction.



under the hanging plate i will have screws, so i can put my pieces onto it and then adjust the height to feed it towards the bed till the correct height is reached. the hanging plate is 19x19". i think i need some walls left and right so i can push into my pieces to hold them tight into position.



here is the 3d file. feel free to use it or improve it



a360.co/2Rb0emT

[Hommer Woods]

Might want to consider something like this. www.amazon.com/Shop-Fox-D2893-Press-Clamp/dp/B0000DD353

[tim]

Oct 24, 2018 16:54:47 GMT Hommer Woods said:

Might want to consider something like this. www.amazon.com/Shop-Fox-D2893-Press-Clamp/dp/B0000DD353

for keep the object stable left and right? how do i use those?    

[Hommer Woods]

Oct 24, 2018 18:02:51 GMT tim said:

Oct 24, 2018 16:54:47 GMT Hommer Woods said:

Might want to consider something like this. www.amazon.com/Shop-Fox-D2893-Press-Clamp/dp/B0000DD353

for keep the object stable left and right? how do i use those?    

Normally it is for making a veneer press. I was thinking you might use something similar to move the hanging plate up and down rather than a jack. Not sure how much clearance you have though.

[Hommer Woods]

Here is another idea.


www.youtube.com/watch?v=ScPrbsF51ms

[tim]

Oct 24, 2018 18:16:54 GMT Hommer Woods said:

Here is another idea.


www.youtube.com/watch?v=ScPrbsF51ms

i'm not skilled enough to builf stufff like that

[Mototech]

Oct 24, 2018 18:25:18 GMT tim said:

Oct 24, 2018 18:16:54 GMT Hommer Woods said:

Here is another idea.


www.youtube.com/watch?v=ScPrbsF51ms

i'm not skilled enough to builf stufff like that

I disagree, I think you are skilled enough. Just need to take a few stabs at it. But torsion or twisting may be a concern with those designs. Thinking aluminum extrusions, like the carve king uses, running vertically would make a solid guide for your movable bed. Thinking threaded rods like in your fusion design spaced half way between each extrusion might do for setting your bed depth.

[tim]

i think i have to remove the bars from the top frame as they would be 1" thick and kinda can disturb my objects to get feed into. the carveking bed is also pretty high, so there might be a chance that my whole thing isn't reaching the spindle. i then have to use longer endmills which kinda isn't optimal i think.
maybe 17" isn't big enough aswell and i should make the cut bigger. propably square. 

[tim]

now i figured out, the bed of the carveking is 1.53" high. if i put that on top of my table, i won't expose enough of my objects. so either i find a way to get rid completely off the bed, or i can't do my vision.

[stever]

Oct 25, 2018 7:40:12 GMT tim said:

now i figured out, the bed of the carveking is 1.53" high. if i put that on top of my table, i won't expose enough of my objects. so either i find a way to get rid completely off the bed, or i can't do my vision.

Instead of cutting the bed of your carve king and now having a hole in which you cannot fix just in case you decide it isn’t what you want to do with your machine, why don’t you just disassemble the front and back extrusion supports from the bed of the carve king and bolt them to the front and back of your steel table? Just make the table the same size as the base of your carve king. That way no change is permanent. Then you can leave the top of the table wide open, or insert a spoil board on top of the wide open table if you want to mill something smaller.