With the sheer number of K40's out there,

With the sheer number of K40’s out there, I thought it might be a good idea to come up with an inexpensive open source solution for an adjustable bed. Quite a few of us have made our own designs, and I figure if we analyze the best features of each design we could have a great design in no time at all. Anyone interested in helping with this project? Or just let us have a peek at your design if you have made an adjustable table.

I’m in. Are we looking for motorized or manual?

I would like it to be motorized if possible. However, we could design it in such a way that a manual knob could replace the stepper to offer a lower cost alternative (Not that steppers are really that expensive)

Do you have the drawing for the current bed surface on the k40

Not yet. Don’t think it is necessary though, I am sure nothing of the original bed will be used.

I am thinking of building one myself, the big thing I see as a draw back on a lot of them, is the room the motor takes up. With this in mind I am thinking of a scissor table, much like a scissor jack. I can then place the motor within the control area after creating a hole between the 2 locations. This will allow it to spin and take up as little room in the build area as possible. I am also looking at cutting a good size hole in the bottom of the unit or I should say front facing edge, so I can put in larger material, and have that opening big enough to support the full raise and lower height of a work bed. (unfortunately it is mainly money and time I am against right now as I am saving for a few other toys as I am working towards a plasma table also)

I like this idea. Although I haven’t done any z-bed, I’m interested in the final product.

I am with you, guys.

I would start by looking at the LO table design (my final choice) and consider what is good and bad about it. Not sure how we would do better? Should we just clone that into a DIY version? I paid $165 for it on amazon.
I looked at other designs. I concluded that scissors cannot get as low as the belt design and may cost more. In the LO design the stepper is in the back out of the way. I added the electronics and driver also in the back out of the way. http://donsthings.blogspot.com/2016/05/k40-zaxis-table-controller-build.html
With the smoothie I am planning to eliminate all the z axis electronics anyway.
I also saw cutting the bottom and front of the machine out as an advantage but then figured at that point I should just repackage the current X & Y axis into a clam shell type of design that would allow larger material to slide in horizontally and thick materials to stick out the bottom. I figured in that design the lift table is built into slides in the frame and below the machine.
The electronics is outside the cutting area in a separate module.

problem is not to go up or down, but to be in focus.
maybe a solution with beam sensor…

The scissors wouldn’t be exactly like a car jack but same idea then you can get a z axis to get the focus is think you can get down to about a inch depth as we are not lifting more than a few lbs at a time. I will see if I can get some time to draw up my idea this weekend

There are a lot of sissor lift designs out there. I am thinking of one that the screw comes out the end and could be manually or motor driven. The screw would not move up and down with the lift.

That is exactly what I was thinking @HalfNormal I am rebuilding a 4" x 4" lab jack to put the screw on the bottom of the jack, eliminating the up and down of the screw, which makes motorizing it a hell of a lot easier.

@funinthefalls @HalfNormal Would a dual screw system be more stable or possibly introduce issues? i.e. a screw on the left & right of the bottom as you both mention.

I think that, screws that lift all four corners in sync (cog belts) is more likely to be easy for the bed to be slewed up and down without alignment problems.

I was leaning towards a 4 post lead screw type. That allows you to even place the stepper outside the case if necessary for room.

@funinthefalls that is how the LO table works.

The lead screws would not have to be that long, we are only talking about a couple of inches of movement.

I posted a pict of the shaft on mine. So annoying that we cannot attach photo!

I figured it would be pretty short, 4"