Self-Adjusting Spine Support

[rob]

bonesgeorge, just a quick correction in terminology. The platen is the glass. The entire thing that holds the book is the cradle, and we've been calling the sides of the cradle "wings".

Wow, some very interesting design improvements indeed. Bonesgeorge, how does your new cradle account for books with varying thickness? I can't see an adjustment - maybe I'm misunderstanding things. Thanks for the great pictures.

Here's my understanding of the mechanism:

The two wings are independent, and the amount they are separated by is determined by the length of the string underneath holding them together. The elastic cords pull the wings apart, so that the string is always taut, and the separation is maintained. To change the spacing, the string's length is adjusted.

[daniel_reetz]

The two wings are independent, and the amount they are separated by is determined by the length of the string underneath holding them together. The elastic cords pull the wings apart, so that the string is always taut, and the separation is maintained. To change the spacing, the string's length is adjusted.

Gawds, it's simpler and smarter than I imagined. I have to cut one this weekend.

[jck57]

Beautiful renderings, bonesgeorge! Your work got my wheels turning. Here's still another idea for attaching the skate bearings to the tables. The 5/16" x 2" bolts and nuts are off the hackerspace scanner material list. The bearing assembly is a press fit between the threaded portions of the bolts and the groove in the ply. The 1/4" hole through the top is so you can remove the assembly with a punch.

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[bonesgeorge]

The two wings are independent, and the amount they are separated by is determined by the length of the string underneath holding them together. The elastic cords pull the wings apart, so that the string is always taut, and the separation is maintained. To change the spacing, the string's length is adjusted.

Gawds, it's simpler and smarter than I imagined. I have to cut one this weekend.

Sorry guys, its gonna be me! This is not my own built, its based on jck57's new cradle and wings . What, in turn, I wanted to contribute with is basically a more material efficient plan for fundamentally the same cradle with "self-adjusting spine support".

I mainly reduced the material usage, in my hopes, to the less till it is possibly able to function the same. So the honor goes to jck, I just jot down my ideas how to be the most efficient as I cam consider.

Daniel, I'll look around for the drawings I made with the figures regarding the. thickness and other dimensions.

Till than, I suggest to take a look at the the picture I shadowed with a proportioned plan of the wing stands that shows good how much less ply we need to basically do the very same!

[bonesgeorge]

Beautiful renderings, bonesgeorge! Your work got my wheels turning. Here's still another idea for attaching the skate bearings to the tables. The 5/16" x 2" bolts and nuts are off the hackerspace scanner material list. The bearing assembly is a press fit between the threaded portions of the bolts and the groove in the ply. The 1/4" hole through the top is so you can remove the assembly with a punch.

I'm really happy that especially you like it! I'll get to my builds Monday, and I'll make some photos too.

EDITED


Jck57, I got it! The ply wouldn't have been thick enough for the classic screwing, and you fixed the problem! Kudos to you!

(I'm actually quite amazed to see photos taken of the sunk bearings I posted just a few hours ago.. )

[bonesgeorge]

We are definitely a model community in this regard. I am extremely grateful to everyone for keeping up such a high standard of contribution and for sharing so freely for the last three years. Really incredible.

So, is there any other community that is to create some other machines, or anyrhing all together, or it's your own idea you have done with Rob?

[daniel_reetz]

Yep, there are other communities - RepRap is probably most like us, a lot of people working together in an open source way toward shared goals... they work on 3D printing technology. CNCZone.com has some forums for people developing CNC routers and mills which operate in a similar way.

Edit: but I've spent a lot of time in other communities and forums, and I have to say, our level of discourse, fairly constant good will and good member behavior, as well as the sheer number of user contributions here - very high compared to the average. People from outside often comment on it when contacting me. Of course they often also comment on the difficulty of searching the forums, etc - we have our own set of problems that we're working on.

[jck57]

jk57, could you confirm my sketches about the wings' bearing track were entirely understandable?

Yes, I think I understand.

In my own design I tried to balance material weight, structural strength, and minimum machining time. Is 6 pounds is too heavy?

Thanks for sharing your ideas.

[bonesgeorge]

Yep, there are other communities - RepRap is probably most like us, a lot of people working together in an open source way toward shared goals... they work on 3D printing technology. CNCZone.com has some forums for people developing CNC routers and mills which operate in a similar way.

Edit: but I've spent a lot of time in other communities and forums, and I have to say, our level of discourse, fairly constant good will and good member behavior, as well as the sheer number of user contributions here - very high compared to the average. People from outside often comment on it when contacting me. Of course they often also comment on the difficulty of searching the forums, etc - we have our own set of problems that we're working on.

Still a model to follow!

The thickness, if we want it strong we need it thick obviously; I don't yet know what thick exactly, or how narrow we can go, but I'm sure 1" is strong enough.

So, the main cross member, the bigger one holding together the wings should be about 1/2" and the stand has to support it with a part of same thickness, 1/2", making 1 all together.

For the other dimensions I'll get back later when I got home to my computer -- now I'm suffering with my cellphone in my hand..

[bonesgeorge]

jk57, could you confirm my sketches about the wings' bearing track were entirely understandable?

Yes, I think I understand.

In my own design I tried to balance material weight, structural strength, and minimum machining time. Is 6 pounds is too heavy?

Thanks for sharing your ideas.

I wasn't quite sure, the drawings of that part are really poor in detail, but the solution was just fine!