CEB 4 design planning

This is a page to display the rationale and get more opinions on CEB 4 design features. Listed below are discussions on which design changes should be made and why.

Hopper Changes

Shape

Problem Statement: In Prototype 3 (P3 for short), the hopper had gaps at the top, and the seams didn't go together well; the 4 sides ended at different heights, making it difficult to mount the grate.

Solution: Dan Schellenberg's CEB used the same general shape of OSE's prototype, but cut off some of the top section, and a portion of the sides. Link to hopper model. This saves material and simplifies mounting the grate. No disadvantages are seen.

MJ: For materials use efficiency, P3 requires one 5'x10' sheet of 1/8" steel. If this requirement is still met, then we should continue.

Mounting, on sides

Problem Statement: The grate supports were time-consuming to mount, and used a lot of material. Also, bolting to the hopper is time consuming.

Back StoryIn P3, we mounted using 4x4 angle supports which bolted to the primary legs and hopper, and 2x2 tubing which bolted to the hopper and into leg-holders on the frame.

Discussion: Dan's machine welded the tubing to the CEB instead of bolting. This uses less material and takes less time. Dis-advantage is that you can no longer easily disassemble tubing from hopper. Arguably, there is no reason you would need to disassemble them anyways. It can be stitch welded, since there's not a lot of force needed to support hopper. This would make disassembly by cut-off wheel feasable.

For the angle supports, He replaced them with more tubing with a bent 1/2" plate welded to it. These attached to the frame via leg-holders. There was 2x2 angle welded to the front of the hopper, and the hopper sat on top of the bent plate. Advantage is easier assembly, cleaner appearance. Disadvantages- can only support force coming downwards, not upwards. We could bolt them together to solve this.

Hopper Interface Plate

Problem Statement: The Hopper interface plate of P3 is arguably obsolete.

Back Story: The initial reasoning was to make hopper removable according to design for disassembly. There were nuts welded to the top of the frame to make that gap. In testing, OSE realized that it let soil leak out thru the sides. So, for the prototype release, the nuts were removed from between the plate and the frame, and the plate simply bolted to the frame, with nuts welded underneath the C-channel.

Discussion: The reason the plate was necessary initially was for shaking, and preventing soil from leaking out around the bottom. Since the shaking is ruled out, the only purpose is preventing leaking. This can be acheived by welding thinner plate (probably 1/4") directly to the frame U channel. This lowers part count, and at least an hour of labor in drilling and torching holes. No disadvantages are seen.

MJ: Interface plate is for purposes of design-for-disassembly, an essential component for lifetime design. Also, that allows entire CEB to be packaged in a 3x3x6' crate.

Assembly Mechanisms

Problem Statement: The previous assembly was time consuming and allowed soil to leak from sides.

Back Story: It was originally built with a few door hinges welded to plates, which attached to the hopper to allow the whole thing to shake more easily, and to be easily disassemblable. Assembly and testing showed that it was very difficult to get the plates close enough to not allow soil to leak out. The seams were duct taped to prevent this.

Discussion Dan's CEB showed that even with the entire hopper welded together, the hopper still shook readily. This proves hinge/shaking theory invalid, allowing us to find easier ways of assembling.

My proposal is for the attachment of side to back, we weld some 2x4" angle, 1/8" thick if available, or 1/4" if not, to the back piece. There will be holes in this which bolt to the side pieces.

Since the joint between the front and side pieces is not a right angle, angle will not work. For people who have a press brake available, Simply bending a piece of 1/8" plate and welding to the front, bolting to sides, would work. Since OSE doesn't have one, other possibilties are using piano hinges, or welding 2 pieces of 1/8" together. If we stitch weld them tightly enough, no soil should leak out, and it won't take as long as welding the whole thing.

Grate Mounting

Problem Statement: In p3, the grate mounted by bolting the grate to the hopper supports and the grate mounts. It was very difficult to install, as it required a person to hold it up, while another person installed bolts. Also, removing the grate is difficult if you need to remove rocks or something from the top of it, as you would need to remove it entirely.

Solution: Dan's machine used hinges welded to the top of the grate which were also welded to the back piece of the hopper. Initial installation would still be a little tricky, but not as hard as getting the bolts in. This then allows the user to tilt up the grate if necessary. It also eliminates the need to mount it from 2 sides, as the hinge supports it, and it sits on top of the hopper.

MJ: Design for disassembly should be maintained.

Shaker

Problem Statement: The old shaker took a lot of time and materials to make.

Solution: Dan's CEB used an entirely different shaker process. The motor attached directly to a circular plate, with a hole drilled off center. It attached via some special adapter for lawn mowers. Photos to come. The circular plate was enclosed between a sandwich of 3 plates, which sheilds the user from any shrapnel. This considerably lowers part count and labor. The only possible disadvantages are that it may not provide as much shaking as the previous model. However, it seemed to shake plenty when I watched it.

Arms

I propose to change the arms from 4x6 angle to 4x4 angle. There is really not much weight on any of the legs, and the 4x6 is overkill. I have not done math to prove it, but even if the entire weight of CEB were on it, its only 2000 lbs. The only downside I can see is that the sensor holders will need to be made longer to read the sensors.

MJ: Practical considerations of carrying with forks and bumping with tractor when loading make 4x6 channel desiarable, and I would make it