User Review

We made a bunch of bricks and found some areas to improve:

Every once in a while the drawer jumped off the rollers and jammed. This is probably due to the hydraulic cylinder not being perfectly in-line with the drawer and pushing it slightly sideways. To fix this we removed the rollers and added 8 bearings, 4 to hold it up and 4 to prevent it moving it sideways. Now it works much better. This will also simplify the construction of the drawer, which now can be made with flat bottom rails.

Once I fix the second and third problems below, I’ll send you images/video

Could be missing something here, but I’m finding the magnet/sensor combination unreliable. – I had the machine working perfectly, but after just having it sit there for two months, the sensors failed to pick up the magnets. Maybe I need to build the hall effect sensors little differently and perhaps out of a different material, but even moving the magnets manually in front of the sensors produced intermittent results.

Have you experienced anything similar? Have you considered other types of sensors/ control mechanisms?

Fried my Aurdrino board. Totally self-inflicted. Had some issues with the software recognizing the cylinder positions at startup, and to override things I wanted to have manual controls. The manual override worked and the cylinders moved into position ok, but the feedback loop killed the board. Have you figured out how to add manual override switches?
Wrt your other email on the power cube, we added an adjustable pressure bypass valve to the pump. This way if a cylinder is bottomed/topped out, the engine can keep running without stressing the pump. The only issue is cosmetic – we didn’t have enough room to do this within the frame and the hose is on the outside of the cube. – photos to follow

Response by MJ

Agreed, the roller guide mechanism is the weak point. We have not had the drawer slip off the rollers when they were adjusted properly with the roller raisers. After a few thousand bricks - the machine loosened up such that the rollers were no longer holding the drawer tight. The drawer slipped off the rails, so we tightened the roller raisers and the drawer did not slip. However - we see this as an issue to be addressed - and we did that in CEB Press Prototype IV with the new modular roller mechanism designed by Marshall Hilton. Since the roller guides were a weak point - we made the rollers modular and more robust for easy installation.
We found the magnet/sernor set finicky as well. We have a new design in CEB Press Prototype IV. See CEB_Press#Electronics_-_CEB_Press_IV.

I've got a CEB Press with the newest roller mechanism (I believe), and haven't had any trouble yet, but also haven't pressed too many bricks yet.
I also just ordered parts to add a pressure relief valve, which should probably be standard.
I would love to know what the new design is that is replacing the old magnet/sensor set (I couldn't find any information on that link you provided other than the new control board I designed.) I'm part way through a rewrite of the code, but would rather wait and work on a newer version if there are new ideas. I was planning on writing an initialization step that required some manual control to 'show' it where the boundaries are, but that will be for nothing if the actual sensors are flakey